rifapentine and Tuberculosis

3 months of weekly rifapentine plus isoniazid (3HP) and 4 months of daily rifampicin (4R) are recommended for tuberculosis preventive treatment. As these regimens have not been compared directly, we used individual patient data and network meta-analysis methods to compare completion, safety, and efficacy between 3HP and 4R.. We conducted a network meta-analysis of individual patient data by searching PubMed for randomised controlled trials (RCTs) published between Jan 1, 2000, and Mar 1, 2019. Eligible studies compared 3HP or 4R to 6 months or 9 months of isoniazid and reported treatment completion, adverse events, or incidence of tuberculosis disease. Deidentified individual patient data from eligible studies were provided by study investigators and outcomes were harmonised. Methods for network meta-analysis were used to generate indirect adjusted risk ratios (aRRs) and risk differences (aRDs) with their 95% CIs.. We included 17 572 participants from 14 countries in six trials. In the network meta-analysis, treatment completion was higher for people on 3HP than for those on 4R (aRR 1·06 [95% CI 1·02-1·10]; aRD 0·05 [95% CI 0·02-0·07]). For treatment-related adverse events leading to drug discontinuation, risks were higher for 3HP than for 4R for adverse events of any severity (aRR 2·86 [2·12-4·21]; aRD 0·03 [0·02-0·05]) and for grade 3-4 adverse events (aRR 3·46 [2·09-6·17]; aRD 0·02 [0·01-0·03]). Similar increased risks with 3HP were observed with other definitions of adverse events and were consistent across age groups. No difference in the incidence of tuberculosis disease between 3HP and 4R was found.. In the absence of RCTs, our individual patient data network meta-analysis indicates that 3HP provided an increase in treatment completion over 4R, but was associated with a higher risk of adverse events. Although findings should be confirmed, the trade-off between completion and safety must be considered when selecting a regimen for tuberculosis preventive treatment.. None.. For the French and Spanish translations of the abstract see Supplementary Materials section.

Topics: Antitubercular Agents; Drug Therapy, Combination; Humans; Isoniazid; Latent Tuberculosis; Network Meta-Analysis; Rifampin; Tuberculosis

Moxifloxacin, an 8-methoxy quinolone, is an important drug in the treatment of multidrug-resistant tuberculosis and is being investigated in novel drug regimens with pretomanid, bedaquiline, and pyrazinamide, or rifapentine, for the treatment of drug-susceptible tuberculosis. Early results of these studies are promising. Although current evidence does not support the use of moxifloxacin in treatment-shortening regimens for drug-susceptible tuberculosis, it may be recommended in patients unable to tolerate standard first-line drug regimens or for isoniazid monoresistance. Evidence suggests that the standard 400-mg dose of moxifloxacin used in the treatment of tuberculosis may be suboptimal in some patients, leading to worse tuberculosis treatment outcomes and emergence of drug resistance. Furthermore, a drug interaction with the rifamycins results in up to 31% reduced plasma concentrations of moxifloxacin when these are combined for treatment of drug-susceptible tuberculosis, although the clinical relevance of this interaction is unclear. Moxifloxacin exhibits extensive interindividual pharmacokinetic variability. Higher doses of moxifloxacin may be needed to achieve drug exposures required for improved clinical outcomes. Further study is, however, needed to determine the safety of proposed higher doses and clinically validated targets for drug exposure to moxifloxacin associated with improved tuberculosis treatment outcomes. We discuss in this review the evidence for the use of moxifloxacin in drug-susceptible tuberculosis and explore the role of moxifloxacin pharmacokinetics, pharmacodynamics, and drug interactions with rifamycins, on tuberculosis treatment outcomes when used in first-line tuberculosis drug regimens.

Topics: Animals; Antitubercular Agents; Drug Interactions; Fluoroquinolones; Humans; Moxifloxacin; Rifampin; Tuberculosis

One-third of the world's population is infected with Mycobacterium tuberculosis (M.tb.). Latent tuberculosis infection (LTBI) can progress to tuberculosis disease, the leading cause of death by infection. Rifamycin antibiotics, like rifampin and rifapentine, have unique sterilizing activity against M.tb. What are the advantages of each for LTBI or tuberculosis treatment? Areas covered: We review studies assessing the pharmacokinetics (PK), pharmacodynamics (PD), drug interaction risk, safety, and efficacy of rifampin and rifapentine and provide basis for comparing them. Expert commentary: Rifampin has shorter half-life, higher MIC against M.tb, lower protein binding, and better distribution into cavitary contents than rifapentine. Drug interactions for the two drugs maybe similar in magnitude. For LTBI, rifapentine is effective as convenient, once-weekly, 12-week course of treatment. Rifampin is also effective for LTBI, but must be given daily for four months, therefore, drug interactions are more problematic. For drug-sensitive tuberculosis disease, rifampin remains the standard of care. Safety profile of rifampin is better-described; adverse events differ somewhat for the two drugs. The registered once-weekly rifapentine regimen is inadequate, but higher doses of either drugs may shorten the treatment duration required for effective management of TB. Results of clinical trials evaluating high-dose rifamycin regimens are eagerly awaited.

Topics: Animals; Antibiotics, Antitubercular; Dose-Response Relationship, Drug; Half-Life; Humans; Latent Tuberculosis; Microbial Sensitivity Tests; Mycobacterium tuberculosis; Rifampin; Tuberculosis

Rifapentine is a rifamycin derivate approved by the US Food and Drug Administration in 1998 for the treatment of active, drug-susceptible tuberculosis (TB). In 2014, rifapentine was approved for the treatment of latent TB infection in patients at high risk of progression to active disease and is currently under evaluation by the European Medicines Agency. Expanding indications of rifapentine largely affect diabetes patients, since about one-third of them harbor latent TB. Clinical consequences of rifapentine use in this population and potentially harmful interactions with hypoglycemic agents are widely underexplored and generally considered similar to the ones of rifampicin. Indeed, rifapentine too may decrease blood levels of many oral antidiabetics and compete with them for protein-binding sites and/or transporters. However, the two drugs differ in protein-binding degree, the magnitude of cytochrome P450 induction and auto-induction, the degree of renal elimination, and so on. Rifapentine seems to be more suitable for use in diabetes patients with renal impairment, owing to the fact that it does not cause renal toxicity, and it is eliminated via kidneys in smaller proportions than rifampicin. On the other hand, there are no data related to rifapentine use in patients >65 years, and hypoalbuminemia associated with diabetic kidney disease may affect a free fraction of rifapentine to a greater extent than that of rifampicin. Until more pharmacokinetic information and information on the safety of rifapentine use in diabetic patients and drug-drug interactions are available, diabetes in TB patients treated with rifapentine should be managed with insulin analogs, and glucose and rifapentine plasma levels should be closely monitored.

Topics: Antibiotics, Antitubercular; Diabetes Mellitus; Drug Interactions; Humans; Hypoglycemic Agents; Latent Tuberculosis; Rifampin; Tuberculosis

Rifamycins inhibit RNA polymerase of most bacterial genera. Rifampicin remains part of combination therapy for treating tuberculosis (TB), and for treating Gram-positive prosthetic joint and valve infections, in which biofilms are prominent. Rifabutin has use for AIDS patients in treating mycobacterial infections TB and Mycobacterium avium complex (MAC), having fewer drug-drug interactions that interfere with AIDS medications. Rifabutin is occasionally used in combination to eradicate Helicobacter pylori (peptic ulcer disease). Rifapentine has yet to fulfill its potential in reducing time of treatment for TB. Rifaximin is a monotherapeutic agent to treat gastrointestinal (GI) disorders, such as hepatic encephalopathy, irritable bowel syndrome, and travelers' diarrhea. Rifaximin is confined to the GI tract because it is not systemically absorbed on oral dosing, achieving high local concentrations, and showing anti-inflammatory properties in addition to its antibacterial activity. Resistance issues are unavoidable with all the rifamycins when the bioburden is high, because of mutations that modify RNA polymerase.

Topics: Anti-Bacterial Agents; Antibiotics, Antitubercular; Drug Resistance, Bacterial; Drug Therapy, Combination; Gastrointestinal Diseases; Humans; Rifabutin; Rifampin; Rifamycins; Rifaximin; Tuberculosis

Tuberculosis (TB), a dreadful disease is one of the most important health problems worldwide, and is responsible for approximately 1.3 million death tolls in 2012. DOTS is the currently used drug therapy in TB and the long term drug regimens and patients' poor compliance lead to emergence of multidrug resistant (MDR) and extensively drug resistant (XDR) TB, which invigorates the research efforts to address the urgent need for the quick diagnosis and for newer antitubercular agents and vaccines to completely eradicate TB. Today we have at least 20 new diagnostic test platforms, 14 TB vaccine candidates in clinical trials and over 35 candidates in preclinical development, and among the antitubercular agents under clinical investigation, 4 anti-TB agents are in Phase III (efficacy) trials and 7 anti-TB agents are in Phase II, early bactericidal activity and sputum culture conversion trials (rifapentine is in a Phase II and a Phase III trial), 5 anti-TB agents in preclinical development and 3 anti-TB agents in Good Laboratory Practice toxicity evaluation. Recently US FDA has approved TMC207 as a part of combination therapy to treat adults with MDR pulmonary TB in the absence of other alternatives. We provide here the concise review on the chemical entities currently in the clinical trials, the new vaccines in the developmental pipeline, and the new diagnostic test.

Topics: Adult; Antitubercular Agents; Clinical Trials as Topic; Diarylquinolines; Directly Observed Therapy; Drug Discovery; Drug Resistance, Bacterial; Drug Therapy, Combination; Humans; Mycobacterium tuberculosis; Rifampin; Tuberculosis; Tuberculosis Vaccines

Topics: Antitubercular Agents; Aza Compounds; Cross-Sectional Studies; Diagnosis, Differential; Diarylquinolines; Fluoroquinolones; Germany; Humans; Moxifloxacin; Nitroimidazoles; Oxazoles; Prognosis; Quinolines; Rifampin; Tuberculosis; Tuberculosis, Multidrug-Resistant

Treatment of latent tuberculosis (TB) infection is an important component of TB control programs in both high- and low-prevalence countries. Clinical trials of treatment of latent TB conducted over several decades have demonstrated that preventive treatment can reduce the risk of developing active TB up to 90%. Although 9 months of daily, self-administered isoniazid has been the most widely used and recommended regimen for the treatment of latent infection, other regimens such as 3 months of daily isoniazid and rifampin, or 4 months of daily rifampin alone have also been recommended and used. Most recently, a 12-dose regimen of once-weekly isoniazid and rifapentine has been shown to be noninferior to 9 months of daily isoniazid in a large and well conducted clinical trial. Adoption of such a regimen on a large scale could have significant implications for TB elimination efforts.

Topics: Animals; Antitubercular Agents; Drug Administration Schedule; Drug Therapy, Combination; Humans; Isoniazid; Latent Tuberculosis; Rifampin; Time Factors; Tuberculosis

Available data on anti-tuberculosis drug research reveal different properties of the agents and provoke speculation about future directions. Higher doses of the rifamycins are promising and are currently being evaluated in regimens of shorter duration that the isoniazid plus rifampin-based, six-to-nine month-course therapy. Moxifloxacin and gatifloxacin might shorten tuberculosis treatment as well, possibly in combination with rifapentine, while SQ109 could enhance the activity of rifampin-containing regimens. On the other hand, co-administration of moxifloxacin and PA-824 could be active against latent tuberculosis, whereas linezolid, PA-824 and TMC207 are candidates for a rifampin-free regimen in multidrug-resistant and extensively-resistant tuberculosis. Unfortunately, shorter than existent treatment regimens based on the new agents discussed here are likely to take at least another decade to be fully developed and implemented in clinical practice.

Topics: Animals; Antitubercular Agents; Clinical Trials as Topic; Drug Administration Schedule; Drug Evaluation, Preclinical; Drug Therapy, Combination; Forecasting; Guinea Pigs; Humans; Mice; Primates; Rabbits; Rifampin; Tuberculosis

Topics: Acetamides; Animals; Antitubercular Agents; Aza Compounds; Diarylquinolines; Fluoroquinolones; Humans; Linezolid; Mice; Moxifloxacin; Oxazolidinones; Quinolines; Rifampin; Tuberculosis; Tuberculosis Vaccines; Vitamin D; Vitamins

Topics: Animals; Antitubercular Agents; Clinical Trials as Topic; Dose-Response Relationship, Drug; Drug Design; Drug Evaluation, Preclinical; Drug Resistance, Bacterial; Fluoroquinolones; Humans; Mycobacterium tuberculosis; Rifamycins; Tuberculosis

Post-operative reactivation of Mycobacterium tuberculosis (TB) is a recognized complication of surgery. We report a case of reactivation TB involving pacemaker wires and review the literature on surgical site TB infections following cardiac surgery to examine the clinical features and outcomes of this rare but important presentation of TB.

Topics: Aged, 80 and over; Antitubercular Agents; Drug Therapy, Combination; Ethambutol; Female; Humans; Isoniazid; Mycobacterium tuberculosis; Pacemaker, Artificial; Recurrence; Rifampin; Surgical Wound Infection; Tomography, X-Ray Computed; Tuberculosis

It is estimated that one third of the global population is infected with MYCOBACTERIUM TUBERCULOSIS. Treatment of M. TUBERCULOSIS infection is an important strategy for tuberculosis elimination, but the effectiveness of this strategy is limited by poor adherence to therapy, which is due at least in part to the long duration of treatment. A 9-month course of isoniazid is the currently preferred treatment regimen for M. TUBERCULOSIS infection, due to the extensive data regarding the effectiveness and tolerability of isoniazid, and limited data on the effectiveness and tolerability of alternative shorter-course regimens. This review covers all currently available regimens, including less established alternative treatment regimens (e.g., rifampin for 4 months and isoniazid + rifampin for 3 months), as well as regimens that are currently under investigation (e.g., isoniazid + rifapentine for 3 months). Potential future regimens and experimental approaches are also discussed.

Topics: Antitubercular Agents; Drug Administration Schedule; Drug Therapy, Combination; Humans; Isoniazid; Mycobacterium tuberculosis; Patient Compliance; Rifampin; Treatment Outcome; Tuberculosis

Topics: Animals; Antibiotics, Antitubercular; Humans; Rifampin; Treatment Outcome; Tuberculosis

To review the pharmacokinetics, efficacy, adverse effects, and cost of the newest antitubercular drug, rifapentine.. A MEDLINE search using key terms such as rifapentine, rifampin, isoniazid, Mycobacterium tuberculosis, and pyrazinamide was conducted for the time period 1966-November 1998.. Animal data were used for basic information and human studies were selected for inclusion if they were randomized, controlled studies assessing efficacy, or if they were single- or multiple-dose studies assessing the pharmacokinetics of rifapentine. Background articles on the pathophysiology of tuberculosis and cost of care and noncontrolled studies assessing drug interactions were also included.. Compared with an oral solution, the relative bioavailability of rifapentine is 70% following oral admninistration of tablets. Food increased bioavailability by 55%. Rifapentine accumulated significantly in human macrophages and its elimination half-life was longer than that of rifampin. Comparative studies of rifapentine and rifampin in humans during intensive- and continuation-phase treatment of tuberculosis suggest that at currently accepted doses, rifapentine was slightly less effective than rifampin. The most significant drug interaction with rifapentine involves indinavir: the maximum concentration and AUC of indinavir are reduced by 55% and 70%, respectively, when rifapentine is coadministered with indinavir. Adverse events of rifapentine may occur less frequently at the currently recommended 600-mg dose as compared with rifampin; however, the difference was not statistically significant. If only drug costs were evaluated during the six-month treatment of tuberculosis, rifapentine is more expensive than rifampin.. Rifapentine can be administered twice weekly during the intensive phase of tuberculosis treatment and then once weekly during the continuation phase of treatment. This may improve patient adherence over some other treatments and possibly reduce costs of treatment by preventing development of resistant tubercular strains due to nonadherence. Rifapentine is well tolerated, with most patients experiencing adverse effects at a similar rate as rifampin. Rifapentine induces cytochrome P450 somewhat less than rifampin, although few drug interaction studies have been done with rifapentine. Its efficacy at the currently approved dosage of 600 mg may be slightly lower than that of rifampin. Studies are needed to determine if equal or greater efficacy can be achieved with higher doses of rifapentine. Rifampin is less expensive than rifapentine. Further pharmacoeconomic studies are needed to evaluate costs of relapse and failure in patients receiving these agents.

Topics: Abnormalities, Drug-Induced; Animals; Antibiotics, Antitubercular; Drug Interactions; Female; Humans; Lactation; Mycobacterium tuberculosis; Pregnancy; Pregnancy Complications; Rifampin; Tuberculosis

Rifapentine is a rifamycin antibiotic with antimycobacterial activity. Rifapentine is generally more active against Mycobacterium tuberculosis than rifampicin (rifampin), although strains resistant to rifampicin are usually cross-resistant to rifapentine. Sputum culture conversion rates were slightly higher after 6 months of rifapentine- versus rifampicin-based therapy in patients with pulmonary tuberculosis in a Western study; however, relapse rates were higher in rifapentine recipients during follow-up. The excess relapses in the rifapentine group appeared to be related to poor compliance with nonrifamycin antituberculosis drugs during the intensive phase (first 2 months) of therapy. Rifapentine- and rifampicin-containing regimens produced similar sputum culture conversion rates with low rates of relapse in 2 randomised clinical trials in patients with smear-positive tuberculosis in China. In one trial, there was no difference in sputum culture conversion rates in patients treated with rifapentine once weekly or rifampicin twice weekly in combination with isoniazid and ethambutol during the continuation phase of treatment. Hyperuricaemia, which was reported only during the intensive phase, elevated ALT and AST levels and neutropenia were the most common treatment-related adverse events reported in patients receiving rifapentine- or rifampicin-containing regimens for tuberculosis in 1 Western study.

Topics: Animals; Antitubercular Agents; Clinical Trials as Topic; Humans; Rifampin; Tuberculosis

Tuberculosis (TB) Trials Consortium Study 31/AIDS Clinical Trials Group A5349, an international randomized open-label phase 3 noninferiority trial showed that a 4-month daily regimen substituting rifapentine for rifampin and moxifloxacin for ethambutol had noninferior efficacy and was safe for the treatment of drug-susceptible pulmonary TB (DS-PTB) compared with the standard 6-month regimen. We explored results among the prespecified subgroup of people with human immunodeficiency virus (HIV) (PWH).. PWH and CD4+ counts ≥100 cells/μL were eligible if they were receiving or about to initiate efavirenz-based antiretroviral therapy (ART). Primary endpoints of TB disease-free survival 12 months after randomization (efficacy) and ≥ grade 3 adverse events (AEs) on treatment (safety) were compared, using a 6.6% noninferiority margin for efficacy. Randomization was stratified by site, pulmonary cavitation, and HIV status. PWH were enrolled in a staged fashion to support cautious evaluation of drug-drug interactions between rifapentine and efavirenz.. A total of 2516 participants from 13 countries in sub-Saharan Africa, Asia, and the Americas were enrolled. Among 194 (8%) microbiologically eligible PWH, the median CD4+ count was 344 cells/μL (interquartile range: 223-455). The rifapentine-moxifloxacin regimen was noninferior to control (absolute difference in unfavorable outcomes -7.4%; 95% confidence interval [CI] -20.8% to 6.0%); the rifapentine regimen was not noninferior to control (+7.5% [95% CI, -7.3% to +22.4%]). Fewer AEs were reported in rifapentine-based regimens (15%) than the control regimen (21%).. In people with HIV-associated DS-PTB with CD4+ counts ≥100 cells/μL on efavirenz-based ART, the 4-month daily rifapentine-moxifloxacin regimen was noninferior to the 6-month control regimen and was safe.. NCT02410772.

Topics: Antitubercular Agents; Drug Therapy, Combination; HIV; HIV Infections; Humans; Isoniazid; Moxifloxacin; Rifampin; Tuberculosis; Tuberculosis, Pulmonary

Standard treatment for drug-susceptible tuberculosis (DS-TB) includes a multidrug regimen requiring at least 6 months of treatment, and this lengthy treatment easily leads to poor adherence. There is an urgent need to simplify and shorten treatment regimens to reduce interruption and adverse event rates, improve compliance, and reduce costs.. ORIENT is a multicenter, randomized controlled, open-label, phase II/III, non-inferiority trial involving DS-TB patients to evaluate the safety and efficacy of short-term regimens compared with the standardized six-month treatment regimen. In stage 1, corresponding to a phase II trial, a total of 400 patients are randomly divided into four arms, stratified by site and the presence of lung cavitation. Investigational arms include 3 short-term regimens with rifapentine 10 mg/kg, 15 mg/kg, and 20 mg/kg, while the control arm uses the standardized six-month treatment regimen. A combination of rifapentine, isoniazid, pyrazinamide, and moxifloxacin is administered for 17 or 26 weeks in rifapentine arms, while a 26-week regimen containing rifampicin, isoniazid, pyrazinamide, and ethambutol is applied in the control arm. After the safety and preliminary effectiveness analysis of patients in stage 1, the control arm and the investigational arm meeting the conditions will enter into stage 2, which is equivalent to a phase III trial and will be expanded to recruit DS-TB patients. If all investigational arms do not meet the safety conditions, stage 2 will be canceled. In stage 1, the primary safety endpoint is permanent regimen discontinuation at 8 weeks after the first dose. The primary efficacy endpoint is the proportion of favorable outcomes at 78 weeks after the first dose for both two stages.. This trial will contribute to the optimal dose of rifapentine in the Chinese population and suggest the feasibility of the short-course treatment regimen containing high-dose rifapentine and moxifloxacin for DS-TB.. The trial has been registered on ClinicalTrials.gov on 28 May 2022 with the identifier NCT05401071.

Topics: Clinical Trials, Phase II as Topic; Humans; Isoniazid; Moxifloxacin; Multicenter Studies as Topic; Pyrazinamide; Randomized Controlled Trials as Topic; Rifampin; Tuberculosis

A 4-month regimen containing rifapentine and moxifloxacin has noninferior efficacy compared to the standard 6-month regimen for drug-sensitive tuberculosis. We evaluated the effect of regimens containing daily, high-dose rifapentine on efavirenz pharmacokinetics and viral suppression in patients with human immunodeficiency virus (HIV)-associated tuberculosis (TB).. In the context of a Phase 3 randomized controlled trial, HIV-positive individuals already virally suppressed on efavirenz--containing antiretroviral therapy (ART) (EFV1), or newly initiating efavirenz (EFV2) received TB treatment containing rifapentine (1200 mg), isoniazid, pyrazinamide, and either ethambutol or moxifloxacin. Mid-interval efavirenz concentrations were measured (a) during ART and TB cotreatment (Weeks 4, 8, 12, and 17, different by EFV group) and (b) when ART was taken alone (pre- or post-TB treatment, Weeks 0 and 22). Apparent oral clearance (CL/F) was estimated and compared. Target mid-interval efavirenz concentrations were > 1 mg/L. Co-treatment was considered acceptable if > 80% of participants had mid-interval efavirenz concentrations meeting this target.. EFV1 and EFV2 included 70 and 41 evaluable participants, respectively. The geometric mean ratio comparing efavirenz CL/F with vs without TB drugs was 0.79 (90% confidence interval [CI] .72-.85) in EFV1 and 0.84 [90% CI .69-.97] in EFV2. The percent of participants with mid-interval efavirenz concentrations > 1mg/L in EFV1 at Weeks 0, 4, 8, and 17 was 96%, 96%, 88%, and 89%, respectively. In EFV2, at approximately 4 and 8 weeks post efavirenz initiation, the value was 98%.. TB treatment containing high-dose daily rifapentine modestly decreased (rather than increased) efavirenz clearance and therapeutic targets were met supporting the use of efavirenz with these regimens, without dose adjustment.. NCT02410772.

Topics: Alkynes; Anti-HIV Agents; Antitubercular Agents; Benzoxazines; Cyclopropanes; HIV Infections; HIV-1; Humans; Moxifloxacin; Rifampin; Tuberculosis

Pregnancy increases the risk of tuberculosis and its complications. A 3-month regimen of weekly isoniazid and rifapentine (3HP) is safe and effective for tuberculosis prevention in adults and children, including those with HIV, but 3HP has not been evaluated in pregnancy.. IMPAACT 2001 was a phase I/II trial evaluating the pharmacokinetics and safety of 3HP among pregnant women with indications for tuberculosis preventative therapy in Haiti, Kenya, Malawi, Thailand, and Zimbabwe (NCT02651259). Isoniazid and rifapentine were provided at standard doses (900 mg/week). Pharmacokinetic sampling was performed with the first (second/third trimester) and twelfth (third trimester/postpartum) doses. Nonlinear mixed-effects models were used to estimate drug population pharmacokinetics.. Of 50 participants, 20 had HIV and were taking efavirenz-based antiretroviral therapy. Among women without HIV, clearance of rifapentine was 28% lower during pregnancy than postpartum (1.20 vs 1.53 L/hour, P < .001), with area under the concentration-time curve (AUCSS) of 786 and 673 mg × hour/L, respectively. In pregnant women with HIV, clearance was 30% higher than women without HIV (P < .001), resulting in lower AUCss (522 mg × hour/L); clearance did not change significantly between pregnancy and postpartum. Pregnancy did not impact isoniazid pharmacokinetics. There were no drug-related serious adverse events, treatment discontinuations, or tuberculosis cases in women or infants.. 3HP does not require dose adjustment in pregnancy. Rifapentine clearance is higher among women with HIV, but all women achieved exposures of rifapentine and isoniazid associated with successful tuberculosis prevention. The data support proceeding with larger safety-focused studies of 3HP in pregnancy.. ClinicalTrials.gov, NCT02651259.

Topics: Adult; Antitubercular Agents; Child; Drug Therapy, Combination; Female; HIV Infections; Humans; Isoniazid; Latent Tuberculosis; Male; Pregnancy; Pregnant Women; Rifampin; Tuberculosis

Scaling up shorter regimens for tuberculosis (TB) prevention such as once weekly isoniazid-rifapentine (3HP) taken for 3 months is a key priority for achieving targets set forth in the World Health Organization's (WHO) END TB Strategy. However, there are few data on 3HP patient acceptance and completion in the context of routine HIV care in sub-Saharan Africa.. The 3HP Options Trial is a pragmatic, parallel type 3 effectiveness-implementation randomized trial comparing 3 optimized strategies for delivering 3HP-facilitated directly observed therapy (DOT), facilitated self-administered therapy (SAT), or informed choice between DOT and SAT using a shared decision-making aid-to people receiving care at a large urban HIV clinic in Kampala, Uganda. Participants and healthcare providers were not blinded to arm assignment due to the nature of the 3HP delivery strategies. We conducted an interim analysis of participants who were enrolled and exited the 3HP treatment period between July 13, 2020 and April 30, 2021. The primary outcome, which was aggregated across trial arms for this interim analysis, was the proportion who accepted and completed 3HP (≥11 of 12 doses within 16 weeks of randomization). We used Bayesian inference analysis to estimate the posterior probability that this proportion would exceed 80% under at least 1 of the 3HP delivery strategies, a coprimary hypothesis of the trial. Through April 2021, 684 participants have been enrolled, and 479 (70%) have exited the treatment period. Of these 479 participants, 309 (65%) were women, mean age was 41.9 years (standard deviation (SD): 9.2), and mean time on antiretroviral therapy (ART) was 7.8 years (SD: 4.3). In total, 445 of them (92.9%, 95% confidence interval (CI): [90.2 to 94.9]) accepted and completed 3HP treatment. There were no differences in treatment acceptance and completion by sex, age, or time on ART. Treatment was discontinued due to a documented adverse event (AE) in 8 (1.7%) patients. The probability that treatment acceptance and completion exceeds 80% under at least 1 of the three 3HP delivery strategies was greater than 99%. The main limitations are that the trial was conducted at a single site, and the interim analysis focused on aggregate outcome data to maintain blinding of investigators to arm-specific outcomes.. 3HP was widely accepted by people living with HIV (PLHIV) in Uganda, and very high levels of treatment completion were achieved in a programmatic setting. These findings show that 3HP can enable effective scale-up of tuberculosis preventive therapy (TPT) in high-burden countries, particularly when delivery strategies are tailored to target known barriers to treatment completion.. ClinicalTrials.gov NCT03934931.

Topics: Adult; Antitubercular Agents; Directly Observed Therapy; Drug Therapy, Combination; Female; HIV Infections; Humans; Isoniazid; Male; Middle Aged; Rifampin; Tuberculosis; Uganda

Targeted preventive therapy for individuals at highest risk of incident tuberculosis might impact the epidemic by interrupting transmission. We tested performance of a transcriptomic signature of tuberculosis (RISK11) and efficacy of signature-guided preventive therapy in parallel, using a hybrid three-group study design.. Adult volunteers aged 18-59 years were recruited at five geographically distinct communities in South Africa. Whole blood was sampled for RISK11 by quantitative RT-PCR assay from eligible volunteers without HIV, recent previous tuberculosis (ie, <3 years before screening), or comorbidities at screening. RISK11-positive participants were block randomised (1:2; block size 15) to once-weekly, directly-observed, open-label isoniazid and rifapentine for 12 weeks (ie, RISK11 positive and 3HP positive), or no treatment (ie, RISK11 positive and 3HP negative). A subset of eligible RISK11-negative volunteers were randomly assigned to no treatment (ie, RISK11 negative and 3HP negative). Diagnostic discrimination of prevalent tuberculosis was tested in all participants at baseline. Thereafter, prognostic discrimination of incident tuberculosis was tested in the untreated RISK11-positive versus RISK11-negative groups, and treatment efficacy in the 3HP-treated versus untreated RISK11-positive groups, during active surveillance through 15 months. The primary endpoint was microbiologically confirmed pulmonary tuberculosis. The primary outcome measures were risk ratio [RR] for tuberculosis of RISK11-positive to RISK11-negative participants, and treatment efficacy. This trial is registered with ClinicalTrials.gov, NCT02735590.. 20 207 volunteers were screened, and 2923 participants were enrolled, including RISK11-positive participants randomly assigned to 3HP (n=375) or no 3HP (n=764), and 1784 RISK11-negative participants. Cumulative probability of prevalent or incident tuberculosis disease was 0·066 (95% CI 0·049 to 0·084) in RISK11-positive (3HP negative) participants and 0·018 (0·011 to 0·025) in RISK11-negative participants (RR 3·69, 95% CI 2·25-6·05) over 15 months. Tuberculosis prevalence was 47 (4·1%) of 1139 versus 14 (0·78%) of 1984 in RISK11-positive compared with RISK11-negative participants, respectively (diagnostic RR 5·13, 95% CI 2·93 to 9·43). Tuberculosis incidence over 15 months was 2·09 (95% CI 0·97 to 3·19) vs 0·80 (0·30 to 1·30) per 100 person years in RISK11-positive (3HP-negative) participants compared with RISK11-negative participants (cumulative incidence ratio 2·6, 95% CI 1·2 to 5·9). Serious adverse events related to 3HP included one hospitalisation for seizures (unintentional isoniazid overdose) and one death of unknown cause (possibly temporally related). Tuberculosis incidence over 15 months was 1·94 (95% CI 0·35 to 3·50) versus 2·09 (95% CI 0·97 to 3·19) per 100 person-years in 3HP-treated RISK11-positive participants compared with untreated RISK11-positive participants (efficacy 7·0%, 95% CI -145 to 65).. The RISK11 signature discriminated between individuals with prevalent tuberculosis, or progression to incident tuberculosis, and individuals who remained healthy, but provision of 3HP to signature-positive individuals after exclusion of baseline disease did not reduce progression to tuberculosis over 15 months.. Bill and Melinda Gates Foundation, South African Medical Research Council.

Topics: Adult; Antitubercular Agents; Biomarkers; Drug Administration Schedule; Female; HIV Seronegativity; Humans; Incidence; Isoniazid; Male; Mycobacterium tuberculosis; Reverse Transcriptase Polymerase Chain Reaction; Rifampin; RNA, Bacterial; South Africa; Treatment Outcome; Tuberculosis; Young Adult

Whether T-cell interferon-γ responses to Mycobacterium tuberculosis-specific antigens can be influenced by tuberculosis preventive treatment in a high-endemic country is uncertain.. In this prospective, open-label, controlled study, 513 individuals with silicosis were randomly selected for TB preventive treatment with rifapentine and isoniazid or for observation. QuantiFERON-TB Gold in-tube (QFT-GIT) assay was used to measure IFN-γ response to M. tuberculosis antigens at baseline (T0) and at 6 (T1) and 33 (T2) months after completion of therapy.. A total of 220 subjects were included in the final analysis: 105 and 115 in the prevention and observation arms, respectively. The proportions of QFT-GIT reversion from baseline to T1 were similar in the prevention and observation arms (18.4% vs 12.8%, P=0.566). However, reversion from baseline to T2 was more frequent in the prevention arm than in the observation arm, but the difference was not significant (24.2% vs 6.3%, P=0.881). No significant difference was observed in the quantitative responses of QFT-GIT between the two arms during follow-up at T1 (P=0.648) and T2 (P=0.918).. Preventive tuberculosis treatment has no effect on interferon-γ responses measured by serial QFT-GIT assays in a high tuberculosis-endemic country.. http://www.clinicaltrials.gov NCT02430259.

Topics: Antigens, Bacterial; Antitubercular Agents; China; Diagnostic Tests, Routine; Endemic Diseases; Female; Follow-Up Studies; Humans; Interferon-gamma; Interferon-gamma Release Tests; Isoniazid; Male; Middle Aged; Prospective Studies; Rifampin; Tuberculin Test; Tuberculosis

Short-course preventive therapy with 12 doses of once-weekly rifapentine (900 mg) plus isoniazid (900 mg) could greatly improve tuberculosis control, especially in areas with high co-endemicity with HIV. However, a small previous trial of such therapy with dolutegravir in healthy, HIV-negative adults was halted early after two of the four patients developed serious adverse events. Because of the potential use of this therapy, and variable safety outcomes of tuberculosis drugs seen in patients with and without HIV, we aimed to characterise safety, pharmacokinetics, and virological suppression in adults who are HIV positive.. DOLPHIN was a phase 1/2, single-arm trial done at The Aurum Institute (Tembisa Clinical Research Site, Tembisa, South Africa), with pharmacokinetic visits done at VxPharma (Pretoria, South Africa). Adults (≥18 years) with HIV infection and undetectable viral load (<40 copies per mL) after at least 8 weeks of efavirenz-based or dolutegravir-based regimens were recruited in three consecutive groups, subject to approval by the independent safety monitoring committee. Participants received 50 mg of daily dolutegravir in place of efavirenz for 8 weeks, then began once-weekly rifapentine (900 mg)-isoniazid (900 mg) for 12 weeks. Groups 1A (n=12) and 1B (n=18) had intensive dolutegravir pharmacokinetic sampling at week 8 (before rifapentine-isoniazid), at week 11 (after the third dose of rifapentine)-isoniazid and at week 16 after the eighth dose. Group 2 (n=30) were treated with the same schedule and had sparse dolutegravir pharmacokinetic sampling at weeks 8, 11, and 16. Participants were followed 4 weeks after completion of prophylactic tuberculosis treatment. HIV viral loads were measured at baseline and at weeks 11 and 24. Primary endpoints were adverse events (grade 3 or higher) and dolutegravir population pharmacokinetics, assessed in participants who began rifapentine-isoniazid. This trial was registered at ClinicalTrials.gov, NCT03435146.. Between Jan 24, 2018, and Nov 25, 2018, 61 participants were enrolled into three groups; one participant withdrew (from group 1A). 43 (70%) of 60 participants were women and all participants were black African. Median age was 40 years (IQR 35-48), CD4 cell count was 683 cells per μL (447-935), and body-mass index was 28·9 kg/m. Our results suggest 12 doses of once-weekly rifapentine-isoniazid can be given for tuberculosis prophylaxis to patients with HIV taking dolutegravir-based antiretroviral therapy, without dose adjustments. Further exploration of the pharmacokinetics, safety, and efficacy in children and pharmacodynamics in individuals naive to antiretroviral therapy is needed.. UNITAID.

Topics: Adult; Drug Administration Schedule; Female; Heterocyclic Compounds, 3-Ring; HIV Infections; HIV-1; Humans; Isoniazid; Male; Middle Aged; Oxazines; Piperazines; Pyridones; Rifampin; South Africa; Treatment Outcome; Tuberculosis; Viral Load

Doravirine (DOR) is a non-nucleoside reverse transcriptase inhibitor indicated for the treatment of HIV-1. Its use in combination with rifapentine (RPT), an antituberculosis (TB) antibiotic, may reduce the exposure of DOR compromising viral suppression in those living with HIV-1 co-infected with TB. We conducted a prospective, phase I, open label, two-period, fixed sequence, drug interaction study to evaluate the effect of once-weekly RPT and isoniazid (INH) on the pharmacokinetics (PKs) of DOR in healthy volunteers. DOR 100 mg was administered alone twice-daily for 4 days in period 1. In period 2, once-weekly RPT + INH were co-administered with multiple doses of DOR 100 mg twice-daily for study days 7, 14, and 21. Plasma was obtained for DOR PKs when given alone and co-administered with RPT + INH. Eleven healthy volunteers enrolled and completed the study. The geometric mean ratios and 90% confidence intervals for DOR area under the concentration-time curve from zero to 12 hours (AUC

Topics: Adolescent; Adult; Antitubercular Agents; Area Under Curve; Drug Administration Schedule; Drug Interactions; Female; Healthy Volunteers; HIV Infections; Humans; Isoniazid; Male; Middle Aged; Prospective Studies; Pyridones; Reverse Transcriptase Inhibitors; Rifampin; Triazoles; Tuberculosis; Young Adult

Tuberculosis is the leading killer of patients with human immunodeficiency virus (HIV) infection. Preventive therapy is effective, but current regimens are limited by poor implementation and low completion rates.. We conducted a randomized, open-label, phase 3 noninferiority trial comparing the efficacy and safety of a 1-month regimen of daily rifapentine plus isoniazid (1-month group) with 9 months of isoniazid alone (9-month group) in HIV-infected patients who were living in areas of high tuberculosis prevalence or who had evidence of latent tuberculosis infection. The primary end point was the first diagnosis of tuberculosis or death from tuberculosis or an unknown cause. Noninferiority would be shown if the upper limit of the 95% confidence interval for the between-group difference in the number of events per 100 person-years was less than 1.25.. A total of 3000 patients were enrolled and followed for a median of 3.3 years. Of these patients, 54% were women; the median CD4+ count was 470 cells per cubic millimeter, and half the patients were receiving antiretroviral therapy. The primary end point was reported in 32 of 1488 patients (2%) in the 1-month group and in 33 of 1498 (2%) in the 9-month group, for an incidence rate of 0.65 per 100 person-years and 0.67 per 100 person-years, respectively (rate difference in the 1-month group, -0.02 per 100 person-years; upper limit of the 95% confidence interval, 0.30). Serious adverse events occurred in 6% of the patients in the 1-month group and in 7% of those in the 9-month group (P = 0.07). The percentage of treatment completion was significantly higher in the 1-month group than in the 9-month group (97% vs. 90%, P<0.001).. A 1-month regimen of rifapentine plus isoniazid was noninferior to 9 months of isoniazid alone for preventing tuberculosis in HIV-infected patients. The percentage of patients who completed treatment was significantly higher in the 1-month group. (Funded by the National Institute of Allergy and Infectious Diseases; BRIEF TB/A5279 ClinicalTrials.gov number, NCT01404312.).

Topics: Adult; AIDS-Related Opportunistic Infections; Antitubercular Agents; CD4 Lymphocyte Count; Drug Administration Schedule; Drug Therapy, Combination; Female; HIV Infections; Humans; Isoniazid; Latent Tuberculosis; Male; Medication Adherence; Rifampin; Tuberculosis

Shorter treatment regimens for tuberculosis (TB) are deemed vital for advancing TB control. Murine studies have suggested potential new regimens; however, Phase II human studies of these drug combinations have not shown clear improvement in 2-month culture conversion over current therapy. Nevertheless, drugs such as rifapentine (RPT) may have additional sterilizing effects after 2 months that are difficult to measure in current Phase II studies.. To model potential bactericidal effects of RPT in a Phase III trial of a 4-month anti-tuberculosis regimen.. We developed a Markov model of anti-tuberculosis treatment to compare two regimens for treating TB: a 6-month standard (rifampin-based) treatment and a 4-month regimen using high-dose RPT. The primary outcome was the number of relapses.. In the base-case scenario, standard therapy resulted in fewer relapses; improvement in 2-month culture conversion rates in the RPT arm did not change this result. However, while RPT has better sterilizing ability during months 3 and 4 (as observed in the mouse model), the 4-month regimen results in fewer relapses.. Higher 2-month culture conversion rates are neither sufficient nor necessary for making a theoretical 4-month anti-tuberculosis treatment regimen advantageous.

Topics: Antitubercular Agents; Decision Support Techniques; Ethambutol; Humans; Isoniazid; Markov Chains; Pyrazinamide; Recurrence; Rifampin; Treatment Outcome; Tuberculosis

Compare the effectiveness, tolerability, and safety of 3 months of weekly rifapentine and isoniazid under direct observation (3HP) versus 9 months of daily isoniazid (9H) in HIV-infected persons.. Prospective, randomized, and open-label noninferiority trial.. The United States , Brazil, Spain, Peru, Canada, and Hong Kong.. HIV-infected persons who were tuberculin skin test positive or close contacts of tuberculosis cases.. 3HP versus 9H.. The effectiveness endpoint was tuberculosis; the noninferiority margin was 0.75%. The tolerability endpoint was treatment completion; the safety endpoint was drug discontinuation because of adverse drug reaction.. Median baseline CD4 cell counts were 495 (IQR 389-675) and 538 (IQR 418-729) cells/μl in the 3HP and 9H arms, respectively (P = 0.09). In the modified intention-to-treat analysis, there were two tuberculosis cases among 206 persons [517 person-years (p-y) of follow-up] in the 3HP arm (0.39 per 100 p-y) and six tuberculosis cases among 193 persons (481 p-y of follow-up) in the 9H arm (1.25 per 100 p-y). Cumulative tuberculosis rates were 1.01 versus 3.50% in the 3HP and 9H arms, respectively (rate difference: -2.49%; upper bound of the 95% confidence interval of the difference: 0.60%). Treatment completion was higher with 3HP (89%) than 9H (64%) (P < 0.001), and drug discontinuation because of an adverse drug reaction was similar (3 vs. 4%; P = 0.79) in 3HP and 9H, respectively.. Among HIV-infected persons with median CD4 cell count of approximately 500 cells/μl, 3HP was as effective and safe for treatment of latent Mycobacterium tuberculosis infection as 9H, and better tolerated.

Topics: Adolescent; Adult; Americas; Antitubercular Agents; Asia; Child; Drug-Related Side Effects and Adverse Reactions; Female; HIV Infections; Humans; Isoniazid; Male; Prospective Studies; Rifampin; Treatment Outcome; Tuberculosis; Young Adult

Concomitant use of rifamycins to treat or prevent tuberculosis can result in subtherapeutic concentrations of antiretroviral drugs. We studied the interaction of efavirenz with daily rifapentine and isoniazid in human immunodeficiency virus (HIV)-infected individuals receiving a 4-week regimen to prevent tuberculosis.. Participants receiving daily rifapentine and isoniazid with efavirenz had pharmacokinetic evaluations at baseline and weeks 2 and 4 of concomitant therapy. Efavirenz apparent oral clearance was estimated and the geometric mean ratio (GMR) of values before and during rifapentine and isoniazid was calculated. HIV type 1 (HIV-1) RNA was measured at baseline and week 8.. Eighty-seven participants were evaluable: 54% were female, and the median age was 35 years (interquartile range [IQR], 29-44 years). Numbers of participants with efavirenz concentrations ≥1 mg/L were 85 (98%) at week 0; 81 (93%) at week 2; 78 (90%) at week 4; and 75 (86%) at weeks 2 and 4. Median efavirenz apparent oral clearance was 9.3 L/hour (IQR, 6.42-13.22 L/hour) at baseline and 9.8 L/hour (IQR, 7.04-15.59 L/hour) during rifapentine/isoniazid treatment (GMR, 1.04 [90% confidence interval, .97-1.13]). Seventy-nine of 85 (93%) participants had undetectable HIV-1 RNA (<40 copies/mL) at entry; 71 of 75 (95%) participants had undetectable HIV-1 RNA at week 8. Two participants with undetectable HIV-1 RNA at study entry were detectable (43 and 47 copies/mL) at week 8.. The proportion of participants with midinterval efavirenz concentrations ≥1 mg/L did not cross below the prespecified threshold of >80%, and virologic suppression was maintained. Four weeks of daily rifapentine plus isoniazid can be coadministered with efavirenz without clinically meaningful reductions in efavirenz mid-dosing concentrations or virologic suppression.. NCT 01404312.

Topics: Administration, Oral; Adult; Alkynes; Anti-HIV Agents; Antitubercular Agents; Benzoxazines; Cyclopropanes; Drug Therapy, Combination; Female; HIV Infections; HIV-1; Humans; Isoniazid; Male; Reverse Transcriptase Inhibitors; Rifampin; RNA, Viral; Tuberculosis

Rifapentine is under active investigation as a potent drug that may help shorten the tuberculosis (TB) treatment duration. A previous rifapentine dose escalation study with daily dosing indicated a possible decrease in bioavailability as the dose increased and an increase in clearance over time for rifapentine and its active metabolite, desacetyl rifapentine. This study aimed to assess the effects of increasing doses on rifapentine absorption and bioavailability and to evaluate the clearance changes over 14 days. A population analysis was performed with nonlinear mixed-effects modeling. Absorption, time-varying clearance, bioavailability, and empirical and semimechanistic autoinduction models were investigated. A one-compartment model linked to a transit compartment absorption model best described the data. The bioavailability of rifapentine decreased linearly by 2.5% for each 100-mg increase in dose. The autoinduction model suggested a dose-independent linear increase in clearance of the parent drug and metabolite over time from 1.2 and 3.1 liters · h(-1), respectively, after a single dose to 2.2 and 5.0 liters · h(-1), respectively, after 14 once-daily doses, with no plateau being reached by day 14. In clinical trial simulations using the final model, rifapentine demonstrated less-than-dose-proportional pharmacokinetics, but there was no plateau in exposures over the dose range tested (450 to 1,800 mg), and divided dosing increased exposures significantly. Thus, the proposed compartmental model incorporating daily dosing of rifapentine over a wide range of doses and time-related changes in bioavailability and clearance provides a useful tool for estimation of drug exposure that can be used to optimize rifapentine dosing for TB treatment. (This study has been registered at ClinicalTrials.gov under registration no. NCT01162486.).

Topics: Adult; Antibiotics, Antitubercular; Biological Availability; Cohort Studies; Dose-Response Relationship, Drug; Female; Healthy Volunteers; Humans; Male; Middle Aged; Nonlinear Dynamics; Rifampin; Time Factors; Tuberculosis; Young Adult

Treatment of latent tuberculosis in patients infected with the human immunodeficiency virus (HIV) is efficacious, but few patients around the world receive such treatment. We evaluated three new regimens for latent tuberculosis that may be more potent and durable than standard isoniazid treatment.. We randomly assigned South African adults with HIV infection and a positive tuberculin skin test who were not taking antiretroviral therapy to receive rifapentine (900 mg) plus isoniazid (900 mg) weekly for 12 weeks, rifampin (600 mg) plus isoniazid (900 mg) twice weekly for 12 weeks, isoniazid (300 mg) daily for up to 6 years (continuous isoniazid), or isoniazid (300 mg) daily for 6 months (control group). The primary end point was tuberculosis-free survival.. The 1148 patients had a median age of 30 years and a median CD4 cell count of 484 per cubic millimeter. Incidence rates of active tuberculosis or death were 3.1 per 100 person-years in the rifapentine-isoniazid group, 2.9 per 100 person-years in the rifampin-isoniazid group, and 2.7 per 100 person-years in the continuous-isoniazid group, as compared with 3.6 per 100 person-years in the control group (P>0.05 for all comparisons). Serious adverse reactions were more common in the continuous-isoniazid group (18.4 per 100 person-years) than in the other treatment groups (8.7 to 15.4 per 100 person-years). Two of 58 isolates of Mycobacterium tuberculosis (3.4%) were found to have multidrug resistance.. On the basis of the expected rates of tuberculosis in this population of HIV-infected adults, all secondary prophylactic regimens were effective. Neither a 3-month course of intermittent rifapentine or rifampin with isoniazid nor continuous isoniazid was superior to 6 months of isoniazid. (Funded by the National Institute of Allergy and Infectious Diseases and others; ClinicalTrials.gov number, NCT00057122.).

Topics: Adult; AIDS-Related Opportunistic Infections; Anti-Retroviral Agents; Antitubercular Agents; Cause of Death; Drug Administration Schedule; Drug Resistance, Bacterial; Drug Therapy, Combination; Female; Follow-Up Studies; HIV Infections; Humans; Isoniazid; Kaplan-Meier Estimate; Male; Mycobacterium tuberculosis; Patient Compliance; Proportional Hazards Models; Rifampin; Risk; Tuberculosis; Tuberculosis, Multidrug-Resistant

Treatment of latent Mycobacterium tuberculosis infection is an essential component of tuberculosis control and elimination. The current standard regimen of isoniazid for 9 months is efficacious but is limited by toxicity and low rates of treatment completion.. We conducted an open-label, randomized noninferiority trial comparing 3 months of directly observed once-weekly therapy with rifapentine (900 mg) plus isoniazid (900 mg) (combination-therapy group) with 9 months of self-administered daily isoniazid (300 mg) (isoniazid-only group) in subjects at high risk for tuberculosis. Subjects were enrolled from the United States, Canada, Brazil, and Spain and followed for 33 months. The primary end point was confirmed tuberculosis, and the noninferiority margin was 0.75%.. In the modified intention-to-treat analysis, tuberculosis developed in 7 of 3986 subjects in the combination-therapy group (cumulative rate, 0.19%) and in 15 of 3745 subjects in the isoniazid-only group (cumulative rate, 0.43%), for a difference of 0.24 percentage points. Rates of treatment completion were 82.1% in the combination-therapy group and 69.0% in the isoniazid-only group (P<0.001). Rates of permanent drug discontinuation owing to an adverse event were 4.9% in the combination-therapy group and 3.7% in the isoniazid-only group (P=0.009). Rates of investigator-assessed drug-related hepatotoxicity were 0.4% and 2.7%, respectively (P<0.001).. The use of rifapentine plus isoniazid for 3 months was as effective as 9 months of isoniazid alone in preventing tuberculosis and had a higher treatment-completion rate. Long-term safety monitoring will be important. (Funded by the Centers for Disease Control and Prevention; PREVENT TB ClinicalTrials.gov number, NCT00023452.).

Topics: Adult; Antitubercular Agents; Directly Observed Therapy; Drug Administration Schedule; Drug Therapy, Combination; Follow-Up Studies; Humans; Intention to Treat Analysis; Isoniazid; Male; Middle Aged; Prospective Studies; Rifampin; Risk Factors; Self Administration; Tuberculosis; Virus Latency

Once-weekly rifapentine 600 mg plus isoniazid (INH) during the continuation phase treatment of tuberculosis is associated with a relapse rate higher than that of twice-weekly rifampin plus INH. The safety and tolerability of higher rifapentine doses need to be determined. We conducted a prospective, randomized, double-blind trial of rifapentine at three doses (600, 900, and 1,200 mg) plus INH 15 mg/kg once weekly in the continuation phase treatment of culture-positive tuberculosis in 150 human immunodeficiency virus-seronegative adults. Outcome measures were discontinuation of therapy for any reason and adverse events on therapy. Treatment was discontinued in 3 of 52 (6%), 2 of 51 (4%), and 3 of 47 (6%) in the rifapentine 600-, 900-, and 1,200-mg treatment arms, respectively. Only one discontinuation, in the rifapentine 1,200-mg arm, was due to an adverse event possibly associated with study therapy. There was a trend toward more adverse events, possibly associated with study therapy, in the highest-dose arms (p = 0.051). Rifapentine 900-mg, once-weekly dosing appears to be safe and well tolerated and is being evaluated in Phase III efficacy trials of treatment of latent tuberculosis. Further evaluation of the safety and tolerability of rifapentine 1,200 mg is warranted.

Topics: Adult; Aged; Antitubercular Agents; Dose-Response Relationship, Drug; Double-Blind Method; Drug Administration Schedule; Drug Therapy, Combination; Female; Follow-Up Studies; Humans; Isoniazid; Male; Middle Aged; Prospective Studies; Reference Values; Rifampin; Treatment Outcome; Tuberculosis

Rifapentine is undergoing development for the treatment of pulmonary tuberculosis. This study was conducted to characterize the single-dose pharmacokinetics of rifapentine and its 25-desacetyl metabolite and to assess the effect of food on the rate and extent of absorption in participants infected with human immunodeficiency virus (HIV). Twelve men and four women, mean age, 38.6 +/- 6.9 years, received a single 600-mg oral dose of rifapentine in an open-label, randomized two-way, complete crossover study. Each volunteer received rifapentine following a high-fat breakfast or during a fasting period. Serial blood samples were collected for 72 h and both rifapentine and its metabolite were assayed by a validated high-performance liquid chromatography method. Pharmacokinetics of rifapentine and 25-desacetylrifapentine were determined by noncompartmental methods. Mean (+/- the standard deviation) maximum concentrations of rifapentine in serum and areas under the curve from time zero to infinity following a high-fat breakfast were 14.09 +/- 2.81 and 373.63 +/- 78.19 micrograms/ml, respectively, and following a fasting period they were 9.42 +/- 2.67 and 256.10 +/- 86.39 micrograms. h/ml, respectively. Pharmacokinetic data from a previously published healthy volunteer study were used for comparison. Administration of rifapentine with a high-fat breakfast resulted in a 51% increase in rifapentine bioavailability, an effect also observed in healthy volunteers. Although food increased the exposure of these patients to rifapentine, the infrequent dosing schedule for the treatment of tuberculosis (e.g., once- or twice-weekly dosing) would be unlikely to lead to accumulation. Additionally, autoinduction has been previously studied and has not been demonstrated with this compound, unlike with rifabutin and rifampin. Rifapentine was well tolerated by HIV-infected study participants. The results of our study suggest that no dosage adjustments may be required for rifapentine in HIV-infected patients (Centers for Disease Control and Prevention classification A1, A2, B1, or B2) undergoing treatment for tuberculosis.

Topics: Administration, Oral; Adult; AIDS-Related Opportunistic Infections; Antitubercular Agents; Cross-Over Studies; Female; Food; HIV Seropositivity; HIV-1; Humans; Male; Middle Aged; Mycobacterium Infections; Rifampin; Tuberculosis

A clinical trial of rifapentine in Hong Kong.. Assessment of the bioavailability of the Chinese rifapentine used in the trial.. The content of rifapentine in serum samples taken from 287 patients during the administration of four batches of the drug was measured by microbiological assay.. An initial comparison of areas under curve obtained in a random allocation to 40 patients of rifapentine either of Western or Chinese origin indicated that the bioavailability of the Chinese drug was 74% of the Western drug. The bioavailability of the second batch was found to be about 66% of the Western drug. The dose of the last two batches of rifapentine was therefore increased from the planned 600 mg to 750 mg, or briefly to 900 mg; serum concentrations were then similar to those obtained with the Western drug. Bioavailability did not change during the use of each drug batch.. A comparison of the results obtained in the trial with the initial two batches and the final batches will estimate the effects of rifapentine dose size on its efficacy and toxicity.

Topics: Adult; Antitubercular Agents; Area Under Curve; Biological Availability; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Design; Drug Stability; Female; Hong Kong; Humans; Male; Middle Aged; Regression Analysis; Rifampin; Treatment Outcome; Tuberculosis

Scaling up a shorter preventive regimen such as weekly isoniazid and rifapentine (3HP) for 3 months is a priority for tuberculosis (TB) preventive treatment (TPT). However, there are limited data on 3HP acceptability and completion from high-burden-TB countries.. We scaled up 3HP from 2018 to 2021 in 2 cities in Pakistan. Eligible participants were household contacts of persons diagnosed with TB disease. Participants were prescribed 3HP after ruling out TB disease. Treatment was self-administered. We analyzed the proportion who completed 3HP.. In Karachi, we verbally screened 22 054 household contacts of all ages. Of these, 83% were clinically evaluated and 3% were diagnosed with TB. Of household contacts without TB disease, 59% initiated the 3HP regimen, of which 69% completed treatment. In Peshawar, we verbally screened 6389 household contacts of all ages. We evaluated 95% of household contacts, of whom 2% were diagnosed with TB disease. Among those without TB disease, 65% initiated 3HP, of which 93% completed. Factors associated with higher 3HP completion included residence in Peshawar (risk ratio [RR], 1.35 [95% confidence interval {CI}: 1.32-1.37]), index patient being a male (RR, 1.03 [95% CI: 1.01-1.05]), and index patient with extrapulmonary TB compared to bacteriologically positive pulmonary TB (RR, 1.10 [95% CI: 1.06-1.14]). The age of the index patient was inversely associated with completion.. We observed a high level of acceptance and completion of 3HP in programs implemented in 2 cities in Pakistan, with differences observed across the cities. These findings suggest that 3HP can be effectively scaled up in urban settings to improve the reach and impact of TPT.

Topics: Antitubercular Agents; Drug Therapy, Combination; Humans; Isoniazid; Latent Tuberculosis; Male; Tuberculosis

The primary objective of this study was to ascertain the acceptance, initiation, implementation and treatment completion rates of tuberculosis (TB) preventive therapy (TPT) using 3HP (INH-Rifapentine) among household contacts of microbiologically confirmed drug sensitive TB cases on anti-tubercular treatment under programmatic real-world settings. The secondary objectives were to estimate the prevalence and predictors of latent TB infection (LTBI) in household contacts of the index TB cases. We also ascertained the safety profile of the 3HP TPT regimen in the household contacts.. This prospective observational study was conducted at 10 TB chest clinics in Delhi, India during 2022-2023. Household contacts aged 14 and older who tested positive for TB infection on a Tuberculin Skin test were initiated on the 3HP regimen. Logistic regression was performed by including statistically significant independent variables in multiple prediction models. p < 0.05 was considered statistically significant. STATA, version 15.1, was used to compute all analyses.. A total of 1067 (84.68%) eligible contacts of microbiologically confirmed, drug sensitive TB cases underwent screening with tuberculin skin test (TST), 614 (95.6%) LTBI positive contacts accepted the initiation of TPT, and 564 (91.8%) of those initiated on TPT completed the treatment. The major reason for refusal of screening was the lack of perception of risk of TB disease due to asymptomatic status. The prevalence of LTBI positivity through TST was 61.5% (95% CI, 58.5%, 64.4%). Adverse events were reported by 195 (31.8%) contacts initiated on 3HP of which 20 participants discontinued TPT. None of the sociodemographic factors showed a significant association with LTBI positivity (except age) or TPT completion rates.. LTBI management with 3HP is feasible among adolescent and adult household contacts in India with high rates of adherence from initiation until treatment completion. The maximum attrition of participants occurred at the time of screening for LTBI using TST.

Topics: Adolescent; Adult; Humans; India; Latent Tuberculosis; Prospective Studies; Tuberculosis

Topics: Humans; Rifampin; Tuberculosis

Topics: Humans; Rifampin; Tuberculosis

Topics: Antibiotics, Antitubercular; Antitubercular Agents; Drug Therapy, Combination; Europe; Humans; Rifampin; Tuberculosis

Topics: Europe; Humans; Isoniazid; Rifampin; Tuberculosis

A once-weekly oral dose of isoniazid and rifapentine for 3 months (3HP) is recommended by the CDC for treatment of latent tuberculosis infection (LTBI). The aim of this study is to assess 3HP-mediated clearance of M. tuberculosis bacteria in macaques with asymptomatic LTBI. Twelve Indian-origin rhesus macaques were infected with a low dose (~10 CFU) of M. tuberculosis CDC1551 via aerosol. Six animals were treated with 3HP and 6 were left untreated. The animals were imaged via PET/CT at frequent intervals. Upon treatment completion, all animals except 1 were coinfected with SIV to assess reactivation of LTBI to active tuberculosis (ATB). Four of 6 treated macaques showed no evidence of persistent bacilli or extrapulmonary spread until the study end point. PET/CT demonstrated the presence of significantly more granulomas in untreated animals relative to the treated group. The untreated animals harbored persistent bacilli and demonstrated tuberculosis (TB) reactivation following SIV coinfection, while none of the treated animals reactivated to ATB. 3HP treatment effectively reduced persistent infection with M. tuberculosis and prevented reactivation of TB in latently infected macaques.

Topics: Animals; Antitubercular Agents; Isoniazid; Latent Tuberculosis; Lung; Macaca mulatta; Mycobacterium tuberculosis; Positron Emission Tomography Computed Tomography; Rifampin; Tuberculosis

Topics: Antitubercular Agents; Drug Prescriptions; Humans; Isoniazid; Rifampin; Tuberculosis; United States; United States Food and Drug Administration

Successful delivery and completion of tuberculosis preventive treatment are necessary for tuberculosis elimination. Shorter preventive treatment regimens currently have higher medication costs, but patients spend less time in care and are more likely to complete treatment. It is unknown how economic costs of successful delivery differ between longer and shorter regimens in high-tuberculosis-burden settings.. We developed survey instruments to collect costs from program and patient sources, considering costs incurred from when household contacts first entered the health system. We compared the cost per completed course of preventive treatment with either 6 months of daily isoniazid (6H) or 3 months of weekly isoniazid and rifapentine (3HP), delivered by the Indus Health Network tuberculosis program in Karachi, Pakistan, between October 2016 and February 2018.. During this period, 459 individuals initiated 6H and 643 initiated 3HP; 39% and 61% completed treatment, respectively. Considering costs to both the program and care recipients, the cost per completed course was 394 US dollars (USD) for 6H and 333 USD for 3HP. Using a new 2020 price for rifapentine reduced the cost per completed course of 3HP to 290 USD. Under varying assumptions about drug prices and costs incurred by care recipients, the cost per completed course was lower for 3HP in all scenarios, and the largest cost drivers were the salaries of clinical staff.. In a high-burden setting, the cost of successful delivery of 3HP was lower than that of 6H, driven by higher completion.

Topics: Antitubercular Agents; Cost-Benefit Analysis; Drug Therapy, Combination; Humans; Isoniazid; Latent Tuberculosis; Rifampin; Tuberculosis

Rifapentine exposure is associated with bactericidal activity against Mycobacterium tuberculosis, but high interindividual variation in plasma concentrations is encountered.. To investigate a genomic association with interindividual variation of rifapentine exposure, SNPs of six human genes involving rifamycin metabolism (AADAC, CES2), drug transport (SLCO1B1, SLCO1B3) and gene regulation (HNF4A, PXR) were evaluated.. We characterized these genes in 173 adult participants in treatment trials of the Tuberculosis Trials Consortium. Participants were stratified by self-identified race (black or non-black), and rifapentine AUC from 0 to 24 h (AUC0-24) was adjusted by analysis of covariance for SNPs, rifapentine dose, sex, food and HIV coinfection. This study was registered at ClinicalTrials.gov under identifier NCT01043575.. The effect on rifapentine least squares mean AUC0-24 in black participants overall decreased by -10.2% for AADAC rs1803155 G versus A allele (Wald test: P = 0.03; false discovery rate, 0.10). Black participants with one G allele in AADAC rs1803155 were three times as likely to have below target bactericidal rifapentine exposure than black participants with the A allele (OR, 2.97; 95% CI: 1.16, 7.58). With two G alleles, the OR was greater. In non-black participants, AADAC rs1803155 SNP was not associated with rifapentine exposure. In both black and non-black participants, other evaluated genes were not associated with rifapentine exposure (P > 0.05; false discovery rate > 0.10).. Rifapentine exposure in black participants varied with AADAC rs1803155 genotype and the G allele was more likely to be associated with below bactericidal target rifapentine exposure. Further pharmacogenomic study is needed to characterize the association of the AADAC rs1803155 with inadequate rifapentine exposure in different patient groups.

Topics: Adult; Antibiotics, Antitubercular; Antitubercular Agents; Carboxylic Ester Hydrolases; Humans; Liver-Specific Organic Anion Transporter 1; Pharmaceutical Preparations; Polymorphism, Single Nucleotide; Rifampin; Tuberculosis; Tuberculosis, Pulmonary

Shorter regimens for tuberculosis prevention can improve completion rates and protection against developing active tuberculosis disease after tuberculosis exposure. We aimed to assess the safety and feasibility of 1 month of daily isoniazid and rifapentine (1HP) in children and adolescents in a low-resource setting in south Asia with low prevalence of HIV.. This prospective cohort study was done in eight tuberculosis facilities in Karachi, Pakistan. Eligible participants were aged 2-19 years and were household contacts of patients with drug-susceptible tuberculosis infection. After clinical, radiological, and laboratory evaluation to rule out tuberculosis disease, participants were prescribed 1HP as a preventive regimen. Isoniazid was administered as 100 mg or 300 mg oral tablets and rifapentine was administered as 150 mg oral tablets. Dosing was according to participant bodyweight. The primary endpoints were the cumulative probability of a household contact completing all stages of the preventive care cascade, assessed in all eligible participants, and the proportion of household contacts completing 1HP, assessed among all those who initiated the regimen. Safety was assessed in all household contacts who initiated the 1HP regimen.. Between Dec 21, 2019, and March 20, 2020, 1395 household contacts of 253 patients with tuberculosis were identified, including 678 household contacts who were eligible to participate. 628 (93%) completed evaluation, of whom ten (2%) had active tuberculosis disease. Of the 618 individuals eligible for tuberculosis prevention, 408 (66%) initiated 1HP, 385 (94%) of whom completed the regimen. The median duration of 1HP was 31 days (IQR 30-32) in those who completed the regimen. The cumulative probability of completing all steps of the tuberculosis prevention cascade was 58%. A girl aged 11 years developed tuberculosis disease within 6 months of completing 1HP. A boy aged 14 years developed a burning sensation during 1HP therapy and discontinued the regimen. No other adverse events were observed.. 1HP can be safely and feasibly implemented as tuberculosis prevention in children and adolescents in programmatic settings.. The Global Fund to Fight AIDS, Tuberculosis and Malaria.

Topics: Adolescent; Antitubercular Agents; Child; Child, Preschool; Cohort Studies; Duration of Therapy; Female; Humans; Isoniazid; Male; Pakistan; Prospective Studies; Rifampin; Treatment Adherence and Compliance; Tuberculosis; Young Adult

Topics: Humans; Moxifloxacin; Rifampin; Tuberculosis

Topics: Animals; Antibiotics, Antitubercular; Antitubercular Agents; Drug Therapy, Combination; Isoniazid; Latent Tuberculosis; Macaca; Models, Animal; Mycobacterium tuberculosis; Rifampin; Treatment Outcome; Tuberculosis

To estimate the cost of a screening program for identifying latent tuberculosis (TB) infections in migrants to Oman.. A Markov model was used to estimate the cost of screening using an interferon-gamma release assay (IGRA) applied to all migrants from high TB endemic countries, followed by preventive TB treatment.. The model compared seven different scenarios, with a comparison of the direct cost and the quality-adjusted life-years (QALYs) saved.. IGRA testing followed by 3 months of preventive treatment with rifapentine/isoniazid (3HP) was the most cost-effective intervention.

Topics: Cost-Benefit Analysis; Female; Humans; Interferon-gamma Release Tests; Isoniazid; Latent Tuberculosis; Markov Chains; Mass Screening; Oman; Quality-Adjusted Life Years; Rifampin; Transients and Migrants; Tuberculosis

Topics: Heterocyclic Compounds, 3-Ring; HIV Infections; Humans; Isoniazid; Oxazines; Piperazines; Pyridones; Rifampin; Tuberculosis

Preventive therapy is essential for reducing tuberculosis (TB) burden among people living with HIV (PLWH) in high-burden settings. Short-course preventive therapy regimens, such as three-month weekly rifapentine and isoniazid (3HP) and one-month daily rifapentine and isoniazid (1HP), may help facilitate uptake of preventive therapy for latently infected patients, but the comparative cost-effectiveness of these regimens under different conditions is uncertain.. We used a Markov state-transition model to estimate the incremental costs and effectiveness of 1HP versus 3HP in a simulated cohort of patients attending an HIV clinic in Uganda, as an example of a low-income, high-burden setting in which TB preventive therapy might be prescribed to PLWH. Our primary outcome was the incremental cost-effectiveness ratio, expressed as 2019 US dollars per disability-adjusted life year (DALY) averted. We estimated cost-effectiveness under different conditions of treatment completion and efficacy of 1HP versus 3HP, latent TB prevalence and rifapentine price.. Assuming equivalent clinical outcomes using 1HP and 3HP and a rifapentine price of $0.21 per 150 mg, 1HP would cost an additional $4.66 per patient treated. Assuming equivalent efficacy but 20% higher completion with 1HP versus 3HP, 1HP would cost $1,221 per DALY averted relative to 3HP. This could be reduced to $18 per DALY averted if 1HP had 5% greater efficacy than 3HP and the price of rifapentine were 50% lower. At a rifapentine price of $0.06 per 150 mg, 1HP would become cost-neutral relative to 3HP.. 1HP has the potential to be cost-effective under many realistic circumstances. Cost-effectiveness depends on rifapentine price, relative completion and efficacy, prevalence of latent TB and local willingness-to-pay.

Topics: Anti-HIV Agents; Antitubercular Agents; Cost-Benefit Analysis; Drug Administration Schedule; Drug Therapy, Combination; Female; HIV Infections; Humans; Isoniazid; Latent Tuberculosis; Male; Quality-Adjusted Life Years; Rifampin; Tuberculosis; Uganda

Topics: HIV; Humans; Isoniazid; Rifampin; Tuberculosis

Topics: HIV; Humans; Isoniazid; Rifampin; Tuberculosis

Topics: HIV; Humans; Isoniazid; Rifampin; Tuberculosis

Clofazimine and high-dose rifapentine have each separately been associated with treatment-shortening activity when incorporated into tuberculosis (TB) treatment regimens. We hypothesized that both modifications, i.e., the addition of clofazimine and the replacement of rifampin with high-dose rifapentine, in the first-line regimen for drug-susceptible TB would significantly shorten the duration of treatment necessary for cure. We tested this hypothesis in a well-established BALB/c mouse model of TB chemotherapy and also in a C3HeB/FeJ mouse model in which mice can develop caseous necrotic lesions, an environment where rifapentine and clofazimine may individually be less effective. In both mouse models, replacing rifampin with high-dose rifapentine and adding clofazimine in the first-line regimen resulted in greater bactericidal and sterilizing activity than either modification alone, suggesting that a rifapentine- and clofazimine-containing regimen may have the potential to significantly shorten the treatment duration for drug-susceptible TB. These data provide preclinical evidence supporting the evaluation of regimens combining high-dose rifapentine and clofazimine in clinical trials.

Topics: Animals; Antibiotics, Antitubercular; Antitubercular Agents; Clofazimine; Disease Models, Animal; Drug Administration Schedule; Drug Therapy, Combination; Mice; Mice, Inbred BALB C; Mice, Inbred C3H; Rifampin; Tuberculosis

As part of the End TB Strategy, the World Health Organization calls for low-tuberculosis (TB) incidence settings to achieve pre-elimination (<10 cases per million) and elimination (<1 case per million) by 2035 and 2050, respectively. These targets require testing and treatment for latent tuberculosis infection (LTBI).. To estimate the ability and costs of testing and treatment for LTBI to reach pre-elimination and elimination targets in California.. We created an individual-based epidemic model of TB, calibrated to historical cases. We evaluated the effects of increased testing (QuantiFERON-TB Gold) and treatment (three months of isoniazid and rifapentine). We analyzed four test and treat targeting strategies: (1) individuals with medical risk factors (MRF), (2) non-USB, (3) both non-USB and MRF, and (4) all Californians. For each strategy, we estimated the effects of increasing test and treat by a factor of 2, 4, or 10 from the base case. We estimated the number of TB cases occurring and prevented, and net and incremental costs from 2017 to 2065 in 2015 U.S. dollars. Efficacy, costs, adverse events, and treatment dropout were estimated from published data. We estimated the cost per case averted and per quality-adjusted life year (QALY) gained.. In the base case, 106,000 TB cases are predicted to 2065. Pre-elimination was achieved by 2065 in three scenarios: a 10-fold increase in the non-USB and persons with MRF (by 2052), and 4- or 10-fold increase in all Californians (by 2058 and 2035, respectively). TB elimination was not achieved by any intervention scenario. The most aggressive strategy, 10-fold in all Californians, achieved a case rate of 8 (95% UI 4-16) per million by 2050. Of scenarios that reached pre-elimination, the incremental net cost was $20 billion (non-USB and MRF) to $48 billion. These had an incremental cost per QALY of $657,000 to $3.1 million. A more efficient but somewhat less effective single-lifetime test strategy reached as low as $80,000 per QALY.. Substantial gains can be made in TB control in coming years by scaling-up current testing and treatment in non-USB and those with medical risks.

Topics: Algorithms; Antitubercular Agents; Calibration; California; Computer Simulation; Cost-Benefit Analysis; Disease Eradication; Epidemics; Humans; Incidence; Isoniazid; Mass Screening; Quality-Adjusted Life Years; Rifampin; Risk Factors; Stochastic Processes; Tuberculin Test; Tuberculosis; World Health Organization

The traditional treatment of tuberculosis (TB) infection (9 months of daily isoniazid [9H]) is safe but completion rates of <50% are reported. Shorter regimens (3 months of once-weekly isoniazid and rifapentine [3HP] or 4 months of daily rifampin [4R]) are associated with improved adherence in adults.. This was a retrospective cohort study (2014-2017) of children (0-18 years old) seen at a children's TB clinic in a low-incidence nation. We compared the frequency of completion and adverse events (AEs) in children receiving 3HP, 4R, and 9H; the latter 2 regimens could be administered by families (termed self-administered therapy [SAT]) or as directly observed preventive therapy (DOPT); 3HP was always administered under DOPT.. TB infection treatment was started in 667 children: 283 (42.4%) 3HP, 252 (37.8%) 9H, and 132 (19.8%) 4R. Only 52% of children receiving 9H via SAT completed therapy. Children receiving 3HP were more likely to complete therapy than the 9H (SAT) group (odds ratio [OR] 27.4, 95% confidence interval [CI]: 11.8-63.7). Multivariate analyses found receipt of medication under DOPT (OR: 5.72, 95% CI: 3.47-9.43), increasing age (OR: 1.09, 95% CI: 1.02-1.17), and the absence of any AE (OR: 1.70, 95% CI: 0.26-0.60) to be associated with completing therapy. AEs were more common in the 9H group (OR: 2.51, 95% CI: 1.48-4.32). Two (0.9%) children receiving 9H developed hepatotoxicity; no child receiving 3HP or 4R developed hepatotoxicity.. Shorter regimens are associated with increased completion rates and fewer AEs than 9H.

Topics: Adolescent; Antitubercular Agents; Child; Child, Preschool; Directly Observed Therapy; Drug Administration Schedule; Drug Therapy, Combination; Female; Humans; Infant; Infant, Newborn; Isoniazid; Male; Medication Adherence; Retrospective Studies; Rifampin; Texas; Tuberculosis

A short-course regimen of 3 months of weekly rifapentine and isoniazid (3HP) has recently been recommended by the World Health Organization as an alternative to at least 6 months of daily isoniazid (isoniazid preventive therapy [IPT]) for prevention of tuberculosis (TB). The contexts in which 3HP may be cost-effective compared to IPT among people living with human immunodeficiency virus are unknown.. We used a Markov state transition model to estimate the incremental cost-effectiveness of 3HP relative to IPT in high-burden settings, using a cohort of 1000 patients in a Ugandan HIV clinic as an emblematic scenario. Cost-effectiveness was expressed as 2017 US dollars per disability-adjusted life year (DALY) averted from a healthcare perspective over a 20-year time horizon. We explored the conditions under which 3HP would be considered cost-effective relative to IPT.. Per 1000 individuals on antiretroviral therapy in the reference scenario, treatment with 3HP rather than IPT was estimated to avert 9 cases of TB and 1 death, costing $9402 per DALY averted relative to IPT. Cost-effectiveness depended strongly on the price of rifapentine, completion of 3HP, and prevalence of latent TB. At a willingness to pay of $1000 per DALY averted, 3HP is likely to be cost-effective relative to IPT only if the price of rifapentine can be greatly reduced (to approximately $20 per course) and high treatment completion (85%) can be achieved.. 3HP may be a cost-effective alternative to IPT in high-burden settings, but cost-effectiveness depends on the price of rifapentine, achievable completion rates, and local willingness to pay.

Topics: Anti-HIV Agents; Antitubercular Agents; Cost-Benefit Analysis; Drug Therapy, Combination; HIV Infections; Humans; Isoniazid; Markov Chains; Rifampin; Tuberculosis

Preclinical treatment outcome evaluation of tuberculosis (TB) occurs primarily in mice. Current designs compare relapse rates of different regimens at selected time points, but lack information about the correlation between treatment length and treatment outcome, which is required to efficiently estimate a regimens' treatment-shortening potential. Therefore we developed a new approach. BALB/c mice were infected with a Mycobacterium tuberculosis Beijing genotype strain and were treated with rifapentine-pyrazinamide-isoniazid-ethambutol (R

Topics: Administration, Oral; Animals; Antitubercular Agents; Disease Models, Animal; Drug Therapy, Combination; Ethambutol; Female; Genotype; Humans; Mice; Mice, Inbred BALB C; Models, Theoretical; Moxifloxacin; Mycobacterium tuberculosis; Pyrazinamide; Rifampin; Treatment Outcome; Tuberculosis

Rifapentine is an anti-tuberculosis (anti-TB) drug with a prolonged half-life, but oral delivery results in low concentrations in the lungs because of its high binding (98%) to plasma proteins. We have shown that inhalation of crystalline rifapentine overcomes the limitations of oral delivery by significantly enhancing and prolonging the drug concentration in the lungs. The delivery of crystalline particles to the lungs may promote inflammation. This in vivo study characterizes the inflammatory response caused by pulmonary deposition of the rifapentine particles. The rifapentine powder was delivered to BALB/c mice by intratracheal insufflation at a dose of 20 mg/kg. The inflammatory response in the lungs and bronchoalveolar lavage (BAL) was examined at 12 h, 24 h, and 7 days post-treatment by flow cytometry and histopathology. At 12 and 24 h post-treatment, there was a significant influx of neutrophils into the lungs, and this returned to normal by day 7. A significant recruitment of macrophages occurred in the BAL at 24 h. Consistent with these findings, histopathological analysis demonstrated pulmonary vascular congestion and significant macrophage recruitment at 12 and 24 h post-treatment. In conclusion, the pulmonary delivery of crystalline rifapentine caused a transient neutrophil-associated inflammatory response in the lungs that resolved over 7 days. This observation may limit pulmonary delivery of rifapentine to once a week at a dose of 20 mg/kg or less. The effectiveness of weekly dosing with inhalable rifapentine will be assessed in murine Mycobacterium tuberculosis infection.

Topics: Administration, Inhalation; Animals; Antibiotics, Antitubercular; Female; Half-Life; Lung; Macrophages; Mice; Mice, Inbred BALB C; Mycobacterium tuberculosis; Neutrophils; Pneumonia; Powders; Rifampin; Tuberculosis

The treatment of latent tuberculous infection (TBI) is a productive and meaningful approach to tuberculosis (TB) control, and an important component of the World Health Organization's (WHO's) new End TB Strategy, especially in high-risk contacts. Unfortunately, although recognized and recommended by the WHO, it continues to be underutilized, and has even been ignored for decades in some high-risk groups, as though it were a taboo. Historical approaches to treating TBI in contacts of drug-susceptible and drug-resistant TB are presented and discussed as compelling experiences. In the United States, the Centers for Disease Control and Prevention have recently shown that a directly observed or even self-administered 12-month regimen to treat TBI with once-weekly isoniazid (INH) and rifapentine is as effective as 9 months of daily INH. Treating TBI in drug-susceptible cases and their contacts should not still be considered taboo-such a short, effective regimen is more akin to the Holy Grail. While not yet confirmed in a clinical trial, treating contacts of drug-resistant TB with the same drugs that are effective in the source case would be expected intuitively and practically to prevent TB in contacts and should be introduced now instead of waiting until clinical trials are completed.

Topics: Antitubercular Agents; Contact Tracing; Drug Therapy, Combination; Global Health; Humans; Isoniazid; Latent Tuberculosis; Rifampin; Taboo; Time Factors; Tuberculosis; World Health Organization

Recent studies have demonstrated that efflux pumps of Mycobacterium tuberculosis (M. tb) provide a crucial mechanism in the development of drug resistant to antimycobacterial drugs. Drugs that inhibit these efflux pumps, such as verapamil, have shown the potential in enhancing the treatment success. We therefore hypothesized that the combined inhaled administration of verapamil and a first-line rifamycin antibiotic will further improve the treatment efficacy. An inhalable dry powder consisting of amorphous verapamil and crystalline rifapentine with l-leucine as an excipient was produced by spray drying. The in vitro aerosol characteristic of the powder, its microbiological activity and stability were assessed. When the powder was dispersed by an Osmohaler, the total fine particle fraction (FPFtotal, wt % of particles in aerosol <5 μm) of verapamil and rifapentine was 77.4 ± 1.1% and 71.5 ± 2.0%, respectively. The combination drug formulation showed a minimum inhibitory concentration (MIC90) similar to that of rifapentine alone when tested against both M. tb H37Ra and M. tb H37Rv strains. Importantly, the combination resulted in increased killing of M. tb H37Ra within the infected macrophage cells compared to either verapamil or rifapentine alone. In assessing cellular toxicity, the combination exhibited an acceptable half maximal inhibitory concentration (IC50) values (62.5 μg/mL) on both human monocytic (THP-1) and lung alveolar basal epithelial (A549) cell lines. Finally, the powder was stable after 3 months storage in 0% relative humidity at 20 ± 3 °C.

Topics: Adenocarcinoma; Administration, Inhalation; Aerosols; Anti-Arrhythmia Agents; Antibiotics, Antitubercular; Cell Survival; Chemistry, Pharmaceutical; Humans; In Vitro Techniques; Lung Neoplasms; Microbial Sensitivity Tests; Monocytes; Mycobacterium tuberculosis; Particle Size; Rifampin; Tuberculosis; Verapamil

Screening for and treating tuberculosis (TB) infection in children and adolescents is an effective way of decreasing future TB cases. However, current approaches leave many children at risk for TB unidentified.. We recruited adolescent students from 2 public high schools (a magnet and a low-income) in the Houston Independent School District. Compared with the magnet school, the student population at the low-income school was larger, primarily Hispanic and economically disadvantaged. Students were educated about TB, and parents completed a risk factor questionnaire. Students with TB risk factors were tested using 2 interferon gamma release assays (IGRAs). Those with a positive IGRA received a 12-dose regimen of weekly isoniazid/rifapentine (3HP) administered via direct observation at school.. Nine hundred twenty-five students received TB education; 73% of their parents submitted the TB questionnaire. Eighty-six percent of students (n = 415) with a TB risk factor identified on the study questionnaire agreed to IGRA testing. Sixteen students had at least one positive IGRA (1% [magnet], 4.1% [low-income]; P = 0.005). Recent student travel to a high-risk country (7) or contact with TB disease (2) were associated with IGRA positivity (P < 0.05). All students with a positive IGRA accepted, tolerated and completed 3HP treatment at school.. School-based TB education, screening, testing using IGRAs and administration of 3HP treatment is feasible to improve the identification and treatment of adolescent students at risk for TB.

Topics: Adolescent; Antitubercular Agents; Directly Observed Therapy; Drug Combinations; Female; Humans; Isoniazid; Male; Mass Screening; Mycobacterium tuberculosis; Poverty; Rifampin; Risk Factors; School Health Services; Students; Surveys and Questionnaires; Texas; Tuberculin Test; Tuberculosis

Traditional treatment of tuberculosis infection (TBI) is efficacious, but adherence is low. Eighty children with TBI received a 12-dose once-weekly isoniazid/rifapentine regimen; 79 (99%) completed therapy, 94% reported no adverse events, 1 child had mildly elevated transaminases but 1 adolescent later developed pulmonary TB. Isoniazid/rifapentine is safe, is well tolerated and has much higher completion rates than traditional TBI regimens.

Topics: Adolescent; Antibiotics, Antitubercular; Antitubercular Agents; Child; Child, Preschool; Drug Administration Schedule; Female; Humans; Isoniazid; Male; Medication Adherence; Rifampin; Skin Tests; Treatment Outcome; Tuberculosis; Tuberculosis, Pulmonary; Young Adult

Thioridazine is an orally administered antipsychotic drug with potential for treatment of drug-resistant tuberculosis (TB). However, drug-induced adverse cardiac effects have been reported when thioridazine was used at an efficacious oral dose of 200mg/day to treat TB. Pulmonary delivery of thioridazine could be a rational approach to reduce dose-related side effects while enabling high drug concentrations at the primary site of infection. The present study compares in vitro aerosol performance, storage stability, and in vitro antimicrobial activity and cytotoxicity of two inhalable powders composed of thioridazine and a first-line anti-TB drug, rifapentine. Formulation 1 is a combination of amorphous thioridazine and crystalline rifapentine, while Formulation 2 consisted of both drugs as amorphous forms. Both thioridazine-rifapentine formulations were found suitable for inhalation with a total fine particle fraction (<5μm) of 68-76%. The two powders had similar MIC90 to rifapentine alone, being 0.000625μg/mL and 0.005μg/ml against Mycobacterium tuberculosis H37Ra and M. tuberculosis H37Rv, respectively. In contrast, thioridazine alone had a MIC90 of 12.5μg/mL and 500μg/mL, against M. tuberculosis H37Ra and M. tuberculosis H37Rv, respectively, demonstrating no synergistic anti-TB activity. However, thioridazine and rifapentine in a ratio of 1:3 enhanced the killing of M. tuberculosis H37Ra within the human monocyte-derived macrophages (THP-1) compared to the single drug treatments. Both powders showed an acceptable half maximal inhibitory concentration (IC50) of 31.25μg/mL on both THP-1 and human lung epithelial (A549) cells. However, Formulation 1 showed greater chemical stability than Formulation 2 after three months of storage under low humidity (vacuum) at 20±3°C. In conclusion, we have demonstrated a novel inhalable powder consisted of amorphous thioridazine and crystalline rifapentine (Formulation 1) with a good aerosol performance, potent anti-TB activity and storage stability, which deserves further in vivo investigations.

Topics: Administration, Inhalation; Antitubercular Agents; Humans; In Vitro Techniques; Powder Diffraction; Powders; Rifampin; Thioridazine; Tuberculosis

In the last century, the United States has transitioned from a high to a low tuberculosis (TB) incidence country. A major factor in this decline has been the emphasis on identification and treatment of patients with tuberculous infection. While identification, testing, and preventive therapy pose challenges, recent developments in childhood TB offer more options for effective strategies that are acceptable to both children and their families. These include screening and testing in non-traditional settings, use of more specific assays (interferon-gamma release assays) for testing, and implementation of shorter-course preventive regimens.

Topics: Antibiotics, Antitubercular; Child; Humans; Incidence; Interferon-gamma Release Tests; Isoniazid; Mass Screening; Rifampin; Tuberculosis; United States

The potential for rifapentine-containing oral therapeutic regimens to significantly shorten the current six-month anti-tubercular treatment regimen is confounded by high plasma protein binding of rifapentine. Inhaled aerosol delivery of rifapentine, a more potent anti-tubercular antibiotic drug, in combination with other first-line antibiotics may overcome this limitation to deliver a high drug dose at the pulmonary site of infection.. A formulation consisting of rifapentine, moxifloxacin and pyrazinamide, with and without leucine, was prepared by spray-drying. This formulation was assessed for its physico-chemical properties, in vitro aerosol performance and antimicrobial activity.. The antibiotic powders, with and without leucine, had similar median aerodynamic diameters of 2.58 ± 0.08 μm and 2.51 ± 0.06 μm, with a relatively high fine particle fraction of 55.5 ± 1.9% and 63.6 ± 2.0%, respectively. Although the powders were mostly amorphous, some crystalline peaks associated with the δ polymorph for the spray-dried crystalline pyrazinamide were identified.. Stabilisation of the powder with 10% w/w leucine and protection from moisture ingress was found to be necessary to prevent overt crystallisation of pyrazinamide after long-term storage. In vitro biological assays indicated antimicrobial activity was retained after spray-drying. Murine pharmacokinetic studies are currently underway.

Topics: Administration, Inhalation; Aerosols; Animals; Antibiotics, Antitubercular; Humans; Mice; Microbial Sensitivity Tests; Microscopy, Electron, Scanning; Particle Size; Powder Diffraction; Powders; Rifampin; Tuberculosis

Mycobacterium tuberculosis, the bacterium that causes tuberculosis (TB), is spread from person to person by the airborne route. It can be transmitted extensively in congregate settings, making investigating exposures and treating infected contacts challenging. In December 2011, a student at a Colorado high school with 1,381 students and school personnel received a diagnosis of pulmonary TB disease. One of five household contacts had TB disease, and the other four had latent M. tuberculosis infection (LTBI). Screening of 1,249 school contacts (90%) found one person with pulmonary TB disease, who was fully treated, and 162 with LTBI, of whom 159 started an LTBI treatment regimen for preventing progression to TB disease and 153 completed a regimen. Only the index patient required inpatient care for TB, and TB caused no deaths. Use of short-course treatment regimens, either 12-dose weekly isoniazid and rifapentine directly observed at school or 4 months of self-supervised rifampin daily, facilitated treatment completion. State and county incident command structures led by county TB control authorities guided a response team from multiple jurisdictions. News media reports brought public scrutiny, but meetings with the community addressed the concerns and enhanced public participation. Two contacts of the index patient outside of the school had TB disease diagnosed after the school investigation. As of July 2013, no additional TB disease associated with in-school exposure had been found. An emergency plan for focusing widespread resources, an integral public communications strategy, and new, efficient interventions should be considered in other large TB contact investigations.

Topics: Antitubercular Agents; Capacity Building; Colorado; Communication; Community-Institutional Relations; Contact Tracing; Drug Therapy, Combination; Humans; Isoniazid; Mycobacterium tuberculosis; Rifampin; School Health Services; Tuberculosis

Novel oral regimens composed of new drugs with potent activity against Mycobacterium tuberculosis and no cross-resistance with existing agents are needed to shorten and simplify treatment for both drug-susceptible and drug-resistant tuberculosis. As part of a continuing effort to evaluate novel drug combinations for treatment-shortening potential in a murine model, we performed two long-term, relapse-based experiments. In the first experiment, several 3- and 4-drug combinations containing new agents currently in phase 2/3 trials (TMC207 [bedaquiline], PA-824 and PNU-100480 [sutezolid], and/or clofazimine) proved superior to the first-line regimen of rifampin, pyrazinamide, and isoniazid. TMC207 plus PNU-100480 was the most effective drug pair. In the second experiment, in which 3- and 4-drug combinations composed of TMC207 and pyrazinamide plus rifapentine, clofazimine, PNU-100480, or both rifapentine and clofazimine were evaluated, the rank order of drugs improving the sterilizing activity of TMC207 and pyrazinamide was as follows: rifapentine plus clofazimine ≥ clofazimine ≥ rifapentine > PNU-100480. The results revealed potential new building blocks for universally active short-course regimens for drug-resistant tuberculosis. The inclusion of pyrazinamide against susceptible isolates may shorten the duration of treatment further.

Topics: Animals; Antitubercular Agents; Drug Therapy, Combination; Female; Isoniazid; Mice; Mice, Inbred BALB C; Mycobacterium tuberculosis; Nitroimidazoles; Oxazolidinones; Pyrazinamide; Rifampin; Tuberculosis; Tuberculosis, Multidrug-Resistant

Rifamycins are key sterilizing drugs in the current treatment of active tuberculosis (TB). Daily dosing of rifapentine (P), a potent rifamycin with high intracellular accumulation, in place of rifampin (R) in the standard antitubercular regimen significantly shortens the duration of treatment needed to prevent relapse in a murine model of active TB. We undertook the current study to compare directly the activities of human-equivalent doses of P and R in a guinea pig model of chronic TB, in which bacilli are predominantly extracellular within human-like necrotic granulomas. Hartley strain guinea pigs were aerosol infected with ~200 bacilli of Mycobacterium tuberculosis H37Rv, and treatment given 5 days/week was initiated 6 weeks later. R at 100 mg/kg of body weight and P at 100 mg/kg were given orally alone or in combination with isoniazid (H) at 60 mg/kg and pyrazinamide (Z) at 300 mg/kg. Culture-positive relapse was assessed in subgroups of guinea pigs after completion of 1 and 2 months of treatment. Human-equivalent doses of R and P showed equivalent bactericidal activity when used alone and in combination therapy. In guinea pigs treated with rifampin, isoniazid, and pyrazinamide (RHZ) or PHZ, microbiological relapse occurred in the lungs of 8/10 animals treated for 1 month and in 0/10 animals treated for 2 months. Substitution of P for R in the standard antitubercular regimen did not shorten the time to cure in this guinea pig model of chronic TB. Data from ongoing clinical trials comparing the activity of these two drugs are awaited to determine the relevance of the guinea pig TB model in preclinical drug screening.

Topics: Animals; Antitubercular Agents; Female; Guinea Pigs; Isoniazid; Mycobacterium tuberculosis; Pyrazinamide; Rifampin; Tuberculosis

Topics: Adult; AIDS-Related Opportunistic Infections; Antitubercular Agents; Drug Resistance, Bacterial; Drug Therapy, Combination; Humans; Infant; Infant, Newborn; Isoniazid; Rifampin; Tuberculosis

Topics: Antitubercular Agents; Humans; Isoniazid; Male; Rifampin; Tuberculosis

TMC207, rifapentine, and moxifloxacin are in clinical testing for the treatment of tuberculosis. Five experimental regimens with various combinations of TMC207, rifapentine, moxifloxacin, and pyrazinamide were tested for their bactericidal and sterilizing potencies in Swiss mice intravenously inoculated with Mycobacterium tuberculosis bacilli. TMC207 had the strongest bactericidal efficacy, while rifapentine was the strongest contributor to sterilizing efficacy. The rank order of sterilizing potencies was different from the rank order of bactericidal potencies, underlining the importance of prioritizing new regimens designed to shorten the treatment duration by their sterilizing potencies rather than by their bactericidal potencies. Both 3 months of treatment with a regimen combining TMC207, pyrazinamide, and rifapentine and 5 months of treatment with a regimen combining TMC207, pyrazinamide, and moxifloxacin resulted in relapse rates similar to the rate obtained by 6 months of treatment with rifampin-isoniazid-pyrazinamide.

Topics: Animals; Antibiotics, Antitubercular; Aza Compounds; Diarylquinolines; Disease Models, Animal; Female; Fluoroquinolones; Mice; Moxifloxacin; Mycobacterium tuberculosis; Pyrazinamide; Quinolines; Rifampin; Tuberculosis

R207910 (TMC207 or J) is a member of the diarylquinolines, a new family of antituberculous drugs with high bactericidal activity when given daily in the murine model of tuberculosis. R207910 exhibits a long half-life and thus is a good candidate for once-weekly therapy of tuberculosis.. To study the activity of once-weekly R207910 monotherapy and combinations of R207910 with other antituberculous agents (isoniazid, rifapentine, moxifloxacin, and pyrazinamide).. The established infection model of murine tuberculosis was used. Colony counts were determined in the lungs.. Eight weeks of monotherapy reduced the bacillary load by 3 to 4 log(10) for rifapentine and by 5 to 6 log(10) for R207910 (P < 0.05). The addition of rifapentine and isoniazid or moxifloxacin did not improve the bactericidal activity of R207910 monotherapy. In contrast, the triple combination of R207910 plus rifapentine plus pyrazinamide given once weekly for 2 months (i.e., a total of only eight administrations), was significantly (P < 0.05) more active than R207910 monotherapy or other R207910 combinations, and led to lung culture negativity in 9 of 10 mice, whereas all lungs were culture positive in the groups treated with other drug combinations. Moreover, R207910 plus rifapentine plus pyrazinamide given once weekly was more active than the current standard regimen of rifampin plus isoniazid plus pyrazinamide given five times per week.. The unprecedented activity of the triple combination of R207910 plus rifapentine plus pyrazinamide suggests that it may be feasible to develop a fully intermittent once-weekly regimen.

Topics: Animals; Antibiotics, Antitubercular; Antitubercular Agents; Colony Count, Microbial; Diarylquinolines; Disease Models, Animal; Drug Therapy, Combination; Female; Lung; Mice; Pyrazinamide; Quinolines; Rifampin; Tuberculosis

Isoniazid given daily for 9 months is the standard treatment for latent tuberculosis infection (LTBI), but its effectiveness is limited by poor completion rates. Shorter course regimens and regimens using directly observed therapy result in improved adherence but have higher upfront costs.. To evaluate the costs and cost-effectiveness of regimens for the treatment of LTBI.. We used a computerized Markov model to estimate total societal costs and benefits associated with four regimens for the treatment of LTBI: self-administered isoniazid daily for 9 months, directly observed isoniazid twice-weekly for 9 months, directly observed isoniazid plus rifapentine once weekly for 3 months, and self-administered rifampin daily for 4 months. In the base-case analysis, subjects were assumed to have newly positive tuberculin skin tests after recent exposure to infectious tuberculosis.. We determined the costs of treatment, quality-adjusted life-years gained, and cases of active tuberculosis prevented. In the base-case analysis, rifampin dominated (less costly with increased benefits) all other regimens except isoniazid plus rifapentine, which was more effective at a cost $48,997 per quality-adjusted life year gained. Isoniazid plus rifapentine dominated all regimens at a relative risk of disease 5.2 times the baseline estimate, or with completion rates less than 34% for isoniazid or 37% for rifampin. Rifampin could be 17% less efficacious than self-administered isoniazid and still be cost-saving compared with this regimen.. In our model, rifampin is cost-saving compared with the standard therapy of self-administered isoniazid. Isoniazid plus rifapentine is cost-saving for extremely high-risk patients and is cost-effective for lower-risk patients.

Topics: Antitubercular Agents; Cost-Benefit Analysis; Directly Observed Therapy; Drug Administration Schedule; Drug Therapy, Combination; Humans; Isoniazid; Markov Chains; Rifampin; Tuberculosis

The role of microbial factors in outcomes of tuberculosis treatment has not been well studied. We performed a case-control study to evaluate the association between a Beijing strain and tuberculosis treatment outcomes. Isolates from patients with culture-positive treatment failure (n = 8) or relapse (n = 54) were compared with isolates from randomly selected controls (n = 296) by using spoligotyping. Patients with Beijing strains had a higher risk for relapse (odds ratio [OR] 2.0, 95% confidence interval [CI] 1.0-4.0, p = 0.04) but not for treatment failure. Adjustment for factors previously associated with relapse had little effect on the association between Beijing strains and relapse. Beijing strains were strongly associated with relapse among Asian-Pacific Islanders (OR 11, 95% CI 1.1-108, p = 0.04). Active disease caused by a Beijing strain was associated with increased risk for relapse, particularly among Asian-Pacific Islanders.

Topics: Antibiotics, Antitubercular; Antitubercular Agents; Asian People; Case-Control Studies; China; HIV Infections; Humans; Mycobacterium tuberculosis; Recurrence; Rifampin; Risk Factors; Treatment Failure; Treatment Outcome; Tuberculosis; Tuberculosis, Pulmonary

Regimens recommended to treat latent tuberculosis infection (LTBI) are 3 to 9 months long. A 2-month rifampin+pyrazinamide regimen is no longer recommended. Shorter regimens are highly desirable. Because substituting rifapentine for rifampin in the standard regimen for active tuberculosis halves the treatment duration needed to prevent relapse in mice, we hypothesized daily rifapentine-based regimens could shorten LTBI treatment to 2 months or less.. To improve an existing model of LTBI chemotherapy and evaluate the efficacy of daily rifapentine-based regimens.. Mice were immunized with a more immunogenic recombinant Bacille Calmette-Guérin strain (rBCG30) and received very low-dose aerosol infection with Mycobacterium tuberculosis to establish a stable lung bacterial burden below 10(4) CFU without drug treatment. Mice received a control (isoniazid alone, rifampin alone, rifampin+isoniazid, rifampin+pyrazinamide) or test (rifapentine alone, rifapentine+isoniazid, rifapentine+pyrazinamide, rifapentine+isoniazid+pyrazinamide) regimen for 8 weeks. Rifamycin doses were 10 mg/kg/d, analogous to the same human doses. Outcomes were biweekly lung CFU counts and relapse after 4 to 8 weeks of treatment.. M. tuberculosis CFU counts remained stable around 3.65 log(10) in immunized, untreated mice. Isoniazid or rifampin left all or most mice culture-positive at week 8. Rifampin+isoniazid cured 0 and 53% of mice and rifampin+pyrazinamide cured 47 and 100% of mice in 4 and 8 weeks, respectively. Rifapentine-based regimens were more active than rifampin+isoniazid and indistinguishable from rifampin+pyrazinamide.. In this improved murine model of LTBI chemotherapy with very low lung burden, existing regimens were well represented. Daily rifapentine-based regimens were at least as active as rifampin+pyrazinamide, suggesting they could effectively treat LTBI in 6 to 8 weeks.

Topics: Animals; Antibiotics, Antitubercular; Disease Models, Animal; Drug Administration Schedule; Female; Lung; Mice; Mice, Inbred BALB C; Mycobacterium tuberculosis; Rifampin; Treatment Outcome; Tuberculosis

Recent studies have demonstrated that combined substitutions of rifapentine for rifampin and moxifloxacin for isoniazid in the standard, daily, short-course regimen of rifampin, isoniazid, and pyrazinamide produces stable cure in 12 weeks or less. This study was designed to more precisely evaluate the contribution of moxifloxacin and isoniazid to rifapentine-based regimens.. We compared bactericidal activity and treatment-shortening potential between regimens consisting of isoniazid or moxifloxacin plus rifapentine and pyrazinamide administered either thrice-weekly or daily.. Using a mouse model of tuberculosis, we assessed bactericidal activity by performing quantitative cultures of lung homogenates over the first 12 weeks of treatment. Relapse rates were assessed after completing 8, 10, and 12 weeks of treatment to determine the duration of treatment necessary for stable cure.. After 4 weeks of treatment, daily and thrice-weekly therapy with rifapentine, moxifloxacin, and pyrazinamide was significantly more active than treatment with rifapentine, isoniazid, and pyrazinamide. By 8 weeks of treatment, all mice receiving the moxifloxacin-containing regimens were lung culture negative, whereas those mice receiving the isoniazid-containing regimens continued to be lung culture positive. However, the duration of treatment necessary to achieve stable cure was 10 weeks for daily regimens and 12 weeks for thrice-weekly regimens, regardless of whether isoniazid or moxifloxacin was used. All mice receiving standard daily therapy with rifampin, isoniazid, and pyrazinamide relapsed after 12 weeks of treatment.. These results suggest that regimens consisting of isoniazid or moxifloxacin plus rifapentine and pyrazinamide may dramatically shorten the duration of treatment needed to cure human tuberculosis.

Topics: Animals; Antibiotics, Antitubercular; Antitubercular Agents; Aza Compounds; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Administration Schedule; Female; Fluoroquinolones; Isoniazid; Lung; Mice; Mice, Inbred BALB C; Moxifloxacin; Pyrazinamide; Quinolines; Recurrence; Rifampin; Time Factors; Treatment Outcome; Tuberculosis

Topics: Animals; Antibiotics, Antitubercular; Disease Models, Animal; Drug Approval; Drug Evaluation, Preclinical; Drug Therapy, Combination; Humans; Mice; Rifampin; Tuberculosis; United States; United States Food and Drug Administration

Topics: Antitubercular Agents; Humans; Isoniazid; Mycobacterium tuberculosis; Pyrazinamide; Rifampin; Tuberculosis; Virus Latency

Availability of an ultra-short-course drug regimen capable of curing patients with tuberculosis in 2 to 3 mo would significantly improve global control efforts. Because immediate prospects for novel treatment-shortening drugs remain uncertain, we examined whether better use of existing drugs could shorten the duration of treatment. Rifapentine is a long-lived rifamycin derivative currently recommended only in once-weekly continuation-phase regimens. Moxifloxacin is an 8-methoxyfluoroquinolone currently used in second-line regimens.. Using a well-established mouse model with a high bacterial burden and human-equivalent drug dosing, we compared the efficacy of rifapentine- and moxifloxacin-containing regimens with that of the standard daily short-course regimen based on rifampin, isoniazid, and pyrazinamide. Bactericidal activity was assessed by lung colony-forming unit counts, and sterilizing activity was assessed by the proportion of mice with culture-positive relapse after 2, 3, 4, and 6 mo of treatment. Here, we demonstrate that replacing rifampin with rifapentine and isoniazid with moxifloxacin dramatically increased the activity of the standard daily regimen. After just 2 mo of treatment, mice receiving rifapentine- and moxifloxacin-containing regimens were found to have negative lung cultures, while those given the standard regimen still harbored 3.17 log10 colony-forming units in the lungs (p < 0.01). No relapse was observed after just 3 mo of treatment with daily and thrice-weekly administered rifapentine- and moxifloxacin-containing regimens, whereas the standard daily regimen required 6 mo to prevent relapse in all mice.. Rifapentine should no longer be viewed solely as a rifamycin for once-weekly administration. Our results suggest that treatment regimens based on daily and thrice-weekly administration of rifapentine and moxifloxacin may permit shortening the current 6 mo duration of treatment to 3 mo or less. Such regimens warrant urgent clinical investigation.

Topics: Animals; Antibiotics, Antitubercular; Antitubercular Agents; Aza Compounds; Colony Count, Microbial; Disease Models, Animal; Drug Administration Schedule; Drug Therapy, Combination; Fluoroquinolones; Isoniazid; Lung; Mice; Mice, Inbred BALB C; Moxifloxacin; Mycobacterium tuberculosis; Pyrazinamide; Quinolines; Rifampin; Secondary Prevention; Time Factors; Tuberculosis

Topics: Animals; Antitubercular Agents; Aza Compounds; Clinical Trials as Topic; Drug Combinations; Fluoroquinolones; Humans; Mice; Moxifloxacin; Quinolines; Rifampin; Treatment Outcome; Tuberculosis

Priorities for developing improved regimens for treatment of latent tuberculosis (TB) infection include (1) developing shorter and/or more intermittently administered regimens that are easier to supervise and (2) developing and evaluating regimens that are active against multidrug-resistant organisms.. By using a previously validated murine model that involves immunizing mice with Mycobacterium bovis bacillus Calmette-Guérin to augment host immunity before infection with virulent Mycobacterium tuberculosis, we evaluated new treatment regimens including rifapentine and moxifloxacin, and assessed the potential of the Mycobacterium leprae heat shock protein-65 DNA vaccine to augment the activity of moxifloxacin.. Quantitative spleen colony-forming unit counts, and the proportion of mice with culture-positive relapse after treatment, were determined.. Three-month, once-weekly regimens of rifapentine combined with either isoniazid or moxifloxacin were as active as daily isoniazid for 6-9 mo. Six-month daily combinations of moxifloxacin with pyrazinamide, ethionamide, or ethambutol were more active than pyrazinamide plus ethambutol, a regimen recommended for latent TB infection after exposure to multidrug-resistant TB. The combination of moxifloxacin with the experimental nitroimidazopyran PA-824 was especially active. Finally, the heat shock protein-65 DNA vaccine had no effect on colony-forming unit counts when given alone, but augmented the bactericidal activity of moxifloxacin.. Together, these findings suggest that rifapentine, moxifloxacin, and, perhaps, therapeutic DNA vaccination have the potential to improve on the current treatment of latent TB infection.

Topics: Animals; Antibiotics, Antitubercular; Aza Compounds; Colony Count, Microbial; Disease Models, Animal; Drug Therapy, Combination; Female; Fluoroquinolones; Follow-Up Studies; Mice; Mice, Inbred BALB C; Moxifloxacin; Mycobacterium tuberculosis; Quinolines; Rifampin; Spleen; Treatment Outcome; Tuberculosis; Vaccines, DNA

Long-half-life drugs raise the hope of once-a-week administration of antituberculous treatment. In a previous study with the murine model of tuberculosis, the most active intermittent regimen which contained rifapentine (RFP), isoniazid (INH), and moxifloxacin (MXF) given once a week during 5.5 months, preceded by 2 weeks of daily treatment with INH, rifampin (RIF), pyrazinamide (PZA), and MXF, was less active than the standard 6-month daily RIF-INH-PZA regimen. We evaluated with the same model similar regimens in which we increased the dosing of rifapentine from 10 to 15 mg/kg of body weight and of moxifloxacin from 100 to 400 mg/kg. Mice infected intravenously by 6.2 x10(6) CFU of Mycobacterium tuberculosis H37Rv were treated 2 weeks later when infection was established. After 6 months of treatment, all mice had negative lung culture. After 3 months of follow-up, no relapse occurred in the two groups that received moxifloxacin at 400 mg/kg, whatever the dosage of RFP, and in the group receiving the standard RIF-INH-PZA control regimen. In contrast, in the two groups receiving moxifloxacin at a lower dosage, the relapse rate was significantly higher (13% in mice receiving RFP at 15 mg/kg and 27% in those receiving RFP at 10 mg/kg). Finally, the fully intermittent once-a-week regimen (26 drug ingestions) of INH, RFP (15 mg/kg), and MXF (400 mg/kg) led to a relapse rate of 11%. In conclusion, when used at high dosage, rifapentine and moxifloxacin are very efficient when combined with isoniazid in a once-a-week treatment in mouse tuberculosis.

Topics: Animals; Animals, Outbred Strains; Antibiotics, Antitubercular; Antitubercular Agents; Aza Compounds; Drug Therapy, Combination; Female; Fluoroquinolones; Mice; Moxifloxacin; Mycobacterium tuberculosis; Quinolines; Random Allocation; Rifampin; Survival Rate; Time Factors; Tuberculosis

Mice infected with 1.6 x 10(7) CFU of Mycobacterium tuberculosis were treated 14 days later for 6 months with a regimen of once-weekly 10 mg of rifapentine and 75 mg of isoniazid per kg of body weight supplemented with either 150 mg of streptomycin per kg or 100 mg of moxifloxacin per kg during either both the 2-week daily initial and once-weekly continuation phases or only in the daily 2-week initial phase. On completion of treatment, all lung cultures were negative, except for three mice, each with a single colony: two whose rifapentine-isoniazid regimen was supplemented with streptomycin during the whole course of therapy and one whose rifapentine-isoniazid regimen had no initial daily phase, but was supplemented with streptomycin and moxifloxacin during the whole course of therapy. After 3 months of follow-up, positive lung cultures were obtained from 61 and 56% of mice supplemented with streptomycin during either the full course of therapy or only the daily 2-week initial phase, respectively, and 15 and 50% of mice supplemented with moxifloxacin during either the full course of therapy or only the daily 2-week initial phase, respectively. These results suggest that moxifloxacin has sterilizing activity against M. tuberculosis.

Topics: Animals; Anti-Bacterial Agents; Anti-Infective Agents; Antibiotics, Antitubercular; Antitubercular Agents; Aza Compounds; Colony Count, Microbial; Drug Resistance, Microbial; Female; Fluoroquinolones; Isoniazid; Lung; Mice; Moxifloxacin; Mycobacterium tuberculosis; Organ Size; Quinolines; Rifampin; Spleen; Streptomycin; Survival Rate; Tuberculosis

The effectiveness of various once-weekly 10 mg/kg rifapentine (P)- containing regimens for treatment of tuberculosis was assessed in mice infected intravenously with 4.3 x 10(6) colony-forming units (cfu) of Mycobacterium tuberculosis H37Rv, and treated 14 d later with various combinations of rifampin (R), P, isoniazid (H), pyrazinamide (Z), ethambutol (E), or streptomycin (S). Control mice treated daily with either 2-mo HRZ + 4-mo HR or 2-mo HRZ + 6-mo HE were rendered spleen and lung culture-negative at 6 mo and 8 mo, respectively. Treatment failure with emergence of R-resistant bacilli occurred in all mice given once-weekly monotherapy with P for 6 mo. Once-weekly PH treatment was successful at 6 mo when it was preceded by a 2-mo daily phase with HRZ. When the initial daily phase was reduced to 2 wk, once-weekly PH-containing treatment was successful, at 6 mo, only if it was supplemented with S during the initial daily and the once-weekly phases, and at 8 mo if it was supplemented with daily H during the once-weekly phase. Without these supplements, once-weekly treatment failed in some mice with selection of R-resistant or H-resistant mutants.

Topics: Animals; Antibiotics, Antitubercular; Antitubercular Agents; Colony Count, Microbial; Drug Administration Schedule; Drug Resistance, Microbial; Drug Therapy, Combination; Ethambutol; Female; Isoniazid; Lung; Mice; Mycobacterium tuberculosis; Pyrazinamide; Rifampin; Spleen; Streptomycin; Tuberculosis

Topics: Antitubercular Agents; Clinical Trials as Topic; Dosage Forms; Drug Administration Schedule; HIV Seronegativity; Humans; Randomized Controlled Trials as Topic; Rifampin; Tuberculosis

Rifapentine is a long-acting rifamycin which may be useful for intermittent drug therapy against tuberculosis. In this study we measured the efficacies of rifapentine-containing intermittent drug regimens for preventive therapy using the Cornell mouse model of latent tuberculosis. We infected groups of mice intravenously with Mycobacterium tuberculosis and then treated them with isoniazid and pyrazinamide for 12 weeks according to the Cornell latency development protocol. After a 4-week interval of no treatment, experimental preventive therapy was administered by esophageal gavage for 12 or 18 weeks. After equilibration and dexamethasone amplification treatment, mouse organs were analyzed by quantitative colony counts to measure the effectiveness of therapy. Our results showed that once-weekly isoniazid plus rifapentine combination therapy for 18 weeks was an effective preventive regimen with sterilizing potency and bacillary load reduction comparable to those of daily isoniazid therapy for 18 weeks. Monotherapy with rifapentine weekly or fortnightly or with rifampin twice weekly for up to 18 weeks did not offer advantages in reducing bacillary load or in sterilizing organs compared to the effects of a placebo. These results with the Cornell mouse model indicate that once-weekly, short-course preventive therapy with isoniazid plus rifapentine is effective and may warrant investigation in humans with latent tuberculosis infection.

Topics: Animals; Antibiotics, Antitubercular; Antitubercular Agents; Colony Count, Microbial; Disease Models, Animal; Drug Therapy, Combination; Female; Isoniazid; Mice; Mycobacterium tuberculosis; Rifampin; Stem Cells; Tuberculosis

Besides direct bactericidal activity, long-term effectiveness is one of the most important features to consider when developing new drugs for chemotherapy. In this study, we evaluated the ability of rifapentine (RFP), in monotherapy and combination therapy, to completely eradicate a Mycobacterium tuberculosis infection and to prevent relapse posttreatment in a Swiss mouse model. The combination of RFP, isoniazid (INH), and pyrazinamide (PZA) administered daily resulted in an apparent clearance of M. tuberculosis organisms in the lungs and spleens of infected mice after 10 weeks of treatment. However, 3 months after the cessation of therapy, bacterial regrowth occurred in mice treated for a 12-week period, indicating a relapse of infection. In intermittent treatment regimens of RFP in combination with INH and PZA, sterilization was achieved when mice were treated two to five times per week for 9 weeks. Bacterial growth was still observed in the once-weekly treatment group. Our results show that mouse models can predict important parameters for new drugs. We stress the necessity for long-term posttreatment observation in animal models for the routine evaluation of new drugs for antituberculosis chemotherapy.

Topics: Animals; Antibiotics, Antitubercular; Antitubercular Agents; Disease Models, Animal; Drug Therapy, Combination; Evaluation Studies as Topic; Female; Isoniazid; Mice; Mycobacterium tuberculosis; Pyrazinamide; Rifampin; Rifamycins; Tuberculosis

Topics: Antibiotics, Antitubercular; Drug Approval; Humans; Rifampin; Tuberculosis; United States; United States Food and Drug Administration

The bactericidal activities of several once-weekly rifapentine (P)-containing combination regimens against Mycobacterium tuberculosis, and their ability to prevent the selection of rifampin (R)-resistant mutants, were compared with those of the standard six-times-weekly regimen consisting of R, isoniazid (H), and pyrazinamide (Z) in a mouse experiment. Mice were infected intravenously with 1.3 x 10(7) cfu of M. tuberculosis strain H37Rv, and 8 wk of treatment began on Day 14 after infection, when mice were randomly allocated to an untreated control group and nine treatment groups of 30 mice each. At the end of 8 wk of treatment, all the tested regimens showed promising bactericidal activities. Once-weekly P alone was less bactericidal than six-times-weekly R alone; likewise, the once-weekly P-containing combined regimens were less bactericidal than the six-times-weekly standard regimen. However, the difference in killing was about 1 log10, which represented only a fraction of the overall 4 log10 to 5 log10 magnitude of killing effects. The addition of streptomycin (S) improved the bactericidal effect of once-weekly PHZ, and the effect of once-weekly PHZS was further enhanced when it was preceded by 2 wk of daily HZS. The latter regimen achieved the same level of activity as the standard six-times-weekly regimen. All of the once-weekly P-containing combined regimens were able to prevent the selection of R-resistant mutants, whereas monotherapy with R or P selected resistant mutants in approximately 50% of animals.

Topics: Animals; Antitubercular Agents; Drug Administration Schedule; Drug Therapy, Combination; Female; Lung; Mice; Mutation; Mycobacterium tuberculosis; Organ Size; R Factors; Rifampin; Spleen; Streptomycin; Tuberculosis

Topics: Antitubercular Agents; Biological Availability; China; Clinical Trials as Topic; Drug Industry; Hong Kong; Humans; Recurrence; Rifampin; Tuberculosis

Topics: Antitubercular Agents; Clinical Trials as Topic; Drug Industry; Ethics, Medical; Humans; Rifampin; Tuberculosis

The effectiveness of intermittent administration of rifapentine (RPT), with or without isoniazid (INH), for preventive therapy of tuberculosis was evaluated in immunocompetent (normal) and nude mice. After infection with a small inoculum of Mycobacterium tuberculosis H37Rv, normal mice developed a chronic and nonfatal infection, and the bacterial population became relatively stable after an initial period of limited multiplication. On the other hand, nude mice developed an acute and fatal infection, and all untreated mice died within 5 wk, with very high colony-forming-unit (CFU) counts in their organs. Various degrees of bactericidal activity were shown in normal mice after daily treatment with rifampin (RMP) plus pyrazinamide (PZA) for 13 wk, INH daily for 26 wk, or RPT once weekly for 13 or 26 wk or once fortnightly for 26 wk. The activity of RPT was significantly enhanced when INH was added at the same dosing frequency. In nude mice the response of M. tuberculosis infection to certain regimens was less favorable than that in normal mice, suggesting that preventive therapy may be less effective in severely immunodeficient hosts even during treatment. After chemotherapy was stopped, virtually all nude mice relapsed within 12 wk regardless of the regimen administered, whereas no or very few relapses were observed in normal mice that had been treated with RMP+PZA daily for 13 wk, or RPT alone or RPT+INH once weekly for 26 wk. The latter three regimens and RPT+INH once weekly for 13 wk may be applied for fixed-duration preventive therapy in human immunodeficiency virus (HIV)-negative subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Antitubercular Agents; Colony-Forming Units Assay; Drug Therapy, Combination; Female; Immunity; Isoniazid; Mice; Mice, Nude; Pyrazinamide; Rifampin; Tuberculosis

The activity of azithromycin (AZI) was evaluated in the beige mouse model of disseminated Mycobacterium avium infection. Mice were infected intravenously with approximately 10(7) viable avium ATCC 49601. AZI at 50, 100, or 200 mg/kg of body weight or clarithromycin (CLA) at 200 mg/kg was given by gavage 5 days per week for 4 weeks. Groups of treated mice were compared with untreated control animals. A dose-related reduction in cell counts in organs was observed with AZI treatment. AZI at 200 mg/kg was more active than CLA at 200 mg/kg against organisms in spleens. The activities of these two agents at 200 mg/kg were comparable against organisms in lungs. In a second study, AZI at 200 mg/kg was given daily for 5 days; this was followed by intermittent AZI treatment for the next 3 weeks. The activities of AZI given on a three-times- and five-times-per-week basis in the continuation phase were comparable. AZI given on a once-weekly basis was less active. The regimen of AZI given in combination with rifapentine on a once-weekly basis for 8 weeks showed promising activity. Clinical evaluation of AZI and rifapentine will help to define the roles of these agents in the treatment of disseminated M. avium complex infection.

Topics: Animals; Azithromycin; Clarithromycin; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Therapy, Combination; Female; Humans; Male; Mice; Mice, Inbred C57BL; Mycobacterium avium; Rifampin; Tuberculosis

The dose-response activity of rifabutin and the comparative activities of rifabutin and rifapentine were evaluated in the beige mouse model of disseminated Mycobacterium avium complex (MAC) infection. In the dose-response study, mice were infected intravenously with approximately 10(7) viable M. avium ATCC 49601. Treatment with rifabutin at 10, 20, or 40 mg/kg of body weight was started 7 days postinfection and was administered daily for 10 days. The mice were sacrificed 3 to 5 days after the last dose. Spleens, livers, and lungs were homogenized, and viable cell counts were determined by serial dilution and plating onto Middlebrook 7H10 agar. A dose-related reduction in MAC cell counts in the organs was noted for this MAC isolate. The comparative activities of rifabutin and rifapentine were determined against a total of five MAC isolates in the beige mouse model. Rifabutin or rifapentine (20 mg/kg each) was administered to infected mice for 10 days. Groups of treated mice were compared with untreated control animals. Despite favorable in vitro susceptibility results, rifabutin and rifapentine had activities in the spleens against only two of the five MAC isolates. For these two MAC isolates, rifabutin was more active than rifapentine. These agents had activities in the lungs against three of five isolates. Further study of rifabutin or rifapentine against a broader range of clinical isolates in a murine infection model may be useful as part of the continuing development of newer rifamycins as anti-MAC agents.

Topics: Animals; Antitubercular Agents; Colony Count, Microbial; Disease Models, Animal; Dose-Response Relationship, Drug; Female; Humans; Lung; Mice; Mice, Inbred C57BL; Mycobacterium avium; Mycobacterium avium Complex; Rifabutin; Rifampin; Tuberculosis

To identify alternative regimens for preventive therapy of tuberculosis, the pharmacokinetics and antimicrobial activities of rifampin (RMP), rifabutin (RBT), and rifapentine (RPT) were compared in BCG-vaccinated and M. tuberculosis-infected immunocompetent mice. RPT showed the highest serum peak level (Cmax) and the longest half-life (t1/2), whereas RBT displayed the lowest Cmax and the shortest t1/2. On weight-to-weight basis, both RPT and RBT were more bactericidal than RMP. The activity of RMP was significantly reduced when the frequency of administration was reduced from six to three times weekly, whereas significant bactericidal activity was still observed in mice treated with RPT, 10 mg/kg up to once fortnightly, or RBT, 10 mg/kg twice weekly. Because the bactericidal activity of RBT, 10 mg/kg six times/wk for 6 wk, or RPT, 10 mg/kg two times/wk for 12 wk, was comparable to that of RMP, 10 mg/kg six times/wk for 12 wk in mice, the two regimens are appropriate for clinical trials of preventive therapy of tuberculosis.

Topics: Animals; Antitubercular Agents; BCG Vaccine; Colony Count, Microbial; Female; Mice; Mycobacterium tuberculosis; Rifabutin; Rifampin; Spleen; Tuberculosis

The activity of TLC G-65 (a liposomal gentamicin preparation), alone and in combination with rifapentine, clarithromycin, clofazimine and ethambutol, was evaluated in the beige mouse (C57BL/6J--bgj/bgj) model of disseminated Mycobacterium avium infection. TLC G-65 was found to be more active than amikacin. The combination of rifapentine and TLC G-65 was more active than either agent alone. The activity of clarithromycin in combination with TLC G-65 was similar to that of either agent alone. Clofazimine improved the activity of TLC G-65 with respect to the spleen, while ethambutol improved the activity with respect to the liver. Clofazimine and ethambutol enhanced the activity of TLC G-65 against bacteria in the lungs. TLC G-65 in combination with rifapentine appears to be an attractive regimen for the treatment of infections caused by bacteria in the M. avium complex.

Topics: Amikacin; Animals; Antitubercular Agents; Clarithromycin; Clofazimine; Culture Media; Drug Therapy, Combination; Erythromycin; Ethambutol; Gentamicins; Liposomes; Mice; Mice, Inbred C57BL; Mycobacterium avium; Rifampin; Tuberculosis

The activity of rifapentine (MDL 473) was evaluated in the beige (C57BL/6J-bgj/bgj) mouse model of disseminated Mycobacterium avium infection. Approximately 10(7) cfu of M. avium, serotype 1, were given iv. Seven days later treatment was started with intraperitoneal rifapentine at 20 mg/kg of body weight. Treatment was given daily for five days followed by twice weekly for three weeks. The mice were killed two days after the last dose. Spleens, livers and lungs were homogenized and cfu/organ determined. Analysis of variance and Tukey honestly significant difference tests indicated that rifapentine reduced cfu in each of the organs compared with untreated controls. A dose-response experiment was performed with a daily rifapentine dose of 10, 20 or 40 mg/kg administered intraperitoneally. Dose-related reductions in cfu counts were observed in each of the organs. The activity of oral rifapentine at 20 mg/kg was demonstrated in a comparative experiment with rifampicin at 20, 40 or 60 mg/kg. Rifapentine significantly reduced cfu counts in organs compared with rifampicin. Rifapentine should be considered for further evaluation in the treatment of M. avium complex infection in humans.

Topics: Administration, Oral; Animals; Antitubercular Agents; Biological Availability; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Administration Schedule; Female; Injections, Intraperitoneal; Male; Mice; Mice, Inbred C57BL; Mycobacterium avium; Rifampin; Tuberculosis

The efficacy of the long-acting rifamycins, rifapentine (RPE) and FCE 22807 (FCE) in experimental murine tuberculosis was studied by counting viable bacilli in spleens. At 2 weeks after infection with Mycobacterium tuberculosis, strain H37Rv, treatment with isoniazid 25 mg/kg, rifampicin 10 mg/kg and pyrazinamide 150 mg/kg was given daily for 6 weeks. The mice were then divided into groups given RPE or FCE at intervals of 1, 2 or 3 weeks with spleen counts after 18 and 24 weeks of chemotherapy. The first experiment showed the great effect of the size of the dose of RPE, which, in once-weekly regimens, caused rapid sterilization at 16 mg/kg, less rapid sterilization at 10 mg/kg and incomplete activity at 6.25 mg/kg. Regimens of RPE given every 2 or 3 weeks were less effective, though 16 mg/kg fortnightly was as good as 6 mg/kg once-weekly. The second experiment compared RPE and FCE each given at 12 or 8 mg/kg. The results were similar though, at 8 mg/kg every 2 or 3 weeks, FCE was slightly more effective than RPE. Serum assays showed that the levels with 8 and 12 mg/kg FCE were lower than those produced even by 6.25 mg/kg RPE, suggesting that FCE would be a better drug than RPE if its bioavailability could be improved, and that the levels following 16 mg/kg RPE were similar to those found in man after 8 mg/kg RPE taken with a fat-rich meal, suggesting good prospects for effective once-fortnightly human treatment. The potential for long-acting rifamycins in the management of pulmonary tuberculosis is discussed.

Topics: Animals; Antitubercular Agents; Drug Administration Schedule; Mice; Mice, Inbred BALB C; Mycobacterium tuberculosis; Rifampin; Rifamycins; Spleen; Tuberculosis

Topics: Animals; Female; Male; Mice; Rifampin; Rifamycins; Tuberculosis

In a comparison of in vitro properties of rifapentine (RIF) and rifampicin (RMP), the minimal inhibitory concentration of RIF against Mycobacterium tuberculosis in Tween-albumin liquid medium was usually 0.02 micrograms/ml, 2-3 times lower than for RMP; the bactericidal activity against a log phase culture was slightly less than that of RMP and the recovery after pulsed exposures to 1 microgram/ml of RIF or RMP lasting 6, 24 and 96 h was identical for the two rifamycins. These findings are used to interpret published data from the chronic experimental murine tuberculosis model and support the view that in the mouse, the efficacy of RIF in widely spaced intermittent chemotherapy is the result of its long half-life.

Topics: Animals; Half-Life; In Vitro Techniques; Mice; Microbial Sensitivity Tests; Mycobacterium tuberculosis; Rifampin; Tuberculosis

Topics: Absorption; Humans; Rifampin; Tuberculosis

The results of recent experiences with experimental tuberculous chemotherapy in the mouse give information on the activity of rifampicin (RMP) administered intermittently and on the activity of Cyclopentyl-Rifampicin (or DL473). The activity of RMP decreases as one spaces the treatment without increasing the dose. These observations are compatible with the known facts concerning the mechanism of action of RMP on RNA polymerase, and are unfavourable as regards the intermittent administration of RMP. Cyclopentyl-Rifampicin, a new derivative of Rifamycine SV, administered once per week, is as active as RMP administered six days per week, both in the initial as well as the continuation phase of treatment.

Topics: Animals; DNA-Directed RNA Polymerases; Drug Therapy, Combination; Female; Isoniazid; Mice; Pyrazinamide; Rifampin; Streptomycin; Tuberculosis

DL 473, a new semisynthetic rifamycin, was 2-10 times more active in vitro than rifampicin (RAMP) against several clinical isolates of Mycobacterium tuberculosis and only slightly less active than RAMP against Gram-positive and Gram-negative bacteria. It showed excellent therapeutic activity in mice in experimental infections caused by Staphylococcus aureus, Streptococcus pyogenes group A, Streptococcus pneumoniae and Klebsiella pneumoniae. In the experimental TB infection in the mouse DL 473 was clearly more active than isoniazide and RAMP, two of the most effective antitubercular drugs in current use. The LD50 in the mouse was significantly higher than that of RAMP and the half-life was about 5 times longer than that of RAMP.

Topics: Animals; Anti-Bacterial Agents; Bacteria; Bacterial Infections; Dose-Response Relationship, Drug; Isoniazid; Mice; Microbial Sensitivity Tests; Rifampin; Tuberculosis