rifampin and dolutegravir

Reduced dose efavirenz, dolutegravir, and/or tenofovir alafenamide (TAF) are likely to be used in the next generation of first-line antiretroviral therapy in resource limited settings, where HIV-associated tuberculosis is common. Rifampicin, which is a key component of first-line antituberculosis therapy, is a potent inducer of many drug transporters and metabolising enzymes. We reviewed the literature for potential or actual drug--drug interactions between these antiretrovirals and rifampicin.. Dose adjustments of standard dose efavirenz are not necessary with rifampicin, because auto-induction of CYP2B6 by efavirenz counteracts the induction of rifampicin. However, patients with extensive metabolizer CYP2B6 genotypes have lower efavirenz concentrations and may have less auto-induction of CYP2B6; the additive inducing effects of rifampicin on CYP2B6 could result in clinically significant reductions of efavirenz concentrations. Doubling the dose of dolutegravir overcomes induction by rifampicin. TAF is more prone to be the victim in drug--drug interactions than tenofovir disoproxil fumarate. Interactions between TAF and rifampicin have not been studied, but there is likely to be significant interaction.. Further research on drug--drug interactions between rifampicin and the next generation of first-line antiretrovirals will be needed before they can be recommended in patients with HIV-associated tuberculosis.

Topics: Adenine; Alanine; Alkynes; Anti-Retroviral Agents; Antitubercular Agents; Benzoxazines; Cyclopropanes; Cytochrome P-450 CYP2B6; Drug Interactions; Heterocyclic Compounds, 3-Ring; HIV Infections; Humans; Oxazines; Piperazines; Pyridones; Rifampin; Tenofovir

Higher doses of rifampicin may improve treatment outcomes and reduce the duration of tuberculosis (TB) therapy. However, drug-drug interactions with antiretroviral therapy (ART) and safety in people with human immunodeficiency virus (HIV) have not been evaluated.. This was a randomized, open-label trial where newly diagnosed TB patients were randomized to higher (35 mg/kg) or standard (10 mg/kg) daily-dose rifampicin. ART treatment-naive patients were randomized to dolutegravir- or efavirenz-based ART. At week 6, trough dolutegravir or mid-dose efavirenz plasma concentrations were assayed. HIV viral load was measured at week 24.. Among 128 patients randomized, the median CD4 count was 191 cells/mm3. The geometric mean ratio (GMR) for trough dolutegravir concentrations on higher- vs standard-dose rifampicin was 0.57 (95% confidence interval [CI], .34-.97; P = .039) and the GMR for mid-dose efavirenz was 0.63 (95% CI, .38-1.07; P = .083). There was no significant difference in attainment of targets for dolutegravir trough or efavirenz mid-dose concentrations between rifampicin doses. The incidence of HIV treatment failure at week 24 was similar between rifampicin doses (14.9% vs 14.0%, P = .901), as was the incidence of drug-related grade 3-4 adverse events (9.8% vs 6%). At week 8, fewer patients remained sputum culture positive on higher-dose rifampicin (18.6% vs 37.0%, P = .063).. Compared with standard-dose rifampicin, high-dose rifampicin reduced dolutegravir and efavirenz exposures, but HIV suppression was similar across treatment arms. Higher-dose rifampicin was well tolerated among people with HIV and associated with a trend toward faster sputum culture conversion.. NCT03982277.

Topics: Anti-HIV Agents; Benzoxazines; HIV; HIV Infections; Humans; Rifampin; Tuberculosis

The drug-drug interaction between rifampicin and dolutegravir can be overcome by supplemental dolutegravir dosing, which is difficult to implement in high-burden settings. We aimed to test whether virological outcomes with standard-dose dolutegravir-based antiretroviral therapy (ART) are acceptable in people with HIV on rifampicin-based antituberculosis therapy.. RADIANT-TB was a phase 2b, randomised, double-blind, non-comparative, placebo-controlled trial at a single site in Khayelitsha, Cape Town, South Africa. Participants were older than 18 years of age, with plasma HIV-1 RNA greater than 1000 copies per mL, CD4 count greater than 100 cells per μL, ART-naive or first-line ART interrupted, and on rifampicin-based antituberculosis therapy for less than 3 months. By use of permuted block (block size of 6) randomisation, participants were assigned (1:1) to receive either tenofovir disoproxil fumarate, lamivudine, and dolutegravir plus supplemental 50 mg dolutegravir 12 h later or tenofovir disoproxil fumarate, lamivudine, and dolutegravir plus matched placebo 12 h later. Participants received standard antituberculosis therapy (rifampicin, isoniazid, pyrazinamide, and ethambutol for the first 2 months followed by isoniazid and rifampicin for 4 months). The primary outcome was the proportion of participants with virological suppression (HIV-1 RNA <50 copies per mL) at week 24 analysed in the modified intention-to-treat population. This study is registered with ClinicalTrials.gov, NCT03851588.. Our findings suggest that twice-daily dolutegravir might be unnecessary in people with HIV-associated tuberculosis.. Wellcome Trust.

Topics: Adult; Anti-Retroviral Agents; Antitubercular Agents; Female; Heterocyclic Compounds, 3-Ring; HIV Infections; Humans; Infant; Isoniazid; Lamivudine; Rifampin; RNA; South Africa; Tenofovir; Tuberculosis; Viral Load

Tuberculosis (TB) is a significant public health problem that causes substantial morbidity and mortality. Current first-line anti-TB chemotherapy, although very effective, has limitations including long-treatment duration with a possibility of non-adherence, drug interactions, and toxicities. Dose escalation of rifampicin, an important drug within the regimen, has been proposed as a potential route to higher treatment efficacy with shorter duration and some studies have suggested that dose escalation is safe; however, these have almost entirely been conducted among human immunodeficiency (HIV)-negative TB patients. TB-HIV co-infected patients on antiretroviral therapy (ART) are at increased risk of drug-drug interactions and drug-related toxicities. This study aims to determine the safety of higher doses of rifampicin and its effect on the pharmacokinetics of efavirenz (EFV) and dolutegravir (DTG) in TB-HIV co-infected patients.. This study is a randomized, open-label, phase IIb clinical trial among TB-HIV infected adult outpatients attending an HIV clinic in Kampala, Uganda. Patients newly diagnosed with TB will be randomized to either standard-dose or high-dose rifampicin (35 mg/kg) alongside standard TB treatment. ART-naïve patients will be randomly assigned to first-line ART regimens (DTG or EFV). Those who are already on ART (DTG or EFV) at enrollment will be continued on the same ART regimen but with dose adjustment of DTG to twice daily dosing. Participants will be followed every 2 weeks with assessment for toxicities at each visit and measurement of drug concentrations at week 6. At the end of intensive-phase therapy (8 weeks), all participants will be initiated on continuation-phase treatment using standard-dose rifampicin and isoniazid.. This study should avail us with evidence about the effect of higher doses of rifampicin on the pharmacokinetics of EFV and DTG among TB-HIV co-infected patients. The trial should also help us to understand safety concerns of high-dose rifampicin among this vulnerable cohort.. ClinicalTrials.gov, ID: NCT03982277. Registered retrospectively on 11 June 2019.

Topics: Adult; Alkynes; Antibiotics, Antitubercular; Antitubercular Agents; Benzoxazines; Clinical Trials, Phase II as Topic; Coinfection; Cyclopropanes; Cytochrome P-450 CYP2B6; Cytochrome P-450 CYP2B6 Inducers; Dose-Response Relationship, Drug; Drug Interactions; Drug Monitoring; Drug Therapy, Combination; Female; Heterocyclic Compounds, 3-Ring; HIV Infections; Humans; Male; Middle Aged; Oxazines; Piperazines; Pyridones; Randomized Controlled Trials as Topic; Rifampin; Treatment Outcome; Tuberculosis; Uganda

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

Once-weekly isoniazid and rifapentine for 3 months is a treatment option in persons with human immunodeficiency virus and latent tuberculosis infection. This study aimed to examine pharmacokinetic drug-drug interactions between this regimen and dolutegravir, a first-line antiretroviral medication.. This was a single-center, open-label, fixed-sequence, drug-drug interaction study in healthy volunteers. Subjects received oral dolutegravir 50 mg once daily alone (days 1-4) and concomitantly with once-weekly isoniazid 900 mg, rifapentine 900 mg, and pyridoxine 50 mg (days 5-19). Dolutegravir concentrations were measured on days 4, 14, and 19, and rifapentine, 25-desacetyl-rifapentine, and isoniazid concentrations were measured on day 19. Cytokines and antidrug antibodies to isoniazid and rifapentine were examined at select time points.. The study was terminated following the development of flu-like syndrome and elevated aminotransferase levels in 2 of 4 subjects after the third isoniazid-rifapentine dose. Markedly elevated levels of interferon-γ, CXCL10, C-reactive protein, and other cytokines were temporally associated with symptoms. Antidrug antibodies were infrequently detected. Dolutegravir area under the curve (AUC) was decreased by 46% (90% confidence interval, 27-110%; P = .13) on day 14. Rifapentine and 25-desacetyl rifapentine levels on day 19 were comparable to reference data, whereas isoniazid AUCs were approximately 67%-92% higher in the subjects who developed toxicities.. The combined use of dolutegravir with once-weekly isoniazid-rifapentine resulted in unexpected and serious toxicities that were mediated by endogenous cytokine release. Additional investigations are necessary to examine the safety and efficacy of coadministering these medications.. NCT02771249.

Topics: Adolescent; Adult; Aged; Antibiotics, Antitubercular; Cytokines; Drug Administration Schedule; Drug Interactions; Female; Healthy Volunteers; Heterocyclic Compounds, 3-Ring; HIV Infections; Humans; Isoniazid; Latent Tuberculosis; Male; Middle Aged; Oxazines; Piperazines; Pyridones; Rifampin; Young Adult

Cotreatment of tuberculosis (TB) and HIV among coinfected patients is now the standard of care. Rifampin (RIF) is a standard part of TB treatment but is a potent inducer of drug metabolizing enzymes. This study evaluated the effect of RIF or rifabutin (RBT) on the pharmacokinetics of the investigational HIV integrase inhibitor, dolutegravir (DTG).. Phase I pharmacokinetic drug interaction study. In arm 1, healthy subjects received 50 mg of DTG once daily for 7 days (period 1), then 50 mg of DTG twice daily for 7 days (period 2), then 50 mg of DTG twice daily together with 600 mg of RIF once daily for 14 days (period 3). In arm 2, subjects received 50 mg of DTG once daily for 7 days (period 1) then 50 mg of DTG once daily together with 300 mg of RBT once daily for 14 days (period 2). PK sampling was performed at the end of each period.. In arm 1, comparing period 3 to period 1, the geometric mean ratio (GMR) for the 24-hour area under the time-concentration curve (AUC0-24) was 1.33 [90% confidence interval (CI): 1.14 to 1.53], and the GMR for the trough (Cτ) was 1.22 (90% CI: 1.01 to 1.48). Comparing period 2 to period 1 in arm 2, the GMR for the AUC0-24 was 0.95 (90% CI: 0.82 to 1.10), and the GMR for the Cτ was 0.70 (90% CI: 0.57 to 0.87).. Regimens including twice-daily DTG and RIF or once-daily DTG and RBT may represent a new treatment option for patients who require concomitant treatment of HIV and TB.

Topics: Adult; Antitubercular Agents; Cross-Over Studies; Drug Interactions; Female; Heterocyclic Compounds, 3-Ring; HIV Integrase Inhibitors; Human Experimentation; Humans; Male; Middle Aged; Oxazines; Piperazines; Pyridones; Rifabutin; Rifampin

Topics: Anti-HIV Agents; Heterocyclic Compounds, 3-Ring; HIV Infections; Humans; Oxazines; Rifampin; Tuberculosis

We present a case of a 53-year-old person living with human immunodeficiency virus and a new diagnosis of latent tuberculosis. The patient had baseline suppressed HIV viral load on fixed dose combination dolutegravir/abacavir/lamivudine when once-weekly rifapentine 900 mg/isoniazid 900 mg/pyridoxine 25 mg was initiated for 12 weeks. An additional 50 mg dolutegravir dose, administered in the evenings, was added to the daily antiretroviral regimen for treatment duration secondary to rifapentine uridine diphosphate glucuronsyl transferase induction. Dolutegravir trough concentrations decreased during concurrent therapy with noted slight HIV viral load rebound. Upon completion of rifapentine use, and a return to dolutegravir 50 mg daily dose, the trough concentrations increased with a return to an undetectable viral load. We provide suggested dolutegravir dosing considerations with concomitant rifapentine use, not currently addressed in recommended guidelines.

Topics: Anti-HIV Agents; Drug Therapy, Combination; HIV Infections; Humans; Isoniazid; Latent Tuberculosis; Middle Aged; Rifampin

Rifamycins are the cornerstone of anti-tuberculosis therapy while they are potent inducers of drug metabolizing enzymes. For the first time, we evaluated the effect of rifampicin (RIF) and rifabutin (RBT) on the pharmacokinetics (PK) of dolutegravir (DTG) in patients with HIV and tuberculosis (TB)/ mycobacterium avium complex (MAC) co-infection.. Both HIV/TB (or MAC) co-infected patients and HIV infected patients without TB/MAC were enrolled. Patients in the RIF group received DTG 50 mg twice daily together with 600mg of RIF, while patients in the RBT group received DTG 50 mg once daily together with 300 mg of RBT. The DTG pharmacokinetic profiles in different groups were assessed.. A total of 13 subjects in the RIF group, 12 subjects in the RBT group, and 10 subjects in non-TB/MAC group were enrolled. The geometric mean ratio (GMR) of the trough concentration (Ctr) of DTG in the RIF group to non-TB/MAC group was 1.33 [90% confidence interval (CI):0.97 to 1.81], while the GMR of the maximum concentration (Cmax) of DTG was 1.29 (90% CI: 1.23 to 1.36). The GMR of the Ctr of DTG in the RBT group to non-TB/MAC group was 0.41 (90% CI: 0.30 to 0.57), while the GMR of the Cmax of DTG was 0.55 (90% CI: 0.52 to 0.57).. Due to the relatively low trough concentrations of DTG with RBT, DTG 50mg once daily together with RBT could only serve as an alternative option for HIV/TB (or MAC) co-infected patients.

Topics: Coinfection; Heterocyclic Compounds, 3-Ring; HIV; HIV Infections; Humans; Mycobacterium avium Complex; Mycobacterium avium-intracellulare Infection; Oxazines; Piperazines; Pyridones; Rifabutin; Rifampin; Tuberculosis

Dolutegravir is being scaled up globally as part of antiretroviral therapy (ART), but for people with HIV and tuberculosis co-infection, its use is complicated by a drug-drug interaction with rifampicin requiring an additional daily dose of dolutegravir. This represents a disadvantage over efavirenz, which does not have a major drug-drug interaction with rifampicin. We sought to describe HIV clinic practices for prescribing concomitant dolutegravir and rifampicin, and characterize virologic outcomes among patients with tuberculosis co-infection receiving dolutegravir or efavirenz.. Within the four sub-Saharan Africa regions of the International epidemiology Databases to Evaluate AIDS consortium, we conducted a site survey (2021) and a cohort study (2015-2021). The cohort study used routine clinical data and included patients newly initiating or already receiving dolutegravir or efavirenz at the time of tuberculosis diagnosis. Patients were followed from tuberculosis diagnosis until viral suppression (<1000 copies/ml), a competing event (switching ART regimen; loss to program/death) or administrative censoring at 12 months.. In the survey, 86 of 90 (96%) HIV clinics in 18 countries reported prescribing dolutegravir to patients who were receiving rifampicin as part of tuberculosis treatment, with 77 (90%) reporting that they use twice-daily dosing of dolutegravir, of which 74 (96%) reported having 50 mg tablets available to accommodate twice-daily dosing. The cohort study included 3563 patients in 11 countries, with 67% newly or recently initiating ART. Among patients receiving dolutegravir (n = 465), the cumulative incidence of viral suppression was 58.9% (95% confidence interval [CI]: 54.3-63.3%), switching ART regimen was 4.1% (95% CI: 2.6-6.2%) and loss to program/death was 23.4% (95% CI: 19.7-27.4%). Patients receiving dolutegravir had improved viral suppression compared with patients receiving efavirenz who had a tuberculosis diagnosis before site dolutegravir availability (adjusted subdistribution hazard ratio [aSHR]: 1.47, 95% CI: 1.28-1.68) and after site dolutegravir availability (aSHR 1.28, 95% CI: 1.08-1.51).. At a programmatic level, dolutegravir was being widely prescribed in sub-Saharan Africa for people with HIV and tuberculosis co-infection with a dose adjustment for the drug-drug interaction with rifampicin. Despite this more complex regimen, our cohort study revealed that dolutegravir did not negatively impact viral suppression.

Topics: Africa South of the Sahara; Anti-HIV Agents; Benzoxazines; Cohort Studies; Coinfection; Heterocyclic Compounds, 3-Ring; HIV Infections; Humans; Oxazines; Piperazines; Pyridones; Rifampin; Tuberculosis

Topics: Adult; Aged; Coinfection; Female; Heterocyclic Compounds, 3-Ring; HIV Infections; HIV Integrase Inhibitors; Humans; Male; Middle Aged; Oxazines; Piperazines; Pyridones; Rifampin; Tuberculosis

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

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

Topics: Adult; Anti-HIV Agents; Drug Therapy, Combination; Female; Heterocyclic Compounds, 3-Ring; HIV Infections; Hospitals, Teaching; Humans; Male; Middle Aged; Oxazines; Piperazines; Pyridones; Rifampin; Treatment Outcome; Tuberculosis; United Kingdom

1. Interspecies allometry scaling for prediction of human excretory amounts in urine or feces was performed for numerous antibacterials. Antibacterials used for urinary scaling were: rifapentine, pefloxacin, trovafloxacin (Gr1/low; <10%); miloxacin, linezolid, PNU-142300 (Gr2/medium; 10-40%); aztreonam, carumonam, cefozopran, doripenem, imipenem, and ceftazidime (Gr3/high; >50%). Rifapentine, cabotegravir, and dolutegravir was used for fecal scaling (high; >50%). 2. The employment of allometry equation: Y = aW(b) enabled scaling of urine/fecal amounts from animal species. Corresponding predicted amounts were converted into % recovery by considering the respective human dose. Comparison of predicted/observed values enabled fold difference and error calculations (mean absolute error [MAE] and root mean square error [RMSE]). Comparisons were made for urinary/fecal data; and qualitative assessment was made amongst Gr1/Gr2/Gr3 for urine. 3. Average correlation coefficient for the allometry scaling was >0.995. Excretory amount predictions were largely within 0.75- to 1.5-fold differences. Average MAE and RMSE were within ±22% and 23%, respectively. Although robust predictions were achieved for higher urinary/fecal excretion (>50%), interspecies scaling was applicable for low/medium excretory drugs. 4. Based on the data, interspecies scaling of urine or fecal excretory amounts may be potentially used as a tool to understand the significance of either urinary or fecal routes of elimination in humans in early development.

Topics: Animals; Anti-Bacterial Agents; Aztreonam; Carbapenems; Cefozopran; Ceftazidime; Cephalosporins; Doripenem; Feces; Fluoroquinolones; Heterocyclic Compounds, 3-Ring; Humans; Imipenem; Linezolid; Naphthyridines; Oxazines; Oxolinic Acid; Pefloxacin; Piperazines; Pyridones; Retrospective Studies; Rifampin