cgp-56697 and HIV-Infections

Malaria is an infectious disease which disproportionately effects children and pregnant women. These vulnerable populations are often excluded from clinical trials resulting in one-size-fits-all treatment regimens based on those established for a nonpregnant adult population. Pharmacokinetic/pharmacodynamic (PK/PD) models can be used to optimize dose selection as they define the drug exposure-response relationship. Additionally, these models are able to identify patient characteristics that cause alterations in the expected PK/PD profiles and through simulations can recommend changes to dosing which compensate for the differences. In this review, we examine how PK/PD models have been applied to optimize antimalarial dosing recommendations for young children, including those who are malnourished, pregnant women, and individuals receiving concomitant therapies such as those for HIV treatment. The malaria field has had great success in utilizing PK/PD models as a foundation to update treatment guidelines and propose the next generation of dosing regimens to investigate in clinical trials. We propose how the malaria field can continue to use modeling to improve therapies by further integrating PK data into clinical studies and including data on drug resistance and host immunity in PK/PD models. Finally, we suggest that other disease areas can achieve similar success in applying pharmacometrics to improve outcomes by implementing three key principals.

Topics: Amodiaquine; Anti-HIV Agents; Antimalarials; Artemether, Lumefantrine Drug Combination; Artemisinins; Artesunate; Child, Preschool; Dose-Response Relationship, Drug; Drug Combinations; Drug Interactions; Drug Therapy, Combination; Female; Global Health; HIV Infections; Humans; Malaria; Malnutrition; Mefloquine; Models, Biological; Pregnancy; Pregnancy Complications, Parasitic; Pyrimethamine; Quinolines; Sulfadoxine; Vulnerable Populations

Treating malaria in HIV-coinfected individuals should consider potential drug-drug interactions. Artemether-lumefantrine is the most widely recommended treatment for uncomplicated malaria globally. Lumefantrine is metabolized by CYP3A4, an enzyme that commonly used antiretrovirals often induce or inhibit. A population pharmacokinetic meta-analysis was conducted using individual participant data from 10 studies with 6,100 lumefantrine concentrations from 793 nonpregnant adult participants (41% HIV-malaria-coinfected, 36% malaria-infected, 20% HIV-infected, and 3% healthy volunteers). Lumefantrine exposure increased 3.4-fold with coadministration of lopinavir-ritonavir-based antiretroviral therapy (ART), while it decreased by 47% with efavirenz-based ART and by 59% in the patients with rifampin-based antituberculosis treatment. Nevirapine- or dolutegravir-based ART and malaria or HIV infection were not associated with significant effects. Monte Carlo simulations showed that those on concomitant efavirenz or rifampin have 49% and 80% probability of day 7 concentrations <200 ng/ml, respectively, a threshold associated with an increased risk of treatment failure. The risk of achieving subtherapeutic concentrations increases with larger body weight. An extended 5-day and 6-day artemether-lumefantrine regimen is predicted to overcome these drug-drug interactions with efavirenz and rifampin, respectively.

Topics: Adolescent; Adult; Aged; Anti-HIV Agents; Antimalarials; Antiretroviral Therapy, Highly Active; Artemether, Lumefantrine Drug Combination; Body Weight; Computer Simulation; Drug Interactions; Female; HIV Infections; Humans; Lopinavir; Lumefantrine; Malaria; Male; Middle Aged; Monte Carlo Method; Ritonavir; Young Adult

When people with human immunodeficiency virus (HIV) infection (PWH) develop malaria, they are at risk of poor anti-malarial treatment efficacy resulting from impairment in the immune response and/or drug-drug interactions that alter anti-malarial metabolism. The therapeutic efficacy of artemether-lumefantrine was evaluated in a cohort of PWH on antiretroviral therapy (ART) and included measurement of day 7 lumefantrine levels in a subset to evaluate for associations between lumefantrine exposure and treatment response.. Adults living with HIV (≥ 18 years), on ART for ≥ 6 months with undetectable HIV RNA viral load and CD4 count ≥ 250/mm. 411 malaria episodes were observed among 186 participants over 5 years. The unadjusted ACPR rate was 81% (95% CI 77-86). However, after PCR correction to exclude new infections, ACPR rate was 94% (95% CI 92-97). Increasing age and living in Ndirande were associated with decreased hazard of treatment failure. In this population of adults with HIV on ART, 54% (51/94) had levels below a previously defined optimal day 7 lumefantrine level of 200 ng/ml. This occurred more commonly among participants who were receiving an efavirenz-based ART compared to other ART regimens (OR 5.09 [95% CI 1.52-7.9]). Participants who experienced treatment failure had lower day 7 median lumefantrine levels (91 ng/ml [95% CI 48-231]) than participants who experienced ACPR (190 ng/ml [95% CI 101-378], p-value < 0.008).. Recurrent malaria infections are frequent in this population of PWH on ART. The PCR-adjusted efficacy of AL meets the WHO criteria for acceptable treatment efficacy. Nevertheless, lumefantrine levels tend to be low in this population, particularly in those on efavirenz-based regimens, with lower concentrations associated with more frequent malaria infections following treatment. These results highlight the importance of understanding drug-drug interactions when diseases commonly co-occur.

Topics: Adult; Antimalarials; Artemether; Artemether, Lumefantrine Drug Combination; Artemisinins; Drug Combinations; Ethanolamines; Fluorenes; HIV Infections; Humans; Lumefantrine; Malaria; Malaria, Falciparum; Malawi; Treatment Outcome

In this study the influence of first-line antimalarial drug artemether-lumefantrine on the pharmacokinetics of the antiretroviral drug nevirapine was investigated in the context of selected single nucleotide polymorphisms (SNPs) in a cohort of adult HIV-infected Nigerian patients.. This was a two-period, single sequence crossover study. In stage 1, 150 HIV-infected patients receiving nevirapine-based antiretroviral regimens were enrolled and genotyped for seven SNPs. Sparse pharmacokinetic sampling was conducted to identify SNPs independently associated with nevirapine plasma concentration. Patients were categorized as poor, intermediate and extensive metabolizers based on the numbers of alleles of significantly associated SNPs. Intensive sampling was conducted in selected patients from each group. In stage 2, patients received standard artemether-lumefantrine treatment with nevirapine, and intensive pharmacokinetic sampling was conducted on day 3.. No clinically significant changes were observed in key nevirapine pharmacokinetic parameters, the 90% confidence interval for the measured changes falling completely within the 0.80-1.25 no-effect boundaries. However, the number of patients with trough plasma nevirapine concentration below the 3400 ng ml. This approach highlights additional increase in the already existing risk of suboptimal trough plasma concentration, especially in extensive metabolizers when nevirapine is co-administered with artemether-lumefantrine.

Topics: Adult; Antimalarials; Artemether, Lumefantrine Drug Combination; Cross-Over Studies; Cytochrome P-450 CYP2B6; Drug Interactions; Female; HIV Infections; Humans; Malaria; Male; Middle Aged; Nevirapine; Nigeria; Polymorphism, Single Nucleotide; Reverse Transcriptase Inhibitors

HIV-infected individuals on antiretroviral therapy (ART) require treatment with artemisinin-based combination therapy (ACT) when infected with malaria. Artemether-lumefantrine (AL) is the most commonly used ACT for treatment of falciparum malaria in Africa but there is limited evidence on the safety and efficacy of AL in HIV-infected individuals on ART, among whom drug-drug interactions are expected. Day-42 adequate clinical and parasitological response (ACPR) and incidence of adverse events was assessed in HIV-infected individuals on efavirenz-based ART with uncomplicated falciparum malaria treated with AL.. A prospective, open label, non-randomized, interventional clinical trial was conducted at St Paul's Hospital in northern Zambia, involving 152 patients aged 15-65 years with uncomplicated falciparum malaria, who were on efavirenz-based ART. They received a 3-day directly observed standard treatment of AL and were followed up until day 63. Day-42 polymerase chain reaction (PCR)-corrected ACPRs (95% confidence interval [CI]) were calculated for the intention-to-treat population.. Enrolled patients had a baseline geometric mean (95% CI) parasite density of 1108 (841-1463) parasites/µL; 16.4% (25/152) of the participants had a recurrent malaria episode by day 42. However, PCR data was available for 17 out of the 25 patients who had malaria recurrence. Among all the 17 patients, PCR findings demonstrated malaria re-infection, making the PCR-adjusted day-42 ACPR 100% in the 144 patients who could be evaluated. Even when eight patients with missing PCR data were considered very conservatively as failures, the day-42 ACPR was over 94%. None of the participants, disease or treatment characteristics, including day-7 lumefantrine concentrations, predicted the risk of malaria recurrence by day 42. AL was well tolerated following administration. There were only two cases of grade 3 neutropaenia and one serious adverse event of lobar pneumonia, none of which was judged as probably related to intake of AL.. AL was well tolerated and efficacious in treating uncomplicated falciparum malaria in HIV co-infected adults on efavirenz-based ART. However, a higher than anticipated proportion of participants experienced malaria re-infection, which highlights the need for additional malaria prevention measures in this sub-population after treatment with AL. Trial registration Pan African Clinical Trials Registry (PACTR): PACTR201311000659400. Registered on 4 October 2013. https://pactr.samrc.ac.za/Search.aspx.

Topics: Adolescent; Adult; Aged; Alkynes; Antimalarials; Artemether, Lumefantrine Drug Combination; Benzoxazines; Cyclopropanes; Female; HIV Infections; Humans; Malaria, Falciparum; Male; Middle Aged; Plasmodium falciparum; Polymerase Chain Reaction; Prospective Studies; Reverse Transcriptase Inhibitors; Young Adult; Zambia

Artemisinin-based combination therapy (ACT) has become the standard of care for the treatment of uncomplicated Plasmodium falciparum malaria. Although several ACT regimens are approved, data guiding optimal choices of ACTs are limited. We compared short- and long-term outcomes in a cohort of young Ugandan children randomized to 2 leading ACTs.. Overall, 312 children were randomized to artemether-lumefantrine or dihydroartemisinin-piperaquine (DP) at the time of the first episode of uncomplicated malaria (median age, 10.5 months). The same treatment was given for all subsequent episodes of uncomplicated malaria and children were followed until they reached 5 years of age. The cohort included a subgroup that was human immunodeficiency virus (HIV) infected (n = 44) or HIV exposed (n = 175) and prescribed trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis. Outcomes included time to recurrent malaria following individual treatments and the overall incidences of treatments for malaria, complicated malaria, and hospitalizations.. Among children not prescribed TMP-SMX prophylaxis, 4443 treatments for malaria were given over 790 person-years following randomization. Treatment with DP was associated with a lower hazard of recurrent malaria over the 84 days after treatment (hazard ratio, 0.66; 95% confidence interval [CI], .61-.70; P < .001). Children randomized to DP had a lower incidence of all treatments for malaria (incidence rate ratio [IRR], 0.85; 95% CI, .75-.96; P = .01), complicated malaria (IRR, 0.12; 95% CI, .04-.39; P < .001), and hospitalizations (IRR, 0.31; 95% CI, .13-.77; P = .01). Among children prescribed TMP-SMX prophylaxis, there were no significant differences in longitudinal outcomes.. Compared to artemether-lumefantrine, the use of DP to treat uncomplicated malaria delayed the time to recurrent malaria and reduced the incidences of treatments for malaria, complicated malaria, and hospitalizations.. NCT00527800.

Topics: Antimalarials; Artemether, Lumefantrine Drug Combination; Artemisinins; Child, Preschool; Cohort Studies; Drug Combinations; Drug Therapy, Combination; Ethanolamines; Female; Fluorenes; HIV Infections; Hospitalization; Humans; Infant; Longitudinal Studies; Malaria, Falciparum; Male; Quinolines; Recurrence; Time Factors; Treatment Outcome; Uganda

Artemisinin-based combination therapies (ACTs) and trimethoprim-sulfamethoxazole (TS) prophylaxis are important tools for malaria control, but there are concerns about their effect on gametocytes, the stage of the parasite responsible for transmission. We conducted a longitudinal clinical trial in a cohort of HIV-infected and uninfected children living in an area of high malaria transmission intensity in Uganda. Study participants were randomized to artemether-lumefantrine (AL) or dihydroartemisinin-piperaquine (DP) for all treatments of uncomplicated malaria (N = 4,380) as well as TS prophylaxis for different durations. The risks of gametocytemia detected by microscopy in the 28 days after antimalarial therapy were compared using multivariate analyses. The risk of gametocyte detection was significantly higher in patients treated with DP compared with AL (adjusted relative risk = 1.85, P < 0.001) and among children prescribed TS prophylaxis (adjusted relative risk = 1.76, P < 0.001). The risk of gametocytemia and its potential for increasing transmission should be considered when evaluating different ACTs and TS prophylaxis for malaria control.

Topics: Antimalarials; Artemether, Lumefantrine Drug Combination; Artemisinins; Child, Preschool; Drug Combinations; Drug Therapy, Combination; Ethanolamines; Fluorenes; HIV Infections; Humans; Infant; Longitudinal Studies; Malaria, Falciparum; Multivariate Analysis; Parasitemia; Plasmodium falciparum; Post-Exposure Prophylaxis; Prevalence; Proportional Hazards Models; Quinolines; Risk Factors; Treatment Outcome; Trimethoprim, Sulfamethoxazole Drug Combination; Trophozoites; Uganda

Co-administration of artemether/lumefantrine with antiretroviral therapy has potential for pharmacokinetic drug interactions. We investigated drug-drug interactions between artemether/lumefantrine and efavirenz or nevirapine.. We performed a cross-over study in which HIV-infected adults received standard six-dose artemether/lumefantrine 80/480 mg before and at efavirenz or nevirapine steady state. Artemether, dihydroartemisinin, lumefantrine, efavirenz and nevirapine plasma concentrations were measured and compared.. Efavirenz significantly reduced artemether maximum concentration (C(max)) and plasma AUC (median 29 versus 12 ng/mL, P < 0.01, and 119 versus 25 ng · h/mL, P < 0.01), dihydroartemisinin C(max) and AUC (median 120 versus 26 ng/mL, P < 0.01, and 341 versus 84 ng · h/mL, P < 0.01), and lumefantrine C(max) and AUC (median 8737 versus 6331 ng/mL, P = 0.03, and 280 370 versus 124 381 ng · h/mL, P < 0.01). Nevirapine significantly reduced artemether C(max) and AUC (median 28 versus 11 ng/mL, P < 0.01, and 123 versus 34 ng · h/mL, P < 0.01) and dihydroartemisinin C(max) and AUC (median 107 versus 59 ng/mL, P < 0.01, and 364 versus 228 ng · h/mL, P < 0.01). Lumefantrine C(max) and AUC were non-significantly reduced by nevirapine. Artemether/lumefantrine reduced nevirapine C(max) and AUC (median 8620 versus 4958 ng/mL, P < 0.01, and 66 329 versus 35 728 ng · h/mL, P < 0.01), but did not affect efavirenz exposure.. Co-administration of artemether/lumefantrine with efavirenz or nevirapine resulted in a reduction in artemether, dihydroartemisinin, lumefantrine and nevirapine exposure. These drug interactions may increase the risk of malaria treatment failure and development of resistance to artemether/lumefantrine and nevirapine. Clinical data from population pharmacokinetic and pharmacodynamic trials evaluating the impact of these drug interactions are urgently needed.

Topics: Adult; Alkynes; Anti-HIV Agents; Antimalarials; Artemether, Lumefantrine Drug Combination; Artemisinins; Benzoxazines; Cross-Over Studies; Cyclopropanes; Drug Combinations; Drug Interactions; Ethanolamines; Female; Fluorenes; HIV Infections; Humans; Malaria; Male; Nevirapine; Plasma; Uganda

Human immunodeficiency virus (HIV) protease inhibitors show activity against Plasmodium falciparum in vitro. We hypothesized that the incidence of malaria in HIV-infected children would be lower among children receiving lopinavir-ritonavir-based antiretroviral therapy (ART) than among those receiving nonnucleoside reverse-transcriptase inhibitor (NNRTI)-based ART.. We conducted an open-label trial in which HIV-infected children 2 months to 5 years of age who were eligible for ART or were currently receiving NNRTI-based ART were randomly assigned to either lopinavir-ritonavir-based ART or NNRTI-based ART and were followed for 6 months to 2 years. Cases of uncomplicated malaria were treated with artemether-lumefantrine. The primary end point was the incidence of malaria.. We enrolled 176 children, of whom 170 received the study regimen: 86 received NNRTI-based ART, and 84 lopinavir-ritonavir-based ART. The incidence of malaria was lower among children receiving the lopinavir-ritonavir-based regimen than among those receiving the NNRTI-based regimen (1.32 vs. 2.25 episodes per person-year; incidence-rate ratio, 0.59; 95% confidence interval [CI], 0.36 to 0.97; P=0.04), as was the risk of a recurrence of malaria after treatment with artemether-lumefantrine (28.1% vs. 54.2%; hazard ratio, 0.41; 95% CI, 0.22 to 0.76; P=0.004). The median lumefantrine level on day 7 after treatment for malaria was significantly higher in the lopinavir-ritonavir group than in the NNRTI group. In the lopinavir-ritonavir group, lumefantrine levels exceeding 300 ng per milliliter on day 7 were associated with a reduction of more than 85% in the 63-day risk of recurrent malaria. A greater number of serious adverse events occurred in the lopinavir-ritonavir group than in the NNRTI group (5.6% vs. 2.3%, P=0.16). Pruritus occurred significantly more frequently in the lopinavir-ritonavir group, and elevated alanine aminotransferase levels significantly more frequently in the NNRTI group.. Lopinavir-ritonavir-based ART as compared with NNRTI-based ART reduced the incidence of malaria by 41%, with the lower incidence attributable largely to a significant reduction in the recurrence of malaria after treatment with artemether-lumefantrine. Lopinavir-ritonavir-based ART was accompanied by an increase in serious adverse events. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development; ClinicalTrials.gov number, NCT00978068.).

Topics: Anti-Retroviral Agents; Antimalarials; Artemether, Lumefantrine Drug Combination; Artemisinins; Child, Preschool; Drug Combinations; Drug Interactions; Drug Therapy, Combination; Ethanolamines; Female; Fluorenes; HIV Infections; HIV Protease Inhibitors; Humans; Incidence; Infant; Kaplan-Meier Estimate; Lopinavir; Malaria; Male; Reverse Transcriptase Inhibitors; Ritonavir; Secondary Prevention; Uganda

Artemether-lumefantrine and nevirapine-based antiretroviral therapy (ART) are the most commonly recommended first-line treatments for malaria and HIV, respectively, in Africa. Artemether, lumefantrine, and nevirapine are metabolized by the cytochrome P450 3A4 enzyme system, which nevirapine induces, creating potential for important drug interactions. In a parallel-design pharmacokinetic study, concentration-time profiles were obtained in two groups of HIV-infected patients: ART-naïve patients and those stable on nevirapine-based therapy. Both groups received the recommended artemether-lumefantrine dose. Patients were admitted for intense pharmacokinetic sampling (0 to 72 h) with outpatient sampling until 21 days. Concentrations of lumefantrine, artemether, dihydroartemisinin, and nevirapine were determined by validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. The primary outcome was observed day 7 lumefantrine concentrations, as these are associated with therapeutic response in malaria. We enrolled 36 patients (32 females). Median (range) day 7 lumefantrine concentrations were 622 ng/ml (185 to 2,040 ng/ml) and 336 ng/ml (29 to 934 ng/ml) in the nevirapine and ART-naïve groups, respectively (P = 0.0002). The median artemether area under the plasma concentration-time curve from 0 to 8 h [AUC((0-8 h))] (P < 0.0001) and dihydroartemisinin AUC((60-68 h)) (P = 0.01) were lower in the nevirapine group. Combined artemether and dihydroartemisinin exposure decreased over time only in the nevirapine group (geometric mean ratio [GMR], 0.76 [95% confidence interval {CI}, 0.65 to 0.90]; P < 0.0001) and increased with the weight-adjusted artemether dose (GMR, 2.12 [95% CI, 1.31 to 3.45]; P = 0.002). Adverse events were similar between groups, with no difference in electrocardiographic Fridericia corrected QT and P-R intervals at the expected time of maximum lumefantrine concentration (T(max)). Nevirapine-based ART decreased artemether and dihydroartemisinin AUCs but unexpectedly increased lumefantrine exposure. The mechanism of the lumefantrine interaction remains to be elucidated. Studies investigating the interaction of nevirapine and artemether-lumefantrine in HIV-infected patients with malaria are urgently needed.

Topics: Adult; Anti-HIV Agents; Antimalarials; Artemether, Lumefantrine Drug Combination; Artemisinins; Drug Combinations; Drug Interactions; Ethanolamines; Female; Fluorenes; HIV Infections; HIV-1; Humans; Malaria; Male; Nevirapine; Reverse Transcriptase Inhibitors; South Africa; Treatment Outcome

Artemisinin combination therapy has become the standard of care for uncomplicated malaria in most of Africa. However, there is limited data on the safety and tolerability of these drugs, especially in young children and patients co-infected with HIV.. A longitudinal, randomized controlled trial was conducted in a cohort of HIV-infected and uninfected children aged 4-22 months in Tororo, Uganda. Participants were randomized to treatment with artemether-lumefantrine (AL) or dihydroartemisinin-piperaquine (DP) upon diagnosis of their first episode of uncomplicated malaria and received the same regimen for all subsequent episodes. Participants were actively monitored for adverse events for 28 days and then passively for up to 63 days after treatment. This study was registered in ClinicalTrials.gov (registration # NCT00527800).. A total of 122 children were randomized to AL and 124 to DP, resulting in 412 and 425 treatments, respectively. Most adverse events were rare, with only cough, diarrhoea, vomiting, and anaemia occurring in more than 1% of treatments. There were no differences in the risk of these events between treatment groups. Younger age was associated with an increased risk of diarrhoea in both the AL and DP treatment arms. Retreatment for malaria within 17-28 days was associated with an increased risk of vomiting in the DP treatment arm (HR = 6.47, 95% CI 2.31-18.1, p < 0.001). There was no increase in the risk of diarrhoea or vomiting for children who were HIV-infected or on concomitant therapy with antiretrovirals or trimethoprim-sulphamethoxazole prophylaxis.. Both AL and DP were safe and well tolerated for the treatment of uncomplicated malaria in young HIV-infected and uninfected children.. ClinicalTrials.gov: NCT00527800; http://clinicaltrials.gov/ct2/show/NCT00527800.

Topics: Antimalarials; Artemether; Artemether, Lumefantrine Drug Combination; Artemisinins; Drug Combinations; Drug Therapy, Combination; Ethanolamines; Female; Fluorenes; Follow-Up Studies; HIV Infections; Humans; Infant; Longitudinal Studies; Malaria, Falciparum; Male; Quinolines; Risk Factors; Treatment Outcome; Uganda

Artemisinin-based combination therapies (ACTs) are the primary treatment for malaria. It is essential to characterize the pharmacokinetics (PKs) and pharmacodynamics (PDs) of ACTs in vulnerable populations at risk of suboptimal dosing. We developed a population PK/PD model using data from our previous study of artemether-lumefantrine in HIV-uninfected and HIV-infected children living in a high-transmission region of Uganda. HIV-infected children were on efavirenz-, nevirapine-, or lopinavir-ritonavir-based antiretroviral regimens, with daily trimethoprim-sulfamethoxazole prophylaxis. We assessed selection for resistance in two key parasite transporters, pfcrt and pfmdr1, over 42-day follow-up and incorporated genotyping into a time-to-event model to ascertain how resistance genotype in relation to drug exposure impacts recurrence risk. Two hundred seventy-seven children contributed 364 episodes to the model (186 HIV-uninfected and 178 HIV-infected), with recurrent microscopy-detectable parasitemia detected in 176 episodes by day 42. The final model was a two-compartment model with first-order absorption and an estimated age effect on bioavailability. Systemic lumefantrine exposure was highest with lopinavir-ritonavir, lowest with efavirenz, and equivalent with nevirapine and HIV-uninfected children. HIV status and lumefantrine concentration were significant factors associated with recurrence risk. Significant selection was demonstrated for pfmdr1 N86 and pfcrt K76 in recurrent infections, with no evidence of selection for pfmdr1 Y184F. Less sensitive parasites were able to tolerate lumefantrine concentrations ~ 3.5-fold higher than more sensitive parasites. This is the first population PK model of lumefantrine in HIV-infected children and demonstrates selection for reduced lumefantrine susceptibility, a concern as we confront the threat to ACTs posed by emerging artemisinin resistance in Africa.

Topics: Antimalarials; Artemether; Artemether, Lumefantrine Drug Combination; Artemisinins; Child; Drug Combinations; Fluorenes; HIV Infections; Humans; Lopinavir; Lumefantrine; Malaria; Malaria, Falciparum; Nevirapine; Ritonavir; Uganda

Atazanavir-ritonavir (ATVr)-based antiretroviral therapy and artemether-lumefantrine (AL) are commonly used drugs for the treatment of human immune deficiency virus (HIV) infection and malaria respectively. However, interaction of both drugs, with Cytochrome P 3A4 (CYP 3A4) isoenzyme, may spawn clinically significant pharmacokinetic interactions. This study evaluated the effects of atazanavir-ritonavir on the pharmacokinetics of lumefantrine.. In a case-control study, twenty participants having Plasmodium falciparum malaria were recruited and divided into two groups (ATVr-arm, n=10; and control-arm, n= 10). All the participants were administered six oral doses of AL 80-480 mg (Coartem). Thereafter, their blood samples were collected at different time intervals over seven days. The concentration of lumefantrine in each sample was quantified with high-performance liquid chromatography (HPLC) and used to determine its pharmacokinetic parameters which were compared between the test and control groups.. ATVr increased the mean day 7 concentration of lumefantrine (ATVr 3847.09 ± 893.35 ng/mL, control 1374.53 ± 265.55 ng/mL, p = 0.016) and the area under its plasma concentration-time curve (ATVr 670529.57 ± 157172.93 ng.h/mL, control 447976.28 ± 80886.99 ng.h/mL, p = 0.224) by 179.88 % and 49.68 %, respectively, but decreased its mean maximum plasma drug concentration (Cmax) (ATVr 13725.70 ± 2658.44 ng/mL, control 15380.48 ± 2332.62 ng/mL, p = 0.645) by 10.76 %.. ATVr increased drug exposure and day 7 plasma concentration of lumefantrine. AL is therefore considered effective for the treatment of malaria in patients taking ATVr-based regimen. However, the safety associated with the interaction requires further elucidation.. Clin ClinicalTrials.gov Identifier: NCT04531072, August 27, 2020. "Retrospectively registered".

Topics: Adult; Anti-Retroviral Agents; Antimalarials; Artemether, Lumefantrine Drug Combination; Atazanavir Sulfate; Case-Control Studies; Chromatography, High Pressure Liquid; Drug Combinations; Female; HIV Infections; Hospitals, Teaching; Humans; Malaria; Male; Middle Aged; Nigeria; Plasmodium falciparum; Racemases and Epimerases; Ritonavir

The choice of malaria treatment for HIV-infected pregnant women receiving efavirenz-based antiretroviral therapy must consider the potential impact of drug interactions on antimalarial exposure and clinical response. The aim of this study was to investigate the effects of efavirenz on artemether-lumefantrine (AL) because no studies have isolated the impact of efavirenz for HIV-infected pregnant women.. A prospective clinical pharmacokinetic (PK) study compared HIV-infected, efavirenz-treated pregnant women with HIV-uninfected pregnant women in Tororo, Uganda. All women received the standard 6-dose AL treatment regimen for Plasmodium falciparum malaria with intensive PK samples collected over 21 days and 42-days of clinical follow-up. PK exposure parameters were calculated for artemether, its active metabolite dihydroartemisinin (DHA), and lumefantrine to determine the impact of efavirenz.. Nine HIV-infected and 30 HIV-uninfected pregnant women completed intensive PK evaluations. Relative to controls, concomitant efavirenz therapy lowered the 8-hour artemether concentration by 76% (P = 0.013), DHA peak concentration by 46% (P = 0.033), and day 7 and 14 lumefantrine concentration by 61% and 81% (P = 0.046 and 0.023), respectively. In addition, there were nonsignificant reductions in DHA area under the concentration-time curve0-8hr (35%, P = 0.057) and lumefantrine area under the concentration-time curve0-∞ (34%, P = 0.063) with efavirenz therapy.. Pregnant HIV-infected women receiving efavirenz-based antiretroviral therapy during malaria treatment with AL showed reduced exposure to both the artemisinin and lumefantrine. These data suggest that malaria and HIV coinfected pregnant women may require adjustments in AL dosage or treatment duration to achieve exposure comparable with HIV-uninfected pregnant women.

Topics: Adolescent; Adult; Alkynes; Anti-HIV Agents; Anti-Retroviral Agents; Antimalarials; Artemether; Artemether, Lumefantrine Drug Combination; Artemisinins; Benzoxazines; Cyclopropanes; Drug Combinations; Drug Interactions; Female; HIV Infections; Humans; Lumefantrine; Malaria; Malaria, Falciparum; Pregnancy; Prospective Studies; Uganda; Young Adult

Coadministration of artemether-lumefantrine and efavirenz has been shown to result in significant interactions. The influence of functional genetic polymorphisms in selected CYPs on the magnitude of this interaction was investigated in pregnant and nonpregnant adults.. A standard 3-day regimen of artemether-lumefantrine was administered to each patient on steady-state efavirenz-based antiretroviral therapy (ART). Pharmacokinetic parameters were obtained from intensive plasma concentration-time data. Genotyping data were tested for compliance with Hardy-Weinberg equilibrium by Chi-square test. Linear regressions, Mann-Whitney U-test or Kruskal-Wallis tests were conducted to examine the association of lumefantrine plasma level with CYP2B6 c.516G>T, NR1I3 152c-1089T>C, CYP2B6 c.983T>C, CYP3A5*3 and CYP3A4*22.. Among a total of 69 malaria-HIV coinfected patients (34 nonpregnant and 35 pregnant), median (interquartile range) age was 33 (27-36.5) years and body weight was 59.5 (50-67.5) kg. In nonpregnant group, CYP2B6 c.516G>T was significantly associated with lower log Cday 7 of lumefantrine using multivariate linear regressions (β = -0.239; P = 0.013). In 59% of women with CYP2B6 c.516T, Cday 7 of lumefantrine was below the target of 280 ng/mL compared to 47% in the noncarriers. CYP2B6 c.983T>C significantly associated with higher log Cday 7 of desbutyl lumefantrine in both pregnant (β = 0.383; P = 0.033) and nonpregnant (β = 0.395; P = 0.023) groups. Composite genotypes for both CYP2B6 Single-nucleotide polymorphisms strongly associated with lumefantrine plasma concentration. An associative trend between lumefantrine pharmacokinetics and NR1I3 152c-1089T>C genotypes indicated that 70% of the Cday 7 of lumefantrine in those with NR1I3 152c-1089TT genotype was below 280 ng/mL compared to 53% in those with NR1I3 152c-1089CC or CT genotype.. The findings revealed that the efavirenz-lumefantrine interaction was accentuated in the group with CYP2B6 c.516T, c.983C and NR1I3 152c-1089T alleles. This warrants further investigations of other drug-drug interactions for optimising dosing in genetically defined subgroups, particularly during drug development.

Topics: Adult; Alkynes; Artemether, Lumefantrine Drug Combination; Benzoxazines; Case-Control Studies; Constitutive Androstane Receptor; Cyclopropanes; Cytochrome P-450 CYP2B6; Cytochrome P-450 CYP3A; Cytochrome P-450 Enzyme System; Female; Genotyping Techniques; HIV Infections; Humans; Malaria; Polymorphism, Single Nucleotide; Pregnancy; Receptors, Cytoplasmic and Nuclear; Treatment Outcome

Patients living with HIV in malarial endemic regions may experience clinically significant drug interaction between antiretroviral and antimalarial drugs. Effects of nevirapine (NVP), efavirenz (EFV) and lopinavir/ritonavir (LPVr) on lumefantrine (LM) therapeutic concentrations and toxicity were evaluated. In a four-arm parallel study design, the blood samples of 40 participants, treated with artemether/lumefantrine (AL), were analysed. Lumefantrine Cmax was increased by 32% (p = 0.012) and 325% (p < 0.0001) in the NVP and LPVr arms respectively but decreased by 62% (p < 0.0001) in the EFV-arm. AUC of LM was, respectively, increased by 50% (p = 0.27) and 328% (p < 0.0001) in the NVP and LPVr arms but decreased in the EFV-arm by 30% (p = 0.019). Median day 7 LM concentration was less than 280 ng/mL in EFV-arm (239 ng/mL) but higher in control (290 ng/mL), NVP (369 ng/mL, p = 0.004) and LPVr (1331 ng/mL, p < 0.0001) arms. There were no clinically relevant toxicities nor adverse events in both control and test arms. Artemether/lumefantrine is safe and effective for treatment of malaria in PLWHA taking NVP and LPVr based ART regimen but not EFV-based regimen.

Topics: Adult; Alkynes; Anti-Retroviral Agents; Antimalarials; Artemether, Lumefantrine Drug Combination; Benzoxazines; Cyclopropanes; Drug Combinations; Drug Interactions; Drug Therapy, Combination; Female; HIV Infections; Humans; Lopinavir; Malaria; Male; Middle Aged; Nevirapine; Nigeria; Ritonavir; Treatment Outcome; Young Adult

Blood smear microscopy remains the gold-standard method to diagnose and quantify malaria parasite density. In addition, parasite genotyping of select loci is the most utilized method for distinguishing recrudescent and new infections and to determine the number of strains per sample. In research settings, blood may be obtained from capillary or venous compartments, and results from these matrices have been used interchangeably. Our aim was to compare quantitative results for parasite density and strain complexity from both compartments.. In a prospective observational study, children and adults presenting with uncomplicated Plasmodium falciparum malaria, simultaneous capillary and venous blood smears and dried blood spots were collected over 42-days following treatment with artemether-lumefantrine. Blood smears were read by two microscopists, any discrepancies resolved by a third reader. Parasite DNA fingerprinting was conducted using six microsatellites. Bland Altman analysis and paired t-test/McNemar's test were used to assess the difference in density readings and measurements.. Two hundred twenty-three participants were included in the analysis (177 children (35 HIV-infected/142 HIV-uninfected), 21 HIV-uninfected pregnant women, and 25 HIV-uninfected non-pregnant adults). Parasite density measurements did not statistically differ between capillary and venous blood smears at the time of presentation, nor over the course of 42-day follow-up. Characterization of merozoite surface protein-2 (MSP-2) genetic polymorphism demonstrated a higher level of strain diversity at the time of presentation in venous samples, as compared with capillary specimens (p = 0.02). There was a high degree of variability in genotype-corrected outcomes when pairs of samples from each compartment were compared using MSP-2 alone, although the variability was reduced with the use of multiple markers.. Parasite density measurements do not statistically differ between capillary and venous compartments in all studied demographic groups at the time of presentation with malaria, or over the course of follow-up. More strains were detected by MSP-2 genotyping in venous samples than in capillary samples at the time of malaria diagnosis. The use of multiple polymorphic markers reduces the impact of variability in strain detection on genotype-corrected outcomes. This study confirms that both capillary and venous compartments can be used for sampling with confidence in the clinical research setting.. The trial was registered at ClinicalTrials.gov under registration no. NCT01717885 .

Topics: Adolescent; Adult; Aged; AIDS-Related Opportunistic Infections; Animals; Antimalarials; Artemether, Lumefantrine Drug Combination; Capillaries; Child; Child, Preschool; Drug Monitoring; Female; Genotype; Genotyping Techniques; HIV; HIV Infections; Humans; Infant; Malaria, Falciparum; Male; Middle Aged; Parasite Load; Parasitemia; Plasmodium falciparum; Uganda; Veins; Young Adult

In sub-Saharan Africa, HIV, syphilis, malaria and anaemia are leading preventable causes of adverse pregnancy outcomes. In Kenya, policy states women should be tested for all four conditions (malaria only if febrile) at first antenatal care (ANC) visit. In practice, while HIV screening is conducted, coverage of screening for the others is suboptimal and early pregnancy management of illnesses is compromised. This is particularly evident at rural dispensaries that lack laboratories and have parallel programmes for HIV, reproductive health and malaria, resulting in fractured and inadequate care for women.. A longitudinal eight-month implementation study integrating point-of-care diagnostic tests for the four conditions into routine ANC was conducted in seven purposively selected dispensaries in western Kenya. Testing proficiency of healthcare workers was observed at initial training and at three monthly intervals thereafter. Adoption of testing was compared using ANC register data 8.5 months before and eight months during the intervention. Fidelity to clinical management guidelines was determined by client exit interviews with success defined as ≥90% adherence.. For first ANC visits at baseline (n = 529), testing rates were unavailable for malaria, low for syphilis (4.3%) and anaemia (27.8%), and near universal for HIV (99%). During intervention, over 95% of first attendees (n = 586) completed four tests and of those tested positive, 70.6% received penicillin or erythromycin for syphilis, 65.5% and 48.3% received cotrimoxazole and antiretrovirals respectively for HIV, and 76.4% received artemether/lumefantrine, quinine or dihydroartemisinin-piperaquine correctly for malaria. Iron and folic supplements were given to nearly 90% of women but often at incorrect doses.. Integrating point-of-care testing into ANC at dispensaries with established HIV testing programmes resulted in a significant increase in testing rates, without disturbing HIV testing rates. While more cases were detected and treated, treatment fidelity still requires strengthening and an integrated monitoring and evaluation system needs to be established.

Topics: Adult; Anemia; Anti-Bacterial Agents; Anti-HIV Agents; Antimalarials; Artemether, Lumefantrine Drug Combination; Artemisinins; Dietary Supplements; Erythromycin; Female; Folic Acid; Guideline Adherence; Health Personnel; HIV Infections; Humans; Iron, Dietary; Kenya; Laboratory Proficiency Testing; Longitudinal Studies; Malaria; Penicillins; Point-of-Care Testing; Pregnancy; Pregnancy Complications, Hematologic; Pregnancy Complications, Infectious; Prenatal Care; Quinine; Quinolines; Syphilis; Trimethoprim, Sulfamethoxazole Drug Combination

The optimal treatment of malaria in human immunodeficiency virus (HIV)-infected children requires consideration of critical drug-drug interactions in coinfected children, as these may significantly impact drug exposure and clinical outcomes.. We conducted an intensive and sparse pharmacokinetic/pharmacodynamic study in Uganda of the most widely adopted artemisinin-based combination therapy, artemether-lumefantrine. HIV-infected children on 3 different first-line antiretroviral therapy (ART) regimens were compared to HIV-uninfected children not on ART, all of whom required treatment for Plasmodium falciparum malaria. Pharmacokinetic sampling for artemether, dihydroartemisinin, and lumefantrine exposure was conducted through day 21, and associations between drug exposure and outcomes through day 42 were investigated.. One hundred forty-five and 225 children were included in the intensive and sparse pharmacokinetic analyses, respectively. Compared with no ART, efavirenz (EFV) reduced exposure to all antimalarial components by 2.1- to 3.4-fold; lopinavir/ritonavir (LPV/r) increased lumefantrine exposure by 2.1-fold; and nevirapine reduced artemether exposure only. Day 7 concentrations of lumefantrine were 10-fold lower in children on EFV vs LPV/r-based ART, changes that were associated with an approximate 4-fold higher odds of recurrent malaria by day 28 in those on EFV vs LPV/r-based ART.. The choice of ART in children living in a malaria-endemic region has highly significant impacts on the pharmacokinetics and pharmacodynamics of artemether-lumefantrine treatment. EFV-based ART reduces all antimalarial components and is associated with the highest risk of recurrent malaria following treatment. For those on EFV, close clinical follow-up for recurrent malaria following artemether-lumefantrine treatment, along with the study of modified dosing regimens that provide higher exposure, is warranted.

Topics: Anti-Retroviral Agents; Antimalarials; Artemether, Lumefantrine Drug Combination; Artemisinins; Child; Child, Preschool; Coinfection; Drug Combinations; Drug Interactions; Ethanolamines; Female; Fluorenes; HIV Infections; Humans; Infant; Malaria; Malaria, Falciparum; Male; Prospective Studies; Treatment Outcome; Uganda

The possibility of drug-drug interactions occurring during the treatment of malaria infection in human immunodeficient virus (HIV) patients receiving antiretroviral drugs is very high and limited data are available. This study reports the effect of lopinavir/ritonavir (LR) an antiretroviral drug on the antimalarial activity of standard dose of artemether/lumefantrine (AL) or artemether (AM) in a mouse model of Plasmodium berghei. The 50% effective dose (ED50) of AM alone (0.80 ± 0.15 and 2.18 ± 0.75 mg/kg) or in combination with LR (0.88 ± 0.40 and 3.53 ± 1.09 mg/kg) on days 4 and 5 post-infection was similar. In addition, treatment with a standard dose of AL alone or in combination with LR resulted in complete suppression of parasite growth. However, co-administration of LR with AL appears to be toxic resulting in lower survival of experimental animals in comparison to those treated with standard dose of AL alone.

Topics: Animals; Anti-Retroviral Agents; Antimalarials; Artemether; Artemether, Lumefantrine Drug Combination; Artemisinins; Coinfection; Disease Models, Animal; Drug Combinations; Drug Interactions; Ethanolamines; Fluorenes; HIV Infections; Lopinavir; Malaria; Mice; Plasmodium berghei; Ritonavir

The objective of this study is to determine the epidemiological effectiveness of a first-line antiretroviral regimen with HIV protease inhibitor for preventing recurrent malaria in children under the range of HIV prevalence levels and malaria transmission intensities encountered in sub-Saharan Africa.. A dynamic model of malaria transmission was developed using clinical data on the protease inhibitor extended posttreatment prophylactic effect of the antimalarial treatment, artemether-lumefantrine, in addition to parameter estimates from the literature.. To evaluate the benefits of HIV protease inhibitors on the health burden of recurrent malaria among children, we constructed a dynamic model of malaria transmission to both HIV-positive and HIV-negative children, parameterized by data from a recent clinical trial. The model was then evaluated under varying malaria transmission and HIV prevalence settings to determine the health benefits of HIV protease inhibitors in the context of artemether-lumefantrine treatment of malaria in children.. Comparing scenarios of low, intermediate and high newborn HIV prevalence, in a range of malaria transmission settings, our dynamic model predicts that artemether-lumefantrine with HIV protease inhibitor based regimens prevents 0.03-0.10, 5.2-13.0 and 25.5-65.8 annual incidences of malaria per 1000 children, respectively. In addition, HIV protease inhibitors save 0.002-0.006, 0.22-0.8, 1.04-4.3 disability-adjusted life-years per 1000 children annually. Considering only HIV-infected children, HIV protease inhibitors avert between 278 and 1043 annual incidences of malaria per 1000 children.. The use of HIV protease inhibitor based regimens as first-line antiretroviral therapy for HIV is an effective measure for reducing recurrent malaria among HIV-infected children in areas where HIV and malaria are coendemic, and artemether-lumefantrine is a first-line antimalarial.

Topics: Africa South of the Sahara; Animals; Antimalarials; Artemether, Lumefantrine Drug Combination; Artemisinins; Child; Child, Preschool; Drug Combinations; Ethanolamines; Fluorenes; HIV Infections; HIV Protease Inhibitors; Humans; Malaria; Recurrence; Treatment Outcome

Malaria and HIV infections are both highly prevalent in sub-Saharan Africa, with HIV-infected patients being at higher risks of acquiring malaria. The majority of antiretroviral (ART) and anti-malarial drugs are metabolized by the CYP450 system, creating a chance of drug-drug interaction upon co-administration. Limited data are available on the effectiveness of the artemether-lumefantrine combination (AL) when co-administered with non-nucleoside reverse transcriptase inhibitors (NNRTIs). The aim of this study was to compare anti-malarial treatment responses between HIV-1 infected patients on either nevirapine- or efavirenz-based treatment and those not yet on ART (control-arm) with uncomplicated falciparum malaria, treated with AL.. This was a prospective, non-randomized, open-label study conducted in Bagamoyo district, with three arms of HIV-infected adults: efavirenz-based treatment arm (EFV-arm) n = 66, nevirapine-based treatment arm (NVP-arm) n = 128, and control-arm n = 75, with uncomplicated malaria. All patients were treated with AL and followed up for 28 days. The primary outcome measure was an adequate clinical and parasitological response (ACPR) after treatment with AL by day 28.. Day 28 ACPR was 97.6%, 82.5% and 94.5% for the NVP-arm, EFV-arm and control-arm, respectively. No early treatment or late parasitological failure was reported. The cumulative risk of recurrent parasitaemia was >19-fold higher in the EFV-arm than in the control-arm (Hazard ratio [HR], 19.11 [95% confidence interval {CI}, 10.5-34.5]; P < 0.01). The cumulative risk of recurrent parasitaemia in the NVP-arm was not significantly higher than in the control-arm ([HR], 2.44 [95% {CI}, 0.79-7.6]; P = 0.53). The median (IQR) day 7 plasma concentrations of lumefantrine for the three arms were: 1,125 ng/m (638.8-1913), 300.4 ng/ml (220.8-343.1) and 970 ng/ml (562.1-1729) for the NVP-arm, the EFV-arm and the control-arm, respectively (P < 0.001). In all three arms, the reported adverse events were mostly mild.. After 28 days of follow-up, AL was statistically safe and effective in the treatment of uncomplicated malaria in the NVP-arm. The results of this study also provide an indication of the possible impact of EFV on the performance of AL and the likelihood of it affecting uncomplicated falciparum malaria treatment outcome.

Topics: Adult; Africa South of the Sahara; Aged; Alkynes; Anti-Retroviral Agents; Antimalarials; Artemether, Lumefantrine Drug Combination; Artemisinins; Benzoxazines; Cyclopropanes; Drug Combinations; Drug Interactions; Ethanolamines; Female; Fluorenes; HIV Infections; Humans; Malaria; Male; Middle Aged; Nevirapine; Prospective Studies; Treatment Outcome; Young Adult

Artemether-lumefantrine is a fixed-dose combination containing 20 mg artemether/120 mg lumefantrine per tablet, used for treating uncomplicated malaria in patients weighing ≥5 kg. It is the first artemisinin-based combination registered in some European countries and in the USA. It is marketed in Europe as Riamet(®) (Novartis, Basel, Switzerland) and in malaria-endemic countries as Coartem(®) (Novartis). Safety concerns prevent early pregnancy usage, while limited postmarketing surveillance has delayed safety assessment and policy development. Large clinical studies, postmarketing surveillance and pharmacovigillance ongoing in some countries may soon bridge safety issues. Fatty diet requirements for optimal absorption, pregnancy-induced changes in pharmacokinetics, pregnancy-related anorexia and food taboos, and emerging reduced parasite sensitivity to artemisinin, challenges optimal artemether-lumefantrine dosing and efficacy during pregnancy. This evaluation addresses drug usage, safety concerns following early exposure, implications for changed pharmacokinetics and reduced parasite susceptibility. Clinical-use updates and strategies to address some knowledge gaps including key operational research are discussed.

Topics: Antimalarials; Artemether, Lumefantrine Drug Combination; Artemisinins; Drug Combinations; Ethanolamines; Female; Fluorenes; HIV Infections; Humans; Malaria; Pregnancy; Pregnancy Complications, Parasitic; Pregnancy Trimesters

Management of coinfection with malaria and HIV is a major challenge to public health in developing countries, and yet potential drug-drug interactions between antimalarial and antiviral regimens have not been adequately investigated in people with both infections. Each of the constituent components of artemether-lumefantrine, the first-line regimen for malaria treatment in Nigeria, and nevirapine, a major component of highly active antiretroviral therapy, are drugs metabolized by the cytochrome P450 3A4 isoenzyme system, which is also known to be induced by nevirapine. We examined potential interactions between lumefantrine and nevirapine in 68 HIV-positive adults, all of whom were diagnosed with asymptomatic Plasmodium falciparum infections by microscopy. Post hoc PCR analysis confirmed the presence of P. falciparum in only a minority of participants. Day 7 capillary blood levels of lumefantrine were significantly higher in HIV-positive participants than in 99 HIV-negative controls (P = 0.0011). Associations between day 7 levels of lumefantrine and risk of persistent parasitemia could not be evaluated due to inadequate power. Further investigations of the impact of nevirapine on in vivo malaria treatment outcomes in HIV-infected patients are thus needed.

Topics: Adult; Anti-HIV Agents; Antimalarials; Antiretroviral Therapy, Highly Active; Artemether, Lumefantrine Drug Combination; Artemisinins; Case-Control Studies; Coinfection; Drug Combinations; Drug Interactions; Ethanolamines; Female; Fluorenes; HIV Infections; Humans; Malaria, Falciparum; Male; Nevirapine; Nigeria

Accurately characterizing a drug's safety profile is essential. Trial harm and tolerability assessments rely, in part, on participants' reports of medical histories, adverse events (AEs), and concomitant medications. Optimal methods for questioning participants are unclear, but different methods giving different results can undermine meta-analyses. This study compared methods for eliciting such data and explored reasons for dissimilar participant responses.. Participants from open-label antimalarial and antiretroviral interaction trials in two distinct sites (South Africa, n = 18 [all HIV positive]; Tanzania, n = 80 [86% HIV positive]) were asked about ill health and treatment use by sequential use of (1) general enquiries without reference to particular conditions, body systems or treatments, (2) checklists of potential health issues and treatments, (3) in-depth interviews. Participants' experiences of illness and treatment and their reporting behaviour were explored qualitatively, as were trial clinicians' experiences with obtaining participant reports. Outcomes were the number and nature of data by questioning method, themes from qualitative analyses and a theoretical interpretation of participants' experiences.. There was an overall cumulative increase in the number of reports from general enquiry through checklists to in-depth interview; in South Africa, an additional 12 medical histories, 21 AEs and 27 medications; in Tanzania an additional 260 medical histories, 1 AE and 11 medications. Checklists and interviews facilitated recognition of health issues and treatments, and consideration of what to report. Information was sometimes not reported because participants forgot, it was considered irrelevant or insignificant, or they feared reporting. Some medicine names were not known and answers to questions were considered inferior to blood tests for detecting ill health. South African inpatient volunteers exhibited a "trial citizenship", working to achieve researchers' goals, while Tanzanian outpatients sometimes deferred responsibility for identifying items to report to trial clinicians.. Questioning methods and trial contexts influence the detection of adverse events, medical histories and concomitant medications. There should be further methodological work to investigate these influences and find appropriate questioning methods.

Topics: Adult; Anti-HIV Agents; Antimalarials; Artemether, Lumefantrine Drug Combination; Artemisinins; Clinical Trials as Topic; Drug Combinations; Drug Interactions; Ethanolamines; Female; Fluorenes; Focus Groups; HIV Infections; Humans; Interviews as Topic; Malaria; Male; Middle Aged; Self Report; South Africa; Tanzania; Treatment Outcome; Truth Disclosure

Intravenous (i.v.) artesunate is now the recommended first-line treatment of severe falciparum malaria in adults and children by WHO guidelines. Nevertheless, several cases of haemolytic anaemia due to i.v. artesunate treatment have been reported. This paper describes the case of an HIV-infected patient with severe falciparum malaria who was diagnosed with haemolytic anaemia after treatment with oral artemether-lumefantrine.The patient presented with fever, headache, and arthromyalgia after returning from Central African Republic where he had been working. The blood examination revealed acute renal failure, thrombocytopaenia and hypoxia. Blood for malaria parasites indicated hyperparasitaemia (6%) and Plasmodium falciparum infection was confirmed by nested-PCR. Severe malaria according to the laboratory WHO criteria was diagnosed. A treatment with quinine and doxycycline for the first 12 hours was initially administered, followed by arthemeter/lumefantrine (Riamet(®)) for a further three days. At day 10, a diagnosis of severe haemolytic anaemia was made (Hb 6.9 g/dl, LDH 2071 U/l). Hereditary and autoimmune disorders and other infections were excluded through bone marrow aspiration, total body TC scan and a wide panel of molecular and serologic assays. The patient was treated by transfusion of six units of packed blood red cell. He was discharged after complete remission at day 25. At present, the patient is in a good clinical condition and there is no evidence of haemolytic anaemia recurrence.This is the first report of haemolytic anaemia probably associated with oral artemether/lumefantrine. Further research is warranted to better define the adverse events occurring during combination therapy with artemisinin derivatives.

Topics: Administration, Oral; Adult; Anemia, Hemolytic; Antimalarials; Artemether, Lumefantrine Drug Combination; Artemisinins; Coinfection; Drug Combinations; Drug Therapy, Combination; Erythrocytes; Ethanolamines; Fluorenes; Hemolysis; HIV; HIV Infections; Humans; Malaria, Falciparum; Male; Plasmodium falciparum; Severity of Illness Index