lumefantrine and Body-Weight

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

Patient data from eight clinical trials were pooled and analyzed to study the efficacy and safety of the six-dose versus four-dose regimen of artemether-lumefantrine (coartemether; Coartem) in children weighing 5-25 kg. A total of 544 patients with uncomplicated P. falciparum malaria (six-dose: 343; four-dose: 201), matched for demographic and baseline characteristics and individual coartemether doses were included in the analysis. Analysis of day 28 cure rate based on the intention-to-treat and evaluable populations yielded corrected cure rates for the six-dose regimen of 93% and 96% compared with 61% and 76%, respectively, for the four-dose regimen (P < 0.0001 for both comparisons). Similarly high cure rates were achieved with the six-dose regimen in non-immune infants weighing as little as 5 kg. The six- and four-dose regimens were equally well tolerated. The main finding of this analysis is that the six-dose regimen of coartemether is safe and more efficacious than the four-dose regimen in children.

Topics: Animals; Antimalarials; Artemether; Artemisinins; Body Weight; Child; Child, Preschool; Clinical Trials as Topic; Drug Administration Schedule; Drug-Related Side Effects and Adverse Reactions; Electrocardiography; Ethanolamines; Female; Fever; Fluorenes; Humans; Infant; Life Cycle Stages; Lumefantrine; Malaria, Falciparum; Male; Time Factors

Day 7 plasma lumefantrine concentration is suggested as a predictor for malaria treatment outcomes and a cut-off of ≥ 200 ng/ml is associated with day 28 cure rate in the general population. However, day 7 lumefantrine plasma concentration can be affected by age, the extent of fever, baseline parasitaemia, and bodyweight. Therefore, this study assessed the usefulness of day 7 lumefantrine plasma concentration as a predictor of malaria treatment outcome in under-fives children treated with generic or innovator drug-containing artemether-lumefantrine (ALu) in Tanzania.. This study was nested in an equivalence prospective study that aimed at determining the effectiveness of a generic ALu (Artefan. The PCR corrected cure rates were 98.7% for children treated with generic and 98.6% for those treated with the innovator product (p = 1.00). The geometric mean (± SD) of day 7 plasma lumefantrine concentration was 159.3 (± 2.4) ng/ml for the generic and 164 (± 2.5) ng/ml for the innovator groups, p = 0.87. Geometric mean (± SD) day 7 lumefantrine plasma concentration between cured and recurrent malaria was not statistically different in both treatment arms [158.5 (± 2.4) vs 100.0 (± 1.5) ng/ml, (p = 0.28) for generic arm and 158.5 (± 2.3) vs 251.2 (± 4.2) ng/ml, (p = 0.24) for innovator arm]. Nutritional status was found to be a determinant of recurrent malaria (adjusted hazardous ratio (95% confidence interval) = 3(1.1-8.2), p = 0.029.. Using the recommended cut-off point of ≥ 200 ng/ml, day 7 plasma lumefantrine concentration failed to predict malaria treatment outcome in children treated with ALu in Tanzania. Further studies are recommended to establish the day 7 plasma lumefantrine concentration cut-off point to predict malaria treatment outcome in children.

Topics: Age Factors; Antimalarials; Artemether, Lumefantrine Drug Combination; Body Weight; Child, Preschool; Female; Hemoglobins; Humans; Infant; Linear Models; Lumefantrine; Malaria; Male; Nutritional Status; Parasitemia; Polymerase Chain Reaction; Recurrence; Sex Factors; Tanzania; Treatment Outcome

Artemisinin-based combination therapy, including artemether-lumefantrine (AL), is currently recommended for the treatment of uncomplicated Plasmodium falciparum malaria. The objectives of the current analysis were to compare the efficacy and safety of AL across different body weight ranges in African children, and to examine the age and body weight relationship in this population.. Efficacy, safety and pharmacokinetic data from a randomized, investigator-blinded, multicentre trial of AL for treatment of acute uncomplicated P. falciparum malaria in infants and children in Africa were analysed according to body weight group.. The trial included 899 patients (intent-to-treat population 886). The modified intent-to-treat (ITT) population (n = 812) comprised 143 children 5 to < 10 kg, 334 children 10 to < 15 kg, 277 children 15 to < 25 kg, and 58 children 25 to < 35 kg. The 28-day PCR cure rate, the primary endpoint, was comparable across all four body weight groups (97.2%, 98.9%, 97.8% and 98.3%, respectively). There were no clinically relevant differences in safety or tolerability between body weight groups. In the three AL body weight dosing groups (5 to < 15 kg, 15 to < 25 kg and 25 to < 35 kg), 80% of patients were aged 10-50 months, 46-100 months and 90-147 months, respectively.. Efficacy of AL in uncomplicated falciparum malaria is similar across body weight dosing groups as currently recommended in the label with no clinically relevant differences in safety or tolerability. AL dosing based on body weight remains advisable.

Topics: Age Factors; Antimalarials; Artemether; Artemether, Lumefantrine Drug Combination; Artemisinins; Body Weight; Child; Child, Preschool; Drug Combinations; Ethanolamines; Female; Fluorenes; Humans; Infant; Lumefantrine; Malaria, Falciparum; Male; Plasmodium falciparum; Polymerase Chain Reaction; Time Factors; Treatment Outcome

An association between artemether-lumefantrine treatment of uncomplicated falciparum malaria and decreases in audiometrically determined hearing thresholds has been reported. Questions arising from this report were whether the effect described is attributable to drug or disease, the effects of subject weight and age on audiometric changes, and whether the changes are reversible. Spearman's correlation coefficients were calculated to look for relationships between audiometric changes and: (1) the interval spanning artemether-lumefantrine exposure and study exit audiogram; (2) subject age; (3) subject weight. The study utilised prospectively collected data from an occupational health clinic in Mozambique (N = 150). The exposure-exit audiogram interval ranged from 3 to 392 days (mean 163.8 days, SD 91.91 days). Spearman's correlation coefficients were effectively zero for analyses (1) and (2), and too weak to contribute significantly to variances for analysis (3). Previous audiometric studies in malaria patients and healthy volunteers point away from malaria as causing irreversible audiometric changes. The audiometric changes associated with the artemether-lumefantrine treatment of malaria appear irreversible. Ototoxicity is common to many antimalarials and the elucidation of a common antiparasitic and ototoxic pathway will assist in the design of safer new antimalarials.

Topics: Adult; Age Factors; Aged; Antimalarials; Artemether; Artemisinins; Audiometry; Body Weight; Drug Therapy, Combination; Ethanolamines; Female; Fluorenes; Hearing Loss; Humans; Lumefantrine; Malaria, Falciparum; Male; Middle Aged; Mozambique; Time Factors; Treatment Outcome

Oral administration of artemether in combination with lumefantrine is approved for the treatment of malaria in adults and children. In adult animals, artemether can produce neurotoxicity with intramuscular, but not oral, administration. Herein, the potential of orally administered artemether to produce neurotoxicity in juvenile rats was investigated.. In the first study, the toxicity of artemether was evaluated in juvenile rats dosed with 0, 10, 30, and 100mg/kg/day on postpartum days (ppds) 7 to 21. In-life, clinical pathology, anatomic pathology, behavioral, and toxicokinetics evaluations were performed. The second study focused on neurotoxicity during different dosing intervals, with doses of 0, 30, and 80 mg/kg/day on ppds 7 to 13, and doses of 0, 30, and 120 mg/kg/day on ppds 14 to 21, 22 to 28, and 29 to 36. For each dosing interval, in-life, extensive histology, toxicokinetics, and behavioral evaluations were performed. In the third study, toxicokinetics evaluations in the adult were conducted at 20 and 200 mg/kg/day.. The first study demonstrated increased mortality, renal necrosis, and brain hemorrhage at ≥30 mg/kg/day with no persistent effects in surviving animals. In the second study, increased mortality, body weight effects, and a trend toward increased exposure were observed in the ppd 14 and younger animals. Neither specific neurotoxicity nor persistent effects were seen. The toxicokinetic study in adults revealed lower exposures as compared to those in the younger juvenile rats.. As in the adult rat, oral administration of artemether in the juvenile rat is not associated with the neurotoxicity produced by intramuscular administration.

Topics: Administration, Oral; Animals; Antimalarials; Artemether; Artemisinins; Body Weight; Dose-Response Relationship, Drug; Ethanolamines; Female; Fluorenes; Kinetics; Lumefantrine; Male; Neurotoxicity Syndromes; No-Observed-Adverse-Effect Level; Rats; Rats, Wistar; Toxicity Tests

The World Health Organization recommends the use of artemisinin-based combination therapies (ACTs) for the treatment of uncomplicated malaria. The two most widely adopted ACT regimens are artemether (AR)-lumefantrine (LR) (the combination is abbreviated AL) and amodiaquine (AQ)-artesunate (AS). Pharmacokinetic (PK) data informing the optimum dosing of these drug regimens is limited, especially in children. We evaluated PK parameters in Ugandan children aged 5 to 13 years with uncomplicated malaria treated with AL (n = 20) or AQ-AS (n = 21), with intensive venous sampling occurring at 0, 2, 4, 8, 24, and 120 h following administration of the last dose of 3-day regimens of AL (twice daily) or AQ-AS (once daily). AS achieved an estimated maximum concentration in plasma (C(max)) of 51 ng/ml and an area under the concentration-time curve from time zero to infinity (AUC(0-infinity)) of 113 ng.h/ml; and its active metabolite, dihydroartemisinin (DHA), achieved a geometric mean C(max) of 473 ng/ml and an AUC(0-infinity) of 1,404 ng.h/ml. AR-DHA exhibited a C(max) of 34/119 ng/ml and an AUC(0-infinity) of 168/382 ng.h/ml, respectively. For LR, C(max) and AUC(0-infinity) were 6,757 ng/ml and 210 microg.h/ml, respectively. For AQ and its active metabolite, desethylamodiaquine (DEAQ), the C(max)s were 5.2 ng/ml and 235 ng/ml, respectively, and the AUC(0-infinity)s were 39.3 ng.h/ml and 148 microg.h/ml, respectively. Comparison of the findings of the present study to previously published data for adults suggests that the level of exposure to LR is lower in children than in adults and that the level of AQ-DEAQ exposure is similar in children and adults. For the artemisinin derivatives, differences between children and adults were variable and drug specific. The PK results generated for children must be considered to optimize the dosing strategies for these widely utilized ACT regimens.

Topics: Amodiaquine; Antimalarials; Area Under Curve; Artemether; Artemisinins; Artesunate; Biotransformation; Body Weight; Child; Child, Preschool; Chromatography, Liquid; Drug Combinations; Ethanolamines; Female; Fluorenes; Half-Life; Humans; Longitudinal Studies; Lumefantrine; Male; Spectrophotometry, Ultraviolet; Uganda