Impact of Efavirenz-, Ritonavir-Boosted Lopinavir-, and Nevirapine-Based Antiretroviral Regimens on the Pharmacokinetics of Lumefantrine and Safety of Artemether-Lumefantrine in Plasmodium falciparum-Negative HIV-Infected Malawian Adults Stabilized on Antiretroviral Therapy

Abstract

There is conflicting evidence of the impact of commonly used antiretroviral therapies (ARTs) on the pharmacokinetics of lumefantrine and the safety profile of artemether-lumefantrine. We compared the area under the concentration-time curve from 0 h to 14 days (AUC_{0-14 days}) of lumefantrine and the safety profile of artemether-lumefantrine in malaria-negative human immunodeficiency virus (HIV)-infected adults in two steps. In step 1, a half-dose adult course of artemether-lumefantrine was administered as a safety check in four groups (n = 6/group): (i) antiretroviral naive, (ii) nevirapine-based ART, (iii) efavirenz-based ART, and (iv) ritonavir-boosted lopinavir-based ART. In step 2, a standard-dose adult course of artemether-lumefantrine was administered to a different cohort in three groups (n = 10 to 15/group): (i) antiretroviral naive, (ii) efavirenz-based ART, and (iii) ritonavir-boosted lopinavir-based ART. In step 1, lumefantrine's AUC_{0-14 days} was 53% (95% confidence interval [CI], 0.27 to 0.82) lower in the efavirenz-based ART group than in the ART-naive group and was 2.4 (95% CI, 1.58 to 3.62) and 2.9(95% CI, 1.75 to 4.72) times higher in the nevirapine- and ritonavir-boosted lopinavir groups, respectively. In step 2, lumefantrine's AUC_{0-14 days} was 1.9 (95% CI, 1.26 to 3.00) times higher in the ritonavir-boosted lopinavir group and not significantly different between the efavirenz- and ART-naive groups (0.99 [95% CI, 0.63 to 1.57]). Frequent cases of hematological abnormalities (thrombocytopenia and neutropenia) were observed in the nevirapine group in step 1, leading to a recommendation from the data and safety monitoring board not to include a nevirapine group in step 2. Artemether-lumefantrine was well tolerated in the other groups. The therapeutic implications of these findings need to be evaluated among HIV-malaria-coinfected adults. (This study has been registered at the Pan African Clinical Trials Registry under numbers PACTR2010030001871293 and PACTR2010030001971409.).

Keywords: antimalarial agents; antiretroviral therapy; artemether-lumefantrine; malaria.