Lumefantrine plasma concentrations in uncontrolled conditions among patients treated with artemether-lumefantrine for uncomplicated plasmodium falciparum malaria in Mwanza, Tanzania

Abstract

BackgroundTherapeutic efficacy of artemether-lumefantrine is highly dependent on adequate systemic exposure to the partner drug lumefantrine particularly day 7 lumefantrine plasma concentration. There has been contradicting findings on the role of the cut-off values in predicting treatment outcomes among malaria patients in malaria endemic regions. This study assesses the day 3 and 7 lumefantrine plasma concentrations including related determinant factors and their influence on treatment outcomes among treated Tanzanian children and adults in uncontrolled conditions (real life condition). MethodsData was nested from an efficacy study employing the WHO protocol, 2015 for monitoring antimalarial drug efficacy. Lumefantrine plasma concentration was measured by high performance liquid chromatography with ultraviolet (HPLC-UV). Results: Lumefantrine plasma concentrations below 175ng/ml and 200ng/ml on day 3 and 7 did not affect adequate clinical and parasitological response (ACPR) and recurrence of infection (p = 0.428 and 0.239 respectively). Age and baseline parasitemia were not associated to day 3 median lumefantrine plasma concentrations (p = 0.08 and 0.31 respectively) and day 7 lumefantrine plasma concentrations (p = 0.07 and 0.41 respectively). However, the day 3 and day 7 lumefantrine plasma concentrations were significantly higher in males compared to females (p = 0.03 and 0.042 respectively). ConclusionLumefantrine plasma concentrations below cut-off points (175ng/ml and 200ng/ml) on day 3 and 7 did not influence treatment outcomes.