Assessment of Pharmacokinetic Parameters of Artemether-Lumefantrine in Patients with Uncomplicated Malaria in Plateau State

Artemether-lumefantrine is the first-line treatment for uncomplicated malaria in Nigeria, and variations in its pharmacokinetic parameters across patient populations can significantly influence treatment outcomes. This study assessed selected pharmacokinetic parameters and clinical response to artemether-lumefantrine in adult patients with confirmed uncomplicated Plasmodium falciparum malaria attending the outpatient unit of a general hospital in Jos, Plateau State, North Central Nigeria. A prospective observational study was conducted over six months in 80 eligible adult patients. Blood samples were collected at defined time intervals following oral dosing and analysed for lumefantrine plasma concentrations using high-performance liquid chromatography. Clinical and parasitological outcomes were assessed at days 3, 7, and 28. Patient demographic, nutritional, and food intake data were recorded. Results showed significant variability in lumefantrine absorption, with fatty meal co-administration associated with a mean three-fold increase in peak plasma concentration compared to fasted administration. Adequate day-7 lumefantrine plasma concentrations (above 200 ng/mL) were achieved in only 68.8 percent of patients, with subtherapeutic levels concentrated among underweight and food-restricted patients. Day-28 adequate clinical and parasitological response was 87.5 percent. Subtherapeutic plasma concentrations were significantly associated with treatment failure (p < 0.01). The study recommends structured counselling on the importance of fatty meal co-administration, targeted nutritional support for malnourished malaria patients, and pharmacokinetic monitoring considerations for at-risk groups in Nigerian malaria treatment programmes. Keywords: artemether-lumefantrine, pharmacokinetics, malaria treatment, Plateau State, lumefantrine plasma concentration