J. KarbwangK. Na-BangchangA. ThanavibulP. MoluntoMahidol University2018-07-042018-07-041998-02-03Annals of Tropical Medicine and Parasitology. Vol.92, No.1 (1998), 31-36000349832-s2.0-0031973066https://repository.li.mahidol.ac.th/handle/20.500.14594/18396Plasma concentrations of artemether and its active plasma metabolite (dihydroartemisinin) were measured in 49 male, Thai patients with acute, uncomplicated, multidrug-resistant, Plasmodium falciparum malaria, following their treatment with oral artemether (300 mg on the first day, then 100 mg daily for another 4 days). Four patients recrudesced (on days 19-22). After the first dose, artemether became undetectable in ≤ 18 h and this drug was also undetectable in samples collected immediately before each dose. Although dihydroartemisinin followed similar trends, three patients had detectable plasma concentrations of this metabolite 24 h after the first dose (i.e. immediately before the second dose). Median (range) values for plasma concentrations of dihydroartemisinin 6 h [354 (150-751)) v. 196 (178-220) ng/ml] and 12 h [158 (25-420) v. 54 (25-115) ng/ml] after the initial dose, estimated antimalarial activities (calculated as dihydroartemisinin equivalents) 6 h [331 (78.2-644.1) v. 23 (183.3-270) nmol/litre] and 12 h [98.3 (10-192.2) v. 56.7 (9.8-59.4) nmol/litre] after the initial dose, and the corresponding 'areas under the curves' (AUC) [3684 (1562-8216) v. 834 (1401-2030) ng.h/ml] were all significantly higher in the patients with sensitive responses than in those who recrudesced.Mahidol UniversityImmunology and MicrobiologyMedicineArticleSCOPUS10.1080/00034989860148