THE PHARMACOKINETICS OF ARTEMISININ SUPPOSITORIES IN VIETNAMESE PATIENTS WITH MALARIA

Eight male Vietnamese malaria patients received 600 mg of artemisinin in a single dose of 3 suppositories containing 200 mg each; 24 h later they received a single oral dose of mefloquine, 15 mg/kg. Plasma arte misinin concentrations were measured until 24 h after dosing, and para sites were counted until none could be detected. Artemisinin concentra tion versus time curves of all subjects were analysed with model-indep endent methods. Mean C-max was 108 mu g/L (SD=60, range 29-169), mean t(lag) was 0.3 h (SD=0), mean t(max) was 6.5 h (SD=3.9, range 2-14). B y comparing the area under the concentration-time curve with that foun d in a previous study on oral artemisinin, average bioavailability rel ative to oral administration was estimated to be approximately 30%. Me dian parasite clearance time was 24 h (range 24-72). We concluded that therapeutic blood concentrations of artemisinin can be reached after rectal administration. There was a large inter-individual variation in blood concentrations attained. The dose given by rectal administratio n should probably be twice the usual oral dose, i.e., at least 20 mg/k g of body weight twice daily.