A comparative study of artesunate and artemether in combination with mefloquine on multidrug resistant falciparum malaria in eastern Thailand.

Plasmodium falciparum in Thailand is highly resistant to chloroquine, sulfadoxine-pyrimethamine and there is increasing resistance to quinine and mefloquine. The use of qinghaosu derivatives alone or in combination with mefloquine has been shown successfully effective against multidrug resistant P. falciparum in many clinical trials. However their applications with ambulatory treatment should be assessed. 394 uncomplicated falciparum malaria cases studied at Trat and Chanthaburi malaria clinics, eastern Thailand, were allocated at random to receive either one of the seven following regimens: A) artesunate 600 mg over 2 days and mefloquine 1,250 mg in divided doses. B) artemether 640 mg over 2 days and mefloquine 1,250 mg in divided doses. C) artesunate alone 700 mg over 5 days period. D) artemether alone 800 mg over 5 days period. E) quinine plus tetracycline for 7 days. F) mefloquine 1,250 mg in divided doses and G) artesunate 600 mg over 2 days period and mefloquine 750 mg. The follow-up was on Days 1, 2, 7, 14, 21 and 28. Patients tolerated all regimens very well and there was no serious side effects. The adverse effects did not differ among the seven regimens. The cure rates were 98.7, 97.1, 97.9, 96.7, 92.3, 100 and 95.2%, respectively. There was no significant difference of cure rates among various regimens. A total of 16 P. vivax and 1 P. malariae reinfections were reported among the study groups during the second half of the follow-up period, 14 of which were from the groups administered short action drugs (artesunate, artemether or quinine). The results suggested that either artesunate 600 mg or artemether 640 mg in combination with mefloquine 1,250 mg over a period of two days should be considered as alternative regimens for treating uncomplicated multi-drug resistant falciparum malaria.