Clinical trial of efficacy of artesunate against plasmodium vivax malaria in a Bangkok Hospital

Abstract

Chloroquine has been the drug of choice for malaria for a long time. However chloroquine-resistant Plasmodium Falciparum was described almost 40 years ago in Thailand. Chloroquine-resistant vivax Malaria is emerging and the evaluation of alternative antimalarial drugs for the treatment of vivax is urgently required. Forty-two patients infected with vivax malaria were enrolled in Mahidol University Hospital in Bangkok. All patients were treated with artesunate for 5 days, followed by primaquine for 14 days. Patients were monitored in hospital for 28 days in order to note relevant clinical features, eliminate the possibility of reinfection, and diagnose reappearance of parasitemia. The mean fever clearance time (FCT) was 14.6 hours. The mean parasite clearance time (PCT) was 36.7 hours. The mean parasite clearance times for 50% and 90% of the parasites were 10.8 hours and 14.1 hours, respectively. Reappearance of parasitemia was seen in 2 patients on days 21-27 respectively. Compared with the conventional regimen of chloroquine and primaquine in the Bangkok Hospital produced a PCT of 64 hours and a FCT of 30 hours. Two cases relapsed and both were treated with the same dosage regimen of artesunate but higher dose of primaquine. No further parasitemia was observed in the following 28 days.