Clinical trials with halofantrine in acute uncomplicated falciparum malaria in Thailand.

The antimalarial efficacy of halofantrine was compared with mefloquine in an open-label, randomized comparative trial in adult male patients with acute uncomplicated falciparum malaria. Twenty-eight patients received halofantrine and 27 received mefloquine. Halofantrine was administered in 3 doses of 500 mg at 6 hour intervals and mefloquine was administered in divided doses of 1,250 mg or 1,500 mg depending on whether the patients weighed less than or more than 60 kg. The patients were followed for 42 days and observed for drug tolerance and evidence of recrudescence. Response to treatment was favorable with both drugs, but three patients (two treated with halofantrine and one with mefloquine) did not completely eliminate malaria parasites from peripheral blood films in seven days. The parasite and fever clearance times were 75.6 and 55.7 hours, and 80.1 and 61.3 hours, respectively for halofantrine and mefloquine. However, 12 patients recrudesced during the 42 day follow-up period. Nine of these had been treated with halofantrine and three with mefloquine. The 42-day cure rate for the two drugs was 56% and 84%, respectively. The side-effects of halofantrine and mefloquine were comparable and transient. These are diarrhea, dizziness, orthostatic hypotension and black out. However, vomiting was found to be more common in mefloquine group (41% vs 22%).