A clinical trial with halofantrine on patients with falciparum malaria in Colombia.

A total of 120 semi-immune adult male malaria patients from an area of multidrug-resistant Plasmodium falciparum malaria were hospitalized for 42 days in Medellin, Colombia (an area of no malaria transmission), and treated with halofantrine in a double-blind, randomized, prospective clinical trial according to five different treatment schedules. Each patient was assigned to one of the following halofantrine schedules: I, one dose of 1000 mg; II, three doses of 500 mg; III, two doses of 500 mg; IV, three doses of 250 mg; and V, one dose of 750 mg. Best results (75% cure rate) were obtained with schedule II, although there was no statistically significant difference compared with the other schedules. A total of 46 patients experienced recrudescent malaria. Drug levels in plasma 72 hours after beginning treatment showed no statistically significant difference between relapsing and cured patients. Side-effects (mainly gastrointestinal) were uncommon and mild. Cardiotoxicity was studied by electrocardiogram. A mean prolongation of 28.5 ms (6.6 +/- 6.3% increase from baseline) was observed in the Q-Tc interval on day 1 of the trial.