THE IN-VITRO ANTIMALARIAL ACTIVITY OF CHLORAMPHENICOL AGAINST PLASMODIUM-FALCIPARUM

The minimum inhibitory concentrations, MIC, of chloramphenicol were de termined for two isolates of Plasmodium falciparum at 48, 96 and 144 h . The MIC decreased from Values greater than 100 mu g/ml at 48 h to 10 .7-12.5 mu g/ml at 96 h. During 144 h of incubation, concentrations of 0.8-1.6 mu g/ml were effective in suppressing parasite growth. These results indicate that the multiplication of malaria parasites can be i nhibited by clinically achievable concentrations of chloramphenicol pr ovided that exposure to the drug is prolonged over several asexual lif e cycles. They suggest that undiagnosed falciparum infections may be c ured when patients with fever of doubtful origin are treated with 10 t o 14 day courses of chloramphenicol. They also raise the possibility t hat this antibiotic may eventually be used, in combination with a rapi dly acting but non-curative drug regimen, to treat patients with falci parum infections in whom the use of tetracyclines is contraindicated, e.g., young children.