Assessment of in vivo antimalarial activity of rifampicin, isoniazide, and ethambutol combination therapy.

The existing armament of drugs for the treatment and prevention of malaria is inadequate due to development of resistance. In addition to this due to lack of economic enticement the rate of new drug development and new drug discovery in the segment of parasitic diseases is very low as compared to the other segments. This has necessitated the better deployment and usage of existing antimalarial drugs as well as discovery of antimalarial activity of drugs which are well characterized for other diseases; these approaches help to reduce the time and cost required for new drug discovery. The present study evaluated the antimalarial activity of antituberculosis drugs rifampicin, isoniazide, and ethambutol in monotherapy and combination in Plasmodium berghei-infected mice. Animals were observed for mortality, parasite progression, and toxicity for a period of 1 month. Rifampicin + isoniazide and rifampicin + isoniazide + ethambutol treatment resulted in an overall survival rate of 60% compared to 0% in vehicle-fed animals by 4 weeks after post-infection without showing any toxicity.