Flunarizine and verapamil inhibit chloroquine-resistant Plasmodium falciparum growth in vitro.

Using pharmacological properties in relation to the biochemistry of P. falciparum, verapamil, flunarizine, and chlorpromazine which are calcium blockers were selected to test for their antimalarial activity against P. falciparum in vitro. Results revealed that the drugs inhibited parasite population growth in the following order of IC50: verapamil 1 X 10(-6) M, chlorpromazine 3.5 X 10(-6) M, and flunarizine 5 X 10(-6) M. These three calcium blockers have antimalarial effects on chloroquine resistant parasite (alone T9/94) but are less potent when compared with the efficacy of quinine or mefloquine in vitro.