Atovaquone

Atovaquone is a broad-spectrum antiprotozoal agent that is active against Plasmodium, Toxoplasma, and Babesia, among other protozoa. It inhibits complex III activity on dihydroorotate in isolated P. falciparum and P. yoelii mitochondria more potently than in rat liver mitochondria (EC50s = 0.95, 0.94, and 510 nM, respectively) and depolarizes the mitochondrial membrane in P. yoelii-infected mouse erythrocytes (EC50 = 260 nM). Atovaquone also inhibits transport mediated by human breast cancer resistance protein (BCRP) and P-glycoprotein in membrane vesicles (IC50s = 0.23 and 6.8 μM, respectively.