In vitro activities of benflumetol against 158 Senegalese isolates of Plasmodium falciparum in comparison with those of standard antimalarial drugs.

The 50% inhibitory concentration (IC50s) of benflumetol (range, 12.5 to 240 nM; mean, 55.1 nM) for 158 Senegalese isolates were evaluated. Ten isolates (6%) showed decreased susceptibility to benflumetol. Benflumetol was slightly more potent against chloroquine-resistant isolates (P < 0.025). No correlation or weak correlations in the responses to benflumetol and pyrimethamine, chloroquine, amodiaquine, artemether, quinine, and pyronaridine were observed, and these correlations are insufficient to suggest cross-resistance. Benflumetol may be an important alternative drug for the treatment of chloroquine-resistant malaria.