Carriers, channels and chloroquine efficacy in Guinea-Bissau.

Recent studies suggest that chloroquine resistance is mediated by an energy-dependent saturable chloroquine efflux carrier. An alternative explanation is that resistance is mediated by a channel. In Guinea-Bissau high doses of chloroquine are effective, well-tolerated and commonly used. This suggests that chloroquine resistance can be overcome by higher doses. Research on the mechanism of chloroquine resistance is of utmost importance and should include the effect of higher doses.