[Drug sensitivity of Plasmodium falciparum in Madagascar. V. Study of the in vitro activity of quinine, mefloquine and halofantrine].

In a nine month fields study in 1983 in Madagascar, in vitro sensitivity to others drugs than 4 aminoquinolines were tested for 39 Plasmodium falciparum isolates, including 2 chloroquine resistant ones. Sensitivity to quinine, mefloquine and halofantrine were recorded from 28, 39 and 11 of these isolates respectively. IC50 with semi-microtest were under 20 nM/1 for mefloquine, under 12 nM/1 for halofantrine and under 560 nM/1 for quinine. All these values are under maximal values observed elsewhere with isolates coming from patients successfully treated with the three drugs.