IN-VITRO ACTIVITY OF THE ENANTIOMERS OF N-DESBUTYL DERIVATIVE OF HALOFANTRINE

The in vitro activity of the enantiomers of N-desbutylhalofantrine, th e major human metabolite of halofantrine, was compared using the semi- microtest against the multidrug-resistant Plasmodium falciparum FCM 29 /Cameroon clone. The mean 50% inhibitory concentration (IC50) values ( +/- standard deviation) of the enantiomers were equivalent (2.07+0.41 and 1.70+/- 0.33 nmol/L). The enantiomers of the metabolite of halofan trine, as well as those of the parent compound, have the same antimala rial activity. Since (+)-halofantrine and enantiomer-1 of the metaboli te attain higher plasma concentrations in man, our study suggests that these enantiomers may be more active in vivo.