In vitro chemosensitivity of Plasmodium falciparum to four chloroquine derivatives.

The antimalarial activity of four chloroquine derivatives has been assessed in vitro by the Trager and Jensen technique against the strain of Plasmodium falciparum FCC, 2spp. Monodesethyl-chloroquine possessed a significant activity, reducing the parasitaemia to 5% with 2 nM ml-1 (base). The hydroxy-metabolite showed a slight activity, reducing the parasitaemia to 39.5% with 2 nM ml-1 (base). No activity was found with the amino-metabolite and the pyrrolidinyl chemical derivative. The anti-malarial activity of monodesethyl-chloroquine should be considered for pharmacokinetics and for optimizing chloroquine treatments.