Prophylactic activity of mefloquine hydrochloride (WR 142490) in drug-resistant malaria

In preliminary studies with mefloquine (WR 142 490) a single dose exerted prolonged suppressive activity against a drug-resistant strain of Plasmodium falciparum. Development of patent parasitaemia was prevented when nonimmune persons were exposed to infected mosquitos 2 weeks after medication, and it was delayed when exposure occurred 3 weeks after drug administration.