title: Gametocytocidal and sporontocidal effects of primaquine and of sulfadiazine with pyrimethamine in a chloroquine-resistant strain of Plasmodium falciparum.
abstract: Studies with 3 volunteers were conducted to determine the effects of a combination of sulfadiazine and pyrimethamine and the effects of primaquine upon mature gametocytes of a strain of chloroquine-resistant Plasmodium falciparum-the Malayan (Camp.) strain. One volunteer was treated with sulfadiazine and pyrimethamine; two other volunteers each received a single dose of 45 mg of primaquine base. The combination of sulfadiazine and pyrimethamine, although active against blood schizonts, did not exert a marked sporontocidal effect against the Malayan (Camp.) strain. In sharp contrast, primaquine, although not effective as a blood schizontocide, exerted a marked gametocytocidal and sporontocidal effect against this strain.The findings emphasize the need for further studies of the sporontocidal and gametocytocidal effects of drugs, particularly primaquine, against chloroquine-resistant strains of P. falciparum and suggest that primaquine may come to play an important role in preventing the transmission of such strains.
mesh_terms: D000328:Adult; D000962:Antimalarials / Q000008:administration & dosage*; D004352:Drug Resistance, Microbial; D006801:Humans; D008297:Male; D010963:Plasmodium falciparum / Q000187:drug effects; D011319:Primaquine / Q000008:administration & dosage; D011739:Pyrimethamine / Q000008:administration & dosage; D013411:Sulfadiazine / Q000008:administration & dosage
chemical_list: D000962:Antimalarials; D013411:Sulfadiazine; D011319:Primaquine; D011739:Pyrimethamine