title: Chemosuppressive field trials in Thailand. II. The suppression of Plasmodium falciparum and Plasmodium vivax parasitemias by a diformyldapsone-pyrimethamine combination.
abstract: In an area of Thailand where chloroquine-resistant falciparum malaria is known to exist, a chemosuppressive field trial was undertaken to test the efficacy of the preparation diformyldapsone (DFD) combined with pyrimethamine (Py) in suppressing falciparum and vivax parasitemias. Six hundred and fifty-nine Thai villagers were randomly assigned to one of five treatment groups: DFD-Py; dapsone (DDS)-Py; DFD alone; Py alone; and placebo. Five hundred and ninety-three study subjects completed the 26-week trial. The combination DFD-Py given weekly was shown to be an effective chemosuppressive against both falciparum and vivax parasitmias, causing a more than fourfold reduction in falciparum and an approximately threefold reduction in vivax parasitemias; however, this combination was not more efficacious than DDS-Py for the chemosuppression of falciparum malaria. DFD alone was only moderately effective, while there was no difference in chemosuppression between Py alone and placebo.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000962:Antimalarials / Q000627:therapeutic use*; D002648:Child; D003622:Dapsone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D004334:Drug Administration Schedule; D004341:Drug Evaluation; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008288:Malaria / Q000188:drug therapy / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D010963:Plasmodium falciparum / Q000302:isolation & purification; D010966:Plasmodium vivax / Q000302:isolation & purification; D011739:Pyrimethamine / Q000008:administration & dosage / Q000627:therapeutic use*; D013785:Thailand
chemical_list: D000962:Antimalarials; D003622:Dapsone; D011739:Pyrimethamine