Studies on the chemotherapy of malaria (III) treatment of falciparum malaria in The Gambia, with BRL 50216 (4, 6-diamino-(3, 4-dichlorobenzylosy)-1, 2-dihydro-2 2-dimethyl-1, 3, 5-triazine hydrochloride) alone and in combination with sulphonamides

Abstract

1. 1. In hospital trials with Gambian children suffering from acute attacks of falciparum malaria the dihydrotriazine derivative and folic acid antagonist BRL 50216 proved effective in eradicating asexual parasitaemias within 2 or 3 days in doses equivalent to 3 mg./kg. daily X 3; 2 daily doses and single doses were unsatisfactory. No toxic effects were encountered. 2. 2. Given in combination with sulphadimethoxine or sulphafurazole potentiation was such that 3 daily doses of BRL 50216 0·3 mg./kg. were equally effective. 3. 3. P. malariae trophozoites proved sensitive to BRL 50216 alone and in combination with sulphadimethoxine but gametocytes persisted for a week or more. 4. 4. Any sporontocidal effect of BRL 50216 alone was not seen but in combination with sulphonamide, sporogony appeared to be interrupted at the early stage of oöcyst development. 5. 5. It is concluded that BRL 50216 is an effective antimalarial but offers no advantages over other folic acid antagonists such as pyrimethamine or proguanil. Rapid excretion excludes single dose therapy.