ENHANCEMENT OF THE ANTIMALARIAL EFFECT OF CHLOROQUINE BY CHLOROPHENIRAMINE IN-VIVO

The efficacy of chloroquine and chloroquine plus chloropheniramine, a histamine H-1 receptor blocker which reverses chloroquine insensitivit y in Plasmodium falciparum in vitro, was studied in 96 children with a cute symptomatic uncomplicated falciparum malaria. The chloroquine/chl oropheniramine combination produced a significantly higher cure rate t han chloroquine alone and cured 77% of children with chloroquine treat ment failures. Children with chloroquine treatment failure had mean pl asma chloroquine concentrations above the minimum therapeutic concentr ation for the area. Chloroquine concentrations in plasma and red blood cells and ratio of red cell to plasma chloroquine concentrations on d ays 3 and 7 after initiation of therapy were not significantly differe nt in the two groups. Chloroquine/chloropheniramine produces a higher cure rate than chloroquine alone and reverses chloroquine insensitivit y in Plasmodium falciparum in vivo. It may be a useful way of optimisi ng the antimalarial effect of chloroquine.