Antimalarial drugs and human neutrophil oxidative metabolism.

The effect of several commonly used antimalarial drugs on human peripheral blood neutrophil oxidative metabolism was studied. The following drugs were tested: chloroquine diphosphate, quinine HCl, mefloquine, proguanil HCl, cycloguanil, pyrimethamine, sulphadoxine, and tetracycline HCl. It was found that none of the antimalarial drugs examined, at clinically obtainable concentrations, had any inhibitory effect on neutrophil oxygen consumption, glucose oxidation, superoxide production, NBT reduction, and chemiluminescence. However, at higher concentrations chloroquine, quinine, mefloquine, and proguanil inhibited neutrophil oxidative burst. There was a slight enhancing effect on neutrophil oxidative metabolism by pyrimethamine, combination of pyrimethamine-sulphadoxine, cycloguanil and tetracycline at concentrations lower than the clinical levels.