Comparative efficacies of quinine and chloroquine as companions to primaquine in a curative drug regimen.

A comparison has been made of the capacities of chloroquine and quinine to serve as companions to primaquine in curing established infections with sporozoites of the M or B strains of Plasmodium cynomolgi in rhesus monkeys. The results indicated that chloroquine was slightly but consistently more effective than quinine in this role. This finding provides support for use of chloroquine as the companion blood schizonticide in the current experimental animal-based search for improved tissue schizonticidal drugs, and bolsters the rather tenuous base for clinical use of this 4-aminoquinoline, rather than quinine, as a companion to primaquine in suppressive-curative and radical-curative regimens.