PRIMAQUINE

synthetic antimalarial drug introduced into medicine in the 1950s. Primaquine is one of an important series of chemically related antimalarial agents, the quinoline derivatives. It is administered orally as primaquine phosphate. Primaquine inhibits the development of the malarial parasites Plasmodium vivax and P. falciparum in both blood and tissue, thus producing complete cures and preventing relapses. Some abdominal discomfort may occur as a side effect.