Quinine, an alkaloid derived from the bark of the cinchona tree, is a blood schizontocidal agent that is more toxic than chloroquine.Quinine is used to treat malaria caused by Plasmodium falciparum. Plasmodium falciparum is a parasite that gets into the red blood cells in the body and causes malaria. Quinine works by killing the parasite or preventing it from growing. This medicine may be used alone or given together with one or more medicines for malaria.
Quinine should not be used to treat or prevent night time leg cramps. This medicine may cause very serious unwanted effects and should only be used for patients with malaria.It is administered parenterally to patients with severe or complicated malaria who cannot take drugs by mouth because of coma, convulsions or vomiting.
It is administered orally to less seriously ill patients with infections likely to be resistant to chloroquine or mefloquine, sometimes in combination with pyrimethamine/sulfadoxine or a tetracycline.
Quinine is an extremely basic compound and is, therefore, always presented as a salt. Various preparations exist, including the hydrochloride, dihydrochloride, sulphate, bisulphate, and gluconate salts; of these the dihydrochloride is the most widely used. Quinine has rapid schizonticidal action against intra-erythrocytic malaria parasites. It is also gametocytocidal for Plasmodium vivax and Plasmodium malariae, but not for Plasmodium falciparum. Quinine also has analgesic, but not antipyretic properties. The anti-malarial mechanism of action of quinine is unknown.
