Quinine
Quinine, drug that reduces fever in the treatment of malaria . Although quinine kills certain forms of the parasite that causes malaria, it cannot kill the parasite in all stages of its life cycle. Quinine, therefore, is not a true cure for malaria, but is useful in suppressing and controlling the recurring attacks of fever that characterize the disease. In many areas, quinine has been largely replaced by synthetic antimalarial drugs that produce fewer side effects and are more effective. However, quinine is still used in areas of the world where the synthetic drugs are not available, are not effective against particular strains of malaria, or are too expensive. Quinine is also used as a muscle relaxant to treat nighttime leg cramps. Quinine is found in the root, bark, and branches of cinchonas and other trees native to the Andes mountains in South America.