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quinidine(kwĭn`ĭdēn'), heart muscle relaxant used to maintain regular heart rhythm patterns. It is an alkaloidalkaloid,
any of a class of organic compounds composed of carbon, hydrogen, nitrogen, and usually oxygen that are often derived from plants. Although the name means alkalilike, some alkaloids do not exhibit alkaline properties.
..... Click the link for more information. chemically similar to quininequinine
, white crystalline alkaloid with a bitter taste. Before the development of more effective synthetic drugs such as quinacrine, chloroquine, and primaquine, quinine was the specific agent in the treatment of malaria.
..... Click the link for more information. and, like quinine, occurs naturally in some species of cinchona trees. Quinidine slows the rate of blood flow in heart chambers and lowers the excitability of the muscle. Quinidine is a general relaxant of smooth muscle and acts as a dilator of larger blood vessels. It has also been used to reduce fever and to treat malaria. Synchronized electric shock has largely replaced quinidine as a method of establishing more normal heart rhythms.
C20H24N2O2 A crystalline alkaloid that melts at 174-175°C (345-347°F) and that may be derived from the bark of cinchona; used as the salt in medicine. Also known as β-quinine.