What is "quinidine"

Quinidine \Quin"i*dine\, n. (Chem.) An alkaloid isomeric with, and resembling, quinine, found in certain species of cinchona, from which it is extracted as a bitter white crystalline substance; conchinine. It is used somewhat as a febrifuge. [Written also chinidine.]

n. (context organic compound medicine English) An isomer of quinine that is used as an antiarrhythmic agent.

n. cardiac drug (trade names Quinidex and Quinora) used to treat certain heart arrhythmias [syn: Quinidex, Quinora]

Quinidine is a pharmaceutical agent that acts as a class I antiarrhythmic agent (Ia) in the heart. It is a stereoisomer of quinine, originally derived from the bark of the cinchona tree. The drug causes increased action potential duration, as well as a prolonged QT interval.