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개요Quinidine is a commonly used class I antiarrhythmic drug. It is a stereoisomer of quinine, originally derived from the bark of the cinchona tree. It exerts its antiarrhythmic effects on the heart by interacting with the electrophysiology mechanisms that cause arrhythmias to modify the abnormalities in impulse initiation and conduction. Quinidine depresses normal automaticity in cardiac fibers that may act as ectopic pacemakers causing arrhythmias. Quinidine also blocks the slowly inactivating, tetrodotoxin-sensitive Na current, the slow inward calcium current (ICa), the rapid (IKr) and slow (IKs) components of the delayed potassium rectifier current, the inward potassium rectifier current (IKI), the ATP-sensitive potassium channel (IKATP) and Ito.

역사In 1820, the French chemists Pierre Pelletier and Joseph Caventou extracted some alkaloids from the cinchona bark, including quinine and quinidine. Subsequently, quinine was demonstrated to play a very important role in the treatment of malaria after a number of scientific researches. Quinidine is the dextroisomer of quinine and has the similar pharmacological properties as quinine, but quinidine’s effects are five to ten times stronger on the heart than quinine.

용도Quinidine occurs in cinchona bark to about0.25–0.3% and also in cuprea bark. It is present in quinine sulfate mother liquor. Itis formed by isomerization of quinine. Itis used in the prevention of certain cardiacarrhythmias.

일반 설명Crystals or white powder.