Quinidine is an alkaloid, obtained from the bark of cinchona tree, dextrorotatory diastereoisomer of quinine . Quinidine (Bisulphate and Sulphate) is the prototype of class IA antiarrythmic drug, used for the management of atrial flutter and fibrillation. Quinidine (Sulphate) is a clasantimuscarinic and alpha-blocking properties. It may be effective in suppressing supraventricular and ventricular arrhythmias. It may itself precipitate rhythm disorders, and is best use on spercialist advise.