Structure
Quinidine sulphate is a stereoisomer of quinine, belonging to the class IA antiarrhythmic agents.
It features a quinoline structure with a stereocenter that distinguishes it from quinine.
Chemical Formula: C₂₄H₂₉NO₄S (C24H29NO4S)
Mode of Action
Class IA Antiarrhythmic: Prolongs the action potential and refractory period by blocking fast sodium channels.
Ventricular and Atrial Myocytes: Slows phase 0 of the cardiac action potential, reducing excitability.
Potassium Channel Blockade: Extends repolarization by inhibiting potassium efflux.
Effect on Heart Rate: Can convert atrial fibrillation to sinus rhythm and prevent reentrant arrhythmias.
Uses of Quinidine Sulphate
Atrial Fibrillation and Flutter: Restores and maintains sinus rhythm.
Ventricular Tachycardia: Treats and prevents ventricular arrhythmias.
Prevention of Reentrant Arrhythmias: Effective in various supraventricular and ventricular arrhythmias.
Antiarrhythmic Prophylaxis: Prevents recurrence of arrhythmias post-cardiac surgery or myocardial infarction.