Quinidine: The Antiarrhythmic Drug for Heart Rhythms
What is Quinidine?
Quinidine is an antiarrhythmic medication used to treat irregular heart rhythms (arrhythmias), including atrial fibrillation, atrial flutter, and ventricular arrhythmias. It works by stabilizing the electrical activity of the heart and preventing abnormal heart rhythms.
How Quinidine Works
Quinidine works by inhibiting sodium channels in the heart, which helps restore normal electrical conduction and rhythm. It also has mild anticholinergic effects, which can help regulate heart rate and rhythm.
When to Use Quinidine
● Atrial Fibrillation: Quinidine is used to restore normal rhythm in patients with atrial fibrillation.
● Ventricular Arrhythmias: It can be used to treat ventricular tachycardia or other life-threatening arrhythmias.
● Atrial Flutter: Quinidine can help control atrial flutter by converting it to normal sinus rhythm.
Dosage
● Adult Dose for Atrial Fibrillation: Typically, 200 mg to 400 mg orally every 6 hours for the first few days, then reduced to 200 mg to 300 mg twice daily.Maximum dose is 600 mg/dose.
● Adult Dose for Ventricular Arrhythmias: Quinidine is often administered orally as sulfate or intravenously, every 6 hours with doses depending on patient’s condition.
Side Effects
● Common Effects: Diarrhea, nausea, dizziness, and headache.
● Serious Adverse Effects: Prolonged QT interval, heart block, and liver toxicity.
Common Indian brands : Natcardine, Quinidine.