Quinidine is a member of the antiarrhythmic class of drugs that acts to suppress abnormal heart rhythm, particularly atrial fibrillation and flutter, paroxysmal atrial trachycardia, paroxysmal ventricular tachycardia, and premature atrial and ventricular contractions. It is also used as an intravenous treatment of malaria in patients who are unable to take drugs orally. Side effects include low blood pressure, skin rash, hives, itching, dizziness, and blurred vision.