Abstract
This article reviews the safety and efficacy of ibutilide for use in patients with atrial fibrillation and flutter. Ibutilide, a methanesulfonamide derivative is a class III antiarrhythmic drug that was approved by the Food & Drug Administration for use on December 28, 1995, is available only for intravenous use because of its extensive first-pass metabolism. It prolongs repolarization time, action potential duration, and refractory period of atrial and ventricular myocardium through its action as a potassium channel blocker, affecting the rapid component of the cardiac delayed rectifier potassium current. The drug is indicated for the rapid restoration of normal sinus rhythm in patients with atrial fibrillation or atrial flutter of recent onset who are hemodynamically stable. The ibutilide effects is dependent on concentration. Clinical trials have established ibutilide's efficacy in converting sustained atrial flutter and atrial fibrillation to normal sinus rhythm. Ibutilide has a conversion rate of up to 75% to 80% in recent-onset atrial fibrillation and flutter; the conversion rate is higher for atrial flutter than for atrial fibrillation. Comparative studies have reported that ibutilide was a more effective intravenous agent than amiodarone, DL-sotalol, procainamide for conversion of atrial flutter and atrial fibrillation. The present review describe the efficacy of ibutilide for rapid conversion of atrial fibrillation and atrial flutter to sinus rhythm is superior to most of the other antiarrhythmic agents.