FOCUS ON IV IBUTILIDE - A NEW ANTIARRHYTHMIC AGENT FOR THE ACUTE TREATMENT OF ATRIAL-FIBRILLATION AND FLUTTER

Ibutilide is a class III antiarrhythmic agent that is structurally rel ated to sotalol but lacks beta-adrenergic receptor blocking effects, L ike other class III antiarrhythmic agents, it prolongs both atrial and ventricular action potential duration but does this by a different io nic mechanism than other class In agents, Ibutilide can Increase the v ariability of atrial fibrillation or flutter cycle length, The drug ap pears to have no effect on QRS duration and produces dose-related QT p rolongation, It is highly distributed in the body, The elimination hal f-life is about 6 hours. Based on drug company sponsored studies, ibut ilide is a relatively effective antiarrhythmic agent for the acute ter mination of atrial fibrillation and flutter of recent onset, Like othe r class III agents, ibutilide can also induce torsades de pointes; the refore, patients treated with this drug should be carefully monitored.