Used primarily in the treatment of cardiac arrhythmias, particularly for the rapid conversion of atrial fibrillation and atrial flutter to normal sinus rhythm. It is administered intravenously in a hospital setting under continuous ECG monitoring due to the risk of inducing life-threatening arrhythmias, such as torsades de pointes. Ibutilide fumarate is especially effective in acute settings where prompt rhythm control is needed. Its action begins within minutes of infusion, making it suitable for urgent cardioversion when electrical methods are not immediately preferred. Due to its proarrhythmic potential, patients are typically monitored for several hours after administration.