Ibutilide

Definition

Ibutilide is a Class III antidysrhythmic drug used to treat atrial fibrillation and atrial flutter. It works by prolonging the action potential duration and refractory period through potassium channel blockade.

5 Must Know Facts For Your Next Test

1. Ibutilide is administered intravenously (IV) for the acute conversion of atrial fibrillation or atrial flutter to normal sinus rhythm.
2. The primary mechanism of action involves blocking potassium channels, which delays repolarization and prolongs the cardiac action potential.
3. Prolonged QT interval is a significant side effect of ibutilide, raising the risk of torsades de pointes, a type of ventricular tachycardia.
4. Patients receiving ibutilide should be monitored with continuous ECG due to the risk of serious arrhythmias.
5. Ibutilide has a rapid onset of action, usually within minutes after administration.

Review Questions

• What is the primary use of ibutilide in clinical practice?
• How does ibutilide affect cardiac action potentials?
• Why is continuous ECG monitoring necessary when administering ibutilide?

Related terms

Amiodarone: A Class III antidysrhythmic that also blocks potassium channels but has additional effects on sodium and calcium channels.

Torsades de Pointes: A potentially life-threatening form of ventricular tachycardia associated with prolonged QT intervals.

Atrial Fibrillation: An irregular, often rapid heart rate that commonly causes poor blood flow and can be treated with medications like ibutilide.