Which medication is classified as an anti-arrhythmic?

Amiodarone is classified as an anti-arrhythmic medication because it primarily works by modifying the electrical activity of the heart to help restore a normal rhythm. This drug is particularly effective at treating various types of arrhythmias, including atrial fibrillation and ventricular tachycardia. Its mechanism of action involves blocking potassium channels, which prolongs the action potential and refractory period in cardiac tissue, thereby stabilizing the heart's rhythm.

While other options may have specific roles in cardiovascular health, they do not function as anti-arrhythmics. For instance, propranolol, which is used primarily for hypertension and anxiety, acts as a beta-blocker and has some impact on heart rate but is not classified as an anti-arrhythmic in the traditional sense. Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) used primarily for pain and inflammation, and digoxin is primarily used for heart failure and to control the ventricular rate in atrial fibrillation, but it is not categorized as a primary anti-arrhythmic agent like amiodarone.

Hence, amiodarone stands out as it has a direct and well-established role in the management of arrhythmias.