Which medication can lead to QT interval prolongation as a side effect?

Amiodarone is known to cause QT interval prolongation as a significant side effect. It is a class III antiarrhythmic agent that is often used to treat various types of dysrhythmias, including atrial fibrillation and ventricular tachycardia. The mechanism behind its effect on the QT interval involves the blockage of potassium channels, which affects the repolarization phase of the cardiac action potential. This prolongation of the QT interval can increase the risk of life-threatening arrhythmias, such as Torsades de Pointes.

In contrast, while digoxin, atenolol, and verapamil have their own profiles of potential side effects and heart rhythm effects, they are not primarily associated with significant QT interval prolongation. Digoxin is more associated with increasing the force of cardiac contractions, atenolol is a beta-blocker primarily used to manage blood pressure and heart rate, and verapamil is a calcium channel blocker that can affect heart rhythm but does not significantly prolong the QT interval in the same way as amiodarone.