Collin College Cardiac Drugs Practice Test 2025 – 400 Free Practice Questions to Pass the Exam

Amiodarone is indeed primarily classified as a potassium channel blocker. It works by prolonging the phase 3 of the cardiac action potential, which corresponds to the repolarization phase. By blocking potassium channels, amiodarone increases the refractory period of the heart, helping to stabilize the cardiac rhythm and reducing the risk of arrhythmias. This mechanism is crucial in the management of various tachyarrhythmias, particularly in patients with atrial fibrillation or ventricular tachycardia.

Additionally, amiodarone has some characteristics of sodium channel blockade and beta-adrenergic blockade, but its principal action that defines its therapeutic effects is that of a potassium channel blocker. This multifaceted action allows it to effectively control heart rate and rhythm, making it a valuable drug in cardiology.