Antiarrhythmic drugs are important for the noninvasive rhythm control therapy of heart rhythm disorders. Antiarrhythmic drugs, which can be categorized into subgroups based on their different effects on ion channels, are clinically used for various types of arrhythmias. Knowledge about these specific electrophysiological effects contributes to a better understanding in order to select the correct drug for each specific arrhythmia. This review summarizes mechanisms, indications, contraindications, and side effects of the different antiarrhythmic drugs and, thus, supports their adequate use in daily clinical routine.