According to the U.S. Food and Drug Administration (FDA),<unk>  can be validly used to maintain a normal heart rhythm in people with life-threatening ventricular arrhythmias (e.g., ventricular tachycardia), or very symptomatic atrial fibrillation or flutter. Due to the risk of serious side effects, the FDA states that<unk>  should generally be reserved for people whose ventricular arrhythmias are life-threatening, or whose fibrillation/flutter cannot be resolved using the Valsalva maneuver or another simple method.
Sotalol
Esmolol
Verapamil
Amiodarone
Bisoprolol
Carvedilol
Ibutilide
Metoprolol