Anti-arrhythmic medications treat rapid heartbeat, or tachycardia, according to Mayo Clinic. They are delivered through injections or in pill form. Anti-arrhythmic drugs are divided into four classes.
Class I medications impede the movement of sodium, which then slows the motion of electricity through the heart, states Texas Heart Institute. Examples include quinidine, disopyramide, procainamide, lidocaine and tocainide, McGill University lists.
Class II drugs are beta blockers, which prevent hormones such as adrenaline from affecting the heart, Texas Heart Institute says. Metoprolol and esmolol are common beta blockers, reports Mayo Clinic.
Sotalol, amiodarone, dofetilide and ibutilide are class III medications, McGill University notes. These obstruct the movement of potassium in the heart, and this reduces the speed of electrical impulses, relates Texas Heart Institute.
Class IV medications work much like beta blockers but limit the movement of calcium in the heart, Texas Heart Institute describes. The drugs verapamil and diltiazem perform this function, specifies Tulane University.
Not all cases of tachycardia need medication, asserts Mayo Clinic. It is possible for the heart rate to self correct. Sometimes people learn the vagal maneuver, which uses a series of actions to slow the heart. If other treatments do not work, a doctor sends an electrical shock to the heart through paddles or patches placed on the patient's chest.