Use of amiodarone in emergency

Amiodarone is one of the most common anti-arrhythmic drugs used in the Emergency Department. Recent guidelines on cardiac arrest with shockable rhythm [refractory ventricular fibrillation (VF)/pulseless ventricular tachycardia (VT)] recommend amiodarone as anti-arrhythmic of first choice. Amiodarone is also first choice drug in the treatment of various ventricular and supra-ventricular tachyarrhythmias. This paper deals with the main therapeutical indications of amiodarone in emergency medicine: dosage, side effects, contraindications and pharmacological interactions are reviewed. Amiodarone is effective for control of hemodynamically stable VT, polymorphic VT and wide-complex tachycardia of uncertain origin. It is also helpful for ventricular rate control of rapid atrial arrhythmias in patients with severely impaired left ventricular (LV) function, when digitalis has been ineffective, and is an adjunct to electrical cardioversion. The major side effects of amiodarone are hypotension, bradycardia and peripheral phlebitis. Major contraindications to the intravenous (i.v.) injection of amiodarone are bradycardia, senoatrial block, severe disturbs of conduction, second or third degree atrio-ventricular blocks. Other contraindications are hypotension, severe respiratory failure, hepatocellular failure and hyperthyroidism. Pharmacological interactions are reported with HMG-CoA reductase inhibitors, class I antiarrhythmic agents and other drugs which contribute to prolong QT interval, digoxin, oral anticoagulants and general anaesthesia.