Amiodarone: Reevaluation of an Old Drug

PURPOSE: To review the pharmacology, electrophysiology, and toxicity of amiodarone and to discuss the clinical results produced when amiodarone is used as therapy for patients with atrial fibrillation, patients with nonsustained ventricular tachycardia and cardiomyopathy, patients who have recently had myocardial infarctions, and patients who have survived out-of-hospital cardiac arrest caused by ventricular tachycardia or ventricular fibrillation. DATA SOURCES: Animal and clinical studies involving the pharmacology and electrophysiology of amiodarone and clinical trials in which amiodarone was used as therapy for the arrhythmias noted above were reviewed. STUDY SELECTION: Relevant studies that reported on the efficacy and toxicity of amiodarone and on long-term therapy using amiodarone were reviewed, and their data were summarized. Reports of ongoing trials using amiodarone were also reviewed and summarized. RESULTS: Amiodarone is useful for the treatment of many rhythm disturbances. Although side effects from this agent are common, serious toxicity necessitating discontinuation of therapy is infrequent. Unlike other antiarrhythmic agents, amiodarone has not been shown to increase mortality in any population studied. CONCLUSION: Amiodarone, a unique antiarrhythmic agent with many pharmacologic actions, is effective in the treatment of a wide range of rhythm abnormalities. Several large, randomized trials will provide further information about the clinical usefulness of this agent.