title: High incidence of clinical and subclinical toxicity associated with amiodarone treatment of refractory tachyarrhythmias.
abstract: Amiodarone has been hailed as the most effective single antiarrhythmic drug for treatment of refractory supraventricular and ventricular arrhythmias. However, questions continue to arise about its long-term potential toxicity and true efficacy rates. We, therefore, reviewed our experience with 78 patients, mean age 59 +/- 14 years, with drug refractory tachyarrhythmias treated with amiodarone. Sixty-two patients were treated for recurrent ventricular tachycardia or ventricular fibrillation, 4 for complex ventricular ectopy and 12 for supraventricular tachyarrhythmias. Patients have been treated for a mean of 9.9 months (range, 1 day to 39.1 months); 34(55%) continued to be successfully treated for ventricular tachycardia/ventricular fibrillation, 2 (50%) for complex ventricular ectopy and 5 (42%) for supraventricular tachyarrhythmias. Amiodarone toxicity was frequent, occurring in 57/72 patients (79%) who were treated for more than one week. Adverse effects led to drug discontinuation in 15 (21%), 3 because of pulmonary toxicity (1 in combination with neuropathy and another with drug-induced hepatitis); 2 because of chemical hepatitis; 1, confusion; 6, neuropathy; 2, arrhythmia exacerbation; 2, symptomatic bradycardia; and 1 because of impotence. Of the 62 ventricular tachycardia/ventricular fibrillation patients who were treated with amiodarone, 8 (13%) expired: 4 died suddenly and 4 from documented ventricular tachycardia during treatment. In contrast, of 16 patients who had discontinued amiodarone because of initial adverse effects or drug failure and were treated with alternative antiarrhythmic medications, 5 (31%) died suddenly. In conclusion, amiodarone appears to be fairly effective in high risk patients with refractory cardiac tachyarrhythmias but results in a rather high incidence of adverse effects in long-term follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000638:Amiodarone / Q000009:adverse effects* / Q000627:therapeutic use; D001572:Benzofurans / Q000009:adverse effects*; D056486:Chemical and Drug Induced Liver Injury / Q000209:etiology; D002648:Child; D002986:Clinical Trials as Topic; D003875:Drug Eruptions / Q000209:etiology; D005128:Eye Diseases / Q000139:chemically induced; D005260:Female; D005500:Follow-Up Studies; D005767:Gastrointestinal Diseases / Q000139:chemically induced; D006801:Humans; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000139:chemically induced; D011653:Pulmonary Diffusing Capacity / Q000187:drug effects; D013610:Tachycardia / Q000188:drug therapy*; D013959:Thyroid Diseases / Q000139:chemically induced; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000188:drug therapy*
chemical_list: D001572:Benzofurans; D000638:Amiodarone