Low dose amiodarone in refractory tachyarrhythmias.

Fifty patients with drug resistant tachyarrhythmias were treated with amiodarone for 6-22 months; 16 for recurrent ventricular tachycardia (VT), 2 for VT followed by ventricular fibrillation (VF), 14 for complex ventricular ectopics, and 18 for supraventricular tachyarrhythmias (SVT). Amiodarone was administered in a dose much lower than that used in western trials. The actual incidence of successful amiodarone therapy was 81.2% at 22 months for patients with VT. Among the patients with SVT, 88.6% patients were successfully treated for 22 months (range 3-22 months). Amiodarone toxicity appeared in 22 of 50 patients (44%) treated for more than 12 weeks. Withdrawal of therapy was required in 4 patients. Despite the lower dose, clinical efficacy and onset of action were comparable to the western experience.