The clinical efficacy of
amiodarone in the management of complex
cardiac arrhythmias refractory to
therapy with two or more conventional or other investigational antiarrhythmic agents was determined by long-term follow-up in patients who had received the
drug for at least 3 months. A total of 181 patients, classified into four groups (group 1, supraventricular arrhythmias, n = 42; group 2, frequent
ventricular premature complexes, n = 46; group 3,
nonsustained ventricular tachycardia, n = 16; and group 4, sustained
ventricular tachycardia, n = 77) received a daily maintenance dose of 200 to 800 mg
amiodarone for up to 30 months. There was a total of 26 deaths (14%). Ten of these were probably attributable to
arrhythmia, although all patients had either good or excellent response to
therapy over a mean follow-up of 14.9 months prior to death. The
drug had to be permanently discontinued because of side effects in only three patients, and in the majority of patients with side effects, symptoms could be alleviated with adjustment of dosage, thyroid replacement
therapy, or temporary cessation of
therapy. We conclude that
amiodarone is highly effective in high-risk patients with complex refractory
cardiac arrhythmias, and that close monitoring and prompt recognition of side effects and appropriate adjustment of dosage or institution of supplemental or replacement
therapy (in less than 5% of patients) will allow continuation of
amiodarone. The benefit of suppression of symptomatic arrhythmias and the potential of prevention of
sudden death clearly outweigh the modest incidence of severe side effects.