INTRAVENOUS AMIODARONE

Intravenous amiodarone was approved in 1995 for the treat ment of mali gnant and resistant ventricular arrhythmia. Al though it is an ''old d rug,'' much has been learned recently about this complex drug and its application in a variety of cardiac arrhythmias. The objectives of thi s review were to summarize what is known about intravenous amiodarone, including its pharmacologic and electrophysiologic effects, to review its efficacy for the treatment of patients viith highly malignant ven tricular arrhythmia and to provide specific information about its clin ical use for this and other indications. The studies that were reviewe d were selected on the basis of time published (from 1983 to 1995) and the completeness of information provided regarding patient clinical c haracteristics, drug dosing and methods of evaluation, efficacy analys es, long-term follow-up and complications. The full data from the thre e controlled trials that formed the basis of the drug's approval are c ontained in published reports that were also extensively reviewed, Int ravenous amiodarone has demonstrable efficacy for the treatment of fre quently recurrent destabilizing ventricular tachycardia and ventricula r fibrillation, with suppression rates of 63% to 91% in uncontrolled t rials. The three pivotal trials confirmed these findings and demonstra ted a dose-response relation, with at least comparable efficacy to bre tylium, a drug with a similar indication. The safety profile has also been well described; cardiovascular adverse effects are the most frequ ent, especially hypotension. Intravenous amiodarone is a useful additi on to the drugs available for the treatment of patients with very seve re ventricular arrhythmia. Its use in patients with other rhythm disor ders appears promising, but final recommendations must await developme nt of definitive data from ongoing clinical trials.