Evaluation of long term use of amiodarone in low dose

ABSTRACT

Thirty two patients with ventricular or supraventricular arrhythmias were treated with amiodarone in low dose [1000 mg/week] for more than 6 months. Amiodarone serum level as well as the level of its metabolite desethylamiodarone was determined biweekly using an HPLC method. Serum levels attained were around the lower end of the therapeutic range. Significant variation in serum level was observed within the same patient over time scale. The low dose used did not produce major side effects but was highly effective in controlling the arrhythmia. The effect on ECG intervals was studied during the steady state period of the drug. The PR interval was prolonged without leading to heart block. The QT interval showed an increase of a mean value of 16% +8.4%. Significant correlation was found between prolongation in ECG intervals and the drug serum level. This correlation was more significant with the metabolite desethylamiodarone than with the parent compound amiodarone. Arrhythmia whether supraventricular or ventricular was controlled in all patients [100%]. It is concluded that low dose amiodarone is highly effective in controlling supraventricular and ventricular arrhythmias with no major side effects