Syndrome of inappropriate antidiuretic hormone secretion (SIADH) induced by amiodarone: a report on two cases.

Background: Amiodarone is an effective antiarrhythmic agent for life-threatening arrhythmias but has some noncardiac toxicity. The syndrome of inappropriate antidiuretic hormone secretion (SIADH) induced by amiodarone during long-term therapy seems to be rare among adverse effects.

Results: We report on two elderly cases that developed hyponatremia caused by SIADH occurring during the initial loading period of amiodarone therapy. Both cases improved within 3 weeks after reduction of the dose, although amiodarone was continued.

Conclusions: Amiodarone-induced SIADH may occur during the initial loading period, and it may be improved by reduction of the dose without discontinuation of the drug.