Hyponatremia during therapy with amiodarone.

We describe an elderly woman who presented with significant hyponatremia caused by the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) during therapy with amiodarone. The hyponatremia resolved after discontinuation of the drug and did not recur during a follow-up period of 6 months. Such an association has previously been reported only once in the medical literature. Since severe hyponatremia can produce significant neurologic damage and is associated with a high mortality rate, clinicians should be aware that this complication may occur during amiodarone therapy.