Syndrome of Inappropriate Antidiuretic Hormone in Association with Amiodarone Therapy: A Case Report and Review of Literature

Abstract

Background: Amiodarone is a class III antiarrhythmic agent that is widely used in the treatment of a variety of arrhythmias. Several different systemic side effects are reported after use of this medication. In this article, we report a case that had developed syndrome of inappropriate antidiuretic hormone (SIADH) after starting treatment with this agent. Case report: The patient is a 66-year-old male with past medical history of hypertension, hyperlipidemia, coronary artery disease, and class III New York Heart Association congestive heart failure who presented with monomorphic nonsustained ventricular tachycardia. A loading dose of amiodarone followed by maintenance dose was started. Baseline serum sodium of 138 mmol/L on admission decreased to 119 mmol/L by day 7, and a diagnosis of SIADH was made. The patient was not taking any other medication known to cause SIADH, nor had any such comorbidity to explain it. Serum sodium increased to 133 and 138 mmol/L, respectively, after 16 and 33 days from discontinuation of amiodarone. Conclusion: SIADH is a rare but serious side effect of amiodarone and practicing physicians should be aware of this complication, particularly after loading dose of the medication.