Antidepressant-Induced Hyponatremia in Older Adults

To describe the prevalence of hyponatremia in older adults related to antidepressive agents and identify potential alternative options in older adults with a low-baseline serum sodium concentration and/or when a patient has experienced hyponatremia as a result of taking an antidepressant.

A PubMed search was conducted on November 10, 2015. Search terms included: antidepressive agents, antidepressive agents second-generation, bupropion, citalopram, desvenlafaxine, duloxetine, escitalopram, fluoxetine, fluvoxamine, hyponatremia, milnacipran, mirtazapine, paroxetine, reboxetine, syndrome of inappropriate antidiuretic hormone, sertraline, trazodone, venlafaxine, and vilazodone. Filters included English language. A search of product labeling was also conducted.

Out of 363 results, 124 publications were identified and reviewed along with 11 additional references. Publications were chosen based on relevance to the review: case reports of patients 60 years of age or older or clinical investigations of the association between hyponatremia and antidepressants in older adults.

Hyponatremia was counted as an adverse effect if an antidepressant was the likely cause of hyponatremia, and hyponatremia was resolved after withdrawal.

Antidepressant-induced hyponatremia in older adults is fairly common. Selective serotonin reuptake inhibitors, serotonin/norepinephrine reuptake inhibitors, and mirtazapine were implicated in the majority of the case reports and clinical studies evaluating older adults. Bupropion, trazodone, and tricyclic antidepressants were implicated less often in the same literature.

Given its unique mechanism of action, bupropion may be the most appropriate antidepressant for older adults at risk for antidepressant-induced hyponatremia.