Psychotropic agents have been implicated in the cause of hyponatremia, including the majority of selective serotonin reuptake inhibitors (SSRIs). The reported incidence of hyponatremia caused by SSRIs varies widely up to 40%. Important risk factors are older age and concomitant use of diuretics. Though there are numerous retrospective studies available, an update of current knowledge SSRI induced hyponatremia is warranted.

To review the incidence, risk factors, mechanism, times of onset and resolution, and treatment of hyponatremia associated with selective serotonin-reuptake inhibitors (SSRIs).

An English language literature search was conducted using Pubmed, EMBASE and Cochrane library (December 1980–December 2015) using the search terms selective serotonin-reuptake inhibitor, hyponatremia, syndrome of inappropriate secretion of antidiuretic hormone, citalopram, escitalopram, fluoxetine, fluvoxamine, paroxetine, and sertraline.

Numerous case reports, observational studies, and case-controlled studies, as well as one prospective clinical trial, have reported hyponatremia associated with SSRI use, with an incidence of 15%. Risk factors for the development of hyponatremia with SSRIs include older age, female gender, and concomitant use of diuretics, low body weight, and lower baseline serum sodium concentration. Predisposing factors, such as volume status, diuretic use, or concomitant use of other agents known to cause SIADH, may predispose to the development of hyponatremia. In published reports, hyponatremia developed within the first few weeks of treatment and resolved within 2weeks after therapy was discontinued.

Practitioners should be on the alert for this potentially life-threatening adverse event, especially in older adults.