Eur J Endocrinol

SSRIs and venlafaxine linked to severe hyponatremia risk

August 26, 2025

Study details: This retrospective cohort study analyzed electronic health records to assess the incidence of profound hyponatremia (serum sodium <125 mEq/L) among patients prescribed SSRIs or venlafaxine. The study included adult patients across multiple clinical settings and adjusted for confounding factors such as age, sex, comorbidities, and concurrent medications.

Results: Within the first three months of SSRI/venlafaxine initiation, the adjusted odds ratio (aOR) for profound hyponatremia was 4.29 (95% confidence interval [CI], 3.34–5.52), peaking at an aOR of 10.06 (95% CI, 5.97–17.00) in the first two weeks. Incidence was highest in older adults: 3% in ages 65–79 and 4% in ≥80 years. Among individuals ≥80 years, incidence was 6.5% for women and 3.4% for men. After one year, risk attenuated (aOR 1.30, 95% CI 0.97–1.75).

Clinical impact: Clinicians should be vigilant for signs of hyponatremia in patients starting SSRIs or venlafaxine, especially in older adults or those with predisposing factors. Routine monitoring of serum sodium may be warranted during the early phase of treatment to prevent severe complications.

Source:

Issa I, et al. (2025, July 8). Eur J Endocrinol. The association of selective serotonin reuptake inhibitors and venlafaxine with profound hyponatremia. https://pubmed.ncbi.nlm.nih.gov/40627725/