Antidepressants and the risk of hyponatremia: A multi‐institutional cohort study using observational medical outcomes partnership—Common Data Model

AIM: Hyponatremia is a common yet potentially serious adverse event associated with antidepressants. Identifying the antidepressant class with the least risk of hyponatremia would improve patient safety. METHODS: Using electronic medical records from 15 hospitals standardized into Observational Medical Outcomes Partnership Common Data Model (2003-2023), we identified patients diagnosed with depression who initiated antidepressants, including selective serotonin reuptake inhibitor (SSRI), serotonin-norepinephrine reuptake inhibitor (SNRI), tricyclic antidepressants (TCA) or others (agomelatine, bupropion, mirtazapine, moclobemide and trazodone) for at least 30 days. The index date was defined as the first antidepressant prescription, and four mutually exclusive cohorts were constructed based on the antidepressant class prescribed on index date. Each cohort was compared with all other antidepressants. The primary outcome was incident hyponatremia (serum sodium