Farmand S, et al. – The risk of hospitalisation attributed to antidepressant induced hyponatremia was assessed across different groups of antidepressants. A strong link was observed between newly initiated treatment with selective serotonin reuptake inhibitors (SSRIs) or venlafaxine and hospitalization due to hyponatremia. Data reported a small to moderate relationship for tricyclic antidepressants (TCA) and mirtazapine. In contrast, researchers found no evidence that ongoing treatment with antidepressants increases the risk for hospitalization due to hyponatremia.

Methods

• In this register based case–control study of patients in the general Swedish population, researchers identified 14 359 individuals with a main diagnosis of hyponatremia.
• For every case, 4 matched controls were included (n=57 382).
• They divided antidepressant exposure into patients with newly initiated and ongoing treatment in order to investigate the temporal aspects of drug-induced hyponatremia.
• They used univariable and multivariable logistic regression to analyse the association of antidepressant use and hospitalization.

Results

• Findings demonstrated that for newly initiated antidepressants, adjusted OR (95% CI) for a main diagnosis of hyponatremia, compared to controls, were for: citalopram 5.50 (4.71-6.44); sertraline 4.96 (3.81-6.48) for; venlafaxine 5.28 (3.20-8.83); tricyclic antidepressants (TCA) 1.59 (1.13-2.24); and mirtazapine 2.54 (2.04-3.16).
• Results showed that adjusted OR (CI) for individuals with ongoing treatment ranged from 0.57 (0.52-0.63) for citalopram to 1.08 (0.85-1.36) for other SSRIs.