Korean J Psychopharmacol.  2008 May;19(3):156-162.

Comparison of the Effects of Selective Serotonin Reuptake Inhibitors and Mirtazapine on Hyponatremia in Patients with Major Depressive Disorder: A Preliminary Report

• Jung YE
• Kim SH
• Seo HJ
• Chae JH
• Jun TY
• Bahk WM

Abstract

OBJECTIVE
Hyponatremia (serum sodium arbitrarily defined as less than 135 mmol/L) is an increasingly recognized adverse effect of antidepressants such as selective serotonin reuptake inhibitors (SSRIs). This study compared the prevalence of hyponatremia associated with the use of SSRIs to that associated with mirtazapine in patients with major depressive disorder (MDD).
METHODS
The retrospective study included inpatients with MDD who had been treated with an antidepressant over a period of at least 4 weeks. The medical records of 58 patients treated with a SSRI and those of 48 patients treated with mirtazapine were analyzed. Demographic variables and serum sodium levels (at baseline, week 2, week 4) were compared between SSRI users and mirtazapine users.
RESULTS
Four patients (6.9%) from the SSRI group (N=58) exhibitedhyponatremia during the study period. At week 2, patients treated with a SSRI had lower serum sodium levels than the patients treated with mirtazapine, but at week 4, serum sodium levels did not differ significantly between the two groups. Elderly subjects (60 years and older) in the SSRI group exhibited lower serum sodium levels at weeks 2 and 4.
CONCLUSIONS
The results indicate that among patients with MDD, SSRI treatment may be associated with decreased serum sodium levels, and that elderly patients are at greater risk for hyponatremia. Further prospective studies would help clarify the relative risks of hyponatremia among various antidepressants, including SSRIs and others.

Keyword

Hyponatremia; SSRI; Mirtazapine; Major depressive disorder

MeSH Terms

Aged
Antidepressive Agents
Depressive Disorder, Major
Humans
Hyponatremia
Inpatients
Medical Records
Mianserin
Prevalence
Retrospective Studies
Serotonin Uptake Inhibitors
Sodium
Antidepressive Agents
Mianserin
Serotonin Uptake Inhibitors
Sodium