Cited 11 times since 2009 (0.7 per year) source: EuropePMC British journal of clinical pharmacology, Volume 68, Issue 2, 1 1 2009, Pages 221-225 Variation in the CYP2D6 gene is associated with a lower serum sodium concentration in patients on antidepressants. Kwadijk-de Gijsel S, Bijl MJ, Visser LE, van Schaik RH, Hofman A, Vulto AG, van Gelder T, Ch Stricker BH

Aim

To study the effect of the CYP2D6*4 polymorphism on serum sodium concentration in users of antidepressants [selective serotonin reuptake inhibitors and tricyclic antidepressants (TCAs)].

Methods

In this population-based cohort study, all subjects in the Rotterdam Study were included who used an antidepressant at baseline and from whom a blood sample was available in which CYP2D6 genotype and serum sodium concentration could be determined (n= 76). Multivariate linear regression was used to study the association between CYP2D6*4 and serum sodium concentration.

Results

CYP2D6 poor metabolizers (PMs) (*4/*4) had a significantly lower mean serum sodium concentration in comparison with CYP2D6 extensive metabolizers (EMs) (*1/*1) [difference -3.9 mmol l(-1); 95% confidence interval (CI) -0.86, -7.03; P= 0.013]. In CYP2D6*4 heterozygotes (*1/*4) serum sodium concentration was 1.7 mmol l(-1) (95% CI -3.48, 0.18) lower compared with CYP2D6 EMs, but this difference was not statistically significant (P= 0.077).

Conclusions

The serum sodium concentration in PMs was lower in users of an antidepressant, especially in TCA users. Therefore CYP2D6 PMs might be at increased risk of developing symptoms of hyponatraemia.

Br J Clin Pharmacol. 2009 8;68(2):221-225