The effect of vilazodone on sexual function during the treatment of major depressive disorder

Sexual dysfunction is common in major depressive disorder (MDD), and many serotonergic antidepressants adversely affect sexual function. Vilazodone, a novel serotonin (5-HT) reuptake inhibitor and 5-HT1A partial agonist approved for MDD, exerts its effects at the 5-HT transporter and at both presynaptic and postsynaptic 5-HT1A receptors. This mechanism may limit sexual dysfunction.

To summarize effects of vilazodone (40 mg/day, with food) on sexual function in adults with MDD.

Data sources were three Phase III studies: two 8-week, placebo-controlled studies (NCT00285376 and NCT00683592) and a 52-week open-label study (NCT00644358). Sexual function was assessed by analyzing changes from baseline to end of treatment (EOT) using validated measures.

Arizona Sexual Experience Scale or Changes in Sexual Functioning Questionnaire.

Population included 869 patients (vilazodone, 436; placebo, 433) from placebo-controlled studies and 599 patients from the open-label study. Sexual dysfunction prevalence was high (50%, men; 68%, women) before treatment and declined during treatment in vilazodone and placebo groups, indicating improvement on average. At EOT, stable/improved sexual function was observed in ≥91% of patients in placebo-controlled studies; treatment group differences in sexual dysfunction at EOT were not statistically significant for either sex. Differences vs. placebo in changes from baseline of sexual function scores were small and were generally not statistically significant; effect sizes (Cohen's D) were generally of low magnitude. In the placebo-controlled studies, 8.0% of vilazodone-treated patients and 0.9% of placebo-treated patients reported ≥1 sexual-function-related treatment-emergent adverse event (P<0.001).

Half of men and two thirds of women with MDD had sexual dysfunction at baseline; sexual function improved on average in both vilazodone and placebo groups. Results suggest that vilazodone may have a small adverse impact on sexual function in adults with MDD relative to the high prevalence of sexual dysfunction at baseline.