Introduction: Depression and antidepressant therapy have been associated with sexual dysfunction in short-term and point-prevalence trials.
Aim: This report describes effects of duloxetine and escitalopram on sexual functioning during acute and long-term treatment of major depressive disorder (MDD).
Methods: In this 8-month, double-blind, placebo-controlled study, adult outpatients with Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV)-defined MDD were randomized to duloxetine 60 mg/day (N = 273; 173 female), escitalopram 10 mg/day (N = 274; 186 female), or placebo (N = 137; 87 female). After the first 8 weeks of treatment, dose increases were permitted to optimize treatment.
Main outcome measure: The 14-item Changes in Sexual Functioning Questionnaire (CSFQ) was used to assess sexual functioning.
Results: Of the 114 patients who did not meet total CSFQ score criteria for global sexual dysfunction at baseline (duloxetine, N = 51; escitalopram, N = 39; placebo, N = 24), the incidence of treatment-emergent sexual dysfunction was significantly higher for escitalopram compared with placebo at 4 and 8 weeks, and significantly higher compared with duloxetine at 4 weeks. At 8 weeks, the incidence of treatment-emergent sexual dysfunction was 17/51 (33.3%) for duloxetine-treated patients; 19/39 (48.7%) for escitalopram-treated patients; and 4/24 (16.7%) for placebo-treated patients (P = 0.01 escitalopram vs. placebo; P = 0.13 duloxetine vs. placebo). After 12 weeks, no significant differences were observed between active drugs. At 8 months, the incidence of treatment-emergent sexual dysfunction was 33.3% for duloxetine, 43.6% for escitalopram, and 25.0% for placebo. Regardless of treatment, patients who achieved remission of MDD showed improvement in global sexual functioning, whereas worsening was observed for patients who did not achieve remission (P < 0.001). Discontinuation rates for sexual side effects did not differ between duloxetine (N = 2) and escitalopram (N = 7) (P = 0.07).
Conclusions: Short-term treatment demonstrated a higher incidence of treatment-emergent sexual dysfunction with escitalopram compared with duloxetine and placebo. After 12 weeks, there were no statistically significant differences between drugs; however, MDD outcome (regardless of treatment) had a significant impact on improvement in global sexual functioning.