An open-label study to evaluate switching from an SSRI or SNRI to tiagabine to alleviate antidepressant-induced sexual dysfunction in generalized anxiety disorder

Background. This study investigated tiagabine monotherapy in subjects with generalized anxiety disorder (GAD) who had been switched from selective serotonin reuptake inhibitors (SSRIs) or serotonin-norepinephrine reuptake inhibitors (SNRIs) as a result of antidepressant-induced sexual dysfunction. Methods. Adults with DSM-IV GAD, an adequate therapeutic response (≥50% decrease in Hamilton Rating Scale for Anxiety [HAM-A] total score) to SSRI or SNRI and sexual dysfunction were switched to open-label tiagabine 4-12 mg/day for 14 weeks. Assessments included the HAM-A, Hospital Anxiety & Depression Scale (HADS) and the Arizona Sexual Experiences Scale (ASEX); assessments were made at baseline and at Weeks 4, 8, and 14. Results. Twenty six subjects were included in the analysis. Tiagabine showed no worsening in baseline symptoms of GAD, with non-significant changes from baseline in mean HAM-A total scores and HADS Anxiety and Depression subscale scores. There was a significant (p < 0.001) reduction in ASEX total scores from baseline following tiagabine, indicating an alleviation of sexual dysfunction. Tiagabine was reasonably tolerated; the most commonly reported adverse events were dizziness/light headedness (n = 6; 23%), nausea (n = 6; 23%) and fatigue (n = 2; 8%). Conclusions. Tiagabine may be useful in subjects who respond to previous antidepressant therapy but develop sexual dysfunction as an adverse event.