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Psych Congress  

Effects of Vilazodone on Sexual Functioning in Healthy Adults: Results from a Randomized, Double-Blind, Placebo- and Active-Controlled Study

Ken Kramer, PhD
Anita H. Clayton, MD
Suresh Durgam, MD
Maju Mathews, MD
Dayong Li, PhD
Changzhen Chen, PhD
Carl Gonmoll, MS
Armin Szegedi, MD
Forest Laboratories, LLC, an affiliate of Actavis, Inc

Background: Since antidepressants have been associated with decreased sexual functioning, a multicenter Phase I study (NCT02097147) was conducted to evaluate the effects of vilazodone on sexual functioning. Methods: Healthy adult subjects received vilazodone (20 or 40 mg/d), paroxetine 20 mg/d, or placebo for 5 weeks of double-blind treatment. The primary endpoint was change from baseline to Day 35 in Change in Sexual Functioning Questionnaire (CSFQ) total score in the ITT Population. To account for non-adherence, CSFQ total score change was also analyzed in 2 modified (mITT) Populations, which excluded patients in the vilazodone or paroxetine groups with no drug concentration at all study visits (mITT-I) or at any study visit (mITT II). Results: In the ITT Population (N=199), mean CFSQ total score changes from baseline were: placebo, -1.0, paroxetine, -3.5, vilazodone 20 mg/d, -1.4, vilazodone 40 mg/d, -1.9. No statistically significant difference was detected between any treatment groups. However, in the mITT-I and mITT-II Populations (N=197 and N=159, respectively), CSFQ total score reduction (worse sexual functioning) was significantly greater (P<.05) with paroxetine ( 4.2 and -5.5) versus placebo (-1.0 and -0.9) and vilazodone 20 mg/d (-1.3 and -1.2), but not vilazodone 40 mg/d (-2.4 and -2.4). No significant differences between placebo and either vilazodone dose were found in the mITT-I or mITT-II Populations. Conclusions: In the ITT Population, no significant between-group differences were found in CFSQ total score change. However, additional analyses that excluded noncompliant subjects suggested that the mean effects of vilazodone and paroxetine on sexual functioning were affected by nonadherence.

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