Effects of Flibanserin on Subdomain Scores of the Female Sexual Function Index in Women With Hypoactive Sexual Desire Disorder

Abstract

Introduction: Flibanserin treatment increases sexual desire and satisfying sexual events while decreasing distress in certain women diagnosed with acquired, generalized hypoactive sexual desire disorder (HSDD). Additional aspects of sexual function and the time course of response have not been fully characterized.

Aim: To evaluate changes in sexual function assessed by the subdomains of the Female Sexual Function Index (FSFI) in women with HSDD treated with flibanserin.

Methods: FSFI data pooled from 3 pivotal flibanserin trials in premenopausal women (flibanserin = 1,165; placebo = 1,203) and FSFI data from one complete flibanserin trial in postmenopausal women (flibanserin = 432; placebo = 463) were subjected to post-hoc analyses. For each FSFI subdomain, least squares mean change from baseline was calculated at each assessment visit (treatment weeks 4, 8, 16, 24) and treatment groups were compared using analysis of covariance. Standardized effect size (Cohen's d) was also determined for each FSFI subdomain.

Main outcome measure: Changes from baseline in FSFI subdomains.

Results: Compared to placebo, both premenopausal (P < .02) and postmenopausal (P < .045) patients in the flibanserin group reported significantly greater increases over baseline in the FSFI subdomain scores of desire, arousal, lubrication, orgasm, and satisfaction. In premenopausal patients, significant improvements were observed at the first assessment of response (week 4) and were maintained through week 24. In postmenopausal patients, significant improvements were observed at week 4 for desire and arousal, while significant improvements in lubrication, orgasm, and satisfaction were observed at week 8. At week 24, excluding the pain subdomain, standardized effect sizes ranged from 0.18 to 0.28 in the premenopausal cohort and 0.12 to 0.29 in the postmenopausal cohort. In both pre- and postmenopausal patients, improvements in pain were smaller and largely undifferentiated between treatment groups.

Clinical implications: While variations in time to response should be taken into consideration, on average, the beneficial impact of flibanserin on overall sexual function occurs within the first month of treatment. The data also suggest that the response to flibanserin is sustained for the duration of treatment.

Strengths and limitations: Sexual function assessments were performed in a large cohort of 2,368 premenopausal women and 895 postmenopausal women. However, the FSFI assesses changes over a 1-month period and time points earlier than 4 weeks could not be assessed.

Conclusion: These analyses suggest that assessment of benefit of flibanserin in HSDD should include improvements across all domains of sexual function, not only desire. Simon JA, Clayton AH, Goldstein I, et al. Effects of Flibanserin on Subdomain Scores of the Female Sexual Function Index in Women With Hypoactive Sexual Desire Disorder. Sex Med 2022;10:100570.

Keywords: Effect Size; Female Sexual Function Index Scores; Flibanserin; Hypoactive Sexual Desire Disorder.

Figure 1

Change from baseline in Female Sexual Function Index subdomain scores in premenopausal women during treatment with flibanserin 100 mg qhs (n = 1165) or placebo (n = 1203).  Sample sizes vary slightly by domain based on available data for each treatment group (see Table 2).  *P < .025.

Figure 2

Mean difference in Female Sexual Function Index subdomain scores between flibanserin and placebo treatment groups in premenopausal women (see Figure 1).  For each mean difference, 95% confidence intervals and p values are shown.

Figure 3

Change from baseline in Female Sexual Function Index subdomain scores in naturally postmenopausal women (Snowdrop trial) during treatment with flibanserin 100 mg qhs (n = 432) or placebo (n = 463).  *P < .045.

Figure 4

Mean difference in Female Sexual Function Index subdomain scores between flibanserin and placebo treatment groups in naturally postmenopausal women (Snowdrop trial; see Figure 3).  For each mean difference, 95% confidence intervals and p values are shown.

Figure 5

Change from baseline in Female Sexual Function Index total scores in premenopausal and postmenopausal women during treatment with flibanserin 100 mg qhs or placebo (see Figures 1 & 3).  The contributions of each subdomain to the total score at Week 4 and Week 24 are shown in the middle and lower panels.  *P < .0035.