Vestibular tissue changes following administration of intravaginal prasterone: a vulvoscopic open-label pilot study in menopausal women with dyspareunia.

Background: Prasterone, an intravaginal dyspareunia treatment in menopausal women, improves vaginal health through intracellular conversion of dehydroepiandrosterone into androgens and estrogens. Phase 3 trials for prasterone showed significant improvement in vaginal tissue health and reduction of pain.

Aim: To assess vestibular changes with daily use of intravaginal prasterone in menopausal women with moderate to severe dyspareunia.

Methods: This open-label prospective pilot study was conducted over 20 weeks. It included 11 menopausal women (median age, 56 years) who were treated daily with intravaginal inserts of 6.5-mg prasterone and assessed monthly. During vulvoscopy, vestibular pain was assessed by cotton-tipped swab testing, and vestibular and vaginal health was independently assessed with the Visual Scale (VS). In addition, vulvoscopic photographs were obtained and assessed via the Vulvoscopic Genital Tissue Appearance (VGTA) scale to evaluate overall genital tissue health. Mean changes from baseline for genital tissue health and pain assessments were analyzed by repeated measures 1-way analysis of variance, followed by a Dunnett post hoc test. Sexual event diaries were completed and adverse events recorded.

Outcomes: Outcomes included indices of genital tissue health: pain assessment by cotton-tipped swab testing, VS of the vestibule and vagina, VGTA, and sexual event diary.

Results: Aggregate scores from the cotton-tipped swab test progressively improved, reaching statistical significance at week 16, which was maintained through week 20 (-7.27,  = .019). VS scores significantly improved from baseline by week 4 and were maintained through week 20 for the vestibule (-3.00,  = .004) and vagina (-4.00,  = .002). An overall 1607 vulvoscopic photographs were examined; all showed reduction in vestibular erythema and pallor at the end of the study. The mean change from baseline at week 20 for the VGTA score was -7.9 ( = .0016). Intercourse associated with pain was reduced from 81.3% of initiated events during the first month of the study to 8.3% during the last month. Sexual activities that were discontinued due to discomfort were reduced from 45.8% to 6.3%. No prasterone-related serious adverse events were reported.

Clinical Implications: Prasterone, a safe and effective intravaginal hormone treatment, significantly improves vestibular health parameters.

Strengths And Limitations: Strengths are the prospective study design and the use of multiple outcome measures to assess vestibular tissue health and pain associated with sexual activity. Limitations are the small study cohort and use of nonvalidated outcome measures.

Conclusion: Our findings suggest that intravaginal prasterone exerts biologic activity on the androgenic endodermal vestibule, as the medication passes from vagina to vestibule, resulting in amelioration of pain associated with sexual activity.