Botox improves sexual function in women with provoked vestibulodynia

Injections of botulinum toxin A (BTA) in women with provoked vestibulodynia (PVD) does not appear to reduce dyspareunia or pain at tampon use when compared with placebo at 12 months’ follow-up, reports a recent study. However, women on BTA have attempted intercourse more often and have better sexual function than those on placebo.

A team of investigators conducted a double-blinded, placebo-controlled trial of twice-repeated injections of 50 units BTA or placebo in the bulbocavernosus muscles, 3 months apart, in women with PVD. Apart from the injections, participants were encouraged to do pelvic floor exercises during month 6 to 12.

Based on an effect size of 20 visual analogue scale units (mean score range 56‒76), 38 women per group were estimated to achieve a statistical power of 80 percent. Self-reported dyspareunia or pain at tampon use was the primary outcome, while secondary ones included vaginal pressure measurements, psychological health, sexual function, and distress.

Of the 88 randomized women with PVD, 75 completed the study at 12 months: 38 in the BTA and 37 in the placebo group. No significant between-group difference was observed in the primary outcome.

At 12 months, women receiving BTA had vaginal pressure restored to pretreatment levels, with no between-group differences noted.

Of note, sexual function increased in the BTA group, with a Female Sexual Function Index of 22.8 compared to 19.7 in the placebo group (p=0.048). No differences were seen in stress, anxiety, and sexual distress between groups. In addition, more women in the BTA cohort attempted intercourse than those on placebo (74 percent vs 43 percent; p=0.005).

Unfortunately, too few women performed the pelvic floor exercises to be eligible for analysis.

“This study highlights BTA as a safe treatment option for patients with PVD,” the investigators said.

“PVD is a common pain disorder afflicting primarily young women, and BTA has been to a limited extent tested as a treatment,” they noted.