Botulinum Toxin A May Improve Sexual Function in Provoked Vestibulodynia

At 12 months, more women with provoked vestibulodynia (PVD) who underwent treatment with injections of botulinum toxin A (BTX-A) attempted intercourse compared with women who received placebo. These findings from a double-blind, placebo-controlled trial were published in The Journal of Sexual Medicine.

Women (N=88) who were nulliparous and had PVD were recruited at the Karolinska Institutet Danderyds Hospital in Sweden to participate in this study (ClinicalTrials.gov Identifier: NCT02773641). The patients were randomly assigned to receive 50 units of BTX-A (n=44) or placebo (n=44) injected into the bulbocavernosus muscles bilaterally twice at 3-month intervals. The women were also instructed to perform pelvic floor exercises between months 6 and 12. The primary outcome was change in the 100-point visual analog scale (VAS) score of pain when using a tampon.

Among women in the intervention and control cohorts, 70% and 68% had menstrual pain, 82% and 75% had a history of yeast infection, 66% and 61% had a history of urinary tract infection, 20% and 16% had primary PVD, and 55% and 64% had secondary PVD, respectively.

At baseline, the average level of pain at tampon use during the previous month was 67.5 mm among women in the intervention cohort and 68.7 mm among women in the control cohort (P =.797). Both the BTX-A and placebo recipients reported reductions in tampon-related pain at 12 months, to scores of 50.0 mm and 57.3 mm, respectively, which did not differ significantly between groups (P =.234).

At the 12-month follow-up, significant group differences were reported for Female Sexual Function Index (FSFI) scores among sexually active participants (mean difference [MD], 3.1; P =.048), FSFI scores among all participants (MD, 4.4; P =.006), and the proportion of women who attempted intercourse (MD, 31%; P =.005), all of which favored the BTX-A intervention.

No other study outcomes differed significantly between cohorts at 12 months.

A major limitation of this study was that few women performed the pelvic floor exercises as instructed; therefore, this variable could not be added to the models due to lack of data.

The study authors found that BTX-A injections for the treatment of PVD did not improve the primary outcome of pain during tampon use. However, there was a positive effect on sexual function and attempted intercourse. The study authors conclude, “For future studies, we suggest that a higher dose should be used and additional pelvic floor muscles targeted.”