Baclofen (vaginal/pelvic use)

Also known as: baclofen, Lioresal (branded)

Sexual Well-Being

In plain English

Baclofen is a muscle relaxant. In compounded vaginal suppositories it is used to ease pelvic-floor muscle spasm that can cause painful sex. Applying it locally aims to relax those muscles while limiting whole-body side effects like drowsiness. Evidence for this specific use is limited and it is typically an add-on to pelvic-floor physical therapy.

The science

Baclofen is a GABA-B receptor agonist that reduces excitatory neurotransmission and skeletal-muscle spasticity; the rationale for vaginal suppositories in high-tone pelvic-floor dysfunction/dyspareunia is local relaxation of hypertonic pelvic-floor musculature with reduced systemic sedation. Direct evidence for vaginal baclofen is limited and largely extrapolated from small combination series (baclofen with diazepam) and from the broader—and mostly disappointing—randomized data on intravaginal muscle relaxants; well-powered controlled trials are lacking. Systemic baclofen is FDA-approved (oral and intrathecal) for spasticity, and abrupt withdrawal of systemic baclofen can be dangerous, though systemic exposure from low-dose vaginal suppositories is expected to be low. Compounded vaginal baclofen (often with diazepam) is off-label, not an FDA-approved formulation, and best used adjunctively with pelvic-floor physical therapy.

References

• Crisp et al., Int Urogynecol J 2013 (intravaginal muscle-relaxant RCT context)
• Rogalski et al., Int Urogynecol J 2010 (vaginal diazepam/adjunct chart review)