The use of botulinum toxin for the treatment of urologic pain

Purpose of review: Botulinum toxin injections into the bladder have become established in the management of refractory detrusor overactivity and overactive bladder. Mechanism of action of the toxin appears to involve both efferent and afferent nerve pathways, as well as having an antinociceptive effect. Over the years, several reports of its use in refractory bladder pain syndrome and interstitial cystitis have emerged. We review the literature with a view to assessing efficacy and adverse events in this setting.

Recent findings: Small open-labelled studies have suggested botulinum neurotoxin serotype A (BoNT-A) to be an effective treatment for the majority of patients with refractory bladder pain syndrome/interstitial cystitis. A single set of injections result in demonstrable improvements in symptom scores and bladder pain, although some studies suggest repeated injections may be better. BoNT-A is more effective in nonulcer-type patients. In chronic pelvic pain syndrome, a recent placebo-controlled trial showed only a modest benefit for BoNT-A over placebo with a response rate of 30%.

Summary: Although botulinum neurotoxin for refractory bladder pain syndrome/interstitial cystitis appears promising, larger-scale studies with adequate follow-up and in particular randomized placebo-controlled studies are required to confirm these findings.