Objectives: To present clinical evidence with botulinum toxin A (BTX-A) suggesting an antinociceptive role in patients with interstitial cystitis (IC). Intriguing evidence in a somatic pain model has suggested that BTX-A injection may have an antinociceptive effect on both acute and chronic (inflammatory) pain.
Methods: Thirteen female patients (6 in the United States and 7 in Poland) with IC according to the criteria of the National Institute of Diabetes, Digestive and Kidney Disease were included. Under short general anesthesia or sedation, 100 to 200 U of Dysport (Polish patients) or Botox (U.S. patients) was injected through a cystoscope into 20 to 30 sites submucosally in the trigone and floor of the bladder. Patients were evaluated with the O'Leary-Sant validated IC questionnaire or with voiding charts and a visual analog pain scale 1 month postoperatively and at subsequent 3-month intervals. The Polish patients also underwent pretreatment and post-treatment urodynamic evaluations.
Results: Overall, 9 (69%) of 13 patients noted subjective improvement after BTX-A treatment. The Interstitial Cystitis Symptom Index and Interstitial Cystitis Problem Index mean scores improved by 71% and 69%, respectively (P <0.05). Daytime frequency, nocturia, and pain by visual analog scale decreased by 44%, 45%, and 79%, respectively (P <0.01). The first desire to void and maximal cystometric capacity increased by 58% and 57%, respectively (P <0.01).
Conclusions: Our results suggest that BTX-A has an antinociceptive effect on bladder afferent pathways in patients with IC, producing both symptomatic and functional (ie, urodynamic) improvements.