Intravesical onabotulinumtoxinA injections for refractory painful bladder syndrome.

BACKGROUND Bladder pain associated with interstitial cystitis and painful bladder syndrome (IC/PBS) is frequently excruciating and intractable. The use of onabotulinumtoxinA (BoNT-A) for relief of this type of bladder pain has not been well described. OBJECTIVES To evaluate the efficacy and safety of intravesical BoNT-A injection for treatment of IC/PBS refractory to conventional treatment. STUDY DESIGN Prospective, non-randomized study. SETTING A tertiary medical center in Taiwan. METHODS Sixty-seven patients with characteristic IC/PBS were enrolled. Intravesical injection of 100U of BoNT-A immediately followed by cystoscopic hydrodistention under intravenous general anesthesia. Changes of the urodynamic parameters, O'Leary-Sant Interstitial Cystitis Symptom Index (ICSI) and Interstitial Cystitis Problem Index (ICPI), visual analog score (VAS) for pain, functional bladder capacity, and global response assessment (GRA) were evaluated at baseline and 6 months after BoNT-A injection. Adverse events that occurred after this procedure were also assessed. RESULTS Significant improvement was shown after intravesical injection of 100 U of BoNT-A. Baseline and 6 months after injection scores were: ICSI and ICPI (23.6 ± 5.9 versus 15.2 ± 8.5, P = 0.000), VAS (5.3 ± 2.2 versus 3.3 ± 2.4, P = 0.000), functional bladder capacity (136 ± 77.6 versus 180 ± 78.2, P = 0.000) and GRA (0.3 ± 0.8 versus 1.4 ± 1.0, P = 0.000). LIMITATIONS This study lacks a placebo control group so the placebo effect cannot be eliminated. This study also does not provide information about the efficacy of this treatment after 6 months. CONCLUSION Intravesical onabotulinumtoxinA injection appears to be a safe and effective therapeutic option for analgesia and increased bladder capacity for patients with IC/PBS. INSTITUTIONAL REVIEW: This study was approved by the Institutional Review Board of the Buddhist Tzu-chi General Hospital.