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.