Persistent Therapeutic Effect of Repeated Injections of Onabotulinum Toxin A in Refractory Bladder Pain Syndrome/Interstitial Cystitis

Abstract

We evaluate the efficacy and safety of repeated intratrigonal injections of onabotulinum toxin A in patients with bladder pain syndrome/interstitial cystitis. This is a single center, long-term, prospective study in which 16 women with bladder pain syndrome/interstitial cystitis refractory to standard treatment received 4 consecutive intratrigonal injections of onabotulinum toxin A. Onabotulinum toxin A (100 U) was injected under cystoscopic control in 10 trigonal sites, each receiving 10 U in 1 ml saline. General anesthesia was used in all treatments. Re-treatment was allowed 3 months after injection. Outcome measures included pain visual analog scale (0-10), O'Leary-Sant score, a 3-day voiding chart and a quality of life questionnaire at the first month and every 3 months after each injection. Voiding dysfunction and urinary tract infections were assessed at 2 weeks and every 3 months afterward. Treatment duration was determined when patients requested another injection. Mean ± SD patient age was 41.8 ± 12.5 years. At baseline pain score was 5.9 ± 1.8, O'Leary-Sant score 28.8 ± 6.3, urinary frequency 16.4 ± 5.3, mean voided volume 112 ± 42 ml and quality of life 5 ± 0.9. Mean decrease in pain score, O'Leary-Sant score, urinary frequency and mean increase in voided volume and quality of life were similar after each treatment. Individual symptom relief lasted 6 to 12 months with an average duration of 9.9 ± 2.4 months. There were no cases of voiding dysfunction. Five patients had noncomplicated urinary tract infections. Symptomatic improvement of bladder pain syndrome/interstitial cystitis persists in a repeated intratrigonal injection program of 100 U onabotulinum toxin A. Time to request re-treatment remained stable. Adverse events were mild, without voiding dysfunction requiring intermittent catheterization.