Purpose: We evaluated the 1-year efficacy and tolerability of botulinum A toxin intravesically injected in patients with painful bladder symptoms associated with increased urinary frequency, refractory to conventional treatments.
Materials and methods: Three men and 12 women were prospectively included in the study. Under short general anesthesia the patients were given injections of 200 U commercially available botulinum A toxin diluted in 20 ml 0.9% NaCl. Injections were performed submucosally in the bladder trigone and lateral walls under cystoscopic guidance. A voiding chart and the visual analog scale for pain were used, and urodynamics were performed before treatment, and 1, 3, 5 and 12 months later.
Results: Overall 13 patients (86.6%) reported subjective improvement at the 1 and 3-month followups. The mean visual analog scale score, and daytime and nighttime urinary frequency were significantly decreased (p <0.05, <0.01 and <0.05, respectively). At the 5-month followup the beneficial effects persisted in 26.6% of cases but increased daytime and nighttime urinary frequency, and an increased visual analog scale score were observed compared to baseline. At 12 months after treatment pain recurred in all patients. Nine patients complained of dysuria 1 month after treatment. Dysuria persisted in 4 cases at the 3-month followup and in 2 at the 5-month followup.
Conclusions: Intravesically injected botulinum toxin A is effective for short-term management of refractory painful bladder syndrome. The beneficial effects decreased progressively within a few months after treatment. Thus, repeat injections of the neurotoxin are required for efficacious treatment in patients with the disease.