Efficacy of botulinum toxin a intradetrusor injections for non-neurogenic urinary urge incontinence: a randomized double-blind controlled trial.

Objective: To determine the efficacy of intradetrusor injections of botulinum toxin A for non-neurogenic urinary urge incontinence.

Methods: We conducted a six-month, randomized, double-blind controlled trial involving women with urinary urge incontinence. Participants received intradetrusor injections of either botulinum toxin (100U in 10 mL) via cystoscopy or a placebo control (saline injection). The primary outcome was maximum bladder capacity at cystoscopy. Secondary outcomes included quality-of-life measures, 24-hour leakage rate, patients' subjective assessment, and safety data.

Results: There were 21 participants: 11 in the botulinum toxin (treated) group and 10 in the placebo (control) group. There were no significant differences between the groups at baseline. After six months the mean maximum bladder capacity at cystoscopy was 161.6 mL greater in the treated group than in the control group (P = 0.018). There were no differences in diary data or quality-of-life measures. The 24-hour pad test (a measure of leakage) after three months showed significant improvement in the treated group (difference 272.12g, P = 0.016); treated subjects also showed subjective benefit at three months (difference 1.29, P = 0.007) and at six months (difference 1.16, P = 0.01). There was no significant difference in rates of urinary tract infection between groups. There was one serious adverse event (a perioperative cardiac event) in the botulinum toxin group.

Conclusion: Botulinum toxin increased bladder capacity at cystoscopy and reduced urinary incontinence on 24-hour pad testing in adult females with urinary urge incontinence. There was one adverse event in the group treated with botulinum toxin.