Botulinum toxin for treatment of urinary incontinence due to detrusor overactivity: a systematic review of effectiveness and adverse effects.

STUDY DESIGN

Systematic review.

OBJECTIVE

To evaluate effectiveness and adverse effects of botulinum toxin (BTX) for treatment of urinary incontinence (UI) due to detrusor overactivity (DO).

METHODS

Randomized controlled trials published in English before November 2006 were included if they enrolled subjects with UI caused by DO and reported incontinence outcomes.

RESULTS

Three trials totaling 104 subjects with DO refractory to antimuscarinic treatment were included. Two BTX-A trials enrolled primarily patients with NDO secondary to spinal cord injury (SCI) (93%). BTX-A decreased daily UI episodes compared to placebo but the reductions were only significantly different at a few of the time intervals during 24 weeks of follow-up. BTX-A was superior in reducing daily UI episodes in SCI subjects compared to intravesical resiniferatoxin at 12 and 18 months after injections. A small crossover study found BTX-B significantly more effective than placebo in reducing weekly UI episodes in subjects with predominately idiopathic DO. Adverse events (AEs) in BTX-A-treated subjects included urinary tract infection, pain at the injection site, hematuria and autonomic dysreflexia. Four subjects treated with BTX-B reported autonomic AEs.

CONCLUSIONS

BTX may improve UI for subjects with refractory DO. The preferred dose and type of BTX is not known. Long-term efficacy and safety remain unclear and require conduct of larger RCT using standardized and validated clinical outcomes measures.