Pharmacotherapy for overactive bladder: minimally invasive treatment -- botulinum toxins

Considered by many a 'revolution' in the treatment of intractable overactive bladder (OAB) and with an increasing number of centers including it in their practice worldwide, botulinum neurotoxin A (BoNT/A) injected into the bladder wall is a treatment of significant potential. In anticipation of the results of multicenter, placebo-controlled, dose-ranging studies, this is a critical review of the available literature on the use of botulinum toxins in the treatment of either neurogenic or idiopathic OAB.

The review is based on the English-language literature published by Medline on the use of botulinum toxins in neurogenic or idiopathic detrusor overactivity/OAB since the seminal publication in 2000. The reader is exposed to the cumulative data as well as to a more critical insight on the clinical efficacy of single and repeat injections of the most widely used formulations, the injection techniques, including different doses, dilutions and injection sites, the mechanism of action, the side effects and the cost-effectiveness of the treatment.

Despite the markedly heterogeneous methodologies, published studies suggest that BoNT/A is effective when a number of outcomes are considered, and is considered safe. As results of large registration studies are awaited, additional research on the optimization of clinical practice parameters such as benefit-risk ratio, injection technique, predictors of response and long-term safety, as well as on the mechanism of action and the cost-effectiveness of the treatment, would be welcome.