Intravesical injection of botulinum toxin for the treatment of overactive bladder

Purpose of review In recent years, botulinum toxin has been investigated for the treatment of various types of lower urinary tract dysfunctions. This review discusses recently published data related to the therapeutic applications of botulinum toxin in overactive bladder as well as the effects of repeated doses, cross-reactivity between different serotypes, and side effects of the toxin injection into the detrusor muscle. Recent findings Botulinum toxin A has been employed initially in the treatment of neurogenic detrusor overactivity in spinal cord injured patients. Since then, several reports, including a large multicenter study, have confirmed the therapeutic effects of this neurotoxin. The application of botulinum toxin A was extended to the treatment of idiopathic detrusor overactivity and similar results were obtained. Repeated injections of botulinum toxin A had the same sustained benefit. Recently, botulinum toxin B was investigated for the treatments of both neurogenic and idiopathic detrusor overactivity as well as for the management of botulinum toxin A resistant cases. Summary Although intradetrusal injection of botulinum toxin is not yet an approved treatment for overactive bladder, available data suggest that botulinum toxin can be a therapeutic option in patients with neurogenic and nonneurogenic detrusor overactivity who are refractory to anticholinergic medications. There is a need, however, for further investigation to determine the optimal conditions for these applications. A randomized, double-blinded, placebo-controlled trial to evaluate the therapeutic effects of botulinum toxin is under way.