New pharmacologic targets for the treatment of the overactive bladder: an update.

Although currently available antimuscarinic agents are the standard of care for overactive bladder (OAB), they are limited by certain side effects, particularly dry mouth and constipation. Research aimed at discovering new therapies for OAB has resulted in the identification of some promising drugs. Investigations of pharmacologic targets in the central nervous system (CNS) have yielded encouraging results with several agents, including tramadol and gabapentin. Further investigation may show that drugs acting at serotonergic and noradrenergic CNS sites are clinically useful as therapies for OAB. Some peripherally acting drugs, such as resiniferatoxin and botulinum toxin, have already been proved to be of clinical value. However, development of other agents that block afferent or efferent nerve impulses in the bladder through activity at vanilloid, purinergic, or opioid-like receptor sites may result in clinically useful drugs.