Muscarinic receptor antagonists for overactive bladder.

Area of Science:

• Urology
• Pharmacology
• Gerontology

Background:

• Overactive bladder (OAB) is a syndrome of urinary urgency, often with frequency and nocturia, frequently associated with detrusor overactivity (DO).
• The prevalence of OAB and DO increases with age and can stem from neurogenic or myogenic causes, with bladder outlet obstruction as a potential contributing factor.
• Acetylcholine binding to muscarinic receptors M(2) and M(3) in the detrusor smooth muscle mediates bladder contraction.

Purpose of the Study:

• To review the current landscape of antimuscarinic drug treatments for overactive bladder (OAB).
• To discuss the efficacy, pharmacokinetic profiles, and adverse events of marketed antimuscarinic agents.
• To explore potential future therapeutic avenues for OAB management.

Main Methods:

• Review of existing literature on antimuscarinic drugs for OAB treatment.
• Analysis of drug properties including receptor selectivity and organ selectivity.
• Examination of adverse event profiles and tolerability in various patient populations.

Main Results:

• Six antimuscarinic drugs (oxybutynin, tolterodine, propiverine, trospium, darifenacin, solifenacin) are available for OAB treatment, each with demonstrated efficacy.
• These drugs differ in pharmacokinetics and side effect profiles due to structural variations and receptor selectivities.
• Common adverse events include dry mouth and constipation, though overall tolerability is generally good, even in special populations.

Conclusions:

• Antimuscarinic agents are effective for OAB/DO, but their non-selective action can lead to bothersome side effects.
• Development of bladder-selective antimuscarinics could improve treatment outcomes by reducing systemic adverse events.
• Investigational therapies targeting other pathways show promise for future OAB management.