Which pharmacologic agents are used to treat urgency urinary incontinence?

• A. Opioids and NSAIDs.
• B. Alpha blockers and calcium channel blockers.
• C. Antimuscarinic agents (oxybutynin, tolterodine, solifenacin) and beta-3 adrenergic agonists (mirabegron).
• D. Antibiotics and diuretics.

Answer: (C)

Urgency urinary incontinence is driven by detrusor overactivity during filling, so treatments aim to reduce involuntary detrusor contractions or relax the bladder to increase storage capacity. Antimuscarinic drugs such as oxybutynin, tolterodine, and solifenacin work by blocking muscarinic receptors on the detrusor muscle, especially the M3 receptor, which dampens spontaneous contractions and increases bladder capacity. A beta-3 adrenergic agonist like mirabegron provides a complementary approach by stimulating beta-3 receptors in the detrusor to promote relaxation during filling, also increasing capacity. This combination directly targets the mechanism of urgency rather than symptoms alone.

Opioids and NSAIDs don’t address detrusor overactivity and carry unrelated risks. Alpha blockers and calcium channel blockers are not standard treatments for urgency incontinence and can cause hypotension or retention. Antibiotics treat infection, not overactive bladder, and diuretics would worsen symptoms by increasing urine production.