About oxybutyninantimuscarinic agent, urinary antispasmodic agent.mechanism of action of oxybutyninthis drug decreases muscle spasms of the bladder by competitively antagonizes the m1, m2, and m3 subtypes of the muscarinic acetylcholine receptor. it also has direct spasmolytic effects on bladder smooth muscle as a calcium antagonist and local anesthetic action at high concentrations.indications for oxybutynin1. urinary incontinence 2. urgency and frequency in the unstable bladder 3. nocturnal enuresis