Oxybutynin chloride (Oxybutynin HCl) is an anticholinergic medication used to relieve urinary and bladder difficulties. It competitively antagonizes the M1, M2, and M3 subtypes of the muscarinic acetylcholine receptor.

Oxybutynin relieves urinary and bladder difficulties, including frequent urination and inability to control urination (urge incontinence), by decreasing muscle spasms of the bladder. Oxybutynin competitively antagonizes the M1, M2, and M3 subtypes of the muscarinic acetylcholine receptor. [1] Oxybutynin also has direct spasmolytic effects on bladder smooth muscle as a calcium antagonist and local anesthetic, but at concentrations far above those used clinically. [2]