Oxybutynin

Oxybutynin

Clinical data
Trade names	Ditropan
AHFS/Drugs.com	Monograph
MedlinePlus	a682141
Pregnancy category	AU: B1 US: B (No risk in non-human studies)
Routes of administration	By mouth, transdermal gel, transdermal patch
ATC code	G04BD04 (WHO)
Legal status
Legal status	AU: S4 (Prescription only) CA: ℞-only UK: POM (Prescription only) US: ℞-only and OTC
Pharmacokinetic data
Protein binding	91–93%
Biological half-life	12.4–13.2 hours
Identifiers
IUPAC name 4-Diethylaminobut-2-ynyl 2-cyclohexyl-2-hydroxy-2-phenylethanoate
CAS Number	5633-20-5 Y
PubChem CID	4634
IUPHAR/BPS	359
DrugBank	DB01062 Y
ChemSpider	4473 Y
UNII	K9P6MC7092
KEGG	D00465 Y
ChEBI	CHEBI:7856 Y
ChEMBL	CHEMBL1231 Y
ECHA InfoCard	100.158.590
Chemical and physical data
Formula	C22H31NO3
Molar mass	357.486 g/mol
3D model (Jmol)	Interactive image
SMILES O=C(OCC#CCN(CC)CC)C(O)(c1ccccc1)C2CCCCC2
InChI InChI=1S/C22H31NO3/c1-3-23(4-2)17-11-12-18-26-21(24)22(25,19-13-7-5-8-14-19)20-15-9-6-10-16-20/h5,7-8,13-14,20,25H,3-4,6,9-10,15-18H2,1-2H3 Y Key:XIQVNETUBQGFHX-UHFFFAOYSA-N Y

Oxybutynin (brand names Ditropan, Lyrinel XL, Lenditro (ZA), Driptane (RU), Uripan (Middle East)) is an anticholinergic medication used to relieve urinary and bladder difficulties, including frequent urination and inability to control urination (urge incontinence), by decreasing muscle spasms of the bladder. Also given to help with symptoms associated with kidney stones.

It 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, but at concentrations far above those used clinically.

Oxybutynin is also a possible treatment of hyperhidrosis (hyperactive sweating).

Oxybutynin contains one stereocenter. Commercial formulations are sold as the racemate. The (R)-enantiomer is a more potent anticholinergic than either the racemate or the (S)-enantiomer, which is essentially without anticholinergic activity at doses used in clinical practice. However, (R)-oxybutynin administered alone offers little or no clinical benefit above and beyond the racemic mixture. The other actions (calcium antagonism, local anesthesia) of oxybutynin are not stereospecific. (S)-Oxybutynin has not been clinically tested for its spasmolytic effects, but may be clinically useful for the same indications as the racemate, without the unpleasant anticholinergic side effects.