Oxybutynin

4.3

4.68

Breast Feeding; Lactation; Muscarinic Antagonists; Parasympatholytics

FDA approved drugs -> Active ingredient

EMA approved medicines: Human medicine

FDA approved drugs -> Active ingredient

122-124

CRYSTALS; MP: 129-130 °C /CHLORIDE/

129 - 130 °C

Warning

H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]

P261, P264, P264+P265, P270, P271, P273, P280, P301+P317, P302+P352, P304+P340, P305+P351+P338, P317, P319, P321, P330, P332+P317, P337+P317, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 2 reports by companies from 2 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

In multiple, large clinical trials of oxybutynin therapy for overactive bladder syndrome, serum enzyme elevations were rare and no more frequent than with placebo, and there were no episodes of clinically apparent liver injury. Since its approval and widespread use for more than four decades, there has been only a single published case of suspected liver injury attributed to oxybutynin – a report of transient serum enzyme elevations without jaundice or apparent symptoms in a patient with a severe ischemic stroke arising within weeks of starting oxybutynin. Thus, clinically apparent liver injury from oxybutynin is very rare if it occurs at all.

The immediate-release form of oxybutynin can cause various adverse effects in patients, including dry mouth (71.4%), dizziness (16.6%), constipation (15.1%), somnolence (14.0%), and nausea (11.6%). Some of the less common adverse effects of immediate-release oxybutynin include blurred vision (9.6%), urinary hesitation (8.5%), urinary retention (6.0%), and dyspepsia (6.0%). Notably, a dry mouth is considered a dose-related adverse effect of oxybutynin. Oxybutynin hydrochloride has a more favorable profile than other antimuscarinic drugs regarding adverse effects on heart rate increase.

G04BD04

G - Genito urinary system and sex hormones

QG - Genito urinary system and sex hormones

Oxybutynin exerts antispasmodic actions on the bladder, relieving the uncomfortable symptoms of overactive bladder, including urinary urgency and frequency. These actions occur through the inhibition of muscarinic receptors. **A note on angioedema and anticholinergic effects** Symptoms of angioedema may occur with oxybutynin therapy. If angioedema is suspected, discontinue oxybutynin immediately and provide appropriate medical treatment. In addition, anticholinergic effects may occur with the administration of this drug. Some symptoms may include hallucinations, confusion, agitation, and drowsiness. It is advisable to avoid operating heavy machinery before the response to oxybutynin has been monitored. Dose adjustments may be required.

Oxybutynin acts to relax the bladder by inhibiting the muscarinic action of acetylcholine on smooth muscle, and not skeletal muscle. The active of oxybutynin is metabolite is N-desethyloxybutynin. It competitively inhibits the postganglionic type 1, 2 and 3 muscarinic receptors. The above actions lead to increased urine capacity in the bladder, decreasing urinary urgency and frequency. In addition, oxybutynin delays the initial desire to void.

RESULTS OF CYSTOMETRIC STUDIES SHOWED THAT THE DRUG INCR BLADDER CAPACITY @ ONSET OF FIRST CONTRACTION & FIRST DESIRE TO VOID, AS WELL AS @ END OF CYSTOMETRY. /CHLORIDE/

Oxybutynin is heavily metabolized by the CYP3A4 enzyme system in both the liver and the wall of the intestine. It undergoes first-pass metabolism, and its resulting primary active metabolite, N-desethyloxybutynin circulates. It is active at the muscarinic receptors in both the bladder and the salivary gland. Hepatic biotransformation also produces its major inactive metabolite, phenylcyclohexylglycolic acid.