Section 17 · Monograph
Oxybutynin
Reviewed Nov 2026FDA label
Ditropan XLAntimuscarinic
- Forms
- Tab: 5mg (IR) | ER tab: 5, 10, 15mg | Patch: 3.9mg/day
- Dose
- IR 5mg BID-TID (max 5mg QID) | ER 5-30mg once daily
- MOA
- Muscarinic (M3) blockade, relaxes detrusor
Indications
- Overactive bladder with symptoms of urge incontinence, urgency and frequencyFDA-labeled
- Detrusor overactivity associated with neurologic conditions (e.g., spina bifida) in pediatric patients 6 years and older (extended-release)FDA-labeled
Mechanism of Action
- Antimuscarinic with direct antispasmodic effect that relaxes detrusor smooth muscle
Full Dosing
Adult / usual
- Immediate-release: 5mg two to three times daily (maximum 5mg four times daily)
- Extended-release (Ditropan XL): start 5-10mg once daily; titrate by 5mg weekly to a maximum of 30mg/day
- Transdermal patch 3.9mg/day applied twice weekly
Contraindications
- Urinary retention
- Gastric retention or severe decreased GI motility
- Uncontrolled narrow-angle glaucoma
- Known hypersensitivity
Drug Interactions
- Other anticholinergics: additive effects
- Cholinesterase inhibitors (donepezil, pyridostigmine) are antagonized
- CYP3A4 inhibitors raise levels
Adverse Effects
- Dry mouth, constipation, blurred vision
- Cognitive impairment and confusion, especially in older adults (Beers criteria: avoid in dementia)
- Urinary retention
- Heat prostration (decreased sweating)
Monitoring Parameters
- Post-void residual in neurogenic bladder
- Cognition in older adults
- Anticholinergic burden
Pregnancy & Lactation
- Limited data; use only if benefit justifies risk
- Excreted in milk in small amounts