Oxybutynin ER
DITROPAN XL
Pronunciation: ox-i-BYOO-ti-nin
“Ox’s booty in a (ditro)pan”
“Mad as a hatter” → BBB-crossing anticholinergic
What it isOxybutynin extended-release (DITROPAN XL, 1998) antagonizes muscarinic and H1 receptors; overactive bladder.
Why this oneIts apparent half-life ~13 h (vs ~2 h IR) smooths exposure and reduces dry mouth versus immediate release.
What limits itDry mouth, constipation, urinary retention, and cognitive impairment give it the heaviest anticholinergic burden among bladder drugs.
Oxybutynin ER prescription history
Animated chart of estimated U.S. prescriptions per year, Overactive bladder meds (1970–2026). Oxybutynin ER enters in 1975 (estimated).
FDA-approved for
- overactive bladder (1998)
Principal riskAnticholinergic burden, worst of the bladder agents
Classes and tags
Clinical profile
Legacy pregnancy categoryC
Defining liabilityGenerally tolerated at therapeutic doses; clinically important risks are agent-specific and increase with interactions or organ impairment.
FDA label
Read the full label on DailyMed ↗
NO BOXED WARNINGS
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Overactive bladder (urge urinary incontinence, urgency, frequency) | Adults | 5 or 10 mg PO once daily | 30 mg/day | |
| Detrusor overactivity associated with a neurological condition (e.g., spina bifida) | Peds ≥6 yr | 5 mg PO once daily | 20 mg/day |
Titration Adjust in 5 mg increments, generally at ~weekly intervals
Renal Undefined
Hepatic Undefined
Instructions
- Swallow whole with liquid; do not chew, divide, or crush
- May be taken with or without food
- Not recommended in children who cannot swallow the tablet whole or under age 6
Available strengths
- ER tab 5, 10, 15 mg
Contraindications
- Urinary retention
- Gastric retention and other severe decreased gastrointestinal motility conditions
- Uncontrolled narrow-angle glaucoma
Cautions
- Angioedema (may occur after the first dose)
- Anticholinergic CNS effects (hallucinations, agitation, confusion, somnolence)
- Aggravation of symptoms in dementia on cholinesterase inhibitors, Parkinson's disease, myasthenia gravis
- Decreased GI motility in autonomic neuropathy
- Urinary retention with bladder outflow obstruction
- GI obstructive disorders / GERD
Adverse reactions
- Dry mouth
- Constipation
- Diarrhea
- Headache
- Somnolence
- Dizziness
- Blurred vision
Pregnancy No adequate data on use in pregnant women
Lactation No data on presence in human milk or effects on the breastfed infant
Cost
| Strength | #/mo | generic $/mo | CostPlus | |
|---|---|---|---|---|
| 5 mg | ER tab | 30 qd | $2.52 | offered |
| 10 mg | ER tab | 30 qd | $2.99 | offered |
| 15 mg | ER tab | 30 qd | $3.75 | offered |
Other forms: Oxybutynin (DITROPAN)
Open Oxybutynin ER in the interactive console ↗
Memory aids: interaction avatars
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Self-check
- Oxybutynin ER: What is its apparent half-life versus IR?
About 13 h versus about 2 h. - Oxybutynin ER: Which adverse effect is reduced versus immediate release?
Dry mouth.