Oxybutynin
DITROPAN
What it isMuscarinic antagonist; overactive bladder.
Why this oneCheap, long-established, and available as a patch that avoids first-pass metabolism.
What limits itThe most anticholinergic of the bladder agents — confusion, dry mouth and constipation — and it crosses the blood-brain barrier, so avoid in dementia.
FDA-approved for
- overactive bladder (~1975)
Off-label
- hyperhidrosis
- hot flashes
FDA label
Read the full label on DailyMed ↗
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Overactive bladder / detrusor overactivity | Adults | 5 mg BID-TID | 5 mg BID-TID | 5 mg QID |
| Overactive bladder / detrusor overactivity | Frail elderly | 2.5 mg BID-TID | ||
| Overactive bladder / detrusor overactivity | Peds >5 yr | 5 mg BID | 5 mg BID | 5 mg TID |
Renal Undefined
Hepatic Undefined
Contraindications
- Urinary retention
- Gastric retention or other severe decreased GI motility conditions
- Uncontrolled narrow-angle glaucoma (or at risk)
Cautions
- Anticholinergic effects (dry mouth, constipation)
- May aggravate urinary/gastric retention and narrow-angle glaucoma
- CNS effects (somnolence, dizziness, blurred vision)
- Heat prostration in hot environments
Adverse reactions
- Dry mouth (dose-related)
- Constipation
- Somnolence
- Dizziness
- Blurred vision
- Nausea
- Dyspepsia
Pregnancy Animal studies show no impaired fertility or fetal harm; safety in pregnant women not established
Lactation Undefined
NO BOXED WARNINGS
Principal riskAnticholinergic burden, worst of the bladder agents
Cost, est. cash$300–$2,500/month
Generic entry2014
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.
Mechanism of action: Oxybutynin ballicule
Open Oxybutynin in the interactive console ↗
Memory aids: mascots and interaction avatars
“Mad as a hatter” → BBB-crossing anticholinergic
