Antimuscarinic
Pregnancy: B
Oxybutynin XL
Brand names: Lyrinel XL, Kentera patch
Adult dose
Dose: 5 mg once daily (XL), titrate to 10–20 mg; patch 3.9 mg/24h twice weekly
Route: oral (XL) or transdermal (patch)
Frequency: once daily (oral) or twice weekly (patch)
Max: 20 mg/day (oral); 3.9 mg/24h (patch)
XL formulation has lower peak levels and fewer CNS/anticholinergic effects than IR; patch bypasses first-pass metabolism
Paediatric dose
Dose: 0.2 mg/kg
Route: oral
Frequency: twice to three times daily
Max: 5 mg three times daily
Concentration: 2.5 mg/5 ml syrup mg/ml
Age ≥5 years: 2.5–5 mg 2–3 times daily for neurogenic bladder; titrate to response and tolerability
Dose adjustments
Renal
No dose adjustment required
Hepatic
Use with caution
Paediatric weight-based calculator
Age ≥5 years: 2.5–5 mg 2–3 times daily for neurogenic bladder; titrate to response and tolerability
Clinical pearls
- XL formulation: lower Cmax reduces dry mouth and CNS effects versus IR
- Transdermal patch: site rotation mandatory; local skin reactions common
- BEERS criteria: strongly avoid in older adults — confusion, delirium, urinary retention, falls
Contraindications
- Urinary retention
- Narrow-angle glaucoma
- Myasthenia gravis
- Severe ulcerative colitis
- Toxic megacolon
Side effects
- Dry mouth
- Constipation
- Blurred vision
- Drowsiness
- Cognitive impairment (particularly IR — BBB penetration)
- Urinary retention
Interactions
- Other antimuscarinics (additive effects)
- Drugs causing QT prolongation
- Amantadine (increased anticholinergic effects)
Monitoring
- Urinary symptoms
- Residual urine volume
- Cognitive function (elderly)
Reference: BNFc; BNF 86; NICE NG123. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.
Drugs