Oxybutynin hydrochloride
Brand names: Ditropan, Cystrin, Lyrinel XL
Oxybutynin hydrochloride is the oral salt of the antimuscarinic oxybutynin, used for overactive bladder and urgency incontinence, and also for neurogenic bladder instability; immediate- and modified-release tablets are available.
ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.
Clinical monograph
How it works
It blocks muscarinic M3 receptors on the detrusor and exerts a direct smooth-muscle relaxant effect, suppressing unstable detrusor contractions and raising functional bladder capacity.
Prescribing in practice
- In elderly and cognitively vulnerable patients immediate-release oxybutynin can cause confusion and worsen cognition, so it is best avoided or replaced with a better-tolerated alternative in this group.
- Contraindicated in untreated angle-closure glaucoma, urinary retention, bladder outflow obstruction and gastrointestinal obstruction or atony.
- Expect anticholinergic effects such as dry mouth and constipation; modified-release formulation can reduce peak-related side effects.
Monitoring
Assess symptom control and tolerability after a treatment trial, monitoring cognition in the elderly and bowel function.
Counselling the patient
- Swallow modified-release tablets whole without crushing.
- Expect dry mouth; report blurred vision, eye pain or inability to pass urine.
Evidence & guidelines
Oxybutynin is well established for overactive and neurogenic bladder, with NICE cautioning against immediate-release oxybutynin as first-line in frail older women.
Reference: NICE NG123; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).
Related
Curated clinical cross-links plus same-class fallbacks.