Oxybutynin
| Evidence Level: L5 | Predicted Indications: 3 |
Table of Contents
Oxybutynin: Restless legs syndrome
One-Sentence Summary
Oxybutynin is an antimuscarinic medicine originally used for overactive bladder, neurogenic bladder and cauda equina syndrome. The TxGNN model predicts it may be effective for restless legs syndrome, but no clinical trials and no publications currently support this top-ranked prediction.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Not recorded in the local data |
| Predicted New Indication | Restless legs syndrome |
| TxGNN Prediction Score | 0.9974 |
| Evidence Level | L5 (model prediction only) |
| Australia Market Status | Listed on the PBS Schedule (1 of 1 items) – TGA (ARTG) registration status is not included in this data |
| Number of PBS Items | 1 (valid: 1) |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Detailed mechanism of action data is not available for this report. Oxybutynin is known to be an antimuscarinic agent with a direct musculotropic antispasmodic action. It blocks muscarinic receptors (mainly M3) on bladder smooth muscle, reducing involuntary contractions.
Restless legs syndrome (rank 1): The only suggested link is a speculative anticholinergic influence on the balance between dopamine and acetylcholine in the brain. Anticholinergics are also reported to worsen restless legs symptoms in some people, so even the direction of effect is uncertain. The high score comes from the TxGNN model (deep learning) and may reflect similarities the model learned between related diseases, not biological evidence.
Other predictions:
- Gastroduodenitis and peptic ulcer disease: Reduced gastric secretion and motility is a theoretical rationale only. The sole literature is historical (1964–1965) plus a 1990 case report of oxybutynin-induced reflux oesophagitis, which points to a possible harm.
- Insomnia: There is no supported therapeutic rationale. Central anticholinergic effects can disturb cognition and sleep.
Clinical Trial Evidence
Currently no related clinical trials are registered for any of the ten predicted indications in the data compiled for this report.
Literature Evidence
Restless legs syndrome (top prediction): Currently no related literature available.
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 18639290 | 2008 | Systematic review | J Urol | Effectiveness and tolerability of intravesical oxybutynin in children with poorly compliant neurogenic bladder |
| 24140548 | 2014 | Systematic review | J Urol | Long-term adherence to antimuscarinic therapy in everyday practice; side effects contribute to poor adherence |
| 40690105 | 2026 | Systematic review and meta-analysis | Int Urol Nephrol | Transcutaneous electrical nerve stimulation versus oxybutynin for overactive bladder in children |
| 22910256 | 2012 | Cohort/pilot study | J Urol | Early oxybutynin in newborns with posterior urethral valves to improve bladder function |
| 30937115 | 2019 | Cohort (long-term) | J Clin Med Res | Long-term efficacy, safety and tolerability of modified intravesical oxybutynin in children with neurogenic bladder |
| 18947791 | 2007 | Clinical study | J Pediatr Urol | Modified intravesical oxybutynin in children with neurogenic bladder |
| 8015832 | 1994 | Clinical study | Paraplegia | Intravesical oxybutynin in 17 patients with neuropathic bladder refractory to intermittent catheterisation |
| 11350411 | 2001 | Clinical study | BJU Int | Side effects of oral versus intravesical oxybutynin in children with spina bifida |
| 16465186 | 2006 | Review | Br J Pharmacol | Muscarinic receptors in the bladder; antimuscarinics are the cornerstone of overactive bladder management |
| 12483499 | 2002 | Clinical study | Spinal Cord | Significance of low compliance bladder in cauda equina injury |
Other predictions (limited, indirect evidence):
| Indication | PMID | Year | Type | Key Findings |
|---|---|---|---|---|
| Peptic ulcer disease | 2360335 | 1990 | Case report | Oxybutynin-induced reflux oesophagitis (an adverse effect) |
| Peptic ulcer disease | 14173506 | 1964 | Early clinical evaluation | Uncontrolled evaluation in gastrointestinal disease |
| ADHD | 17707010 | 2007 | Clinical study | Desmopressin plus oxybutynin versus imipramine for enuresis in children with ADHD (comorbid symptom, not ADHD itself) |
| Insomnia | 33890538 | 2021 | Observational cohort | Antimuscarinic use in older adults with dementia and overactive bladder; not evidence of benefit for insomnia |
Australia Market Information
| ARTG Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| ARTG 13957N | Ditropan | Oral tablet containing oxybutynin hydrochloride 5 mg | Not recorded in the data compiled for this report |
Safety Considerations
Contraindications (from drug-disease associations in the knowledge graph, not product label text):
- Gastrointestinal: paralytic ileus, intestinal obstruction, toxic megacolon, ulcerative colitis and inflammatory bowel disease, gastro-oesophageal reflux disease, oesophagitis, hiatus hernia
- Eye: angle-closure glaucoma
- Neuromuscular: myasthenia gravis
- Urinary: bladder neck obstruction, benign prostatic hyperplasia, pyoureter
- Cardiovascular: hypertension, coronary artery disease, sudden cardiac arrest, heart conduction disease
- Other: kidney disease, liver disease, gallbladder disease, hyperthyroidism (including Graves disease)
Drug Interactions (100 interactions were identified; the 20 listed in the data compiled for this report include):
- Major: potassium citrate and potassium chloride
- Moderate: other anticholinergic or antimuscarinic agents (hyoscyamine, atropine, glycopyrronium, dicyclomine, trospium, propantheline, clidinium, mepenzolate, methscopolamine), opioids (morphine, opium), and loperamide, eluxadoline, metoclopramide, aprepitant and pramlintide
Class-related considerations from the literature: anticholinergic burden, central nervous system effects (cognition, sleep), dry mouth, constipation, and a reported case of reflux oesophagitis.
For label warnings and contraindications, please refer to the TGA-approved Product Information (PI).
Conclusion and Next Steps
Decision: Hold (for restless legs syndrome, the top-ranked prediction)
Rationale:
- The top prediction rests on a model score alone, with no trials or publications. The suggested mechanism is speculative, and anticholinergics may worsen restless legs symptoms.
- Eight of the ten predictions are rated Evidence Level L4–L5 and Hold. Several have a plausible risk of harm rather than benefit (insomnia, peptic ulcer disease and reflux).
- It has a coherent mechanism and supportive systematic reviews, cohort studies and small clinical studies. However, it is close to oxybutynin’s existing indications, and there are no Phase 3 RCTs specific to this indication.
To proceed, the following is needed:
- Detailed mechanism of action data (MOA)
- TGA Product Information with warnings and contraindications, and the approved indication text for ARTG 13957N
- For restless legs syndrome: a systematic literature review, including the direction of effect of anticholinergics, before any further consideration
- Confirmation of route and formulation compatibility.
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.