Methadone
| Evidence Level: L4 | Predicted Indications: 7 |
Table of Contents
Methadone: Tourette syndrome
One-Sentence Summary
Methadone is a long-acting opioid that acts as a mu-opioid receptor agonist and NMDA receptor antagonist. The TxGNN model predicts it may be effective for Tourette syndrome, with a score of 0.9976. Support is limited: no registered clinical trials and a single small, dated clinical report (1992), which places the evidence at Level L4.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Not recorded in the local data |
| Predicted New Indication | Tourette syndrome |
| TxGNN Prediction Score | 0.9976 |
| Evidence Level | L4 |
| Canada Market Status | Marketed (marketed DINs: 19 of 19) |
| Number of DINs | 19 (marketed: 19) |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Detailed mechanism-of-action data are not available in the data compiled for this report. Based on the known pharmacology, methadone is a mu-opioid receptor agonist with NMDA receptor antagonist activity. Opioid modulation of dopaminergic and striatal circuits is a plausible route to tic suppression.
A 1992 report (PMID 1728167) describes methadone treatment of Tourette’s disorder. A 2007 preclinical paper (PMID 17102981) links atypical opiates to 5-HT2A/C receptor-mediated behaviours relevant to obsessive-compulsive disorder and Tourette syndrome, and notes that opiate drugs have been reported as effective in treatment-refractory cases.
The evidence is thin: it consists of one small case-level report and one preclinical paper. Dependence and abuse liability are serious barriers in a chronic condition that often starts in childhood.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 1728167 | 1992 | Case series / clinical report | Am J Psychiatry | Report of methadone treatment in Tourette’s disorder; no abstract available |
| 17102981 | 2007 | Preclinical | Psychopharmacology | Atypical opiates and 5-HT2A/C-mediated behaviour relevant to OCD; opiates noted as effective in refractory OCD and Tourette syndrome |
| 15247538 | 2004 | Review | Curr Opin Neurol | Review of non-genetic causes of chorea; only indirectly related |
| 39086469 | 2024 | Review | Palliat Care Soc Pract | Novel analgesic drugs for neuropathic pain in advanced cancer; only indirectly related |
Canada Market Information
| DIN | Product Name |
|---|---|
| 02552736 | PMS-METHADONE HYDROCHLORIDE ORAL CONCENTRATE |
| 02495872 | ODAN-METHADONE |
| 02241377 | METADOL |
| 02394618 | METHADOSE |
| 02533669 | APO-METHADONE |
The list shows 5 of the 19 valid single-ingredient licences.
Safety Considerations
- Drug Interactions (100 interactions recorded; examples of major-level interactions): alvimopan, bupropion, morphine, dexamethasone, clarithromycin, picosulfuric acid, polyethylene glycol (3350 with electrolytes), cisapride.
- Other cautions from the literature: a report of methadone-induced bradycardia (PMID 15961013), and reports of cluster headache induced or worsened by high-dose methadone (PMID 25487851).
For warnings and contraindications, please refer to the package insert.
Conclusion and Next Steps
Decision: Hold
Rationale: The only direct support for Tourette syndrome is a single small 1992 clinical report, with no registered trials. Dependence and abuse liability are major concerns in a chronic, often paediatric condition.
To proceed, the following is needed:
- Review of the full 1992 report and a systematic search for any later clinical data in Tourette syndrome
- Detailed mechanism-of-action data
- Package insert warnings and contraindications from Health Canada
- A risk–benefit assessment addressing dependence, QT prolongation and respiratory risks, particularly in younger patients
- A well-designed controlled study before any clinical consideration
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.