Piribedil
| Evidence Level: L5 | Predicted Indications: 10 |
Table of Contents
- Piribedil
- Piribedil: From Parkinson Disease to Retinal Dystrophy with or without Extraocular Anomalies
Piribedil: From Parkinson Disease to Retinal Dystrophy with or without Extraocular Anomalies
One-Sentence Summary
Piribedil is a dopamine agonist originally used to treat Parkinson disease and other parkinsonian disorders. The TxGNN model predicts it may be effective for retinal dystrophy with or without extraocular anomalies, but there are currently 0 clinical trials and 1 publication (which does not study piribedil) supporting this direction. The prediction is computational only.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Parkinson disease / parkinsonian disorder |
| Predicted New Indication | Retinal dystrophy with or without extraocular anomalies |
| TxGNN Prediction Score | 99.34% |
| Evidence Level | L5 |
| Singapore Market Status | ✓ Marketed |
| Number of Registrations | 1 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Piribedil is a D2/D3 dopamine receptor agonist with alpha-2 adrenergic antagonist activity. Its use in Parkinson disease rests on stimulating dopamine receptors to compensate for lost dopaminergic signalling.
Dopamine does play a role in normal retinal physiology. However, no link has been shown between this activity and the pathogenesis of inherited retinal dystrophy. The only publication retrieved concerns syncope in Kearns-Sayre syndrome, a mitochondrial disorder that can include retinopathy, and it does not evaluate piribedil. The high TxGNN score therefore reflects a computational association, not demonstrated efficacy.
Other top-ranked predictions are of mixed plausibility:
- Plausible (symptomatic dopaminergic therapy): juvenile parkinsonism (Hunt type), juvenile-onset Parkinson disease 19A (flagged as a research question), and PLA2G6-associated neurodegeneration. None has trials or literature specific to piribedil, and these predictions largely reflect similarity to the existing indication.
- Weak rationale: X-linked myopia (two forms), where dopamine modulates eye growth, but the genetic cause and the need for systemic dosing make benefit unlikely.
- No identified rationale: perisylvian polymicrogyria, lethal infantile mitochondrial myopathy, congenital disorder of glycosylation with defective fucosylation, and atypical glycine encephalopathy.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 17086014 | 2006 | Review | The American Heart Hospital Journal | Pathophysiology and management of syncope in Kearns-Sayre syndrome (a mitochondrial disorder); piribedil is not evaluated, so this offers only indirect context |
Singapore Market Information
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| SIN09947P | TRIVASTAL RETARD 50 TABLET 50 mg | Film-coated tablet (oral) | Not listed in the data compiled for this report |
Safety Considerations
Please refer to the package insert for safety information.
No drug-interaction records were found in the data compiled for this report.
Conclusion and Next Steps
Decision: Hold
Rationale: The prediction rests only on a model score. No clinical trials exist, the single retrieved publication does not involve piribedil, and no mechanistic link to retinal dystrophy is established. Evidence is at L5.
To proceed, the following is needed:
- Package insert warnings and contraindications from HSA. This is a blocking gap for safety screening.
- Detailed mechanism of action data (for example, from DrugBank).
- Preclinical or mechanistic evidence linking dopamine D2/D3 agonism or alpha-2 antagonism to retinal dystrophy pathology.
- If a repurposing programme is pursued, consider prioritising the parkinsonism-related candidates (juvenile parkinsonism, juvenile-onset Parkinson disease 19A), which are mechanistically more coherent. These would be framed as research questions on symptomatic management.
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.