Levodopa
| Evidence Level: L5 | Predicted Indications: 10 |
Table of Contents
Levodopa: From Parkinson’s Disease to Rasmussen Subacute Encephalitis
One-Sentence Summary
Levodopa is a dopamine-replacement medicine, used mainly for Parkinson’s disease and marketed in South Africa in several combination products. The TxGNN model predicts it may be effective for Rasmussen subacute encephalitis, but there are 0 clinical trials and 0 publications supporting this direction. The high score is a graph-based prediction only, with no mechanistic rationale identified.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Parkinson’s disease (standard use of levodopa products; the SAHPRA indication text was not captured in the source data) |
| Predicted New Indication | Rasmussen subacute encephalitis |
| TxGNN Prediction Score | 99.06% |
| Evidence Level | L5 (model prediction only) |
| South Africa Market Status | Marketed |
| Number of SAHPRA Registrations | 6 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data is not available for this record. Levodopa is known to act as a dopamine precursor, and its efficacy in parkinsonism is well established.
Rasmussen encephalitis is an immune-mediated inflammatory disease that affects one brain hemisphere. Dopamine replacement has no established role in it, so this prediction has no clear mechanistic link. No trials or publications were retrieved for this pairing. The high TxGNN score most likely reflects patterns in the knowledge graph rather than a biologically supported new use.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
Currently no related literature available.
Other Predicted Indications With More Evidence
The same Evidence Pack contains other predictions with more support than the top-ranked one. All are symptomatic (dopaminergic) rationales, not disease modification.
| Predicted Indication | TxGNN Score | Evidence Level | Key Points |
|---|---|---|---|
| PLA2G6-associated neurodegeneration | 98.75% | L3 | Case series and reviews report levodopa-responsive parkinsonism, but the response is often partial and wanes over time. Several retrieved papers concern other NBIA genes and are only indirectly relevant. |
| Lewy body dementia | 97.25% | L4 | Reviews and consensus reports discuss levodopa for motor features. There is no direct levodopa RCT, and dopaminergic therapy may worsen hallucinations. |
| Multiple system atrophy, parkinsonian type | 97.02% | L4 | Reviews and case reports show modest, non-sustained benefit. One Phase 1/2 trial (NCT06831500, recruiting) examines the carbidopa/levodopa ratio on orthostatic hypotension. Its intervention needs verification. |
| Progressive supranuclear palsy-corticobasal syndrome | 97.58% | L4 | Only reviews and non-interventional or device studies. Response is usually poor or transient. |
| Paralysis agitans, juvenile, of Hunt | 98.03% | L5 | Biologically plausible, but likely a synonym or ontology overlap with Parkinson’s disease. Needs manual disease-term review. |
The remaining predictions (myelitis, transaldolase deficiency, fructose-1,6-bisphosphatase deficiency, X-linked intellectual disability-ataxia-apraxia syndrome) have no mechanistic link or only indirect evidence.
South Africa Market Information
Six SAHPRA registrations were found. The five main ones are listed below; approved indication text was not available in the source data.
| Registration Number | Product Name | Dosage Form |
|---|---|---|
| Reg. No. 32/5.4.1/0081 | Teva carbi-levo 25/100 | Tablet |
| Reg. No. 31/5.4.1/0194 | Madopar HBS 100mg/25mg | Capsule |
| Reg. No. 45/5.4.1/0765 | Lecardop 25/100 | Tablet |
| Reg. No. R/3.1/50 | Panamor AT | Tablet |
| Reg. No. 8/5.4.1/0138 | Stalevo 100/25 | Tablet |
All available products are oral (tablet or capsule).
Safety Considerations
Please refer to the SAHPRA-approved Professional Information (PI) for safety information. Report adverse drug reactions to SAHPRA.
Conclusion and Next Steps
Decision: Hold
Rationale: The top-ranked prediction (Rasmussen subacute encephalitis) has no trials, no literature and no plausible mechanism. It is a model output only (L5) and should not be pursued.
To proceed, the following is needed:
- SAHPRA package insert warnings and contraindications (a blocking gap for safety screening)
- Mechanism of action data from DrugBank
- Manual review of the disease-term mapping, especially for “paralysis agitans, juvenile, of Hunt”
- If the team wants to advance a levodopa candidate, consider PLA2G6-associated neurodegeneration, Lewy body dementia or MSA-P as research questions instead. Each needs prospective evidence beyond case series and reviews.
This report is for research reference only and does not constitute medical advice. Repurposing candidates require clinical validation before any clinical use.
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.