Tyrosine
| Evidence Level: L5 | Predicted Indications: 10 |
Table of Contents
Tyrosine: From Maple Syrup Urine Disease (Acute Decompensation) to Cauda Equina Syndrome
One-Sentence Summary
Tyrosine (marketed in the EU as Maapliv) was originally authorised for acute decompensation episodes of maple syrup urine disease (MSUD) in patients who cannot use an oral or enteral BCAA-free formulation. The TxGNN model predicts it may be effective for cauda equina syndrome, but no clinical trials and no publications currently support this prediction, so it is a computational hypothesis only.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Maple syrup urine disease (MSUD) presenting with an acute decompensation episode in patients from birth who are not eligible for an oral and enteral BCAA-free formulation |
| Predicted New Indication | Cauda equina syndrome |
| TxGNN Prediction Score | 99.77% |
| Evidence Level | L5 |
| EU Market Status | Cancelled only (no currently valid authorisation) |
| Number of Authorizations | 1 (cancelled) |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data is not available. Tyrosine is an amino acid and a precursor of catecholamines (dopamine, norepinephrine) and thyroid hormones. Its role in MSUD relates to nutritional and metabolic support during acute decompensation.
The data compiled for this report do not support a mechanistic link between tyrosine and cauda equina syndrome. That condition involves compression of the lumbosacral nerve roots, causing radiculopathy and bladder, bowel and sphincter dysfunction. The high TxGNN score (99.77%) is a computational prediction only. No supporting trials or literature were found, and tyrosine’s role as a catecholamine precursor has no established relevance to this condition.
Clinical Trial Evidence
Currently no related clinical trials registered for cauda equina syndrome.
For context, among the other predicted indications, one trial exists for hyperthyroidism (rank 4):
| Trial Number | Phase | Status | Enrollment | Key Findings |
|---|---|---|---|---|
| NCT06264544 | Not applicable | Not yet recruiting | 150 | Randomised, double-blind, placebo-controlled trial of a zinc, selenium and L-tyrosine supplement for preventing thyrotoxicosis in adults with elevated TPOAb and the SEPP1 r25191G/A polymorphism. Tyrosine is not clearly the tested agent, and no results are available. |
Literature Evidence
Currently no related literature available for cauda equina syndrome.
For context, the closest items among the other predicted indications are:
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 42812246 | 2026 | Cohort | Frontiers in Medicine | Plasma amino acid alterations in early primary angle-closure glaucoma (an association study, not a treatment study) |
| 39063020 | 2024 | Case report | Int J Mol Sci | Chronic fatigue syndrome responding to alpha-methyl-p-tyrosine, a tyrosine hydroxylase inhibitor with opposing pharmacology (predicted for POTS, rank 5) |
| 36848916 | 2023 | Review | Lancet Diabetes Endocrinol | General review of hyperthyroidism; does not assess tyrosine efficacy |
EU Market Information
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| EMEA/H/C/005557 (cancelled) | Maapliv | Not specified | Maple syrup urine disease (MSUD) presenting with an acute decompensation episode in patients from birth who are not eligible for an oral and enteral branched-chain amino acids free (BCAA-free) formulation. |
Safety Considerations
Please refer to the SmPC for safety information. No drug interaction records were found, and the knowledge graph lists no contraindicated diseases for this drug.
Conclusion and Next Steps
Decision: Hold
Rationale: The prediction for cauda equina syndrome rests only on a model score, with no trials, no literature and no plausible mechanism. The only authorisation is cancelled, and safety data are missing. The other top-ranked predictions (thyroid-related and glaucoma conditions) also lack tyrosine-specific evidence, and some are mechanistically counterproductive, such as supplementing a thyroid hormone precursor in hyperthyroidism.
To proceed, the following is needed:
- Safety information (warnings and contraindications) from the EMA product information
- Mechanism of action data for tyrosine
- A biological rationale linking tyrosine to cauda equina syndrome, or a review of other predicted indications for more plausible candidates
- Preclinical or exploratory clinical evidence of benefit
- Clarification of why the Maapliv authorisation was cancelled, and of the route of administration, since the product was intended for acute use in patients who cannot take enteral formulations
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.