Tyrosine
| Evidence Level: L5 | Predicted Indications: 10 |
Table of Contents
Tyrosine: From Parenteral Nutrition Amino Acid Component to Cauda Equina Syndrome
One-Sentence Summary
Tyrosine is an amino acid used as a component of parenteral nutrition (amino acid infusion) products marketed in Singapore. The TxGNN model predicts it may be effective for cauda equina syndrome, but this is a computational prediction only, with 0 clinical trials and 0 publications supporting this specific indication. Among the other top-ranked predictions, only hyperthyroidism has a registered trial, and that trial is not of tyrosine alone.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Not stated in the registration data (the products are amino acid infusion and nutrition products) |
| Predicted New Indication | Cauda equina syndrome |
| TxGNN Prediction Score | 99.77% |
| Evidence Level | L5 |
| Singapore Market Status | ✓ Marketed |
| Number of Registrations | 15 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data is not available. Tyrosine is a known amino acid and a precursor of catecholamines (dopamine and norepinephrine) and of thyroid hormones. It is supplied in Singapore as a component of parenteral nutrition products.
For cauda equina syndrome, no mechanistic link was identified in the data compiled for this report. The condition is a compressive injury of the nerve roots of the cauda equina, and nothing in the data connects catecholamine precursor supply to that injury. The high score (0.998) is a graph-based prediction only and should be read as a hypothesis, not as evidence.
Other top-ranked predictions show the same pattern:
- Hyperthyroidism, hyperthyroxinemia, and thyroid hormone resistance: Tyrosine is a substrate for thyroid hormone synthesis, but supplying more substrate would be expected to be neutral or unfavorable when the goal is to lower hormone activity. This is a safety concern as well as a lack of evidence.
- Postural orthostatic tachycardia syndrome: A link to autonomic function is plausible, since tyrosine is a catecholamine precursor. However, the only paper retrieved is a case report of chronic fatigue syndrome treated with alpha-methyl-p-tyrosine, a tyrosine hydroxylase inhibitor that acts opposite to tyrosine.
- Glaucoma-related conditions (angle-closure, traumatic, neovascular, aqueous misdirection): None of the retrieved papers tests tyrosine as a treatment. Two predictions share an identical score, which suggests they are driven by shared graph neighbours rather than tyrosine-specific biology.
- Obsolete neurogenic bladder (disease): The term is flagged as obsolete in the ontology and needs to be mapped to a current term before any assessment.
Clinical Trial Evidence
For the top prediction (cauda equina syndrome), currently no related clinical trials are registered.
The only trial found among the top 10 predictions is for hyperthyroidism:
| Trial Number | Phase | Status | Enrollment | Key Findings |
|---|---|---|---|---|
| NCT06264544 | Not applicable | Not yet recruiting | 150 | Placebo-controlled trial of a zinc, selenium, and L-tyrosine supplement for preventing thyrotoxicosis in people with the SEPP1 r25191G/A polymorphism and raised TPOAb. Tyrosine is part of a combination, so it gives no direct evidence for tyrosine alone. No results are available. |
Literature Evidence
For the top prediction (cauda equina syndrome), currently no related literature is available.
The most relevant publications among the other predictions are listed below. None tests tyrosine as a treatment.
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 39063020 | 2024 | Case report | Int J Mol Sci | Chronic fatigue syndrome responded to alpha-methyl-p-tyrosine, a tyrosine hydroxylase inhibitor. This is the opposite of tyrosine supplementation, and the condition is not POTS. |
| 42812246 | 2026 | Cohort | Front Med | Plasma amino acid alterations are associated with ocular parameters in early primary angle-closure glaucoma. This is a biomarker association, not evidence of benefit. |
| 36848916 | 2023 | Review | Lancet Diabetes Endocrinol | General review of hyperthyroidism causes, diagnosis, and management. Does not address tyrosine therapy. |
| 35087972 | 2021 | Review | Rom J Ophthalmol | Review of neovascular glaucoma. Treatment centres on VEGF inhibition, with no link to tyrosine. |
| 10579356 | 1999 | Mechanistic study | Endocrinology | Thyroid hormone receptor beta mutations that impair ligand binding in thyroid hormone resistance. Does not test tyrosine. |
| 15135777 | 2004 | Review | Growth Horm IGF Res | Molecular mechanisms of end-organ hormone resistance. Does not test tyrosine. |
Singapore Market Information
All 15 registrations are valid single-ingredient products. The registration data contain no approved indication text. The five main authorizations are listed below.
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| SIN11682P | AMINOVEN SOLUTION FOR INFUSION 5% | Injection | Not stated |
| SIN11829P | AMINOVEN SOLUTION FOR INFUSION 10% | Injection | Not stated |
| SIN16337P | AMINOVEN SOLUTION FOR INFUSION 15% | Infusion, solution | Not stated |
| SIN08352P | AMINOPLASMAL-15% INFUSION | Injection | Not stated |
| SIN07846P | TROPHAMINE INJECTION 10% | Injection | Not stated |
The remaining 10 registrations include amino acid, peritoneal dialysis, and multi-chamber parenteral nutrition products (for example Nutrineal PD4, Vaminolact, Aminoplasmal B.Braun 10% E, Oliclinomel, and SmofKabiven variants).
Safety Considerations
Please refer to the package insert for safety information.
One point can be noted from the predictions themselves: for the thyroid-related predictions (hyperthyroidism, hyperthyroxinemia), tyrosine is a substrate for thyroid hormone synthesis, so supplementation could be unfavorable in those patients. This needs to be assessed before any further work in these indications.
Conclusion and Next Steps
Decision: Hold
Rationale: The prediction for cauda equina syndrome rests only on a graph-based score, with no clinical trials, no literature, and no identified mechanism. The same is true of the other top predictions. For the thyroid-related predictions, the biology suggests possible harm rather than benefit.
To proceed, the following is needed:
- Detailed mechanism of action data, and a plausible mechanistic link between tyrosine and the target condition
- Package insert warnings and contraindications from the HSA, which are currently missing and block safety screening
- Approved indication text for the Singapore registrations, to define the original indication
- A targeted literature and trial search on tyrosine itself for the predicted indications, excluding tyrosine kinase inhibitor papers
- Mapping of the obsolete neurogenic bladder term to a current ontology term
- Route and formulation compatibility assessment, since current products are all parenteral nutrition formulations
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.