Tyrosine

Evidence Level: L5

Predicted Indications: 10

Tyrosine

Pharmacist Assessment Report

Tyrosine: From an Unspecified Nutritional Indication to Cauda Equina Syndrome

One-Sentence Summary

Tyrosine is an amino acid used as a nutrient component in parenteral nutrition products marketed in Canada. The TxGNN model predicts it may be effective for cauda equina syndrome, but the data compiled for this report contain no clinical trials and no publications supporting this prediction. This is a computational prediction only.

Quick Overview

Item	Content
Original Indication	Not specified in the Canadian license data
Predicted New Indication	Cauda equina syndrome
TxGNN Prediction Score	0.9977
Evidence Level	L5
Canada Market Status	Marketed (marketed DINs on record: at least 20)
Number of DINs	at least 20
Recommended Decision	Hold

Why is This Prediction Reasonable?

Currently, detailed mechanism of action data is not available. Tyrosine is a precursor of catecholamines (dopamine, norepinephrine) and thyroid hormones. Its Canadian products are amino acid solutions for parenteral nutrition, but no approved indication text is recorded.

Nothing in the data compiled for this report connects tyrosine to compressive injury of the lumbosacral nerve roots, which is the basis of cauda equina syndrome. The high TxGNN score reflects a model output and is not supported by any trial or publication, so the prediction should be treated as a hypothesis only.

Other predictions reviewed (all Hold, L5 unless noted):

Predicted Indication	TxGNN Score	Observation
Obsolete neurogenic bladder	0.9955	No supporting evidence; the disease term is obsolete
Angle-closure glaucoma	0.9954	Only associative biomarker data (plasma amino acid changes); no therapeutic evidence
Hyperthyroidism	0.9951	Safety concern: tyrosine is a thyroid hormone substrate and could theoretically worsen thyrotoxicosis
Postural orthostatic tachycardia syndrome	0.9946	Plausible indirect link via catecholamines (L4); the only paper is a case report of a drug with the opposite action
Hyperthyroxinemia	0.9946	Supplementation could theoretically raise thyroxine
Resistance to thyroid hormone (THRB mutation)	0.9940	Receptor defect that a precursor would not correct
Traumatic glaucoma, aqueous misdirection, neovascular glaucoma	99.35–0.9932	No credible mechanism or supporting evidence

Clinical Trial Evidence

Currently no related clinical trials registered for cauda equina syndrome.

For reference, one trial was found for the rank 4 prediction (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 to prevent thyrotoxicosis in adults with elevated TPO antibodies and the SEPP1 polymorphism. Tyrosine is not the sole evaluated agent, so it provides no direct evidence for tyrosine.

Literature Evidence

Currently no related literature available for cauda equina syndrome.

For reference, the most relevant publications retrieved for other predictions are listed below. None tests tyrosine as a treatment.

PMID	Year	Type	Journal	Key Findings
42812246	2026	Cohort	Frontiers in Medicine	Plasma amino acid alterations in early primary angle-closure glaucoma (biomarker observation only)
39063020	2024	Case report	Int J Mol Sci	Chronic fatigue syndrome case treated with alpha-methyl-p-tyrosine, a tyrosine hydroxylase inhibitor that acts opposite to tyrosine; indirect relevance to POTS
36848916	2023	Review	Lancet Diabetes Endocrinol	General review of hyperthyroidism causes, diagnosis, and management
30886364	2019	Review	Nat Rev Endocrinol	Role of thyroglobulin tyrosine residues in thyroid hormone synthesis (background mechanism)
10579356	1999	Preclinical	Endocrinology	Thyroid hormone receptor beta mutations impairing ligand binding (background mechanism)
35087972	2021	Review	Rom J Ophthalmol	Review of neovascular glaucoma causes and treatment

Canada Market Information

All 20 licenses are valid single-ingredient products. Dosage form and approved indication text are not recorded in the data compiled for this report. The first five are shown below.

DIN	Product Name	Dosage Form	Approved Indication
02046709	CLINIMIX	Not recorded	Not recorded
02013932	CLINIMIX	Not recorded	Not recorded
02013940	CLINIMIX	Not recorded	Not recorded
00872296	TRAVASOL	Not recorded	Not recorded
02013886	CLINIMIX	Not recorded	Not recorded

Other marketed products include CLINIMIX E, ESSEPNA, 20% PROSOL, PRIMENE 10%, OLIMEL 5.7% and 7.6%, and SMOFKABIVEN electrolyte-free formulations.

Safety Considerations

Theoretical thyroid concern: Tyrosine is a substrate for thyroid hormone synthesis. For hyperthyroidism and hyperthyroxinemia, supplementation could in theory worsen the condition rather than treat it.
Drug interactions: No interaction records were found.

For other safety information, please refer to the package insert.

Conclusion and Next Steps

Decision: Hold

Rationale: The prediction for cauda equina syndrome rests solely on a model score, with no trials, no publications, and no identified mechanism. The other top predictions are likewise unsupported, and several (hyperthyroidism, hyperthyroxinemia) raise theoretical safety concerns.

To proceed, the following is needed:

Package insert warnings and contraindications from Health Canada
Mechanism of action data for tyrosine
Original approved indication text for the Canadian products
A plausible biological rationale linking tyrosine to cauda equina syndrome, followed by preclinical or clinical studies
Consideration of the rank 5 prediction (postural orthostatic tachycardia syndrome), which has a plausible catecholamine link, as a better-motivated alternative, although direct evidence is still absent
Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.