Methylthioninium
| Evidence Level: L5 | Predicted Indications: 10 |
Table of Contents
- Methylthioninium
- Methylthioninium: From an Unspecified Approved Indication to Irritable Bowel Syndrome
Methylthioninium: From an Unspecified Approved Indication to Irritable Bowel Syndrome
One-Sentence Summary
Methylthioninium (methylene blue) is registered in Singapore as an injectable solution, but the approved indication text is not available in the data compiled for this report. The TxGNN model predicts it may be effective for irritable bowel syndrome, but there are currently 0 clinical trials and 0 publications supporting this direction, so the prediction rests on the model score alone.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Not available in the data compiled for this report |
| Predicted New Indication | Irritable bowel syndrome |
| TxGNN Prediction Score | 90.43% |
| Evidence Level | L5 |
| Singapore Market Status | ✓ Marketed |
| Number of Registrations | 1 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data is not available. Based on known information, methylene blue is described in the broader literature as an inhibitor of nitric oxide synthase and guanylate cyclase, and as a modulator of monoamine oxidase. These actions could plausibly affect gut motility and visceral signalling, which are relevant to irritable bowel syndrome.
This link is speculative. The original approved indication is not recorded in the data, so the relationship between the original and new indications cannot be assessed. The prediction rests on the TxGNN score (0.904) alone.
Other predicted indications are listed below for context. All are L5 (model prediction only) with a Hold recommendation, except where noted:
| Rank | Predicted Indication | TxGNN Score | Comment |
|---|---|---|---|
| 2 | Dysthymic disorder | 88.53% | Theoretical link via reversible MAO inhibition and nitric oxide signalling |
| 3 | Anaphylaxis | 88.06% | Possible vasopressor-sparing role via the nitric oxide/guanylate cyclase pathway |
| 4 | Food-dependent exercise-induced anaphylaxis | 87.75% | Extension of the anaphylaxis hypothesis; highly speculative |
| 5 | Bronchitis | 85.52% | No substantiated mechanism |
| 6 | Anxiety | 80.59% | One indirect preclinical publication (see below) |
| 7 | Obsolete rare pulmonary disease | 75.18% | Obsolete ontology entry; likely should be excluded |
| 8 | Variably protease-sensitive prionopathy | 74.85% | Loose rationale based on anti-aggregation activity |
| 9 | Autonomic nervous system disease | 74.49% | Speculative link to vasoplegia |
| 10 | Pulmonary edema | 73.87% | Theoretical nitric oxide/cGMP rationale |
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
No literature is available for irritable bowel syndrome. For the sixth-ranked prediction (anxiety), one publication was linked:
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 29375308 | 2017 | Preclinical (unverified) | Frontiers in Molecular Neuroscience | A leuco-methylthioninium salt (LMTM) reduced α-synuclein aggregation in cellular and transgenic mouse models of synucleinopathy. It does not show anxiety-related outcomes, so it is indirect evidence at most. |
Singapore Market Information
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| SIN16319P | PROVEBLUE SOLUTION FOR INJECTION 5MG/ML | Injection, solution | Not available |
Safety Considerations
Please refer to the package insert for safety information.
Conclusion and Next Steps
Decision: Hold
Rationale: The irritable bowel syndrome prediction has no supporting trials or literature, so it remains a model prediction (L5). The approved indication and mechanism of action are also missing, which limits any assessment of how the original and new indications relate.
To proceed, the following is needed:
- The HSA package insert, covering the approved indication, warnings and contraindications (a blocking gap for safety screening)
- Mechanism of action data for methylthioninium
- A systematic search for clinical and preclinical evidence on methylene blue in irritable bowel syndrome
- Assessment of route compatibility, since only an injectable form is registered in Singapore and this may not suit a chronic gastrointestinal condition
- Drug interaction review. Methylene blue is a known monoamine oxidase inhibitor, but no interaction data were found in the compiled data.
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.