Ammonia N-13
| Evidence Level: L5 | Predicted Indications: 2 |
Table of Contents
- Ammonia N-13
- Ammonia N-13: From Diagnostic PET Myocardial Perfusion Imaging to Non-Syndromic Esophageal Malformation
Ammonia N-13: From Diagnostic PET Myocardial Perfusion Imaging to Non-Syndromic Esophageal Malformation
One-Sentence Summary
Ammonia N-13 is a short-lived radioactive PET tracer used as a diagnostic agent for myocardial perfusion imaging, not as a treatment. The TxGNN model predicts it may be relevant to non-syndromic esophageal malformation, but 0 clinical trials and 0 publications support this prediction. It is a computational hypothesis only, and no mechanistic link has been identified.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Diagnostic PET myocardial perfusion imaging (the license records contain no indication text) |
| Predicted New Indication | Non-syndromic esophageal malformation |
| TxGNN Prediction Score | 99.73% |
| Evidence Level | L5 |
| US Market Status | ✓ Marketed |
| Number of NDAs | 20 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data is not available. Ammonia N-13 is a positron-emitting radiotracer with a half-life of about 10 minutes. It is used to image blood flow in the heart, and it has no known therapeutic pharmacology.
The prediction is hard to justify on mechanistic grounds. A congenital structural malformation of the esophagus is not a plausible target for a diagnostic tracer. The high score (0.997) most likely reflects the structure of the knowledge graph, such as how nitrogen- or ammonia-related nodes are connected, rather than a real therapeutic signal.
The second-ranked prediction, esophageal disease (score 99.65%), has the same problem. It has no trials or literature behind it. Any diagnostic use of the tracer in esophageal imaging would be a separate question from drug repurposing, and no evidence for it was found here.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
Currently no related literature available.
US Market Information
Showing 5 of 20 authorizations.
| Authorization Number | Product Name | Dosage Form | Manufacturer |
|---|---|---|---|
| ANDA211740 | Ammonia N 13 | Injection | University of Wisconsin System |
| ANDA203938 | Ammonia | Injection | Kreitchman PET Center |
| ANDA209507 | Ammonia | Injection, solution | The University of Texas Southwestern Medical Center |
| ANDA203779 | Ammonia | Injection | 3D Imaging Drug Design and Development LLC |
| NDA022119 | Ammonia N 13 | Injection | The Feinstein Institutes for Medical Research |
The source records contain no approved-indication text for these authorizations, so that column is omitted.
Safety Considerations
Please refer to the package insert for safety information.
Conclusion and Next Steps
Decision: Hold
Rationale: The prediction is model output only (L5), with no clinical trials, no literature, and no plausible mechanism. Ammonia N-13 is a diagnostic tracer with a roughly 10-minute half-life, so a therapeutic effect on esophageal malformation is not credible.
To proceed, the following is needed:
- Mechanism of action data, and a mechanistic argument connecting a diagnostic tracer to esophageal development or disease
- Package insert warnings and contraindications (currently a blocking gap for safety screening)
- Any preclinical or clinical evidence linking the drug to esophageal conditions
- Clarification of whether the intent is therapeutic repurposing or diagnostic imaging, since these need different evidence
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.