Phentermine
| Evidence Level: L5 | Predicted Indications: 10 |
Table of Contents
Phentermine: From Obesity to Hypervitaminosis
One-Sentence Summary
Phentermine is a sympathomimetic appetite suppressant, originally used to treat obesity. The TxGNN model ranks hypervitaminosis as its top predicted new indication, but no clinical trials and no publications support it, and no plausible pharmacological link was identified.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Obesity (also hypotensive disorder and monogenic obesity in the knowledge graph; the Singapore licences list no indication text) |
| Predicted New Indication | Hypervitaminosis |
| TxGNN Prediction Score | 99.57% |
| Evidence Level | L5 |
| Singapore Market Status | ✓ Marketed |
| Number of Registrations | 4 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data is not available. Phentermine is known as a sympathomimetic anorectic that releases norepinephrine, which suppresses appetite. This explains its use in obesity, and it could in theory raise blood pressure.
Obesity and hypervitaminosis have no clear pharmacological connection. Hypervitaminosis results from excess vitamin intake, and nothing in phentermine's mechanism would treat or prevent it. The high score (99.57%) most likely reflects a pattern in the knowledge graph rather than a real biological relationship, so this prediction should be treated as a model artifact.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
Currently no related literature available.
Singapore Market Information
| Authorization Number | Product Name | Dosage Form |
|---|---|---|
| SIN05315P | PANBESY CAPSULE 15 MG | Capsule |
| SIN01256P | DUROMINE CAPSULE 30 mg | Capsule |
| SIN05113P | PANBESY CAPSULE 30 mg | Capsule |
| SIN01255P | DUROMINE CAPSULE 15 mg | Capsule |
All four are valid single-ingredient oral products. The approved indication text is not available for them.
Safety Considerations
- Contraindications (from the knowledge graph, not label text): Cardiovascular conditions (hypertension, pulmonary hypertension, congestive heart failure, heart valve disease, heart conduction disease, sudden cardiac arrest, arteriosclerosis obliterans), psychiatric conditions (psychotic, schizoaffective and other mental disorders), substance abuse/dependence, glaucoma, hyperthyroidism (Graves disease, thyrotoxicosis), type 1 diabetes with diabetic ketoacidosis, and preeclampsia.
- Drug Interactions: 100 interactions were recorded. The 20 reviewed include major interactions with tramadol, bupropion and methylene blue. Moderate interactions include other sympathomimetics (phenylephrine, pseudoephedrine, epinephrine, isometheptene), beta-agonists (salbutamol, formoterol, arformoterol), amitriptyline, opioids (fentanyl, alfentanil), ethanol, and several antidiabetic agents (metformin, pioglitazone, alogliptin, acarbose, albiglutide).
Label warnings were not available for this report. Please refer to the package insert for complete safety information.
Conclusion and Next Steps
Decision: Hold
Rationale: The top-ranked prediction has only model-based support (L5), with no trials, no literature and no plausible mechanism. It is not clinically actionable.
For context, the best-supported candidate among the other predictions is fatty liver disease (rank 7, score 77.7%, evidence L3). It has one completed Phase 4 trial, NCT03849729 (n=92, intrahepatic fat as an endpoint, results not available), and several reviews of anti-obesity drugs in MASLD. Any benefit would likely be indirect, through weight loss. It is worth considering as a research question rather than hypervitaminosis.
To proceed, the following is needed:
- Mechanism of action data
- Package insert warnings and contraindications from the Singapore regulator (HSA)
- Published results of NCT03849729, if fatty liver disease is pursued instead
- A cardiovascular and psychiatric safety plan, given the contraindications and the major drug interactions
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.