Aprepitant
| Evidence Level: L5 | Predicted Indications: 10 |
Table of Contents
- Aprepitant
- Aprepitant: From Chemotherapy-Related Nausea and Vomiting to Nephrogenic Syndrome of Inappropriate Antidiuresis
Aprepitant: From Chemotherapy-Related Nausea and Vomiting to Nephrogenic Syndrome of Inappropriate Antidiuresis
One-Sentence Summary
Aprepitant is an NK1 receptor antagonist and is marketed in Singapore as an oral capsule. The approved indication text is not available in the data compiled for this report. The TxGNN model predicts it may be effective for nephrogenic syndrome of inappropriate antidiuresis (NSIAD), but there are currently 0 clinical trials and 0 relevant publications supporting this direction. This is a model-only prediction.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Not available (no approved indication text in the Singapore licence records) |
| Predicted New Indication | Nephrogenic syndrome of inappropriate antidiuresis |
| TxGNN Prediction Score | 99.97% |
| Evidence Level | L5 |
| Singapore Market Status | ✓ Marketed |
| Number of Registrations | 3 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Detailed mechanism of action data is not available in the data compiled for this report. Aprepitant is known to be a substance P/neurokinin-1 (NK1) receptor antagonist, and it penetrates the central nervous system.
NSIAD is caused by a gain-of-function change in the vasopressin V2 receptor, which leads to water retention and low blood sodium. No established link connects NK1 antagonism to this V2 receptor mechanism. The only argument is speculative: substance P might modulate water balance through the vasopressin axis, and no data supports it.
The high TxGNN score therefore most likely reflects similarity in the knowledge-graph network, not a demonstrated pharmacological rationale. The prediction should be treated as a hypothesis only.
Other high-ranking predictions have the same limitation. Hypertrichosis, leprosy, pulmonary hypertension, subarachnoid haemorrhage and several rare congenital disorders were also predicted, and none has supporting trials or relevant literature. Subarachnoid haemorrhage and pulmonary hypertension have only weak, indirect preclinical hypotheses involving substance P/NK1 signalling.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
Currently no related literature available for nephrogenic syndrome of inappropriate antidiuresis.
Singapore Market Information
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| SIN12369P | EMEND CAPSULE 80 mg | Capsule | Not stated |
| SIN12371P | EMEND TRI-PACK CAPSULE | Capsule | Not stated |
| SIN16363P | INAPITANT TRI-PACK CAPSULE | Capsule | Not stated |
All three licences are valid single-ingredient products, and none is cancelled. The only route of administration is oral.
Safety Considerations
- Contraindications (knowledge-graph signal, not label text): The TxGNN knowledge graph records a contraindication link with liver failure. This should be verified against the official package insert.
- Drug Interactions: The interaction query returned 100 records, and the first 20 are in the data compiled for this report. Several are rated Major:
- Fentanyl
- Alfentanil
- Acalabrutinib
Examples rated Moderate include paclitaxel, abemaciclib, nifedipine, ibuprofen, hydrocortisone, fluvoxamine, fosphenytoin, gefitinib, rabeprazole, lidocaine and levonorgestrel. Dolutegravir is rated Minor. Aprepitant is metabolised through CYP3A4, which is a likely reason for many of these interactions. A full interaction review would be needed before any new use.
Warnings and contraindications from the package insert are not available. Please refer to the package insert for complete safety information.
Conclusion and Next Steps
Decision: Hold
Rationale: The prediction score is high, but the evidence level is L5. There are no clinical trials and no relevant literature. There is also no plausible mechanistic link between NK1 antagonism and the V2 receptor gain-of-function that causes NSIAD. Package insert safety data are also missing, which blocks safety screening.
To proceed, the following is needed:
- Package insert warnings and contraindications from the HSA website, to enable safety screening
- Mechanism of action data from DrugBank, and a mechanistic assessment of any substance P and vasopressin link
- Approved indication text for the Singapore licences, to confirm the original indication
- Preclinical or literature evidence showing NK1 antagonism affects water balance or V2 receptor signalling
- A review of the major drug interactions (opioids, CYP3A4-related drugs) and of the liver failure signal for the target population
- Route compatibility and similarity-to-original assessments, which are still pending
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.