Iohexol
| 證據等級: L5 | 預測適應症: 10 個 |
目錄
Iohexol: From Contrast Imaging Agent to Insomnia
One-Sentence Summary
Iohexol is a non-ionic iodinated contrast medium widely used in diagnostic radiology — including myelography, angiography, and body cavity imaging — rather than a conventional therapeutic drug. The TxGNN model predicts it may be relevant to Insomnia, achieving a model score of 99.87%, yet zero clinical trials and zero publications specifically support this as a therapeutic direction; the high score almost certainly reflects a knowledge graph false positive.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Iodinated contrast agent for medical imaging (myelography, angiography, CT) |
| Predicted New Indication | Insomnia (disease) |
| TxGNN Prediction Score | 99.87% |
| Evidence Level | L5 |
| India Market Status | Not Marketed |
| Number of Registrations | 0 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Iohexol is a low-osmolality, non-ionic iodinated contrast agent. Its only pharmacological mechanism is X-ray attenuation via the high atomic weight of iodine — it does not bind to receptors, modulate neurotransmitters, or exert any physiological effect beyond transient osmotic load during excretion. It is considered pharmacologically inert for therapeutic purposes.
Insomnia is a disorder of sleep initiation or maintenance, typically managed through GABAergic agents (benzodiazepines, Z-drugs), melatonin agonists, orexin receptor antagonists, or behavioural therapies. There is no plausible mechanistic bridge between iohexol’s contrast properties and central nervous system sleep regulation.
The TxGNN high prediction score (99.87%) almost certainly originates from knowledge graph co-occurrence artefacts: patients undergoing contrast imaging procedures (e.g., CT, myelography) have documented comorbidities including anxiety and sleep disorders, creating indirect graph edges. This is a characteristic false positive pattern for diagnostic-tool compounds in KG-based repurposing models — the model conflates clinical co-occurrence with therapeutic relevance.
Clinical Trial Evidence
Currently no related clinical trials registered for Iohexol in insomnia.
Literature Evidence
Currently no related literature available for Iohexol in insomnia.
India Market Information
Iohexol has no registered products in India at this time (0 authorisations on record).
Safety Considerations
Please refer to the package insert for safety information.
Appendix: All Predicted Indications — Pattern Analysis
All 10 TxGNN-predicted indications for iohexol share a common verdict. The table below summarises the full prediction list to document the systematic evaluation:
| Rank | Predicted Indication | TxGNN Score | Trials | Publications | Evidence Level | Decision | Key Reason for Rejection |
|---|---|---|---|---|---|---|---|
| 1 | Insomnia | 99.87% | 0 | 0 | L5 | Hold | No CNS/sleep mechanism; KG co-occurrence artefact |
| 2 | Anxiety | 99.25% | 6 (all Grade C) | 6 (all off-target) | L5 | Hold | All trials use iohexol as GFR probe or imaging tool, not anxiety treatment |
| 3 | Rheumatoid Arthritis | 98.87% | 1 (Phase 1, GFR probe) | 0 | L5 | Hold | NCT01484561 uses iohexol to measure renal clearance, not treat RA |
| 4 | Antithrombin Deficiency Type 2 | 98.75% | 0 | 0 | L5 | Hold | No anticoagulant mechanism; vascular imaging co-occurrence |
| 5 | Factor V Excess / Spontaneous Thrombosis | 98.73% | 0 | 0 | L5 | Hold | No anticoagulant activity; indirect KG vascular-imaging linkage |
| 6 | Sleep Disorder (Initiating and Maintaining) | 98.61% | 0 | 0 | L5 | Hold | Duplicate of Rank 1 in different terminology (SNOMED) |
| 7 | Heparin Cofactor 2 Deficiency | 98.61% | 0 | 0 | L5 | Hold | Rare coagulopathy; no protein-supplementation mechanism |
| 8 | Fibromyalgia | 98.46% | 0 | 0 | L5 | Hold | Central sensitisation disorder; no analgesic/neuromodulatory mechanism |
| 9 | Conjunctivitis | 98.45% | 0 | 0 | L5 | Hold | No ophthalmic formulation; theoretical iodine antimicrobial effect unvalidated |
| 10 | Tendinitis | 98.44% | 0 | 14 (all imaging use) | L5 | Hold | All 14 publications use iohexol for arthrography/tenography diagnosis; steroid co-injected is the therapeutic agent |
Conclusion and Next Steps
Decision: Hold (across all 10 predicted indications)
Rationale: Iohexol is a pharmacologically inert contrast medium with no therapeutic mechanism applicable to any of the 10 TxGNN-predicted indications. All retrieved clinical trials (7 total) and publications (20 total) use iohexol exclusively as a diagnostic tool — a GFR measurement probe, an imaging contrast agent, or an arthrographic medium — never as the therapeutic intervention. The uniformly high TxGNN scores reflect a systematic knowledge graph artefact: patients requiring contrast imaging often carry comorbidities (insomnia, anxiety, chronic kidney disease, rheumatic conditions), creating false co-occurrence edges in the KG. This is a recognised limitation of graph-based repurposing models applied to diagnostic agents.
To proceed, the following would be needed:
- Fundamental reassessment: Iohexol should be flagged at the pipeline ingestion level as a diagnostic agent and excluded from therapeutic repurposing candidate lists
- Model calibration: The KG should be annotated to distinguish diagnostic-use compounds from therapeutic compounds, preventing similar false positives for other contrast media (iopamidol, iodixanol, gadolinium chelates, etc.)
- Root cause analysis: Investigate which KG node/edge types are generating the co-occurrence signal to improve future prediction specificity for this drug class
⚠️ Disclaimer: This report is for research reference only and does not constitute medical advice. Drug repurposing candidates require clinical validation before any therapeutic application.
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.