Paraldehyde
| Evidence Level: L5 | Predicted Indications: 10 |
Table of Contents
Paraldehyde: From Sedative-Hypnotic Use to Irritable Bowel Syndrome
One-Sentence Summary
Paraldehyde is a legacy sedative-hypnotic and anticonvulsant, registered in Singapore as an injection. The TxGNN model predicts it may be effective for irritable bowel syndrome, but no clinical trials and no publications currently support this prediction, so it rests on a computational score alone.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Not stated in the registration data (approved indication text is blank) |
| Predicted New Indication | Irritable bowel syndrome |
| TxGNN Prediction Score | 99.97% |
| 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. Paraldehyde is known as a sedative-hypnotic and anticonvulsant with central nervous system (CNS) depressant activity, probably through GABA-like effects, but this has not been confirmed in the data compiled for this report.
A possible link to irritable bowel syndrome (IBS) would run through central modulation of the gut-brain axis or reduced visceral hypersensitivity. This is speculative and has no supporting studies. Paraldehyde's poor tolerability (strong odor, tissue irritation, and a problematic toxic metabolite profile) also works against it.
The high score (99.97%) is a computational prediction only and should not be read as evidence of efficacy.
Other predicted indications (all prediction-only, Hold unless noted):
| Rank | Predicted Indication | TxGNN Score | Evidence Level | Comment |
|---|---|---|---|---|
| 2 | Cauda equina syndrome | 99.97% | L5 | A surgical emergency; a sedative has no disease-modifying role |
| 3 | Obsolete neurogenic bladder (disease) | 99.88% | L5 | Obsolete ontology term; needs remapping to a current concept |
| 4 | Neurocirculatory asthenia | 99.75% | L5 | Anxiolytic effect conceptually plausible, but unsupported |
| 5 | Rhinitis | 99.60% | L5 | No plausible mechanism |
| 6 | Insomnia (disease) | 99.30% | L4 | Biologically coherent with its historical hypnotic use; only one indirect 1992 review. Research Question |
| 7 | Dysautonomia | 98.91% | L5 | Indirect link only |
| 8 | Autonomic nervous system disease | 98.46% | L5 | Broad parent category, likely ontology proximity |
| 9 | Ancylostomiasis | 98.42% | L5 | No anthelmintic activity; likely a model artifact |
| 10 | Mitral valve prolapse (disease) | 97.96% | L5 | No plausible mechanism |
Insomnia is the only prediction with a coherent mechanism, but it largely reflects paraldehyde's historical use. Modern alternatives exist, so it is better treated as a confirmatory finding than a new repurposing opportunity.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
For the top-ranked indication (irritable bowel syndrome), currently no related literature available.
For the insomnia prediction, one indirect publication was found:
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 1585214 | 1992 | Review | South African Medical Journal | General review of sleep-disorder treatment (narcolepsy, sleep apnoea, etc.); no paraldehyde trial-level data |
Singapore Market Information
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| SIN00325P | Paraldehyde Injection BP (Hospira Australia Pty Ltd) | Injection | Not stated |
Safety Considerations
Drug Interactions (40 interactions recorded; examples of the main ones):
- Major: morphine, codeine, hydrocodone, disulfiram
- Moderate: ethanol, opium, bupropion, metoclopramide, promethazine, dronabinol, nabilone, sibutramine, diazoxide, phentolamine, amyl nitrite, chlorpheniramine, cetirizine, dextromethorphan, brompheniramine
- Minor: warfarin
The Major interactions with opioids are consistent with additive CNS and respiratory depression. Combination with disulfiram is also flagged as Major.
Please refer to the package insert for warnings and contraindications, which could not be obtained for this report.
Conclusion and Next Steps
Decision: Hold
Rationale: The prediction for irritable bowel syndrome is supported only by a model score, with no trials or publications. The mechanism is speculative, and paraldehyde's tolerability and interaction profile are unfavorable. Safer, better-characterized options exist for the predicted indications.
To proceed, the following is needed:
- Package insert warnings and contraindications from the Singapore HSA (currently blocking any safety screening)
- Mechanism of action data (e.g., from DrugBank) to support or refute a gut-brain or visceral hypersensitivity link
- Preclinical or early clinical evidence for irritable bowel syndrome
- Remapping of the obsolete neurogenic bladder term to a current disease concept, if that indication is to be revisited
- Confirmation of the original approved indication, which is blank in the registration record
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.