Chlormezanone
| Evidence Level: L4 | Predicted Indications: 1 |
Table of Contents
Chlormezanone: From Anxiety to Insomnia
One-Sentence Summary
Chlormezanone is a centrally acting agent originally used to treat anxiety. The TxGNN model predicts it may be effective for insomnia, with no registered clinical trials and 2 publications (1979 and 1983) currently supporting this direction.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Anxiety |
| Predicted New Indication | Insomnia |
| TxGNN Prediction Score | 0.9994 |
| Evidence Level | L4 |
| India Market Status | Listed in a compiled Indian medicine price dataset (2 of 2) – CDSCO approval status is not included in this data |
| Number of Listed Products | 2 (valid: 2) |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data is not available. Based on known information, chlormezanone is a centrally acting anxiolytic and muscle relaxant of the thiazinone class. Its efficacy in anxiety is the basis of its original use, and its sedative effects plausibly relate to central nervous system depression, which could improve sleep onset. This mechanistic link is inferred and is not supported by mechanistic data.
Anxiety and insomnia often occur together, and calming agents can help with both. The two available publications, however, studied sleep disturbance caused by rheumatic stiffness or arthritis. The benefit may therefore be indirect, through relief of muscle tension or musculoskeletal discomfort, rather than a primary sleep-inducing action.
The very high TxGNN score (0.9994) is a computational prediction only. It does not replace clinical evidence.
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 6354600 | 1983 | Clinical study (double-blind, crossover) | Current Medical Research and Opinion | In 31 patients with rheumatoid arthritis or osteoarthritis and disease-related insomnia, 7-day courses of chlormezanone 400 mg and 200 mg were compared with placebo. Patients rated it significantly more effective than placebo for sleep disturbance (p < 0.025) and preferred the 400 mg dose. |
| 316373 | 1979 | Clinical study (open-label) | Current Medical Research and Opinion | In 61 general-practice patients with rheumatic sleep disturbance, chlormezanone 400 mg nightly for 2 weeks led to steady sleep improvement. 75% rated effectiveness as good or excellent, and only 1 patient stopped treatment because of side effects. |
India Market Information
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| 248962 | Zoxanak MR 250mg/325mg/50mg Tablet | Strip of 10 tablets | Not specified |
| 157385 | Nacpo Tablet | Strip of 10 tablets | Not specified |
Safety Considerations
- Drug Interactions: 35 interactions were identified in total. The main ones are below.
- Major: Morphine, Codeine, Hydrocodone (additive CNS and respiratory depression is the likely concern).
- Moderate: Ethanol, Bupropion, Dronabinol, Nabilone, Metoclopramide, Opium, Sibutramine, Dextromethorphan, and sedating antihistamines (Promethazine, Chlorpheniramine, Cetirizine, Brompheniramine, Carbinoxamine, Clemastine, Mepyramine, Doxylamine, Azelastine nasal).
Please refer to the package insert for warnings and contraindications.
Conclusion and Next Steps
Decision: Hold
Rationale: The evidence is limited to two small, older studies (1979 and 1983) in patients whose insomnia was caused by rheumatic disease, with no registered clinical trials. The high TxGNN score is a model prediction only, so the evidence does not yet support moving forward for general insomnia.
To proceed, the following is needed:
- Package insert warnings and contraindications for the marketed Indian products. These are currently missing and block the safety screening.
- Mechanism of action data, for example from DrugBank, to test the proposed link to sleep.
- Controlled trials in insomnia that is not secondary to rheumatic disease.
- A review of the sedation-related interaction risks, especially with opioids, alcohol, and sedating antihistamines.
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.