Carisoprodol

證據等級: L5

預測適應症: 1 個

Carisoprodol: From Musculoskeletal Pain to Insomnia

One-Sentence Summary

Carisoprodol is a centrally-acting skeletal muscle relaxant approved in several markets for short-term relief of acute musculoskeletal pain and spasm. The TxGNN model predicts it may be effective for Insomnia, with a high prediction score of 99.02%. However, actual clinical evidence supporting this repurposing direction is very limited: 0 clinical trials and only 1 tangentially related publication were identified, placing this at an early exploratory stage.

Quick Overview

Item	Content
Original Indication	Skeletal muscle relaxant for acute musculoskeletal pain and spasm
Predicted New Indication	Insomnia
TxGNN Prediction Score	99.02%
Evidence Level	L4 — Mechanism/preclinical basis only
India Market Status	✗ Not marketed
Number of Registrations	0
Recommended Decision	Hold

Why is This Prediction Reasonable?

Carisoprodol is a prodrug of meprobamate: after oral administration, it is metabolised in the liver to meprobamate, a compound known to act as a positive allosteric modulator of GABA-A receptors. This GABAergic central nervous system depression produces sedation and anxiolysis in addition to muscle relaxation — a pharmacological profile that, in principle, overlaps with the mechanism of older hypnotic-sedative agents.

Because insomnia is partly mediated by insufficient GABAergic inhibitory tone (the same pathway targeted by benzodiazepines and Z-drugs), the TxGNN knowledge graph can plausibly link carisoprodol’s mechanism to sleep-onset or sleep-maintenance benefit. The model’s high score (0.990) most likely reflects this mechanistic similarity rather than observed clinical evidence.

However, this theoretical connection must be weighed against a critical safety concern: meprobamate carries a high risk of physical dependence, tolerance, and abuse, which is precisely why it was displaced by benzodiazepines and subsequently by non-benzodiazepine hypnotics (zolpidem, eszopiclone, etc.) decades ago. The prediction is mechanistically coherent but clinically superseded.

Clinical Trial Evidence

Currently no related clinical trials registered for Carisoprodol in insomnia.

Literature Evidence

PMID	Year	Type	Journal	Key Findings
22963024	2012	Review / Clinical Overview	American Family Physician	Review of nocturnal leg cramps; notes that recurrent, painful calf-muscle tightening can cause severe insomnia in up to 60% of affected adults; carisoprodol appears on the list of associated medications — indirectly linking the drug to the insomnia symptom burden rather than its treatment

Note: This publication discusses insomnia as a consequence of nocturnal leg cramps, not as an indication directly treated by carisoprodol. Its relevance to the repurposing hypothesis is indirect.

India Market Information

Carisoprodol is not currently registered or marketed in India. No product authorisations were identified.

Safety Considerations

Drug Interactions (158 interactions on record):

Key interactions by severity level:

Severity	Interacting Drug	Clinical Implication
Major	Morphine	Additive CNS/respiratory depression; avoid combination
Major	Morphine (liposomal)	Additive CNS/respiratory depression; avoid combination
Moderate	Dronabinol	Enhanced CNS depression
Moderate	Nabilone	Enhanced CNS depression
Moderate	Opium	Additive sedation and respiratory risk
Moderate	Sibutramine	CNS interaction
Moderate	Difenoxin	Enhanced CNS depression
Moderate	Diphenoxylate	Enhanced CNS depression
Moderate	Metoclopramide	CNS interaction

An additional 149 interactions of Unknown or lower severity are on record. The pattern of Major interactions with opioids and Moderate interactions with CNS-active agents is consistent with carisoprodol’s broad central depressant profile via its meprobamate metabolite.

Please refer to the package insert for complete warnings and contraindications — these data were not available in the current evidence pack.

Conclusion and Next Steps

Decision: Hold

Rationale: Although the GABAergic mechanism of carisoprodol’s active metabolite (meprobamate) provides a plausible theoretical basis for sedation/sleep promotion, there is zero clinical trial evidence and only one indirectly relevant review paper for the insomnia indication. Furthermore, the abuse and dependence liability of meprobamate creates a significant safety barrier that modern insomnia pharmacotherapy has already addressed with safer alternatives.

To proceed, the following is needed:

Formal package insert review — Obtain and parse the full prescribing information (warnings, contraindications, abuse-potential labelling) before any clinical assessment can begin (currently a Blocking data gap)
Mechanism of action documentation — Confirm MOA via DrugBank API or primary pharmacology literature; specifically quantify GABA-A binding affinity relative to approved hypnotics
Regulatory status clarification — Assess whether India’s CDSCO has any stance on meprobamate/carisoprodol given its international controlled-substance status (Schedule IV in the US; banned in several EU countries)
Abuse liability risk assessment — Any repurposing proposal must address whether scheduling restrictions would make clinical development or market access feasible
Comparative effectiveness analysis — Benchmark against existing insomnia treatments (zolpidem, eszopiclone, lemborexant) to determine whether any unmet need remains that carisoprodol could plausibly address
Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.