Carisoprodol
Skeletal muscle relaxants and spasmolytics
Skeletal muscle relaxants and spasmolytics
A centrally acting muscle relaxant for short-term muscle injuries. Its metabolite meprobamate is sedating and habit-forming.
Quick facts
- Group
- Skeletal muscle relaxants and spasmolytics
- Target
- Central nervous system (sedative action; metabolite meprobamate)
- Used for
- Short-term relief of pain
- Key effects
- Drowsiness and dizziness · Headache · Fast heart rate
- Monitor
- Sedation and fall risk · Breathing when combined
- ATC
- M03BA02
No doses: the clinician sets them by the current guideline.
Mechanism of action
Carisoprodol acts in the brain and spinal cord rather than on muscle. Its relaxant effect appears to rely largely on sedation and on blocking nociceptive pathways. CYP2C19 converts it mainly into meprobamate, a sedative-anxiolytic with abuse potential; without sedation its effectiveness is poor.
- Carisoprodol is converted to meprobamate by CYP2C19
- Both depress the central nervous system
- Sedation eases muscle spasm and pain
Indications
- Short-term relief of pain and discomfort from muscle strains, sprains and other acute muscle injuries, with rest and physiotherapy
Adverse effects
Common
- Drowsiness and dizziness
- Headache
- Fast heart rate
- Upset stomach and vomiting
Contraindications
- Porphyria
- Hypersensitivity to carisoprodol
Key interactions
- Alcohol, opioids, benzodiazepines and other CNS depressants
- Additive sedation and respiratory depression
- Omeprazole
- May interact with carisoprodol; it is reviewed before starting
- St John's wort and aspirin
- May interact; they are reviewed before starting
What is monitored
- Sedation and fall risk
- Signs of misuse or early refills
- Breathing when combined with other depressants
Administration and safety
- Oral tablets for short courses; use beyond 3 weeks is reviewed with the treating team
- Controlled medicine (schedule IV in the United States): stored and recorded as such
- Not stopped suddenly after prolonged use
Pregnancy and breastfeeding
There is limited information in pregnancy; it is a decision for the treating team.
Nursing care
- Ask about alcohol, substance use and other sedatives
- Avoid in older adults where possible: less safe and effective than alternatives
- Teach not to drive until the drowsiness is known
- Watch for withdrawal symptoms after long use
Pharmacokinetics
- Metabolism
- By CYP2C19, mainly to meprobamate (also active and controlled)
Test yourself
Think of the answer, then tap the question to see it.
What is the main metabolite of carisoprodol?
Meprobamate, formed by CYP2C19.
Why is carisoprodol a controlled medicine?
It and its metabolite meprobamate cause dependence and can be misused.
Which inherited disorder contraindicates carisoprodol?
Porphyria.
Connections
← Back to the class: Skeletal muscle relaxants and spasmolytics
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Carisoprodol: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2026); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).
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Representative model, for educational purposes only.