Section 09 · Monograph

Carisoprodol

Reviewed Nov 2026FDA label

SomaMuscle relaxant

Indications

Relief of discomfort associated with acute, painful musculoskeletal conditions in adults, as an adjunct to rest and physical therapy — FDA labeling limits use to short periods (up to 2-3 weeks); NOT FDA-indicated for spasticity from CNS/upper motor neuron disorders.FDA-labeled

Occasionally used off-label for chronic musculoskeletal pain, though this is discouraged given abuse/dependence potential and lack of long-term efficacy/safety data — most guidelines recommend against use beyond 2-3 weeks or in chronic pain regimens.Off-label

Exact mechanism of action not fully established.
Carbamate derivative; does not directly relax skeletal muscle.
Effects thought to be due to sedative properties and altered interneuronal activity within the spinal cord and descending reticular formation of the brain, rather than a direct musculoskeletal action.
Metabolized primarily via CYP2C19 to meprobamate, an active metabolite with anxiolytic/sedative and additional abuse potential of its own; meprobamate contributes substantially to sedative and dependence-forming effects.

Adult: 250-350 mg orally three times daily and at bedtime.
Limit duration of use to up to 2-3 weeks, as the labeling states acute, painful musculoskeletal conditions are generally of short duration and there is no evidence of established efficacy for longer-term use.
Not recommended in patients under 16 years of age (safety/efficacy not established).
CYP2C19 poor metabolizers or concomitant CYP2C19 inhibitors (e.g., omeprazole, fluvoxamine): increased carisoprodol exposure — consider dose reduction and monitor closely.

Elderly / hepatic or renal impairment: use with caution — reduced clearance may increase risk of excess sedation and adverse effects; consider lower doses.

Acute intermittent porphyria (carisoprodol and its metabolites may precipitate porphyric crises).
Hypersensitivity to carisoprodol or to other carbamates (e.g., meprobamate, a major active metabolite).

CNS depressants (alcohol, benzodiazepines, opioids, tricyclic antidepressants, other sedative-hypnotics) — additive CNS/respiratory depression; concomitant use with opioids and/or benzodiazepines significantly increases risk of profound sedation, respiratory depression, coma, and death.
CYP2C19 inhibitors (omeprazole, fluvoxamine, fluoxetine) — may increase carisoprodol plasma concentrations.
Other carbamates (meprobamate) — additive sedative/CNS effects due to shared active metabolite.

Common (>2%): drowsiness/sedation, dizziness, headache.
Serious: abuse, misuse, and physical/psychological dependence with prolonged use (Schedule IV controlled substance); withdrawal syndrome on abrupt discontinuation after prolonged use (insomnia, vomiting, abdominal cramps, headache, tremors, muscle twitching, ataxia, hallucinations, psychosis); CNS depression/respiratory depression especially with opioids/alcohol; seizures; idiosyncratic reactions (severe weakness, ataxia, dysarthria within minutes of first dose in a small subset of patients); hematologic reactions (rare aplastic anemia, leukopenia); anaphylactoid/hypersensitivity reactions.

Screen for personal/family history of substance use disorder and assess abuse risk before prescribing.
Duration of therapy — reassess continued need beyond 2-3 weeks; avoid long-term/chronic prescribing.
Monitor for signs of CNS/respiratory depression, particularly with concomitant opioids, benzodiazepines, or alcohol.
Monitor for signs of withdrawal if discontinuing after prolonged regular use — consider tapering.
Mental status and level of sedation, especially in elderly patients.

Pregnancy: older FDA Pregnancy Category C — animal studies showed decreased offspring survival and weight at maternally toxic doses; no adequate well-controlled human studies; neonates of mothers who used carisoprodol/meprobamate chronically near term may be at risk for withdrawal; use only if benefit justifies risk.
Lactation: carisoprodol is excreted into human breast milk at concentrations reported to be 2-4 times maternal plasma levels; caution advised due to risk of sedation/poor feeding in the breastfed infant — consider risks versus benefits of breastfeeding during therapy.