Metaxalone
Also sold as: Metaxall, Skelaxin
Related Medications
These drugs share a pharmacologic classification but are NOT interchangeable. Listing here does not imply clinical equivalence. A physician must evaluate each drug individually for the patient's specific condition.
Classification: Centrally-mediated Muscle Relaxation (source: RxClass/NLM)
Insurance Coverage User-Reported
No community coverage data yet for metaxalone.
Coverage data submission coming soon.
Drug Information
Mechanism of Action
Mechanism of Action The mechanism of action of metaxalone in humans has not been established, but may be due to general central nervous system (CNS) depression. Metaxalone has no direct action on the contractile mechanism of striated muscle, the motor end plate, or the nerve fiber.
Indications & Uses
INDICATIONS AND USAGE Metaxalone is indicated as an adjunct to rest, physical therapy, and other measures for the relief of discomforts associated with acute, painful musculoskeletal conditions. The mode of action of this drug has not been clearly identified, but may be related to its sedative properties. Metaxalone does not directly relax tense skeletal muscles in man.
Dosage & Administration
DOSAGE AND ADMINISTRATION The recommended dose for adults and children over 12 years of age is one 800 mg tablet three to four times a day.
Warnings & Precautions
WARNINGS Serotonin Syndrome Cases of serotonin syndrome, a potentially life-threatening condition, have been reported during concomitant use of serotonergic drugs with Metaxalone used within the recommended dosage range (see PRECAUTIONS: Drug Interactions ) and with Metaxalone as a single agent taken at doses higher than the recommended dose (see OVERDOSAGE ). Serotonergic drugs include selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), triptans, 5-HT3 receptor antagonists, opioids (particularly fentanyl, meperidine, and methadone), drugs that affect the serotonergic neurotransmitter system (e.g., mirtazapine, trazodone, tramadol), and drugs that impair metabolism of serotonin (including monoamine oxidase (MAO) inhibitors, both those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue) (see PRECAUTIONS: Drug Interactions ). Serotonin syndrome symptoms may include mental status changes (e.g., agitation, hallucinations, coma), autonomic instability (e.g., tachycardia, labile blood pressure, hyperthermia), neuromuscular aberrations (e.g., hyperreflexia, incoordination, rigidity), and/or gastrointestinal symptoms (e.g., nausea, vomiting, diarrhea). The onset of symptoms generally occurs within several hours to a few days, but may occur later than that. Discontinue Metaxalone if serotonin syndrome is suspected. Risks from Concomitant Use with Alcohol or other CNS Depressants The sedative effects of Metaxalone and other CNS depressants (e.g., alcohol, benzodiazepines, opioids, tricyclic antidepressants (TCAs)) may be additive. Exercise caution with patients who take more than one of these CNS depressants simultaneously. Follow patients closely for signs and symptoms of respiratory depression and sedation (see PRECAUTIONS: Drug Interactions ).
Side Effects (Adverse Reactions)
ADVERSE REACTIONS The most frequent reactions to metaxalone include: CNS : drowsiness, dizziness, headache, and nervousness or “irritability”; Digestive : nausea, vomiting, gastrointestinal upset. Other adverse reactions are: Immune System : anaphylaxis, hypersensitivity reaction, rash with or without pruritus; Hematologic : leukopenia; hemolytic anemia; Hepatobiliary : jaundice; CNS : cases of serotonin syndrome, a potentially life-threatening condition, have been reported during concomitant use of serotonergic drugs with metaxalone used within the recommended dosage range and with metaxalone as a single agent taken at doses higher than the recommended dose (see WARNINGS , PRECAUTIONS: Drug Interactions , and OVERDOSAGE ).
Drug Interactions
Drug Interactions CNS Depressants : The sedative effects of Metaxalone and other CNS depressants (e.g., alcohol, benzodiazepines, opioids, tricyclic antidepressants (TCAs)) may be additive. Exercise caution with patients who take more than one of these CNS depressants simultaneously. Follow patients closely for signs and symptoms of respiratory depression and sedation (see WARNINGS ). Serotonergic Drugs : Serotonin syndrome has resulted from concomitant use of serotonergic drugs with Metaxalone used within the recommended dosage range (see WARNINGS ). If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation and dose adjustment. Discontinue Metaxalone if serotonin syndrome is suspected. Examples of serotonergic drugs include: selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), triptans, 5-HT3 receptor antagonists, opioids (particularly fentanyl, meperidine, and methadone), drugs that affect the serotonin neurotransmitter system (e.g., mirtazapine, trazodone, tramadol), monoamine oxidase (MAO) inhibitors (those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue).
Contraindications
CONTRAINDICATIONS Known hypersensitivity to any components of this product. Known tendency to drug induced, hemolytic, or other anemias. Significantly impaired renal or hepatic function.
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Medical Disclaimer: Information on this page is sourced from FDA-approved labeling data and is for educational reference only. It does not constitute medical advice. This information does not establish a provider-patient relationship. Always verify with current prescribing information and consult a licensed healthcare professional before any clinical decision. Read full disclaimer.
Data sourced from RxNorm (NLM/NIH), FDA Orange Book, OpenFDA, DailyMed. Last updated: 2026-03-02.