Metaxalone
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From MedlinePlus, U.S. National Library of Medicine
Muscle Relaxant
Dosing in kidney impairment
Renal Impairment Metaxalone Tablets, 640 mg are contraindicated in patients with severe renal impairment . Metaxalone Tablets, 640 mg should be used with caution and additional monitoring should be considered in patients with mild to moderate renal impairment. The effect of renal impairment on metaxalone pharmacokinetics is unknown; however, metaxalone undergoes renal excretion as unidentified metabolites [see Clinical Pharmacology ] .
Dosing in liver impairment
Hepatic Impairment Metaxalone Tablets. 640 mg are contraindicated in patients with severe hepatic impairment . Metaxalone Tablets, 640 mg should be used with caution and additional monitoring should be considered in patients with mild to moderate hepatic impairment. The effect of hepatic impairment on metaxalone pharmacokinetics is unknown; however, metaxalone undergoes extensive hepatic metabolism [see Clinical Pharmacology ] .
Drug interactions
Check metaxalone against a medication listLabel text (5 paragraphs)
7 DRUG INTERACTIONS
7.1 Serotonergic Drugs If concomitant use of Metaxalone Tablets, 640 mg and another serotonergic drug is warranted, carefully observe the patient, particularly during treatment initiation and dosage modification. Discontinue Metaxalone Tablets, 640 mg if serotonin syndrome is suspected or if it occurs. Serotonin syndrome has resulted from concomitant use of metaxalone (within the recommended dosage range) and other serotonergic drugs [see Warnings and Precautions (5.1) ].
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).
7.2 Depressants If concomitant use of Metaxalone Tablets, 640 mg and another CNS depressant is warranted, closely monitor for signs of respiratory depression and sedation, particularly during treatment initiation and dosage modification. Due to the additive pharmacologic effect, concomitant use of Metaxalone Tablets, 640 mg with other CNS depressants may increase the risk of sedation and respiratory depression [see Warnings and Precautions (5.2) ].
7.3 Interaction of Metaxalone with Benedict’s Tests False-positive Benedict's tests, due to an unknown reducing substance, have been noted in metaxalone-treated patients. A glucose-specific test will differentiate findings.
Contraindications
The use of Metaxalone Tablets, 640 mg is contraindicated in patients with: Known hypersensitivity to any components of this product. Known tendency for drug-induced, hemolytic, or other anemias. Severe renal or hepatic impairment. • Known hypersensitivity to any components of this product. ( 4 ) • Known tendency to drug induced, hemolytic, or other anemias. ( 4 ) • Severe renal or hepatic impairment. ( 4 )
Safety data
Reported adverse events (FAERS)
Liver injury (LiverTox)
ELikelihood score E: Unlikely cause of clinically apparent liver injury.
Metaxalone is a centrally acting skeletal muscle relaxant that has been in use for more than 40 years. Metaxalone has not been associated with serum aminotransferase elevations during therapy or with clinically apparent hepatic injury.
ABCDEA: well known cause; E: unlikely cause. [HD]: high doses only.
Pregnancy and lactation
Pregnancy
8.1 Pregnancy Risk Summary There are no available data on metaxalone use in pregnancy to evaluate for a drug-associated risk of major birth defects, miscarriage or other adverse maternal or fetal outcomes despite decades of metaxalone use. Reproduction studies in rats have not revealed evidence of impaired fertility or harm to fetus due to metaxalone. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S.
general population, the estimated risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.
For breastfeeding, also see LactMed (National Library of Medicine), which summarizes milk levels and infant effects.
Supply and cost
Drug shortage status
Recalls (last 24 months)
Therapeutic equivalence (Orange Book)
Price ladder
Not the price at the counterThese are not what a patient pays at the pharmacy counter. They are what pharmacies, health plans, and government buyers pay, before manufacturer rebates. A patient's cost depends on their insurance (copay, coinsurance, or deductible) or the pharmacy's cash price.