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metaxalone(me-tax -a-lone) ,
Pregnancy Category: UK
ClassificationTherapeutic: skeletal muscle relaxants
Muscle spasm associated with acute painful musculoskeletal conditions (with rest and physical therapy).
Skeletal muscle relaxation, probably as a result of CNS depression.
Skeletal muscle relaxation.
Absorption: Well absorbed following oral administration.
Metabolism and Excretion: Mostly metabolized by the liver; metabolites excreted in urine.
Half-life: 2–3 hr.
|PO||1 hr||2 hr||4–6 hr|
Contraindicated in: Hypersensitivity;Significant hepatic/renal impairment;History of drug-induced hemolytic anemia or other anemia.
Use Cautiously in: Hepatic impairment;History of seizures; Obstetric / Lactation / Pediatric: Pregnancy, lactation or children ≤12 yr (safety not established); Geriatric: Appears on Beers list. Poorly tolerated due to anticholinergic effects.
Adverse Reactions/Side Effects
Central nervous system
- drowsiness (most frequent)
- dizziness (most frequent)
- nausea (most frequent)
- dry mouth
- GI upset
- urinary retention
Drug-Drug interaction↑ CNS depression with other CNS depressants including alcohol, antihistamines, opioid analgesics, and sedative/hypnotics.Concomitant use of kava-kava, valerian, or chamomile can ↑ CNS depression.
Oral (Adults) 800 mg 3–4 times daily.
Availability (generic available)
Tablets: 800 mg Cost: Generic — $409.39 / 100
- Assess for pain, muscle stiffness, and range of motion before and periodically during therapy.
- Geriatric: Assess geriatric patients for anticholinergic effects (sedation and weakness).
- Lab Test Considerations: Monitor hepatic function tests closely in patients with pre-existing liver damage.
- May cause false-positive Benedict’s tests.
Potential Nursing DiagnosesAcute pain (Indications)
Impaired bed mobility (Indications)
Risk for injury (Side Effects)
- Provide safety measures as indicated. Supervise ambulation and transfer.
- Oral: Administer 3–4 times daily.
- Instruct patient to take medication as directed. Take missed doses within 1 hr; if not, return to regular dosing schedule. Do not double doses.
- Encourage patient to comply with additional therapies prescribed for muscle spasm (rest, physical therapy, heat).
- Medication may cause dizziness, drowsiness, and blurred vision. Advise patient to avoid driving and other activities requiring alertness until response to drug is known.
- Instruct patient to make position changes slowly to minimize orthostatic hypotension.
- Advise patient to avoid concurrent use of alcohol and other CNS depressants while taking this medication.
- Instruct patient to notify health care professional if skin rash or yellowish discoloration of the skin or eyes occurs.
- Emphasize the importance of routine follow-up exams to monitor progress.
- Decreased musculoskeletal pain and muscle spasticity.
- Increased range of motion.
Skelaxin™A centrally acting muscle relaxant.
Nausea, vomiting, gastrointestinal upset, drowsiness, dizziness, headache, irritability, rash, pruritus, leukopenia, haemolytic anaemia, jaundice.