Metaxalone

Key facts

• Metaxalone (sold as Skelaxin) is a centrally acting muscle relaxant used short-term for acute, painful muscle spasm.
• It is usually taken 3 to 4 times a day for no more than 2 to 3 weeks, alongside rest and physical therapy.
• It is sedating and can impair coordination: avoid driving or operating machinery until you know how it affects you, and avoid alcohol and other sedating drugs.
• Seek urgent care for a severe rash, yellowing of the skin or eyes, or signs of a serious allergic reaction.

What metaxalone treats

Metaxalone treats acute musculoskeletal pain and muscle spasm from a sprain, strain or similar injury, used alongside rest and physiotherapy. It does not treat spasticity from neurological conditions such as cerebral palsy or multiple sclerosis, and it is not intended for long-term pain management.

How metaxalone works

Metaxalone's exact mechanism is not fully established. It is thought to act within the central nervous system, dampening the nerve signaling between the brain, spinal cord and muscles that keeps a muscle tightly contracted, rather than acting directly on the muscle tissue itself.

Before you take it

• Do not take metaxalone if you have significant liver or kidney impairment, or a history of drug-induced hemolytic anemia.
• Tell your prescriber about alcohol use or other sedating medicines, such as opioids, benzodiazepines or sleep aids, since combining these raises the risk of extreme drowsiness and dangerously slowed breathing.
• Avoid driving or operating machinery until you know how the drug affects you.

Side effects

Common effects include drowsiness, dizziness, nausea and headache.

Stop and seek urgent medical care for:

• Severe rash or swelling of the face or tongue, a sign of an allergic reaction.
• Yellowing of the skin or eyes, a possible sign of liver injury.
• Unusual tiredness or unusually pale skin, which can signal rare hemolytic anemia.
• Fainting.

Safety essentials

• Metaxalone is sedating; do not drive or use machinery until you know your response, and avoid alcohol and other central-nervous-system depressants, which multiply the drowsiness and can dangerously slow breathing.
• Avoid it if you have significant liver or kidney disease, since these conditions raise drug levels in the body.
• Report yellowing skin or eyes, or unusual fatigue, promptly, since rare liver injury and hemolytic anemia have been reported.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.