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Metaxalone

Generic name: metaxalone [ me-TAX-a-lone ]
Brand name: Skelaxin
Dosage form: oral tablet (400 mg; 800 mg)
Drug class: Skeletal muscle relaxants

Medically reviewed by Drugs.com on Mar 29, 2024. Written by Cerner Multum.

What is metaxalone?

Metaxalone is used together with rest and physical therapy to treat muscle conditions that cause pain or injury, in adults and children at least 12 years old.

Metaxalone may also be used for purposes not listed in this medication guide.

Metaxalone side effects

Get emergency medical help if you have signs of an allergic reaction: hives, difficult breathing, swelling of your face, lips, tongue, or throat.

Seek medical attention right away if you have symptoms of serotonin syndrome, such as: agitation, hallucinations, fever, sweating, shivering, fast heart rate, muscle stiffness, twitching, loss of coordination, nausea, vomiting, or diarrhea.

Metaxalone may cause serious side effects. Stop using metaxalone and call your doctor at once if you have:

Drowsiness or dizziness may last longer in older adults. Use caution to avoid falling or accidental injury.

Common side effects of metaxalone may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Metaxalone side effects (more detail)

Warnings

You should not use metaxalone if you have anemia (low red blood cells), or severe kidney or liver disease.

Before taking this medicine

You should not use metaxalone if you are allergic to it, or if you have:

Tell your doctor if you have ever had:

Tell your doctor if you also use stimulant medicine, opioid medicine, herbal products, or medicine for depression, mental illness, Parkinson's disease, migraine headaches, serious infections, or prevention of nausea and vomiting. An interaction with metaxalone could cause a serious condition called serotonin syndrome.

It is not known whether metaxalone will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

Ask a doctor if it is safe to breastfeed while using this medicine.

How should I take metaxalone?

Follow the directions on your prescription label and read all medication guides or instruction sheets. Never use metaxalone in larger amounts, or for longer than prescribed.

You may take metaxalone with or without food. Taking this medicine with food may cause increased drowsiness or dizziness.

This medicine can affect the results of certain medical tests. Tell laboratory staff or any doctor who treats you that you are using metaxalone.

Your treatment may also include rest, physical therapy, or other pain relief measures. Follow your doctor's instructions.

Store at room temperature away from moisture and heat.

Metaxalone dosing information

Usual Adult Dose for Muscle Spasm:

Recommended dosage: 640 mg orally 3 to 4 times a day
Maximum dose: 2,560 mg (one tablet 4 times a day)

Comments:
-Metaxalone tablets 640 mg, and SKELAXIN 800 mg are not mutually substitutable on a mg-to-mg basis due to differences in pharmacokinetic profiles.
-When appropriate to switch a patient taking SKELAXIN 800 mg tablets on an empty stomach to 640 mg tablets:
---Stop SKELAXIN 800 mg 3 times a day and start 640 mg tablets 3 times a day on an empty stomach, OR
--- Stop SKELAXIN 800 mg 4 times a day and start 640 mg tablets 4 times a day on an empty stomach.
-For patients taking either product with food, do not switch between SKELAXIN 800 mg and 640 mg tablets.

Use: Painful musculoskeletal conditions as an adjunct to rest, physical therapy, and other measures

Usual Pediatric Dose for Muscle Spasm:

Recommended dosage: 640 mg orally 3 to 4 times a day
Maximum dose: 2,560 mg (one tablet 4 times a day)

Comments:
-Metaxalone tablets 640 mg, and SKELAXIN 800 mg are not mutually substitutable on a mg-to-mg basis due to differences in pharmacokinetic profiles.
-When appropriate to switch a patient taking SKELAXIN 800 mg tablets on an empty stomach to 640 mg tablets:
---Stop SKELAXIN 800 mg 3 times a day and start 640 mg tablets 3 times a day on an empty stomach, OR
--- Stop SKELAXIN 800 mg 4 times a day and start 640 mg tablets 4 times a day on an empty stomach.
-For patients taking either product with food, do not switch between SKELAXIN 800 mg and 640 mg tablets.

Use: Painful musculoskeletal conditions as an adjunct to rest, physical therapy, and other measures in patients 13 years of age and older

Detailed Metaxalone dosage information

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose can be fatal.

What should I avoid while taking metaxalone?

Do not drink alcohol. Dangerous side effects could occur.

Avoid driving or hazardous activity until you know how metaxalone will affect you. Dizziness or drowsiness can cause falls, accidents, or severe injuries.

What other drugs will affect metaxalone?

Using metaxalone with other drugs that slow your breathing can cause dangerous side effects or death. Ask your doctor before using opioid medication, a sleeping pill, a muscle relaxer, or medicine for anxiety or seizures.

Other drugs may affect metaxalone, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all other medicines you use.

Metaxalone drug interactions (more detail)

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer

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