Metaxalone

Medically Reviewed by Dr. Harshi Dhingra, M.D.

Last Reviewed: Apr 29, 2024

Warnings


Metaxalone (Skelaxin) Risks, Warnings, and Complications


Metaxalone can cause or worsen health problems in some people. Talk to your doctor or pharmacist about taking other muscle relaxants if you are at an increased risk of complications from metaxalone use. Some of the risks of taking metaxalone include:

  • SEROTONIN SYNDROME: Serotonin is a natural substance in the central nervous system. Serotonin syndrome is a potentially life-threatening condition that occurs due to too much serotonin in the body. It can occur in people taking high doses of metaxalone or those taking metaxalone with other serotonergic drugs (medications that can increase serotonin levels). 

    Symptoms of serotonin syndrome may include changes in mental status (such as agitation, hallucinations, and loss of consciousness), fast heart rate, changes in blood pressure, high body temperature, increased reflexes, loss of coordination, muscle rigidity, nausea, vomiting, and diarrhea. These symptoms usually occur within a few hours to days but can occur later as well. Seek emergency medical help if you develop these symptoms. 

  • DRUG INTERACTIONS: Metaxalone has sedative effects. Other CNS depressants such as benzodiazepines (anti-anxiety medications), opioids, and alcohol can have additive sedative effects if taken with metaxalone. Give your doctor a complete list of your medications before starting treatment with this muscle relaxant. Seek emergency medical help if you develop extreme drowsiness or weak or shallow breathing while on this medicine. 

  • EFFECTS ON CONCENTRATION: Metaxalone can cause drowsiness, dizziness, a lightheaded feeling, and reduced concentration and focus. The risk is higher in elderly patients (age 65 and above) if you take metaxalone with food or if you drink alcohol while on this medication. Be cautious during activities such as driving and operating machinery until you know how metaxalone affects you.

  • LIVER AND KIDNEY DISEASE: You should not take metaxalone if you have severe liver disease or severe kidney disease. These organs help to eliminate the medicine from the body. If they are not working properly, there can be a buildup of the drug in the body, putting you at risk of serious adverse reactions. 

  • LABORATORY TESTS: Metaxalone can interfere with the results of certain medical tests. Tell all your healthcare providers and laboratory personnel you are on this medicine.


Precautions Before Starting Metaxalone (Skelaxin)

Tell your doctor if you have ever had an allergic reaction to metaxalone, any of the active or inactive ingredients in metaxalone tablets, or any other drugs. Your pharmacy can give you a list of ingredients.

Give your doctor and pharmacist a complete list of your medications, including prescription drugs, over-the-counter medicines, dietary supplements, vitamins, and herbal remedies. This can help avoid potentially dangerous drug interactions.

Check all medicine labels to see if they contain metaxalone. This medication may be present in combination products with other medicines. Taking multiple products containing metaxalone can put you at risk of an overdose. 

Give your doctor a complete medical history. Metaxalone may not be safe for people with certain medical conditions, including blood disorders such as low red blood cells, kidney disease, liver disease, or seizures. 

Inform your doctor if you are pregnant, might be pregnant, are planning a pregnancy, or are breast-feeding a nursing baby. It is unclear if this drug can harm an unborn baby or if it passes into breast milk.

If you are age 65 or above, talk to your doctor about the potential benefits versus risks of taking metaxalone. There may be other safer muscle relaxants available for older adults.

Precautions During Use of Metaxalone (Skelaxin)

Keep all your medical and lab appointments while on metaxalone. 

Metaxalone can make you drowsy and dizzy. Avoid driving a car, operating machinery, or doing other hazardous tasks until you know how this medication affects you. Alcohol can make these side effects worse. Avoid drinking alcohol while on metaxalone. Read all food and medicine labels to make sure they don’t contain alcohol.

Call your doctor if you become pregnant while on metaxalone.

Tell all your doctors you are on metaxalone, especially before any surgery, including dental procedures.

Metaxalone (Skelaxin) Drug Interactions

Certain other drugs can affect how metaxalone works. Possible interactions between metaxalone and other medicines can increase the risk of severe adverse effects. The following medications can have interactions with metaxalone:

  • Tricyclic antidepressants (TCAs) such as amitriptyline, nortriptyline (Pamelor), and others
  • Selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine (Prozac), sertraline (Zoloft), citalopram (Celexa), and others
  • Serotonin-norepinephrine reuptake inhibitors (SNRIs) such as venlafaxine (Effexor XR), duloxetine (Cymbalta), and others
  • Serotonin modulators such as trazodone (Desyrel)
  • Monoamine oxidase (MAO) inhibitors such as isocarboxazid, selegiline, phenelzine, tranylcypromine, linezolid, and methylene blue
  • Atypical tetracyclic antidepressants such as mirtazapine
  • Triptans (migraine medications) such as sumatriptan, frovatriptan, zolmitriptan, eletriptan, and naratriptan
  • Opioid pain medications such as fentanyl, tramadol, methadone, and meperidine
  • 5-HT3 receptor antagonists (nausea medications) such as ondansetron

The above list does not include all possible interactions of metaxalone. Give your doctor or pharmacist a complete list of your medications, including prescription drugs, OTC medications, dietary supplements, and herbal remedies. Also, tell your healthcare professional if you smoke, drink alcohol, or use recreational drugs because some of these substances can cause serious health complications when used with prescription medications.