Metaxalone (Oral route)
Skeletal Muscle Relaxant, Centrally Acting
Uses of This Medicine:
Metaxalone is used to help relax the muscles in your body and relieve the discomfort caused by acute (short-term), painful muscle or bone conditions. However, this medicine does not take the place of rest, exercise, physical therapy, or other treatments that your doctor may recommend for your condition.
Metaxalone is a skeletal muscle relaxant. It acts on the central nervous system (CNS) to relax muscles.
This medicine is available only with your doctor's prescription.
Before Using This Medicine:
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Appropriate studies have not been performed on the relationship of age to the effects of metaxalone in children 12 years of age and younger. Safety and efficacy have not been established.
Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of metaxalone in the elderly. However, elderly patients are more likely to have CNS effects and age-related kidney or liver problems, which may require caution in patients receiving metaxalone.
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Chloral Hydrate
- Gabapentin Enacarbil
- Gamma Hydroxybutyrate
- Methylene Blue
- Morphine Sulfate Liposome
- Opium Alkaloids
- Sodium Oxybate
- St John's Wort
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other medical problems—
The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:
- Anemia (eg, drug-induced, hemolytic) or
- Kidney disease, severe or
- Liver disease, severe—Should not be used in patients with these conditions.
- Kidney disease or
- Liver disease—Use with caution. The effects may be increased because of slower removal of the medicine from the body.
Proper Use of This Medicine:
Take this medicine only as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered.
The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For relaxing muscles:
- For oral dosage form (tablets):
- Adults and children 13 years of age and older—800 milligrams (mg) 3 to 4 times a day.
- Children 12 years of age and younger—Use and dose must be determined by your doctor.
- For oral dosage form (tablets):
If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Ask your healthcare professional how you should dispose of any medicine you do not use.
Precautions While Using This Medicine:
It is very important that your doctor check your and your child's progress at regular visits to make sure this medicine is working properly and to check for unwanted effects.
Check with your doctor right away if you have anxiety, restlessness, a fast heartbeat, fever, sweating, muscle spasms, twitching, nausea, vomiting, diarrhea, or see or hear things that are not there. These may be symptoms of a serious condition called serotonin syndrome. Your risk may be higher if you also take certain other medicines that affect serotonin levels in your body or if you take metaxalone for a long time.
This medicine may make you dizzy, drowsy, or less alert than you are normally. These effects may be increased if you take this medicine with food. Do not drive or do anything else that could be dangerous until you know how this medicine affects you.
Check with your doctor before using this medicine with alcohol or other medicines that affect the central nervous system (CNS). The use of alcohol or other medicines that affect the CNS with metaxalone may worsen the side effects of this medicine, such as dizziness, poor concentration, drowsiness, unusual dreams, and trouble with sleeping. Some examples of medicines that affect the CNS are antihistamines or medicine for allergies or colds, sedatives, tranquilizers, or sleeping medicines, medicine for depression, medicine for anxiety, prescription pain medicine or narcotics, medicine for attention deficit and hyperactivity disorder, medicine for seizures or barbiturates, other muscle relaxants, or anesthetics, including some dental anesthetics.
Make sure any doctor or dentist who treats you knows that you are using this medicine. This medicine may affect the results of certain medical tests.
Side Effects of This Medicine:
- Incidence not known
- back, leg, or stomach pains
- black, tarry stools
- bleeding gums
- chest pain
- clay-colored stools
- dark urine
- difficulty in breathing or swallowing
- fast heartbeat
- general body swelling
- hives, itching, skin rash
- loss of appetite
- painful or difficult urination
- pale skin
- poor coordination
- puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
- redness of the skin
- sore throat
- sores, ulcers, or white spots on the lips or in the mouth
- stomach pain
- swelling of the face, throat, or tongue
- swollen glands
- talking or acting with excitement you cannot control
- tightness in the chest
- trembling or shaking
- unpleasant breath odor
- unusual bleeding or bruising
- unusual tiredness or weakness
- vomiting of blood
- yellowing of the eyes or skin
- More common
- stomach or bowel upset
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Last Updated: 8/28/2020