Generic Name: cyclobenzaprine (sye-kloe-BEN-za-preen) (Oral route)
Medically reviewed by Drugs.com. Last updated on Nov 22, 2020.
The Flexeril brand name has been discontinued in the U.S. If generic versions of this product have been approved by the FDA, there may be generic equivalents available.
Commonly used brand name(s)
In the U.S.
- FusePaq Tabradol
Available Dosage Forms:
- Capsule, Extended Release
Therapeutic Class: Skeletal Muscle Relaxant, Centrally Acting
Uses for Flexeril
Cyclobenzaprine is used to help relax certain muscles in your body. It helps relieve pain, stiffness, and discomfort caused by strains, sprains, or injuries to your muscles. However, this medicine does not take the place of rest, exercise or physical therapy, or other treatment that your doctor may recommend for your medical problem. Cyclobenzaprine acts on the central nervous system (CNS) to produce its muscle relaxant effects. Its actions on the CNS may also cause some of this medicine's side effects.
This medicine is available only with your doctor's prescription.
Before using Flexeril
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 cyclobenzaprine extended-release capsules in the pediatric population. Safety and efficacy have not been established.
Because of the possibility of higher blood levels in the elderly as compared to younger adults, use of cyclobenzaprine extended-release capsules is not recommended in the elderly.
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.
Interactions with medicines
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 not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
- Methylene Blue
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.
- Aripiprazole Lauroxil
- Arsenic Trioxide
- Calcium Oxybate
- Gabapentin Enacarbil
- Glycopyrronium Tosylate
- Inotuzumab Ozogamicin
- Magnesium Oxybate
- Morphine Sulfate Liposome
- Potassium Oxybate
- Secretin Human
- Sodium Oxybate
- Sodium Phosphate
Interactions with food/tobacco/alcohol
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. 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 is usually not recommended, but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use this medicine, or give you special instructions about the use of 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:
- Congestive heart failure or
- Heart attack, recent or
- Heart block or
- Heart rhythm problems (eg, arrhythmia) or
- Hyperthyroidism (overactive thyroid)—Should not be used in patients with these conditions.
- Glaucoma, angle closure, history of or
- Trouble urinating, history of—Use with caution. May these conditions worse.
- Liver disease—Use with caution. The effects may be increased because of slower removal of the medicine from the body. .
Proper use of Flexeril
This section provides information on the proper use of a number of products that contain cyclobenzaprine. It may not be specific to Flexeril. Please read with care.
Take this medicine only as directed by your doctor. Do not take more of it and do not take it more often than your doctor ordered. To do so may increase the chance of serious side effects.
Swallow the extended-release capsule whole. If you cannot swallow the capsule whole, you may open the capsule and sprinkle the contents over one tablespoon of applesauce. Swallow the mixture right away without chewing. Rinse the mouth to make sure all of the medicine have been swallowed. Do not save any of the mixture to use later.
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 stiff muscles:
- For oral dosage form (extended-release capsules):
- Adults—15 milligrams (mg) once a day. Some patients may need 30 mg (one 30 mg capsule or two 15 mg capsules) per day.
- Children—Use and dose must be determined by your doctor .
- For oral dosage form (tablets):
- Adults and children 15 years of age and older—10 milligrams (mg) 3 times a day. The largest amount should be no more than 60 mg (six 10-mg tablets) a day.
- Children younger than 15 years of age—Use and dose must be determined by your doctor.
- For oral dosage form (extended-release capsules):
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 Flexeril
It is very important that your doctor check your progress at regular visits. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to take it.
If your condition does not improve within 2 or 3 weeks, or if it becomes worse, check with your doctor.
Do not use the extended-release capsules if you have used an MAO inhibitor (MAOI) such as Eldepryl®, Marplan®, Nardil®, or Parnate® within 14 days of each other.
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.
This medicine will add to the effects of alcohol and other CNS depressants (medicines that slow down the nervous system, possibly causing drowsiness). Some examples of CNS depressants are antihistamines or medicine for hay fever, other allergies, or colds, sedatives, tranquilizers, or sleeping medicine, prescription pain medicine or narcotics, medicine for seizures or barbiturates, other muscle relaxants, or anesthetics, including some dental anesthetics. Check with your doctor before taking any of the above while you are using this medicine.
This medicine may cause some people to have blurred vision or to become drowsy, dizzy, or less alert than they are normally. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or are not alert and able to see well.
Cyclobenzaprine may cause dryness of the mouth. For temporary relief, use sugarless candy or gum, melt bits of ice in your mouth, or use a saliva substitute. However, if your mouth continues to feel dry for more than 2 weeks, check with your medical doctor or dentist. Continuing dryness of the mouth may increase the chance of dental disease, including tooth decay, gum disease, and fungus infections.
Flexeril side effects
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:
- Clumsiness or unsteadiness
- mental depression
- problems in urinating
- ringing or buzzing in the ears
- skin rash, hives, or itching occurring without other symptoms of an allergic reaction listed above
- unusual thoughts or dreams
- yellow eyes or skin
Get emergency help immediately if any of the following symptoms of overdose occur:
Symptoms of overdose
- Convulsions (seizures)
- drowsiness (severe)
- dry, hot, flushed skin
- fast or irregular heartbeat
- hallucinations (seeing, hearing, or feeling things that are not there)
- increase or decrease in body temperature
- troubled breathing
- unexplained muscle stiffness
- unusual nervousness or restlessness (severe)
- vomiting (occurring together with other symptoms of overdose)
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:
- Blurred vision
- dizziness, drowsiness, or lightheadedness
- dryness of the mouth
Less common or rare
- Bloated feeling or gas, indigestion, nausea or vomiting, or stomach cramps or pain
- excitement or nervousness
- frequent urination
- general feeling of discomfort or illness
- muscle twitching
- numbness, tingling, pain, or weakness in hands or feet
- pounding heartbeat
- problems in speaking
- trouble sleeping
- unpleasant taste or other taste changes
- unusual muscle weakness
- unusual tiredness
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.
Frequently asked questions
More about Flexeril (cyclobenzaprine)
- Side Effects
- During Pregnancy or Breastfeeding
- Dosage Information
- Patient Tips
- Drug Images
- Drug Interactions
- Compare Alternatives
- Support Group
- 169 Reviews
- Generic Availability
- Drug class: skeletal muscle relaxants
- FDA Alerts (1)
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