By Medically reviewed by hellodoktor

Generic Name: Flexeril Brand Name(s): Generics only. No brands available.


What is Flexeril® (cyclobenzaprine) used for?

Flexeril® is commonly used as a muscle relaxant. It works by blocking nerve impulses (or pain sensations) that are sent to your brain.

Flexeril® is used together with rest and physical therapy to treat skeletal muscle conditions such as pain or injury.

How should I take Flexeril® (cyclobenzaprine)?

Take this medicine by mouth with a full glass of water, usually three times a day but you should consult your doctor.

Flexeril® is the only part of a complete program of treatment that may also include rest, physical therapy, or other pain relief measures. Follow your doctor’s direction.

How do I store Flexeril® (cyclobenzaprine)?

Flexeril® is best stored at room temperature away from direct light and moisture. To prevent drug damage, you should not store Flexeril® in the bathroom or the freezer. There may be different brands of Flexeril® that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush Flexeril® down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Precautions & warnings

What should I know before using Flexeril® (cyclobenzaprine)?

Before using this drug, tell your doctor if:

  • You are pregnant or breastfeeding. This is because, while you are expecting or feeding a baby, you should only take medicines on the recommendation of a doctor.
  • You are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, such as herbal and complementary medicines.
  • You have allergy with any of active or inactive ingredients of Flexeril® or other medications.
  • You have any other illnesses, disorders, or medical conditions.

Do not take Flexeril® if you have used an MAO inhibitor such as isocarboxazid (Marplan), tranylcypromine (Parnate), phenelzine (Nardil), or selegiline (Eldepryl, Emsam) within the past 14 days. Serious, life-threatening side effects can occur if you take Flexeril® before the MAO inhibitor has cleared from your body.

Do not use Flexeril® if you have recently had a heart attack, or if you have:

Is it safe during pregnancy or breastfeeding?

There are no adequate studies in women for determining risk when using this medication during pregnancy or while breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking this medication. This medication is pregnancy risk category B according to the US Food and Drug Administration (FDA).

FDA pregnancy risk category reference below:

  • A=No risk
  • B=No risk in some studies
  • C=There may be some risk
  • D=Positive evidence of risk
  • X=Contraindicated
  • N=Unknown

Side effects

What side effects can occur from Flexeril® (cyclobenzaprine)?

If you suffer from these serious side effects, you need to stop using Flexeril® and call your doctor immediately:

  • Fast heartbeats
  • Chest pain or heavy feeling
  • Pain spreading to the arm or shoulder, nausea, sweating, general ill feeling
  • Sudden numbness or weakness, especially on one side of the body
  • Sudden headache, confusion, problems with vision, speech, or balance
  • Feeling light-headed, fainting
  • Confusion, weakness, lack of coordination
  • Nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes)
  • Seizure
  • Unusual thoughts or behavior, hallucinations
  • Easy bruising or bleeding, unusual weakness

Here are less serious side effects of Flexeril®:

  • Dry mouth or throat
  • Blurred vision
  • Drowsiness
  • Dizziness
  • Tired feeling
  • Loss of appetite
  • Stomach pain
  • Nausea
  • Diarrhea, constipation, gas
  • Muscle weakness

Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.


What drugs may interact with Flexeril® (cyclobenzaprine)?

Flexeril® may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.

Products that may interact with this drug are:

  • Tricyclic antidepressants (such as amitriptyline, imipramine)
  • Atropine (Donnatal, and others), benztropine (Cogentin), dimenhydrinate (Dramamine), methscopolamine (Pamine), or scopolamine (Transderm-Scop)
  • A bronchodilator such as ipratroprium (Atrovent) or tiotropium (Spiriva)
  • Glycopyrrolate (Robinul)
  • Guanethidine (Ismelin)
  • Mepenzolate (Cantil)
  • Tramadol (Ultram)
  • Bladder or urinary medications such as darifenacin (Enablex), flavoxate (Urispas), oxybutynin (Ditropan, Oxytrol), tolterodine (Detrol), or solifenacin (Vesicare)
  • Irritable bowel medications such as dicyclomine (Bentyl), hyoscyamine (Anaspaz, Cystospaz, Levsin, and others), or propantheline (Pro-Banthine)

Does food or alcohol interact with Flexeril® (cyclobenzaprine)?

Alcohol can increase the nervous system side effects of Flexeril® such as dizziness, drowsiness, and difficulty concentrating. Some people may also experience impairment in thinking and judgment. You should avoid or limit the use of alcohol while being treated with Flexeril®.

What health conditions may interact with Flexeril® (cyclobenzaprine)?

Flexeril® may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.

Health conditions that may interact with this drug are:

  • Cardiovascular disease
  • Problems with urination
  • Enlarged prostate
  • Glaucoma
  • Liver disease


The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using this medication.

What is the dose of Flexeril® (cyclobenzaprine) for an adult?

For most patients, the recommended dose of Flexeril® is 5 mg three times a day. Based on individual patient response, the dose may be increased to 10 mg three times a day. Use of Flexeril® for periods longer than two or three weeks is not recommended.

What is the dose of Flexeril® (cyclobenzaprine) for a child?

Flexeril should be used with extreme caution in children younger than 15 years old. The dosage has not been established in pediatric patients. It may be unsafe for your child. It is always important to fully understand the safety of the drug before using. Please consult with your doctor or pharmacist for more information.

How is Flexeril® (cyclobenzaprine) available?

Flexeril® is available in the following dosage:

  • Tablet

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of Flexeril®, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.

Hello Health Group does not provide medical advice, diagnosis or treatment.

Review Date: July 12, 2017 | Last Modified: September 12, 2019

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