In the U.S.—

In Canada—

• Skeletal muscle relaxant

Cyclobenzaprine (sye-kloe-BEN-za-preen) is used to help relax certain muscles in your body. It helps relieve the pain, stiffness, and discomfort caused by strains, sprains, or injuries to your muscles. However, FLEXERIL 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 FLEXERIL's side effects.

Cyclobenzaprine may also be used for other conditions as determined by your doctor.

Cyclobenzaprine is available only with your doctor's prescription, in the following dosage form:

Oral
• Tablets (U.S. and Canada)

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 cyclobenzaprine, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to cyclobenzaprine. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Studies on birth defects with cyclobenzaprine have not been done in humans. However, cyclobenzaprine has not been shown to cause birth defects or other problems in animal studies.

Breast-feeding—It is not known whether cyclobenzaprine passes into breast milk. Although most medicines pass into the breast milk in small amounts, many of them may be used safely while breast-feeding. Mothers who are taking FLEXERIL and who wish to breast-feed should discuss this with their doctor.

Children—Studies on FLEXERIL have been done only in adult patients, and there is no specific information comparing use of cyclobenzaprine in children with use in other age groups.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of cyclobenzaprine in the elderly with use in other age groups.

Other 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 cyclobenzaprine, it is especially important that your health care professional know if you are taking any of the following:

• Alcohol or
• Central nervous system (CNS) depressants (medicines that cause drowsiness) or
• Tricyclic antidepressants (amitriptyline [e.g., Elavil], amoxapine [e.g., Asendin], clomipramine [e.g., Anafranil], desipramine [e.g., Pertofrane], doxepin [e.g., Sinequan], imipramine [e.g., Tofranil], nortriptyline [e.g., Aventyl], protriptyline [e.g., Vivactil], trimipramine [e.g., Surmontil])—The chance of side effects may be increased

• Monoamine oxidase (MAO) inhibitors (furazolidone [e.g., Furoxone], phenelzine [e.g., Nardil], procarbazine [e.g., Matulane], selegiline (e.g., Eldepryl), tranylcypromine [e.g., Parnate])—Taking cyclobenzaprine while you are taking or within 2 weeks of taking MAO inhibitors may increase the chance of side effects

• Glaucoma or
• Problems with urination—Cyclobenzaprine can make your condition worse

• Heart or blood vessel disease or
• Overactive thyroid—The chance of side effects may be increased

Take FLEXERIL 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.

Dosing—

The dose of cyclobenzaprine will be different for different people. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of cyclobenzaprine. If your dose is different, do not change it unless your doctor tells you to do so.

• For the oral dosage form (tablets):
  • For relaxing stiff muscles:
    • Adults and teenagers 15 years of age and older—The usual dose is 10 milligrams (mg) three times a day. The largest amount should be no more than 60 mg (six 10-mg tablets) a day.
    • Children and teenagers up to 15 years of age—Dose must be determined by your doctor.

Missed dose—

If you miss a dose of FLEXERIL and remember within an hour or so of the missed dose, take it right away. Then go back to your regular dosing schedule. But if you do not remember until later, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage—

To store FLEXERIL:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store FLEXERIL in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.