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Generic Name: cyclobenzaprine (sye kloe BEN za preen)
Brand Name: Amrix, Comfort Pac with Cyclobenzaprine, Fexmid
Medically reviewed on September 19, 2016.
What is cyclobenzaprine?
Cyclobenzaprine is a muscle relaxant. It works by blocking nerve impulses (or pain sensations) that are sent to your brain.
Cyclobenzaprine is used together with rest and physical therapy to treat skeletal muscle conditions such as pain or injury.
Cyclobenzaprine may also be used for purposes not listed in this medication guide.
What is the most important information I should know about cyclobenzaprine?
You should not use cyclobenzaprine if you have a thyroid disorder, heart block, congestive heart failure, a heart rhythm disorder, or you have recently had a heart attack.
Do not use cyclobenzaprine if you have taken an MAO inhibitor in the past 14 days, such as isocarboxazid, linezolid, phenelzine, rasagiline, selegiline, or tranylcypromine.
What should I discuss with my healthcare provider before taking cyclobenzaprine?
Do not use cyclobenzaprine if you have taken an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, phenelzine, rasagiline, selegiline, and tranylcypromine.
You should not use cyclobenzaprine if you are allergic to it, or if you have:
a heart rhythm disorder, or you have recently had a heart attack;
congestive heart failure;
heart block; or
a thyroid disorder.
To make sure cyclobenzaprine is safe for you, tell your doctor if you have:
enlarged prostate; or
problems with urination.
Older adults may be more sensitive to the side effects of this medicine.
Cyclobenzaprine is not expected to harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment.
It is not known whether cyclobenzaprine passes into breast milk or if it could harm a nursing baby. Tell your doctor if you are breast-feeding a baby.
How should I take cyclobenzaprine?
Cyclobenzaprine is usually taken once daily for only 2 or 3 weeks. Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.
Take the medicine at the same time each day.
Do not crush, chew, break, or open an extended-release capsule. Swallow it whole.
You may have unpleasant withdrawal symptoms when you stop taking cyclobenzaprine after long-term use. Ask your doctor how to avoid withdrawal symptoms when you stop using this medicine.
Cyclobenzaprine is only part of a complete program of treatment that may also include rest, physical therapy, or other pain relief measures. Follow your doctor's instructions.
Store at room temperature away from moisture, heat, and light.
What happens if I miss a dose?
Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose of cyclobenzaprine can be fatal.
What should I avoid while taking cyclobenzaprine?
This medication may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.
Drinking alcohol can increase certain side effects of cyclobenzaprine.
Cyclobenzaprine side effects
Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Stop using cyclobenzaprine and call your doctor at once if you have:
severe drowsiness, fast heart rate;
tremors or shaking;
pounding heartbeats or fluttering in your chest; or
agitation, hallucinations, fever, overactive reflexes, nausea, vomiting, diarrhea, loss of coordination, fainting.
Common side effects may include:
drowsiness, tired feeling;
blurred vision, dry mouth or throat, altered sense of taste; or
nausea, upset stomach, constipation.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
See also: Side effects (in more detail)
What other drugs will affect cyclobenzaprine?
Taking cyclobenzaprine with other drugs that make you sleepy or slow your breathing can cause dangerous or life-threatening side effects. Ask your doctor before taking cyclobenzaprine with a sleeping pill, narcotic pain medicine, other muscle relaxer, or medicine for anxiety, depression, or seizures.
This list is not complete. Other drugs may interact with cyclobenzaprine, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.
Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
Copyright 1996-2012 Cerner Multum, Inc. Version: 4.02. Revision Date: 2015-12-02, 1:14:15 PM.
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- Drug class: skeletal muscle relaxants