Skip to Content
Diagnosed with AS? Biologics can help >

Fexmid

Generic Name: cyclobenzaprine (sye kloe BEN za preen)
Brand Name: Amrix, Comfort Pac with Cyclobenzaprine, Fexmid

Medically reviewed: September 19, 2016

What is Fexmid?

Fexmid is a muscle relaxant. It works by blocking nerve impulses (or pain sensations) that are sent to your brain.

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

Fexmid may also be used for purposes not listed in this medication guide.

Important Information

You should not use Fexmid 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 Fexmid if you have taken an MAO inhibitor in the past 14 days, such as isocarboxazid, linezolid, phenelzine, rasagiline, selegiline, or tranylcypromine.

Before taking this medicine

Do not use Fexmid 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 Fexmid 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 Fexmid is safe for you, tell your doctor if you have:

Older adults may be more sensitive to the side effects of this medicine.

Fexmid 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 Fexmid 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 Fexmid?

Fexmid 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 Fexmid after long-term use. Ask your doctor how to avoid withdrawal symptoms when you stop using this medicine.

Fexmid 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 Fexmid can be fatal.

What should I avoid while taking Fexmid?

This medication may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Avoid drinking alcohol. Dangerous side effects could occur.

Fexmid 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 Fexmid and call your doctor at once if you have:

Common side effects may include:

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 Fexmid?

Taking Fexmid with other drugs that make you sleepy or slow your breathing can cause dangerous or life-threatening side effects. Ask your doctor before taking a sleeping pill, narcotic pain medicine, prescription cough medicine, a 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.

Further information

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.

Medical Disclaimer

Hide