Fexmid

Generic Name: cyclobenzaprine
Other Brand Names: Flexeril, cyclobenzaprine

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 to treat pain, tenderness, and limited motion caused by muscle spasms. This medication is used together with rest and physical therapy for short-term treatment (2 to 3 weeks).

Cyclobenzaprine may also be used for purposes other than those listed in this medication guide.

Uses Side Effects Precautions Interactions Overdose
What should I discuss with my healthcare provider before taking cyclobenzaprine?

Do not take cyclobenzaprine 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 cyclobenzaprine before the MAO inhibitor has cleared from your body.

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

  • a heart rhythm disorder;

  • congestive heart failure;

  • heart block; or

  • an overactive thyroid.

Before using this medication, tell your doctor if you have:

  • problems with urination;

  • enlarged prostate;

  • glaucoma; or

  • liver disease.

If you have any of these conditions, you may not be able to use cyclobenzaprine, or you may need a dosage adjustment or special tests during treatment.

FDA pregnancy category B. This medication is not expected to be harmful to 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. Do not use this medication without telling your doctor if you are breast-feeding a baby.

Do not give this medication to a child younger than 12 years old.

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

How should I take cyclobenzaprine?

Take this medication exactly as it was prescribed for you. Do not take the medication in larger amounts, or take it for longer than recommended by your doctor.

Take each dose with a full glass of water.

This medication is usually taken three times each day for a period of 2 to 3 weeks. Do not use cyclobenzaprine for longer than 3 weeks unless your doctor has told you to.

Do not stop taking cyclobenzaprine suddenly if you have been taking it for longer than 1 week. Stopping suddenly may cause nausea, headache and general discomfort.

This medication can cause you to have unusual results with certain medical tests. Tell any doctor who treats you that you are using cyclobenzaprine.

Store cyclobenzaprine at room temperature away from moisture and heat.

What happens if I miss a dose of cyclobenzaprine?

Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at the next regularly scheduled time. Do not take extra medicine to make up the missed dose.

Where can I get more information about cyclobenzaprine?
Your pharmacist has information about cyclobenzaprine written for health professionals that you may read.
What are the possible side effects of cyclobenzaprine?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop using cyclobenzaprine and call your doctor at once if you have any of these serious side effects:

  • fast, pounding, or uneven 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 (convulsions);

  • unusual thoughts or behavior, hallucinations (seeing things); or

  • easy bruising or bleeding, unusual weakness.

Continue using cyclobenzaprine and talk with your doctor if you have any of these less serious side effects:

  • dry mouth, increased thirst;

  • blurred vision;

  • drowsiness, dizziness, tired feeling;

  • feeling nervous or irritable;

  • heartburn, loss of appetite, stomach pain, nausea, vomiting;

  • muscle weakness;

  • diarrhea, constipation, gas; or

  • sore throat, cold symptoms.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.

What is the most important information I should know about cyclobenzaprine?

Do not take cyclobenzaprine 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 cyclobenzaprine before the MAO inhibitor has cleared from your body.

You should not take cyclobenzaprine if you have recently had a heart attack, or if you have a heart rhythm disorder, congestive heart failure, heart block, or an overactive thyroid.

Do not stop taking cyclobenzaprine suddenly if you have been taking it for longer than 1 week. Stopping suddenly may cause nausea, headache and general discomfort.

Avoid drinking alcohol, which can increase some of the side effects of cyclobenzaprine.

Cyclobenzaprine can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.

What should I avoid while taking cyclobenzaprine?

Cyclobenzaprine can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.

Avoid using other medicines that make you sleepy (such as cold medicine, pain medication, muscle relaxers, and medicine for seizures, depression or anxiety). They can add to sleepiness caused by cyclobenzaprine.

Avoid drinking alcohol, which can increase some of the side effects of cyclobenzaprine.

What other drugs will affect cyclobenzaprine?

Before taking cyclobenzaprine, tell your doctor if you are using any drugs that make you sleepy (such as alcohol, cold medicine, pain medication, muscle relaxers, and medicine for seizures, depression or anxiety).

Medications that can increase drowsiness caused by cyclobenzaprine include:

  • antidepressants such as amitriptyline (Elavil), clomipramine (Anafranil), desipramine (Norpramin), imipramine (Tofranil), or nortriptyline (Pamelor);

  • antidepressants such as amitriptyline (Elavil), citalopram (Celexa), clomipramine (Anafranil), desipramine (Norpramin), escitalopram (Lexapro), fluoxetine (Prozac, Sarafem), fluvoxamine (Luvox), imipramine (Tofranil), nortriptyline (Pamelor), paroxetine (Paxil), or sertraline (Zoloft);

  • narcotic pain medicine such as meperidine (Demerol), morphine (MS Contin, MSIR), propoxyphene (Darvon, Darvocet), hydrocodone (Lorcet, Vicodin), oxycodone (Percocet, Percodan), fentanyl (Duragesic), and codeine (Tylenol #3, and prescription cough medicines);

  • sedatives such as phenobarbital (Solfoton, Luminal), amobarbital (Amytal), and secobarbital (Seconal);

  • phenothiazines such as chlorpromazine (Thorazine), fluphenazine (Prolixin), mesoridazine (Serentil), perphenazine (Trilafon), prochlorperazine (Compazine), thioridazine (Mellaril), and trifluoperazine (Stelazine); or

  • tranquilizers such as diazepam (Valium), alprazolam (Xanax), lorazepam (Ativan), or clorazepate (Tranxene).

If you are using any of these drugs, you may not be able to use cyclobenzaprine, or you may need dosage adjustments or special tests during treatment.

There may be other drugs not listed that can affect cyclobenzaprine. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

What happens if I have an overdose of cyclobenzaprine?

Seek emergency medical attention if you think you have used too much of this medicine. An overdose of cyclobenzaprine can be fatal.

Symptoms of a cyclobenzaprine overdose may include drowsiness, fast heartbeat, tremors or shaking, slurred speech, confusion, nausea, vomiting, hallucinations (seeing things), chest pain, or seizure (convulsions).

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. Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.
Content provided by Multum - Last Updated 2/11/2008