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Flexeril Oral Precautions and Side Effects


IMPORTANT NOTE: The following information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist or other healthcare professional. It should not be construed to indicate that use of the drug is safe, appropriate or effective for you. Consult your healthcare professional before using this drug.

Table of Contents

Generic Name: CYCLOBENZAPRINE - ORAL
Pronounced: (sye-klo-BENZ-uh-preen)

Flexeril Oral Side Effects

Drowsiness, dry mouth, fatigue, dizziness, lightheadedness, constipation or blurred vision may occur as your body adjusts to the medication. If any of these effects persist or worsen, notify your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor immediately if any of these unlikely but serious side effects occur:

  • mental/mood changes (e.g., confusion, hallucinations)
  • difficulty urinating


Tell your doctor immediately if any of these highly unlikely but very serious side effects occur:

  • fast/pounding/irregular heartbeat
  • fainting
  • yellowing of the eyes/skin
  • stomach/abdominal pain
  • persistent nausea/vomiting/lack of appetite
  • dark urine
  • seizures
  • loss of coordination


A serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction include:

  • rash
  • itching/swelling (especially of the face/tongue/throat)
  • severe dizziness
  • trouble breathing


This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Flexeril Oral Precautions

Before taking cyclobenzaprine, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have:

  • overactive thyroid (hyperthyroidism)
  • irregular heartbeats (arrhythmia)
  • other heart problems (congestive heart failure, heart block or conduction disorders)
  • recent heart attack
  • moderate or severe liver disease


Before using this medication, tell your doctor or pharmacist your medical history, especially of:

  • severe difficulty urinating (urinary retention)
  • glaucoma
  • mild liver disease


This drug may make you dizzy or drowsy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Limit alcoholic beverages.

To minimize dizziness and lightheadedness, get up slowly when rising from a seated or lying position.

Caution is advised when using this drug in the elderly because they may be more sensitive to its side effects, especially drowsiness, mental/mood changes, and possibly heart problems which could lead to a fall.

This medication should be used only when clearly needed during pregnancy. Discuss the risks and benefits with your doctor.

Based on information for similar drugs, cyclobenzaprine may pass into breast milk. Therefore, consult your doctor before breast-feeding.


CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.
Copyright 2007 First DataBank, Inc.

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