Generic Flexeril

Common use

Flexeril is a muscle relaxant used to relieve muscle spasms and pain associated with acute musculoskeletal conditions. It works by blocking nerve impulses (or pain sensations) sent to the brain, helping to reduce muscle stiffness and discomfort. Flexeril is typically prescribed in combination with rest and physical therapy. It is intended for short-term use, usually not exceeding 2 to 3 weeks.

Dosage and direction

The usual adult dose is 5 to 10 mg taken three times daily, as directed by a healthcare provider. It should be taken by mouth with or without food, and doses should be spaced evenly throughout the day. Do not increase the dose or use it for longer than prescribed. Always follow your doctor’s instructions for safe and effective use.

Precautions

Flexeril should be used cautiously in individuals with a history of heart conditions, glaucoma, urinary retention, or liver disease. It may cause drowsiness, dizziness, or blurred vision, so avoid driving or operating heavy machinery until you know how it affects you. Alcohol or other CNS depressants can increase side effects like sedation. Use in elderly patients should be monitored closely due to increased sensitivity to side effects.

Contraindications

Do not use Flexeril if you are currently taking a monoamine oxidase inhibitor (MAOI) or have taken one in the past 14 days. It is contraindicated in individuals with cardiac arrhythmias, heart block, or recent myocardial infarction. People with hyperthyroidism should also avoid this medication. Known allergy to cyclobenzaprine is a contraindication.

Possible side effect

Common side effects include drowsiness, dry mouth, dizziness, and fatigue. Less commonly, it may cause nausea, constipation, or blurred vision. Rare but serious effects include irregular heartbeat, confusion, or allergic reactions such as rash and swelling. Report any unusual or severe symptoms to your doctor immediately.

Drug interaction

Flexeril may interact with MAO inhibitors, tricyclic antidepressants, opioids, benzodiazepines, and alcohol. These interactions can increase the risk of sedation, respiratory depression, or serotonin syndrome. Inform your doctor of all medications, supplements, and herbs you’re using. Avoid combining with other CNS depressants unless advised by a healthcare provider.

Missed dose

If you miss a dose of Flexeril, take it as soon as you remember. If it is almost time for your next dose, skip the missed one and resume your regular schedule. Do not double the dose to catch up. Keeping a regular schedule helps maintain consistent relief from symptoms.

Overdose

Symptoms of overdose may include severe drowsiness, rapid or irregular heartbeat, tremors, or confusion. In extreme cases, seizures or loss of consciousness may occur. Seek immediate medical help or contact a poison control center if overdose is suspected. Supportive treatment in a hospital setting may be required.

Storage

Store Flexeril at room temperature (20–25°C / 68–77°F) away from moisture, heat, and light. Keep it in its original container and out of reach of children. Do not use after the expiration date printed on the label. Dispose of unused medication properly according to local guidelines.

Disclaimer

We provide only general information about medications which does not cover all directions, possible drug integrations, or precautions. Information at the site cannot be used for self-treatment and self-diagnosis. Any specific instructions for a particular patient should be agreed with your health care adviser or doctor in charge of the case. We disclaim reliability of this information and mistakes it could contain. We are not responsible for any direct, indirect, special or other indirect damage as a result of any use of the information on this site and also for consequences of self-treatment.

Clinical Verification

Last Clinically Updated: August 15, 2026

Written By

Dr. Elena Vance, PharmD

Clinical Specialist in Neuropharmacology

Fact Checked By

Marcus Thorne, MS

Biomedical Data & FDA Label Verification

Medically Reviewed By

Dr. Arthur Campbell, MD

Board-Certified Psychiatrist (ABPN)