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Is Flexeril addictive, will it show up on a drug test?

Medically reviewed by Leigh Ann Anderson, PharmD. Last updated on May 8, 2023.

Official answer

by Drugs.com

Flexeril is not a physically addictive drug like an opioid or a benzodiazepine. It is not a controlled substance. Flexeril would not normally be tested for in a routine workplace drug screen; however, there have been reports of Flexeril causing a false-positive urine drug screen for tricyclic antidepressants (TCAs). Flexeril is closely related structurally to the tricyclic antidepressants, e.g., amitriptyline and imipramine.

Some people can become psychologically addicted to any medication, especially of they have taken it for an extended period of time for pain. Stopping treatment can be difficult in these circumstances, especially when the medicine is used to help alleviate pain. In general, muscle relaxants like Flexeril are usually only taken for a few weeks or less, which should help lessen this effect.

Although Flexeril has not been associated with physical addiction and drug-seeking behavior, abruptly stopping this medication after long-term use may lead to symptoms such as nausea, headache, and a general sense of feeling unwell (malaise). Ask your healthcare provider if you should slowly stop treatment (taper your dose) rather than abruptly discontinuing, and the best way to do this.

If you are scheduled to take a drug test, be sure to inform the testing site of all of the medications you take, both prescription and over-the-counter, including vitamins and herbal or dietary supplements.

The brand Flexeril has been discontinued from the US market, so you may hear this drug called by its generic name "cyclobenzaprine" from the pharmacy.

Learn more: Can a Drug Test Lead to a False Positive?

What is Flexeril commonly prescribed for?

The generic name for Flexeril is cyclobenzaprine, a frequently prescribed skeletal muscle relaxant used for a few weeks or less to help quiet the spasm and ease pain.

  • Using cyclobenzaprine for acute back pain (a "pulled muscle" in your back) is one of its most common uses. It relieves skeletal muscle spasms without interfering with muscle function.
  • Cyclobenzaprine is also used "off-label" for fibromyalgia in some patients, meaning it may be prescribed by your doctor for a use not specifically approved by the FDA or listed in package labeling.
  • It is a central nervous system (CNS) depressant and can cause side effects like drowsiness (fatigue), dizziness, or confusion.

Its chemical structure and how it works is related to the tricyclic antidepressants (TCAs), an older class of medications used to treat depression, nerve-associated pain, migraine and other conditions.

This is not all the information you need to know about Flexeril for safe and effective use and does not take the place of your doctor’s directions. Review the full product information and discuss this information and any questions you have with your doctor or other health care provider.

References
  • Cyclobenzaprine. Product Information. FDA. Accessed May 8, 2023 at https://www.drugs.com/pro/cyclobenzaprine.html
  • Van Hoey NM. Effect of cyclobenzaprine on tricyclic antidepressant assays.
    Ann Pharmacother. 2005 Jul-Aug; 39 (Epub 2005 Jun 14.): 1314-1317
  • Moeller K, Lee K, Kissack J. Urine Drug Screening: Practical Guide for Clinicians. Mayo Clin Proc. 2008;83:66-76. Accessed August 8, 2021 at https://www.mayoclinicproceedings.org/article/S0025-6196(11)61120-8/fulltext
  • Common Urine Drug Test Panels. Quest Diagnostics. 2/2019. Accessed August 8, 2021 at questdiagnostics.com/dms/Documents/Employer-Solutions/Brochures/quest-common-urine-drug-test-panels-2019v2/Common%20urine%20drug%20test%20panels.pdf

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