What is the interaction between Naproxen (Naproxen) and Cyclobenzaprine (Flexeril)?

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From the Guidelines

Naproxen and Flexeril (cyclobenzaprine) can be taken together under the guidance of a healthcare provider to manage pain and muscle spasms, but it's crucial to weigh the benefits against the potential for increased adverse events, particularly of the central nervous system, as indicated by a higher-quality Cochrane review 1. When considering the use of naproxen and Flexeril together, it's essential to understand their mechanisms of action and potential interactions. Naproxen, a nonsteroidal anti-inflammatory drug (NSAID), reduces inflammation and pain, while Flexeril, a muscle relaxant, helps relieve muscle spasms. The typical adult dose for naproxen is 250-500 mg twice daily, and for Flexeril, it is usually 5-10 mg taken up to three times daily. Key considerations when taking these medications together include:

  • Following the healthcare provider's instructions precisely to minimize side effects.
  • Being aware of potential side effects such as drowsiness, dizziness, dry mouth, and stomach upset.
  • Avoiding driving or operating machinery until the effects of the medications are known, due to the risk of significant drowsiness.
  • Taking naproxen with food to reduce stomach irritation.
  • Avoiding alcohol consumption, as it can increase drowsiness and the risk of stomach bleeding. The combination of naproxen and Flexeril can provide comprehensive relief by addressing both the inflammatory component of pain and muscle tension. However, the decision to use them together should be based on the individual patient's needs and under the guidance of a healthcare provider, considering the potential for increased risk of adverse events, as noted in the review 1.

From the FDA Drug Label

Concomitant administration of cyclobenzaprine hydrochloride tablets and naproxen or diflunisal was well tolerated with no reported unexpected adverse effects However combination therapy of cyclobenzaprine hydrochloride tablets with naproxen was associated with more side effects than therapy with naproxen alone, primarily in the form of drowsiness The use of naproxen and Flexeril (cyclobenzaprine) together may be associated with more side effects, primarily drowsiness, compared to using naproxen alone 2.

From the Research

Naproxen and Flexeril (Cyclobenzaprine) Combination

  • The combination of naproxen and cyclobenzaprine has been studied in the treatment of acute low back pain and muscle spasm 3, 4, 5.
  • A randomized clinical trial published in JAMA in 2015 found that adding cyclobenzaprine or oxycodone/acetaminophen to naproxen alone did not improve functional outcomes or pain at 1-week follow-up in patients with acute low back pain 3.
  • However, a smaller open-label trial published in 1990 found that combination therapy with cyclobenzaprine and naproxen was associated with less objective muscle spasm and tenderness, and greater motion of the lumbosacral spine, compared to naproxen alone 4.
  • A systematic review published in 2004 found that cyclobenzaprine was effective compared to placebo in patients with musculoskeletal conditions, including acute back or neck pain 6.

Efficacy and Safety of Naproxen

  • Naproxen is a nonsteroidal anti-inflammatory drug (NSAID) that is commonly used to treat acute pain, including dysmenorrhea, headache, and dental pain 7.
  • A review of the literature published in 2020 found that OTC naproxen is effective for treating a variety of types of acute pain, and has a favorable safety profile 7.

Comparison of Treatments for Acute Low Back Pain

  • A comparison of naproxen with cyclobenzaprine, oxycodone-acetaminophen, and placebo for the treatment of acute low back pain found that the addition of cyclobenzaprine or oxycodone with acetaminophen to naproxen did not result in improved functional outcomes at one week compared to placebo 5.
  • The same study found that the combination of naproxen and cyclobenzaprine was not more effective than naproxen alone in improving functional outcomes or reducing pain in patients with acute low back pain 5.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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