What is the recommended dose of Cyclobenzaprine (Flexeril) for muscle pain?

From the Guidelines

Cyclobenzaprine should be prescribed at a dose of 5-10 mg three times daily for acute muscle pain and spasms, with a maximum recommended daily dose of 30 mg and treatment duration limited to 2-3 weeks, as supported by the evidence from a Cochrane review 1. The medication works as a muscle relaxant by acting on the central nervous system to reduce nerve impulses from the brain to skeletal muscles, thereby decreasing muscle tone and relieving pain associated with muscle spasms. Some key points to consider when prescribing cyclobenzaprine include:

• Starting with a dose of 5 mg three times daily and increasing to 10 mg if needed based on response and tolerability
• Limiting treatment duration to 2-3 weeks, as the medication hasn't been studied for longer periods and may lose effectiveness over time
• Common side effects, such as drowsiness, dry mouth, and dizziness, and taking the medication before bedtime if drowsiness occurs
• Avoiding alcohol and other CNS depressants while taking this medication
• Contraindications, including heart conditions, hyperthyroidism, or taking MAO inhibitors, as noted in the evidence 1. The evidence from the Cochrane review 1 suggests that skeletal muscle relaxants, including cyclobenzaprine, are moderately superior to placebo for short-term pain relief, but may be associated with a higher total number of adverse events and central nervous system adverse events compared with placebo.

From the FDA Drug Label

For most patients, the recommended dose of cyclobenzaprine hydrochloride tablets is 5 mg three times a day. Based on individual patient response, the dose may be increased to 10 mg three times a day. The recommended dose of cyclobenzaprine for muscle pain is:

• 5 mg three times a day for most patients
• Up to 10 mg three times a day based on individual patient response 2

From the Research

Muscle Pain Treatment with Cyclobenzaprine

• Cyclobenzaprine is a muscle relaxant effective in improving muscle spasm, reducing local pain and tenderness, and increasing range of motion in acute, painful musculoskeletal conditions 3.
• The usual dosage of cyclobenzaprine is 10 mg three times a day (TID), but studies suggest that a lower dose of 5 mg TID may produce less sedation while maintaining efficacy 3, 4.
• A study comparing cyclobenzaprine 5 mg TID with combination therapy of cyclobenzaprine 5 mg TID and ibuprofen found that the combination therapy was not superior to cyclobenzaprine alone in adult patients with acute neck and back pain with muscle spasm 4.
• Cyclobenzaprine has been evaluated in the most clinical trials and has consistently been found to be effective in treating musculoskeletal conditions, particularly acute back or neck pain 5.

Dosage and Efficacy

• A systematic review found that cyclobenzaprine, carisoprodol, orphenadrine, and tizanidine are effective compared to placebo in patients with musculoskeletal conditions 5.
• However, another study found that skeletal muscle relaxants, including cyclobenzaprine, do not improve outcomes more than placebo in patients with acute low back pain treated with a nonsteroidal anti-inflammatory drug 6.
• The efficacy of cyclobenzaprine may not be associated with age, sex, or baseline pain severity 6.

Safety and Side Effects

• Cyclobenzaprine is generally well-tolerated, with somnolence and dry mouth being the most common adverse effects, which are mild and dose-related 3, 4.
• A study found that cyclobenzaprine was associated with a higher incidence of adverse medication effects compared to placebo 6.
• However, the safety of cyclobenzaprine compared to other muscle relaxants, such as baclofen and tizanidine, is still being investigated, with some studies suggesting that baclofen may be associated with a higher risk of injury and delirium in older adults 7.