Cyclobenzaprine Dosage and Frequency for Muscle Spasms
For most patients with acute, painful musculoskeletal spasms, cyclobenzaprine should be prescribed at 5 mg three times daily for a maximum of 2-3 weeks, with the option to increase to 10 mg three times daily based on individual response if needed. 1
Standard Dosing Regimen
- Initial dose: 5 mg three times daily
- Maximum dose: Can be increased to 10 mg three times daily based on patient response
- Duration: Limited to short-term use (2-3 weeks maximum)
- Extended-release option: 15-30 mg once daily (alternative to immediate-release formulation)
Special Population Considerations
Elderly Patients
- Start with lower doses (5 mg three times daily)
- Less frequent dosing should be considered due to increased risk of adverse effects 1
- Monitor closely for anticholinergic side effects and sedation
Hepatic Impairment
- Start with 5 mg three times daily
- Titrate slowly upward if needed
- Not recommended for moderate to severe hepatic impairment 1
Efficacy Evidence
- Clinical studies demonstrate that 5 mg three times daily is as effective as 10 mg three times daily for relieving muscle spasm 2
- The 5 mg dose is associated with fewer side effects, particularly sedation, compared to the 10 mg dose 2
- Onset of relief typically occurs within 3-4 doses of the 5 mg regimen 2
- The 2.5 mg three times daily dose was not significantly more effective than placebo 2
Administration Timing
- Administer doses approximately 8 hours apart to maintain therapeutic effect
- Extended-release formulation (CER) provides comparable systemic exposure to immediate-release formulation (CIR) with once-daily dosing 3, 4
- CER exhibits a more consistent concentration-time profile with a single peak compared to multiple peaks and troughs with CIR 3
Important Limitations and Precautions
- Cyclobenzaprine is indicated only for relief of muscle spasm associated with acute, painful musculoskeletal conditions 1
- Not effective for spasticity associated with cerebral or spinal cord disease 1
- Not indicated for use in children with cerebral palsy 1
- Contraindicated in patients:
- Taking MAO inhibitors or within 14 days of discontinuing MAOIs
- In acute recovery phase of myocardial infarction
- With heart block, conduction disturbances, or arrhythmias
- With hyperthyroidism
Common Side Effects to Monitor
- Sedation/somnolence (most common)
- Dry mouth
- Dizziness
- Fatigue
- Constipation
Clinical Pearls
- Efficacy is independent of sedation - patients who don't experience somnolence still benefit from treatment 2
- Combination therapy with ibuprofen does not provide additional benefit over cyclobenzaprine alone for neck or back pain with muscle spasm 5
- Extended-release formulation may be associated with less somnolence than immediate-release formulation 6
- Median time to "a lot" or "complete" relief from local pain is approximately 5-6 days with cyclobenzaprine treatment 6
Remember that cyclobenzaprine should only be used short-term (2-3 weeks maximum) as there is inadequate evidence supporting longer use, and muscle spasm associated with acute musculoskeletal conditions is generally of short duration 1.