Patient Information: Mid Back Pain Treatment with Flexeril (Cyclobenzaprine)
What You Need to Know About Your Medication
Flexeril (cyclobenzaprine) is FDA-approved only for short-term use of 2-3 weeks maximum as an adjunct to rest and physical therapy for acute muscle spasm. 1 The medication works through sedative properties rather than directly relaxing muscles, and its effectiveness is greatest in the first 4 days of treatment. 2
How to Take Your Medication
- Standard dosing: Cyclobenzaprine 5 mg three times daily is as effective as 10 mg three times daily but causes less drowsiness. 3
- Duration: Use for 7-14 days maximum, as evidence does not support longer treatment courses. 1, 2
- Timing: The medication works for 4-6 hours per dose, with symptom improvement typically appearing within the first 3-4 doses. 3
What to Expect
- Effectiveness: You are nearly 5 times more likely to report symptom improvement by day 14 compared to placebo, though the improvement is modest. 2
- Peak benefit: The greatest relief occurs in the first 4 days, with declining effectiveness after the first week. 2
- Combination benefit: When combined with NSAIDs (like naproxen or ibuprofen), cyclobenzaprine provides greater pain relief than NSAIDs alone. 4
Common Side Effects
- Drowsiness/sedation: The most common side effect, occurring in a dose-related manner. 3, 5
- Dry mouth: Second most common side effect. 3
- Important: The medication's pain-relieving effects work independently of sedation, so effectiveness is not dependent on feeling drowsy. 3
Critical Safety Warnings
Do not take cyclobenzaprine if you:
- Are taking or have taken MAO inhibitors within the past 14 days (life-threatening interactions possible). 1
- Are taking SSRIs, SNRIs, tricyclic antidepressants, tramadol, bupropion, meperidine, or verapamil without discussing with your doctor (risk of serotonin syndrome). 1
Use extreme caution with:
- Alcohol or other sedating medications (enhanced sedation effects). 1
- Driving or operating machinery (impaired mental and physical abilities). 1
- History of urinary retention, glaucoma, or increased eye pressure. 1
What You Should Be Doing Alongside Medication
Stay active and avoid bed rest - this is critical for recovery. 6, 7
- Activity restriction prolongs recovery and delays return to normal function. 7
- Continue normal activities as tolerated rather than resting in bed. 6
Apply heat to the affected area using heating pads or heated blankets for short-term relief. 7
When to Contact Your Doctor
Seek immediate medical attention if you experience:
- Signs of serotonin syndrome: agitation, confusion, rapid heart rate, high blood pressure, dilated pupils, muscle twitching, sweating, diarrhea, fever. 1
- Severe drowsiness that interferes with daily function
- Urinary retention or difficulty urinating
- Vision changes
Contact your doctor if:
- No improvement occurs within 4-7 days. 2
- Pain worsens or new symptoms develop
- You need medication beyond 2-3 weeks. 1
Important Limitations
- Not for chronic pain: Cyclobenzaprine has limited evidence for chronic back pain and should not be used long-term. 6
- Not for all types of muscle problems: This medication is not effective for spasticity from spinal cord or brain conditions. 1
- Better alternatives exist: For certain conditions like radiculopathy (nerve pain radiating down the leg), other muscle relaxants like tizanidine have stronger evidence. 8
Optimal Treatment Strategy
Your best approach combines:
- Cyclobenzaprine 5 mg three times daily for 7-14 days maximum 3, 2
- NSAIDs (like ibuprofen or naproxen) at the lowest effective dose 6, 7
- Staying active and avoiding bed rest 7
- Applying heat to the painful area 7
This combination provides superior pain relief compared to any single treatment alone. 4