How It Works
Cyclobenzaprine is a drug used to relax muscles. Experts do not know exactly how this drug works to improve fibromyalgia. Cyclobenzaprine is chemically similar to amitriptyline hydrochloride, a tricyclic antidepressant, so experts believe that the two drugs may work in similar ways.1
Why It Is Used
Doctors may prescribe cyclobenzaprine to treat the pain, stiffness, and sleep problems that occur with fibromyalgia. This is currently an unlabeled use of the drug.
How Well It Works
People with fibromyalgia who take cyclobenzaprine seem to notice an overall improvement in their symptoms, and they especially note improved sleep.2 The medicine's effects may decrease over time.3
Side Effects
Side effects include:
- Drowsiness.
- Dry mouth.
- Dizziness.
Less common side effects include fatigue, weakness, nausea, constipation, stomach upset, blurred vision, nervousness, and confusion.
See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)
What To Think About
It is difficult to measure improvements in painful diseases like fibromyalgia. This makes it hard to tell how effective a drug is in treating this condition.
Complete the new medication information form (PDF)
(What is a PDF document?) to help you understand this medication.
References
Citations
Goldenberg DL, et al. (2004). Management of fibromyalgia syndrome. JAMA, 292(19): 2388–2395.
Tofferi JK, et al. (2004). Treatment of fibromyalgia with cyclobenzaprine: A meta-analysis. Arthritis and Rheumatism, 51(1): 9–13.
Bradley LA, Alarcon GS (2005). Fibromyalgia section of Miscellaneous rheumatic diseases. In WJ Koopman, LW Moreland, eds., Arthritis and Allied Conditions: A Textbook of Rheumatology, 15th ed., vol. 2, pp. 1869–1910. Philadelphia: Lippincott Williams and Wilkins.
Credits
| Author | Shannon Erstad, MBA/MPH |
| Editor | Kathleen M. Ariss, MS |
| Associate Editor | Tracy Landauer |
| Associate Editor | Pat Truman, MATC |
| Primary Medical Reviewer | Anne C. Poinier, MD - Internal Medicine |
| Specialist Medical Reviewer | Stanford M. Shoor, MD - Rheumatology |
| Last Updated | October 30, 2007 |