Muscle Relaxant Medications for Fibromyalgia

Managing chronic pain is no easy task, and for many people, muscle relaxants are part of the long-term plan to find relief. But how well do these medications actually work over time—and what are the trade-offs? In this study published in Pharmacy and Clinical Pharmacology on September 19, 2024, Dr. Benjamin Oldfield and his team take a deep dive into the long-term use of muscle relaxants for chronic pain. Through a systematic review of existing research, they explore how effective these drugs really are and what side effects patients might face with ongoing use.

Treatments for Fibromyalgia and Similar Conditions

Researchers looked at 11 studies involving 391 people to see how well certain muscle relaxant medications worked for fibromyalgia and related conditions. Out of these studies, 7 were high-quality clinical trials, and 4 were observational studies.

Here’s what they found:

Cyclobenzaprine

• Used in 5 studies, all clinical trials.

• Helped with sleep problems in 3 studies.

• Didn’t show much improvement in other symptoms compared to a placebo (a “sugar pill”).

• One study compared cyclobenzaprine to amitriptyline (another medication), and both worked equally well after 6 months.

• Side effects happened in 0% to 98% of people and included feeling sleepy, dry mouth, and numbness under the tongue for those using a version that dissolves under the tongue.

Tizanidine

• Used in 3 studies, all observational.

• Helped reduce pain while people were taking it.

• When people stopped taking it, their pain got worse again.

• Side effects (in up to 66% of people) included sleepiness, headaches, and dizziness.

Other Medications

• Chlormezanone and carisoprodol: These didn’t help with pain more than the placebo in the studies.

• Eperisone: In one study, it helped reduce pain better than another pain medication (celecoxib) after 2, 4, and 6 weeks.

• Chlormezanone caused nausea in nearly half of the participants, while no side effects were reported for carisoprodol or eperisone.

Notes:

• RCT = Randomized Controlled Trial (high-quality study)

• Cohort Study = Observational study (lower-quality evidence than RCTs)

SEE THE FULL STUDY IN THE JAMA NETWORK AMERICAN MEDICAL ASSOCIATION PUBLICATION HERE