Muscle Relaxants Ineffective for Low Back Pain and Fibromyalgia

By Pat Anson

Muscle relaxants are increasingly prescribed “off label” as an alternative to opioid medication, but according to a new analysis they are no more effective than a placebo in treating fibromyalgia and low back pain. They may be beneficial, however, for patients suffering from muscle cramps, neck pain and trigeminal neuralgia.

Researchers reviewed 44 studies involving nearly 2,500 patients who were prescribed a muscle relaxant for various pain conditions. Nine skeletal muscle relaxants (SMRs) were assessed, drugs that were initially developed and then approved by the FDA as anti-spasticity and anti-spasmodic medications:

• Carisoprodol (Soma)

• Baclofen

• Tizanidine

• Cyclobenzaprine

• Eperisone

• Quinine

• Orphenadrine

• Chlormezanone

• Methocarbamol

Despite a lack of evidence on their effectiveness beyond 3 weeks, prescribing of SMRs doubled between 2005 and 2016, with office visits for refills of SMR prescriptions tripling over the same period, indicating they were increasingly being used long-term and off-label. According to a 2021 study, over a third of patients prescribed SMRs did not have a musculoskeletal disorder, a sign of “unnecessary or inappropriate use.”

Researchers involved in the current study, published in JAMA Network Open, reached a similar conclusion that muscle relaxants are overprescribed.

“Despite increasing prevalence and increasing risks of their use, our systematic review suggests only limited evidence of efficacy for long-term use of SMRs for a small subset of pain syndromes,” wrote lead author Benjamin Oldfield, MD, an Assistant Clinical Professor of Internal Medicine at Yale School of Medicine.

“Evidence for effectiveness was strongest for SMRs used for muscle spasms, painful cramps, and neck pain; in studies of SMRs for fibromyalgia, low back pain, headaches, and other syndromes, some showed small benefits and some did not, and on balance studies did not suggest a benefit.”

Oldfield and his colleagues say physicians should consider deprescribing SMRs to pain patients who have been using them long-term without apparent benefit.   

Adverse side effects from SMRs include sedation, somnolence, dizziness and dry mouth. The FDA also warns against taking the drugs with opioids, which could raise the risk of respiratory depression and overdose.

SMRs also increase the risk of falls, fractures, and vehicle crashes. Because of those risks, muscle relaxants should be avoided altogether in elderly patients, according to the American Geriatrics Society.

Long-Term Use of Muscle Relaxants Has Tripled

By Pat Anson, PNN Editor

Long-term use of muscle relaxants has nearly tripled in the U.S. since 2005, according to a new study by researchers at the University of Pennsylvania, who say the drugs are often prescribed inappropriately for chronic pain and to older adults.

Skeletal muscle relaxants (SMRs) like carisoprodol (Soma) and metaxalone (Skelaxin) were approved years ago for short-term treatment of muscle spasms and back pain. Researchers believe many doctors are now prescribing the drugs as an alternative to opioids for long-term pain management.

"There are few studies on the short-term efficacy and safety of skeletal muscle relaxants, and almost no data on their long-term effects, so it is very concerning that patients, and particularly older adults, are using these drugs for an extended period of time," said Charles Leonard, PharmD, an assistant professor of Epidemiology at Perelman School of Medicine. "Providers seem to be reaching for them despite incomplete information on their potential benefits and risks."

Medical guidelines generally recommend limiting the use of muscle relaxants to three weeks because they have not been shown to work for muscle spasms beyond that duration. The drugs can also have side effects such as falls, fractures, vehicle crashes, abuse and dependence. Because of those risks, muscle relaxants should be avoided altogether in elderly patients, according to the American Geriatrics Society.

To measure national trends in muscle relaxant prescribing, researchers analyzed the number of office visits that resulted in muscle relaxant prescriptions from 2015 to 2016. They found the number of new prescriptions remained stable at about 6 million per year. But office visits for renewals of muscle relaxant prescriptions tripled -- from 8.5 million in 2005 to 24.7 million in 2016.

Over two-thirds (67%) of the patients getting renewals for muscle relaxants in 2016 were also taking opioid medication, despite an FDA warning that co-prescribing the drugs could lead to respiratory depression and overdose. Older adults accounted for about one in four (22%) office visits for muscle relaxants.

"For older adults, I think the message should be to avoid using muscle relaxants, especially when we consider the side effects and increased risk of falls and fractures, and to find alternatives for pain management," said first author Samantha Soprano, MPH, a research coordinator and student in Penn's Master of Behavioral and Decision Sciences program.

In addition to potential side effects, researchers say muscle relaxants may not be any more effective in managing pain than medications like Tylenol or Advil.

"Muscle relaxants' place in therapy is really limited. Based on most guidelines, they're normally reserved as second- or third-line therapies," Leonard said. "Our findings suggest that prescribers may be reaching for these drugs sooner than that."

The findings are published in JAMA Network Open.

Stop Demonizing the ‘Holy Trinity’

Lynn Kivell Ashcraft, Guest Columnist    

If we are to have any hope of a rational, scientific discussion about the issues involved in both pain management and addiction treatment, we need to end patient shaming and the use of sensational language that has no basis in clinical practice.

First on my list is to stop using the term “Holy Trinity” when referring to the use of multiple medication classes to manage pain. It is a sensational propagandizing use of terminology that has no place in any meaningful clinical discussion.

Holy Trinity was a term coined by law enforcement when discussing the behavior of addicts. The original Holy Trinity – the so-called “Houston Cocktail” -- referred to the simultaneous ingestion of the short acting drugs hydrocodone (Vicodin), alprazolam (Xanax) and carisoprodol (Soma) by addicts. Other combinations of opioids, muscle relaxants and anti-anxiety drugs such as benzodiazepines are also used.

“The cocktail is commonly known on the black market as the ‘holy trinity’ and is particularly sought-after by addicts, but is also particularly dangerous,” is how the DEA describes the drugs in criminal complaints, search warrants and training guides.  

SOURCE: DEA TRAINING GUIDE

Taken together, the three drugs can be risky and cause respiratory depression, overdose and death. But when used under medical supervision, they enable individuals with painful and disabling conditions to improve their quality of life and restore bodily functions.

Holy Trinity was never used originally to refer to any medication combination prescribed by physicians caring for pain patients. But with the advent of the opioid crisis, the term is being used as a scare tactic by law enforcement and even some medical providers to deny patients a combination of medications previously used successfully.

The unintended consequence of this careless usage has been the deaths and needless renewal of pain and disability for patients who were being safely prescribed these medications.  

There is no one-size-fits-all treatment for chronic severe centralized pain. In fact, the current Pain Management and Dosing Guide from the American Pain Society lists opioids plus other central nervous system depressants and valium (a diazepine) as potential treatments for neuropathic pain.

It is well acknowledged that successful treatment often requires polypharmacy regimens tailored to the needs of individual patients to achieve pain relief and provide quality of life. The potential risks of using multiple medications can be reduced by prescribing both long-acting forms of these drugs and by directing patients to take them separately. 

To use the Holy Trinity as an inflammatory term is to demonize certain medications that have been abused by addicts while being used successfully by intractable pain patients. The use of this derogatory term has caused the undeserved transference of the deeply held negative societal bias against “addicts” onto some of the frailest and medically complex patients, many of whom are struggling to achieve some quality of life. 

According to the CDC, about 20 percent of adults in the U.S. have chronic pain and 8 percent have severe “high impact” chronic pain that frequently limits their life or work activities. The 2011 Institute of Medicine report puts the number of Americans with pain at 100 million, which is more than those living with diabetes, heart disease and cancer combined.

The difference between the two reports highlights some of the issues with using and understanding statistics.  However, no matter which report you use, both numbers represent a staggering number of Americans living in pain who deserve effective treatment.

Let’s lose the term Holy Trinity and allow doctors to prescribe whatever medications they deem necessary for the restoration of function and the relief of pain in their patients. Name calling and the use of disrespectful terminology doesn’t solve either the problem of addiction or the problem of pain.

Lynn Kivell Ashcraft is an Analytic Software Consultant and writer who lives in Arizona. Lynn has lived with chronic intractable pain for almost 30 years and works with Dr. Forest Tennant as part of the Arachnoiditis Research and Education Project. 

The information in this column should not be considered as professional medical advice, diagnosis or treatment. It is for informational purposes only and represent the author’s opinions alone. It does not inherently express or reflect the views, opinions and/or positions of Pain News Network.