Back pain plagues many Americans, and new research shows that doctors are doling out muscle relaxant prescriptions to treat the pain -- often along with an opioid painkiller.
Experts worry that muscle relaxants may not help much and could cause troubling side effects, especially in older patients.
The study found the rate of long-term prescriptions for muscle relaxants to treat back and other muscle pain tripled between 2005 and 2016.
Also concerning, nearly 70 percent of those prescribed muscle relaxants were given a prescription for an opioid pain-relieving medication like oxycodone (OxyContin) at the same time. Taking these medications together increases the potential risk of ill effects, the researchers said.
"We tried to develop a picture of the national [use] of skeletal muscle relaxants under the hypothesis that maybe physicians -- concerned about the use of opioids -- might be prescribing skeletal muscle relaxants more often," said study lead author Charles Leonard. He's an assistant professor of epidemiology at the University of Pennsylvania Perelman School of Medicine.
"We saw about a threefold increase in patients on continued therapy with skeletal muscle relaxants. People get put on these drugs and they stay on these drugs," Leonard said. But the problem is they haven't been studied for long-term use.
Skeletal muscle relaxants are approved for short-term treatment of muscle spasms and back pain. Examples of muscle relaxants include baclofen (Lioresal), carisoprodol (Soma), cyclobenzaprine (Fexmid) and tizanidine (Zanaflex).
Recommendations generally limit the use of these drugs to a maximum of three weeks, since they have not been shown to work for muscle spasms beyond that time.
Leonard said these medications can be very sedating. Serious side effects associated with their use include dizziness, falls, fractures, car accidents, dependence, and overdose.
Muscle relaxants pose a significant risk to people over 65, and the American Geriatrics Society advises against their use in this age group.
Despite this recommendation, nearly a quarter of office visits for muscle relaxants in 2016 were for seniors, the study noted. This group makes up less than 15 percent of the general population.
"Older adults seem to disproportionately get these drugs," Leonard said, adding that seniors are often taking other medications as well, which can boost the odds of an adverse reaction.
In particular, the U.S. Food and Drug Administration cautions against using muscle relaxants and opioids together, noting the combination can cause difficulty breathing and death, according to background notes.
The study was based on national prescribing data from 2005 to 2016. The researchers looked at the total number of visits a year, what medications were prescribed and if the prescription was new or ongoing.
The most common reason people were taking muscle relaxants was to treat back problems.
Leonard said the research didn't look specifically at why doctors were prescribing these medications more, but he suspects there are at least a few factors driving the increase. One is that there aren't really any good alternative drugs, so doctors may not want to take them away. Another is that patients may put some pressure on their doctor to treat their pain.
But skeletal muscle relaxants shouldn't be considered a first-line treatment for back pain or muscle spasms, Leonard said. He said physical therapy and over-the-counter medications like Advil or Tylenol can help lessen the pain.
"The data shows that while skeletal muscle relaxants are better than a placebo, there's no evidence that they provide benefit beyond nonsteroidal anti-inflammatory drugs," Leonard said.
Dr. David Sibell is a professor of anesthesiology and perioperative medicine from the Oregon Health and Science University School of Medicine and Comprehensive Pain Center.
"The one thing that hit me hardest was the steady beat of new patients prescribed skeletal muscle relaxants that don't come off them," said Sibell, who wasn't involved in the study.
"If there is effectiveness for skeletal muscle relaxants, it's only short-term. There's no long-term data. And those 65 and older are very vulnerable to all of the adverse effects of these drugs," he said.
Sibell said there are other treatment options available. In addition to physical therapy and over-the-counter medications, a prescription anti-inflammatory topical gel may help some people. There are also certain procedures a pain management specialist can offer, he said.
"I think people need to have a greater appreciation of the toxicity of this class of medication. They should not be used for more than a few days at a time," Sibell advised. The study findings were published June 24 in JAMA Network Open.