(Reuters Health) - A growing number of people in the U.S. are taking anti-anxiety drugs like Valium and Xanax not just for anxiety or depression but also for chronic pain, researchers say.

These drugs are in a family of medicines known as benzodiazepines, which also include drugs like Ativan and Klonopin. Benzodizepines are used primarily for anxiety but also for conditions like insomnia, seizures, panic attacks, nausea, alcohol withdrawal and muscle relaxation.

Although overdoses and injuries related to benzodiazepines have surged in recent years, researchers don’t have a complete picture of prescribing trends.

For the current study, researchers examined data on 386,457 outpatient visits from 2003 to 2015 and found the proportion that involved a benzodiazepine prescription doubled from 3.8 percent to 7.4 percent.

Prescriptions for anxiety and depression remained the most common use of these drugs, rising from about 27 percent to 34 percent.

The biggest surge, however, was in prescriptions for back pain or other forms of chronic pain, which rose from 3.6 percent to 8.5 percent over the study period.

“Benzodiazepines are almost never a good alternative to opioids to treat pain,” said study co-author Dr. Sumit Agarwal, a primary care physician at Brigham and Women’s Hospital in Boston.

“When they were first introduced, benzodiazepines were a huge improvement over their predecessor, barbiturates, and there are very real benefits to these drugs, particularly when they are prescribed for short-term use and for intermittent use,” Agarwal said.

However, benzodiazepines have side effects that are eerily similar to opioids, including the potential for addiction and suppressed breathing, Agarwal added.

“They are involved in falls and fractures, motor vehicle accidents, overdoses, and deaths,” Agarwal said. “These risks are even more pronounced when they are combined with other drugs that alter the central nervous system.”

During the study period, the proportion of benzodiazepine prescriptions for people also taking opioids quadrupled from 0.5 to 2 percent, the researchers report in JAMA Network Open.

Over that same time, the proportion of benzodiazepine prescriptions for people taking other sedating medications doubled from 0.7 to 1.5 percent.

Use of benzodiazepines by psychiatrists held steady at about 30 percent of visits during the study period. Increased use of these drugs came instead from primary care physicians and other providers.

Primary care physicians accounted for about half of the visits involving benzodiazepine prescriptions in the study. Primary care visits involving these drugs increased from 3.6 to 7.5 percent during the study period.

The study wasn’t designed to assess the reasons for the increased use of benzodiazepines, or to determine how any increased use might impact patients’ health.

One limitation of the study is that researchers lacked data on the exact reason for the benzodiazepine prescriptions, and they assumed that the chief complaints listed in patients’ medical records of their visits were the problem the drugs were intended to treat.

“It’s possible that primary care physicians are increasingly prescribing benzodiazepines as a safer, more effective alternative to opioids, but there’s little evidence to support this,” said Marissa Seamans, a researcher at the Johns Hopkins Bloomberg School of Public Health in Baltimore who wasn’t involved in the study.

“Patients must be informed of and weigh the risks and benefits of using benzodiazepines, particularly if they are taking other medications that affect the central nervous system,” Seamans said by email. “For conditions other than anxiety such as chronic non-cancer pain, non-pharmacologic treatments and non-opioid pain relievers should be sought first.”

SOURCE: bit.ly/2BfynfY JAMA Network Open, online January 25, 2019.