– The growing use of anti-anxiety pills reminds some doctors of the early days of the opioid crisis.

Considered relatively safe and nonaddictive by the general public and many doctors, Xanax, Valium, Ativan and Klonopin have been prescribed to millions of Americans for decades to calm jittery nerves and promote a good night’s sleep.

But the number of people taking the sedatives and the average length of time they’re taking them have shot up since the 1990s, when doctors also started liberally prescribing opioid painkillers.

As a result, some state and federal officials are now warning that excessive prescribing of a class of drugs known as benzodiazepines or “benzos” is putting more people at risk of dependence on the pills and is exacerbating the fatal overdose toll of painkillers and heroin. Some local governments are beginning to restrict benzo prescriptions.

When taken in combination with painkillers or illicit narcotics, benzodiazepines can increase the likelihood of a fatal overdose as much as tenfold, according to the National Institute on Drug Abuse. On their own, the medications can cause debilitating withdrawal symptoms that last for months or years.

Public health officials also warn that people who abruptly stop taking benzodiazepines risk seizures or even death.

With heightened public awareness of the nation’s opioid epidemic, some state and local officials are insisting that these anti-anxiety medications start sharing some of the scrutiny.

“What we’re seeing is just like what happened with opioids in the 1990s,” said Anna Lembke, a researcher and addiction specialist at Stanford University. “It really does begin with overprescribing. Liberal therapeutic use of drugs in a medical setting tends to normalize their use. People start to think they’re safe and, because they make them feel good, it doesn’t matter where they get them or how many they use.”

The number of adults filling a benzodiazepine prescription increased by two-thirds between 1996 and 2013, from 8 million to nearly 14 million, according to a review of market data by Lembke and others in the New England Journal of Medicine. Despite the known dangers of co-prescribing painkillers and anti-anxiety medications, the rate of combined prescriptions nearly doubled between 2001 and 2013.

Since then, prescriptions for benzodiazepines may have leveled off or declined slightly, according to recent data from a market research firm that tracks prescription drug sales, the IQVIA Institute for Human Data Science. Still, Lembke said, the level of prescribing is much higher than it was in the mid-1990s.

First marketed in the early 1960s, benzodiazepines have been cyclically abused throughout their history. What’s notable now, Lembke said, is that overuse of benzos is coinciding with overuse of opioids.

But a newly formed group of researchers and pharmacologists, the International Task Force on Benzodiazepines, wrote in an editorial that recent negative publicity has made it difficult for many doctors around the world to prescribe medications they consider essential.

Psychiatrists, including Lembke, agree that relatively inexpensive benzodiazepines can be effective at relieving acute cases of anxiety and sleeplessness. But physicians also agree that benzos should not be used long term to solve psychiatric problems.