(CNN) The use of benzodiazepines, such as Xanax and Valium, is on the rise, and the number of overdose deaths related to them soared in recent years, new research says.
Benzodiazepines are a class of medication with sedative properties that are prescribed for anxiety, insomnia and other conditions. The potential danger of benzodiazepines is no secret: They were involved in about 30% of prescription drug overdose deaths in 2013, second only to opioids, which were involved in 70% of overdose deaths, according to the Centers for Disease Control and Prevention.
Researchers were hopeful that the last few years might see a decrease in benzodiazepine prescriptions.
"Going into this study, we thought that prescribing would be steady or decline in the late 2000s [because] people became more aware of opioids so there might be more attention" to benzodiazepines, said Dr. Marcus A. Bachhuber, assistant professor of medicine at Montefiore Medical Center and Albert Einstein College of Medicine. Bachhuber led the study, which was published in the American Journal of Public Health.
But any hope that benzodiazepine prescriptions slowed was dashed as Bachhuber and his colleagues looked at national surveys of U.S. households taken between 1996 and 2013.
The survey data revealed that the percentage of adults in the United States who filled a benzodiazepine prescription per year increased by about 30%, from 4.1% in 1996, to 5.6% in 2013. In addition, the amount of benzodiazepine medicine -- whether Xanax, Valium, Ativan, Klonopin or other drugs in this class -- in a prescription doubled over this time period.
This trend is "very concerning," Bachhuber said. It is not clear what's driving the continued increase in benzodiazepine prescribing, whether more anxiety and insomnia are being diagnosed, or benzodiazepines are becoming more common go-to treatments for these conditions, he said. The study found that anxiety was the most frequent reason these medications were given, accounting for 56% of prescriptions.
The study found that the overdose death rate related to benzodiazepines more than quadrupled between 1999 and 2010, from 0.58 per 100,000 adults to 3.07 per 100,000 adults. The largest increase was among adults 18 to 64 years of age.
Between 2010 and 2013, the rate of overdose deaths leveled off as they only plateaued among white adults, who make up the largest group of benzodiazepine users. Overdose deaths continued to rise among black and Hispanic people.
The fact that the overall rise in benzodiazepine overdose deaths between 1999 and 2010 was greater than the rise in benzodiazepine prescribing during this same period suggests that "people used benzodiazepines in more risky ways as time went on," Bachhuber said.
It could be that people were taking higher doses of medication -- which could be reflected in the increase in the amount of medication per prescription -- or they could be combining it with other medications, illegal drugs or alcohol, he said.
The big danger comes with mixing benzodiazepines with other substances.
"The risk of overdose and death from benzodiazepines themselves is generally low-to-moderate in otherwise health adults," said Dr. Gary Reisfield, professor of psychiatry at the University of Florida, who was not involved in the current study. But in combination with other sedatives, often opioids and alcohol, "their lethality is magnified," Reisfield said.
In recent research, 75% of benzodiazepine overdose deaths were found to also involve opioid use. Although the abuse of prescription opioids has been decreasing in recent years, Reisfield said, they are still rampant. In addition, the rate of opioid drug overdose death, unlike benzodiazepine deaths, has continued to increase since 2010. In addition, there has been an uptick in deaths related to illegal opioids, such as heroin and fentanyl.
The plateau in overdose deaths involving benzodiazepines, at least among white adults, is "reassuring to finally see," Reisfield said. There are probably a number of factors responsible for the plateau, he added, including the increase in statewide prescription drug monitoring programs, which collect data on substances that have been dispensed. Some states also require doctors to check these programs before prescribing painkillers, which could have helped reduce benzodiazepine overdose
The current study could help shine a light on the problem of benzodiazepine abuse and overdose.
"Much attention has been paid to the explosion of prescription opioid prescribing and the associated morbidity and mortality. Much less attention has been paid to the shadow epidemic of benzodiazepine prescribing and its consequences," Reisfield said.
Despite the recent leveling off in benzodiazepine overdose deaths, the data overall shows that efforts to curtail benzodiazepine prescribing, such as creating clinical guidelines, have not been successful, Reisfield said.
It is important for patients and providers to know about alternative treatments, and about the potential harms of benzodiazepines, both on their own and in combination with opioid painkillers and alcohol, Bachhuber said.
"[One] intervention would be to promote alternative medications or talk therapy instead of benzodiazepines," Bachhuber said.