During the 18-year study period, the benzodiazepine overdose death rate increased four-fold, prompting researchers to call for interventions to reduce use.
Published in the American Journal of Public Health, the study was conducted by researchers at Albert Einstein College of Medicine and the Montefiore Health System in New York, as well as the Perelman School of Medicine at the University of Pennsylvania.
Patients are prescribed benzodiazepines for conditions such as anxiety, mood disorders and insomnia; in the US each year, an estimated 1 in 20 adults fill a prescription for a benzodiazepine.
These sedatives are considered a safe and effective treatment, but their long-term use can lead to addiction. Furthermore, there are certain side effects attached to them, including daytime drowsiness and a "hung-over feeling," increasing risk of automobile accidents.
They can also make breathing problems worse and can lead to falls in the elderly.
When used with alcohol, benzodiazepines can be dangerous, and overdoses can be serious.
In 2013, overdoses from the class of drugs made up 31% of the 23,000 prescription drug overdose deaths in the US. However, little was known about benzodiazepine prescribing trends or fatalities.
'People are taking benzos in a riskier way'
To further investigate, the researchers, led by Dr. Marcus Bachhuber, looked at data from 1996-2013, using the Medical Expenditure Panel Survey and multiple-cause-of-death data from the Centers for Disease Control and Prevention (CDC).
They found that the number of adults who filled a benzodiazepine prescription increased by 67% during the study period, which spanned 18 years; it went from 8.1 million prescriptions in 1996 to 13.5 million in 2013.
And for those adults who filled a prescription, the average quantity that was filled during each year more than doubled from 1996-2013.
Furthermore, the overdose rate increased four-fold, from 0.58 deaths per 100,000 adults in 1996 to 3.14 deaths per 100,000 adults in 2013.
"We found that the death rate from overdoses involving benzodiazepines, also known as 'benzos,' has increased more than four-fold since 1996 - a public health problem that has gone under the radar," says Dr. Bachhuber. He adds:
"Overdoses from benzodiazepines have increased at a much faster rate than prescriptions for the drugs, indicating that people have been taking them in a riskier way over time."
The researchers note that the rate of overdose deaths has leveled off since 2010. However, in adults over the age of 65 and blacks and Hispanics, the post-2010 overdose death rate has continued to rise.
'We need more constructive approach than popping pills'
Senior study author Dr. Joanna Starrels says there may be two possible reasons for the increase in benzodiazepine deaths. Firstly, those "at risk for fatal overdose may be obtaining diverted benzodiazepines," meaning they are obtaining them from sources other than medical providers.
Another reason is that using benzodiazepines with alcohol or drugs puts people at greater risk for fatal overdoses. She says opioids are involved in 75% of overdose deaths that involve benzodiazepines.
Study coauthor Sean Hennessy, PhD, from Penn's Perelman School of Medicine, says:
"This epidemic is almost entirely preventable, as the most common reason to use benzodiazepines is anxiety - which can be treated effectively and much more safely with talk therapy. Given the high prevalence of anxiety symptoms, we need a more constructive approach to the problem than popping pills."
The researchers conclude their study by writing that we need "interventions to reduce the use of benzodiazepines or improve their safety."
Medical News Today recently reported that, contrary to the findings of previous research, benzodiazepines do not increase dementia risk.