Buprenorphine for the treatment of opioid-use disorder (OUD) may also mitigate the risk associated with concomitant benzodiazepine and Z-drug use, which is frequent in this patient population, new research suggests.
A case-crossover study of more than 20,000 participants with OUD showed that drug treatment days in which benzodiazepines and Z-drugs were taken were associated with an 88% increase in nonfatal overdose; buprenorphine appeared to reduce this risk by almost 40%.
“One of our two primary findings is that patients with opioid use disorder can still benefit substantially from buprenorphine treatment, even if they have benzodiazepines on board,” lead author Kevin Xu, MD, a resident at the Washington University, St. Louis, told this news organization.
The other key finding was that “not all benzodiazepines are equal” and that some are associated with higher risk than others, Dr. Xu added.
“If anything, patients who are on buprenorphine and benzodiazepines do not necessarily need to be abruptly tapered off their benzodiazepines. Our data actually demonstrate that there are safe avenues for them,” he added.
The findings were published online March 3 in the American Journal of Psychiatry.
Cloudy relationship
Buprenorphine is commonly used to treat patients with OUD because of its ability to decrease all-cause mortality. However,
In addition, recent research shows that benzodiazepine/Z-drug use is associated with a variety of potential adverse effects, including respiratory depression, overdose, and addiction risk.
The relationship between benzodiazepine use and buprenorphine treatment outcomes is poorly characterized in individuals with OUD. Although some studies suggest benzodiazepines may enhance retention in buprenorphine maintenance treatment, others suggest a link to increased adverse events, including all-cause mortality, drug-related poisonings, and accidental injury–related emergency department visits.
In addition, there has been little research on the potential adverse effects associated with use of selective benzodiazepine receptor modulators in patients with OUD. These so-called Z-drugs include zolpidem, zaleplon, and eszopiclone.
Nevertheless, previous research in the general population shows that these medications have a range of adverse effects similar to those of benzodiazepines, with comparable dose-response effects on all-cause mortality.
“The challenge for any clinician is that many patients who are addicted to opioids are also polysubstance users,” said Dr. Xu. “There are so many hopeful articles regarding the benefits of buprenorphine treatment in opioid use disorder patients, but it seems like the individuals with polysubstance use are largely ignored in the setting of the opioid epidemic.”
“And this is really the back story that got me inspired to study this particular topic,” he added.
Improve, nullify, or reverse?
Given these questions, the researchers set out to quantify the odds of nonfatal drug-related poisoning, including overdoses, associated with benzodiazepine or Z-drug use by patients with OUD who were also taking buprenorphine.
“While the drug-related poisoning variable encompasses opioid overdoses, we used a broad definition per CDC guidelines to also include other types of drug overdoses – including poisoning events involving stimulants, overdoses involving sedatives, and overdoses involving psychotropic prescription drugs” that are commonly used by patients with OUD, said Dr. Xu.
They also wanted to determine whether the use of benzodiazepines or Z-drugs would improve, nullify, or reverse the protective effect of buprenorphine. The researchers also evaluated whether different sedative and hypnotic subtypes of these drugs were associated with different poisoning risks.
The researchers analyzed pharmaceutical claims data from 304,676 individuals (aged 12-64 years) in the IBM MarketScan Commercial and Multi-State Medicaid Databases. All had received buprenorphine treatment for OUD between Jan. 1, 2006, and Dec. 31, 2016.
Buprenorphine use was converted to a daily milligram dose and was classified as either greater than 12 mg or less than or equal to 12 mg, because previous research suggests there may be differences in treatment retention associated with this dose. Given the case-control nature of the investigation, patients who did not experience a drug-related poisoning were excluded from the analysis.
The study’s primary unit of observation was person-days, which were those days during which patients were enrolled in a health insurance plan. Participants were evaluated for 1 year before their first drug-related poisoning and 1 year after their first such poisoning. The primary outcome was nonfatal drug-related poisonings, including overdoses. The primary exposure was determined on the basis of benzodiazepine or Z-drug prescriptions.
The daily dose of benzodiazepines or Z-drugs was standardized as a function of diazepam-equivalent milligrams. Doses were classified as either high dose (diazepam-equivalent mg dose >30 mg) or low dose (≤30 mg). The drugs were also distinguished on the basis of their pharmacologic properties, such as whether they were short-acting or long-acting.