Benzodiazepine Use in Patients Receiving Opioid Treatment

Deaths associated with concurrent injection of benzodiazepines and buprenorphine have been documented in Europe. To examine the risk of adverse effects (extreme drowsiness, unconsciousness, or overdose) from concurrent benzodiazepine use, Australian researchers surveyed 250 subjects, recruited from syringe exchange and opioid treatment programs, who had ever received buprenorphine or methadone treatment.

• Subjects who had received both methadone and buprenorphine in the past (n=164) were significantly more likely to report extreme drowsiness (odds ratio [OR], 2.7) and overdose (OR, 10.0) with methadone than with buprenorphine.
• Subjects reporting adverse effects with buprenorphine were significantly more likely than subjects reporting adverse effects with methadone to have injected their opioid treatment (51% versus 21%).
• Of the 193 subjects who had ever received buprenorphine, 67% reported ever concurrently using benzodiazepines (median dose equivalent to 30 mg of diazepam).
• In adjusted analyses, concurrent daily benzodiazepine use (versus no use) increased the odds of adverse effects significantly in subjects who had received methadone (OR, 2.2) and borderline significantly in subjects who had received buprenorphine (OR, 2.1).

Comments:

In this study, specific adverse effects were less common with buprenorphine use than with methadone use. Further, concurrent benzodiazepine use was not associated with a higher risk of adverse effects in subjects who received buprenorphine than in those who received methadone. These findings require replication in patients taking the combined formulation of buprenorphine/naloxone. Nonetheless, the results are reassuring to buprenorphine/naloxone prescribers in North America where benzodiazepine use is prevalent but buprenorphine injection is still relatively uncommon.

Peter D. Friedmann, MD, MPH

Reference:

Nielsen S, Dietze P, Lee N, et al. Concurrent buprenorphine and benzodiazepines use and self-reported opioid toxicity in opioid substitution treatment. Addiction. 2007;102(4):616–622.