Benzodiazepines linked to overdose deaths among those treated for opioid dependency

Individuals treated for opioid dependency who also take benzodiazepines are almost three times more likely to die from an overdose, research published in PLoS Medicine (26 November 2019) has suggested^[1]
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Researchers examined data on 12,118 UK primary care patients prescribed opioid agonist treatment (OAT) between 1998 and 2014. Data on whether individuals had died and, if so, their cause of death were available for 7,016 (57.9%) of them.

The researchers looked at associations between the use of benzodiazepines, z-drugs or gabapentinoids, and co-prescription of OAT, including duration of treatment and death.

They found that individuals additionally prescribed benzodiazepines had an increased risk of death from drug-related poisoning, despite staying in treatment for longer (adjusted hazard ratio 2.96; 95% confidence interval 1.97–4.43; P<0.001). The same pattern was not seen with the other additional prescribed medicines.

The researchers adjusted for a variety of confounding factors, but acknowledged that the association they observed may not be causal; nevertheless, they recommend that doctors generally avoid prescribing benzodiazepines to opioid-dependent individuals.

“GPs and other medical practitioners should consider changing their prescribing practice,” said John Macleod, professor in clinical epidemiology and primary care at Bristol Medical School, and lead author of the study.

“There may be unusual circumstances where co-prescription is clinically justified, but these should be the exception rather than the rule.”