April 2026
Large opioid dose reductions linked to higher risk of mental health-related ED presentations
Sasha Ellery BM BCh
Large reductions in prescribed opioid dose and abrupt opioid discontinuation are associated with increased odds of subsequent mental health-related emergency department (ED) presentations in adults receiving long-term opioid therapy, an Australian case-crossover study finds.
Published in Pain, researchers analysed data from primary care, as well as from three metropolitan hospitals in Victoria, on 1458 adults who had a mental health-related or substance use-related ED presentation between April 2018 and May 2022. All participants had received four or more opioid prescriptions in the preceding 12 months.
Professor Suzanne Nielsen, a study author and Deputy Director of the Monash Addiction Research Centre, Melbourne, said, ‘Previous studies have identified that, for some people, [opioid] tapering can be a high-risk period, and it can increase the risk of either a mental health crisis, or substance use and overdose.’
Compared with periods in which patients had no opioid prescriptions in the previous 30 days, dose reductions of more than 25% were associated with higher odds of a mental health- or substance use-related ED presentation (adjusted odds ratio [aOR], 1.78; 95% confidence interval [CI], 1.44-2.21). Opioid discontinuation was associated with about double the odds of presentation (aOR, 2.04; 95% CI, 1.48-2.82).
By contrast, smaller dose reductions of 10 to 25% were associated with lower odds of presentation, as were stable or increased doses.
‘Current guidelines are largely consensus and expert opinion-based, because there hasn’t been a lot of research on this topic. The good news is that what we found is consistent with the recommended rate of reduction of 10 to 25% over a one-month period,’ Professor Neilsen told Medicine Today.
The study also found that concurrent prescribing of gabapentinoids, benzodiazepines or other psychotropic medicines with a reduction in opioid dose of more than 25% was associated with increased odds of mental health-related or substance use-related ED presentation. Professor Nielsen said this finding might be another way to identify patients at higher-risk of such presentations.
‘If you are planning a taper with [higher-risk patients], you can make sure there are additional supports in place to protect their safety.’
The authors acknowledged several study limitations, including that opioid doses were derived from prescription records and median supply durations rather than actual use, and that the prescribing data largely represented general practice care.
‘We’re not recommending avoiding opioid tapering where it is clinically recommended – e.g. where the patient is no longer benefiting from the opioids, or where the risks outweigh the benefits,’ Professor Nielsen explained. ‘But we were able to identify patients who appear to be a high-risk group, and those are the patients we would want to target resources towards, put structures in place to support and ensure their mental health needs are attended to.’