New Monash University research has found that rapidly reducing or abruptly stopping prescription opioids significantly increases the risk of mental health or substance use-related emergency presentations.
Researchers analysed data from 1,458 Victorian adults on long-term opioid therapy who presented to emergency departments for mental health or substance use-related conditions between 2018 and 2022, using records from 562 general practices and three major hospital networks (Monash Health, Eastern Health and Peninsula Health).
The study, published in the journal Pain, found that rapid dose reductions of more than 25 per cent over a 30-day period, or stopping opioids entirely, were associated with more than 10 times the odds of emergency presentation compared with gradual reductions of 10-25 per cent.
Smaller dose reductions of 10-25 per cent, as recommended in Australia's opioid deprescribing guidelines, were not associated with increased emergency department presentations.
The research also found that concurrent prescriptions for gabapentinoids, benzodiazepines, or other psychotropic medications further increased risks during opioid dose reductions.
The most common mental health presentations were depressive episodes (16.9 per cent), suicidal ideation (12.7 per cent) and anxiety disorders (11 per cent).
Opioids have remained the leading cause of drug-induced deaths in Australia for over two decades, with two-thirds of opioid-related fatalities involving prescription opioids.
While opioid prescribing in Australia has declined by 18 per cent since 2016-2017, millions of Australians continue to be prescribed opioids for pain management, making safe deprescribing practices critically important.
Lead author Dr Monica Jung said the findings have important implications for clinical practice.
"Our research shows that when opioid doses are reduced gradually, there isn't an increased risk of mental health emergencies," Dr Jung said.
"However, larger or abrupt reductions can have serious consequences. This tells us that deprescribing opioids requires careful planning, patient support and close monitoring. The good news is that gradual tapering appears to be a safer approach."
Study author and Deputy Director of Monash Addiction Research Centre, Professor Suzanne Nielsen, said the findings highlighted the need for better support systems during opioid tapering.
"While reducing opioid prescribing overall is important for public health, we need to ensure individual patients are supported through this process," Professor Nielsen said.
"For patients taking gabapentinoids, benzodiazepines, or other psychotropic medications, extra caution and support may be needed during opioid dose reductions to prevent adverse outcomes."
Professor Nielsen said the results should inform clinical practice and policy development.
"These findings suggest we need better systems to identify patients at risk during opioid tapering, and more resources to support safer deprescribing, particularly for those with mental health conditions or taking multiple medications," Professor Nielsen said.
