In one of the largest and most detailed studies to date, researchers from the National Drug and Alcohol Research Centre (NDARC) at UNSW Sydney have analysed findings from a five-year cohort of 1514 people who have been prescribed opioids for chronic non-cancer pain.
The researchers wanted to examine daily opioid doses taken by the study cohort; how prevalent problematic opioid use was; the association between the opioid dose and problematic opioid behaviours; and the independent risk factors, patient characteristics and opioid dose that were associated with problematic behaviours.
Lead author Dr Gabrielle Campbell, a Senior Research Fellow at the University of the Sunshine Coast and adjunct at NDARC, said this report suggested that risk for problematic opioid outcomes is related to a combination of patient characteristics and pre-existing factors, rather than opioid dose alone.
“The most important and consistent patient risk factors associated with problematic opioid use in our study were younger age and histories of substance use and/or mental health problems – that’s consistent with previous research,” she said.
The report found that at cohort entry, participants had been prescribed an opioid for a median of four years. At the five-year follow up, 85 per cent remained on opioid medication, with over half (56 per cent) taking more than 50mg Oral morphine equivalent (OME) per day. Approximately 9 per cent of the cohort met criteria for opioid dependence.
“Long-term opioid use for people living with chronic non-cancer pain is common. This has traditionally been associated with concerns of increased rates of adverse harms related to opioid use, particularly dependence and overdose,” said Dr Campbell.
The report comes in response to concerns that patients with chronic non-cancer pain have been exposed to abrupt and forced tapering and cessation of opioids simply for being on a high dose – which can lead to added harms, including increased mortality – and concern that a higher dose is associated with problematic opioid behaviours.
“It is possible that this emphasis on dose comes from the ability to easily measure and respond to dose thresholds, compared with the relative complexity and time considerations of assessing other clinical factors that substantially contribute to opioid-related risk,” said Dr Campbell.
“We need to assess the risks and benefits experienced by patients in a more nuanced way, and avoid relying on opioid dose as a predictor of these problems.
“Although there are valid concerns about the safety and limited evidence of efficacy for the use of opioids for chronic non-cancer pain, long-term opioid use may be of benefit in carefully selected and monitored patients.”