Despite earlier hopes, making it harder to crush or dissolve prescription opioids did little to curb the harms of the opioid epidemic, a major Australian study reveals.
The 2014 introduction of tamper-resistant oxycodone (OxyContin, Mundipharma) did appear to cause less tampering among people who injected drugs in Australia, without causing them to switch to other opioids.
Nevertheless, when researchers combined this data from injecting drug users and those who reported tampering with drugs, with health and sales data across the country, they found that broader harms from opioids in the community were relatively unchanged.
Australia’s growing opioid consumption continued unimpeded after the introduction of the reformulated drugs, the National Drug and Alcohol Research Centre researchers found.
Sales data also showed that while high-strength tablets became less popular after the April 2014 reformulation, this was offset by an increase in the purchase of low-strength oxycodone tablets.
Meanwhile, hospital admissions, emergency department presentations, ambulance call outs for overdoses and other population-level harms were unchanged by the introduction of the tamper-resistant drugs.
Lead author Dr Briony Larance said that while the new formulation led to a drop in the use of that particular drug by injecting drug users, a multifaceted response was needed to adequately combat the harms of the opioid epidemic.
“This includes increasing the availability of non-medication approaches to chronic pain, good clinical practice in long-term opioid treatment, and harm reduction among people who use opioids outside the recommendations of their prescriber,” she said.
“Approximately 2.9 million Australians were prescribed an opioid in 2014, compared with an estimated 93,000 people who injected drugs,” she added. “As a population-wide strategy to reduce harm of overuse or overprescription of opioids, the introduction of tamper-resistant formulations alone will not be sufficient to affect these outcomes.”
Published in The Lancet, the study incorporated 17 datasets spanning five years, including annual surveys of people who inject drugs and interviews with a cohort of 606 people who reported tampering with opioids both before and after the introduction of the reformulated drugs.
The study was welcomed as the “most complete and compelling evaluation of replacing a controlled release opioid analgesic with a tamper resistant formulation of controlled-release oxycodone” in an accompanying editorial.
This was partly thanks to the introduction of reformulated tablets in Australia occurring amid few other major policy or socioeconomic changes that might have impacted the use of opioids.
On the other hand, the introduction of tamper-resistant opioids into the US occurred in tandem with a suite of other strategies to curb opioid use, such as prescription-monitoring programmes, a crackdown on overprescribing doctors, public awareness campaigns and changes to clinical guidelines.
Overall, the authors reported “almost no discernible effect of the introduction of the tamper-resistant formulation of controlled-release oxycodone at the population level”.
Lancet 2018; online 11 January