Shuoqi Chen is a PhD student at King’s College London. Her research focuses on opioid-related mortality in the UK. Working with data from the National Programme on Substance Use Mortality, her research aims to address important evidence gaps in understanding drug-related deaths and the impact of both established and emerging opioids. Her work spans several areas, including opioid mortality surveillance, overdose prevention and novel synthetic opioids. The findings of her research are intended to support healthcare professionals, researchers, policymakers, and public health agencies in developing evidence-based responses to drug-related harms.

Abstract

The overlap between prescribed and illicit opioid use in fatal poisonings

Aims: Opioid-related deaths frequently involve multiple substances. However, little is known about the relative contribution of prescribed versus illicitly sourced opioids within these fatalities. This study aimed to characterise the involvement of prescribed and non-prescribed opioids in fatal opioid poisonings to better inform safer opioid prescribing practices and highlight the importance of assessing concurrent ‘on top’ opioid use.

Methods: Cases with at least one opioid implicated in causing death, where prescription history was provided, and where death occurred 2019–2023, were extracted from the National Programme on Substance Use Mortality. A comparison was conducted with regards to whether implicated opioids had been prescribed or illicitly obtained.

Results: There were 5,105 cases identified, of which there were 2,762 cases where the opioid(s) had not been prescribed, 835 cases where only some opioids had been prescribed, and 1,508 cases where all implicated opioids had been prescribed. Methadone was the most commonly prescribed opioid (n=1,344), followed by morphine (n=549) and codeine (n=350; including combination product). Morphine plus codeine (n=48), and morphine plus tramadol (n=30) were the most common combinations.

Conclusions: These findings demonstrate that prescribed opioids are commonly implicated in fatal opioid poisonings, either alone or in combination with non-prescribed opioids. This highlights the importance of careful opioid prescribing practices and routine assessment of concurrent ‘on top’ opioid use, particularly in patients receiving opioids for pain management or opioid substitution therapy.