Research shows nonprescribed fentanyl and stimulants were the major cause for overdose mortality

Reviewed by James Ives, M.Psych. (Editor)Aug 24 2020

Nonprescribed fentanyl and stimulants were the primary contributors to overdose mortality, while few people had prescribed opioids in their systems, according to new toxicology research in CMAJ (Canadian Medical Association Journal).

With health professional organizations introducing guidelines to reduce prescribing of opioids and other controlled substances, understanding the relative contribution of prescribed substances and illicitly obtained substances to overdose deaths is key to developing effective programs to reduce overdose mortality."

Alexis Crabtree, BC Centre for Disease Control, University of British Columbia

The postmortem study looked at deaths from drug overdoses identified by the BC Coroners Service between 2015 and 2017 with 1 or more illicit drugs. The deaths were linked to the person's prescription medication history in British Columbia's PharmaNet database.

Of the total 2872 deaths, toxicology results were available for 1789 deaths, in which the majority (85.5%) had 1 or more opioids present. However, only 8.7% of individuals had taken prescribed opioids, and methadone and buprenorphine, used in opioid agonist therapy, were rarely detected in postmortem toxicology.

Of the deaths linked to nonprescribed opioids, fentanyl or fentanyl analogues were found in 79% of cases. Stimulants were found in 71% of deaths, almost all nonprescribed. Of the deaths in which benzodiazepines were detected, 63% had not been prescribed.

Death rates from illicit drugs increased more than fourfold between 2014 and 2018, which has been attributed to the contamination of the illicit drug supply. Over the past 5 years, British Columbia has had the highest rates of deaths from illicit drug use in Canada.

"Prescribing policies are insufficient to address the current overdose crisis in Canada and additional strategies are needed," write the authors. "Physicians should be encouraged to practise patient-centred opioid prescribing."

They suggest removing barriers to medically supervised opioid agonist therapy to provide a safer alternative to illegal drugs and supporting harm reduction organizations to provide care to people using nonprescribed medications.

In a related commentary, Dr. Mark Tyndall, School of Population and Public Health, University of British Columbia, Vancouver, BC, writes, "In the last 5 years, the major responses to the overdose crisis have been to reverse overdoses through harm reduction programs, build a better addiction care system, and create better housing and social services."

"Although these may be important actions and aspirations in the long term, they will not address the current emergency. Unless there is a radical change in our approach to the epidemic, overdose deaths will continue unabated. It is time to scale up safe supply and decriminalize drug use."

"Toxicology and prescribed medication histories among people experiencing fatal illicit drug overdose in British Columbia, Canada" is published August 24, 2020.