Prevalence and characteristics of opioid-related deaths involving alcohol in Ontario, Canada

BACKGROUND: While it is well known that patients receiving opioids should refrain from alcohol consumption, little is known about the involvement of alcohol in opioid-related deaths. METHODS: We conducted a population-based analysis of opioid-related deaths in Ontario with and without alcohol involvement between 1993 and 2013, and reported rates overall and stratified by manner of death. We compared the characteristics of individuals who died of an opioid overdose based on the presence or absence of alcohol involvement. RESULTS: The rate of opioid-related deaths increased 288% from 11.9 per million (95% confidence interval (CI) 9.8-13.9 per million) in 1993-46.2 per million (95% CI 42.6-49.8 per million) in 2013. The rate of opioid-related deaths without alcohol involvement increased 388% from 7.4 per million to 36.1 per million, while deaths involving alcohol increased by 125% from 4.5 per million to 10.1 per million. Therefore, although the annual number of opioid-related deaths involving alcohol rose, the proportion of opioid-related deaths involving alcohol declined from 37.8% in 1993-21.9% by 2013. Generally, opioid-related deaths involving alcohol were less likely to involve other central nervous system depressants, and more likely to occur among men and those with a history of alcohol use disorder. CONCLUSIONS: Although the relative contribution of alcohol in opioid-related deaths has declined, 1 in 5 fatal opioid overdoses still involved alcohol in 2013. Our findings highlight the ongoing need for targeted messaging around risks of opioids alone, and in combination with alcohol and other CNS depressants.