By Xiguang Liu , Mendel E. Singer 

The combination of opioids and cocaine has been increasingly implicated in overdose fatalities, but it is unknown how much is intentional vs. fentanyl-adulterated drug supply. 2017–2019 data from the nationally representative National Survey on Drug Use and Health (NSDUH) was used. Variables included sociodemographics, health, and 30-day drug use. Opioid use captured heroin, and prescription pain reliever use not according to own doctor. Modified Poisson regressions were used to estimate prevalence ratios (PRs) for variables associated with opioid and cocaine use. Among the 167,444 responders, 817(0.49%) reported use of opioids on a regular or daily basis. Of these, 28% used cocaine ≥1 of prior 30 days, 11% >1 day. Of 332(0.20%) who used cocaine on a regular/ daily basis, 48% used opioids ≥1 of prior 30 days, 25% >1 day. People with serious psychological distress were >6 times as likely to use both opioids and cocaine regularly/daily (PR = 6.48; 95% CI = [2.82–14.90]) and people who have never been married were 4 times as likely (PR = 4.17; 95% CI = [1.18–14.75]). Compared to those living in a small metropolitan region, people living in a large metropolitan region were >3 times as likely (PR = 3.29; 95% CI = [1.43–7.58]) and the unemployed were twice as likely (PR = 1.96; 95% CI = [1.03–3.73]). People with post-high school education were 53% less likely to use opioids and cocaine at least occasionally (PR = 0.47; 95% CI = [0.26–0.86]). People who use opioids or cocaine commonly choose to use the other. Knowing the characteristics of those most likely to use both should guide interventions for prevention and harm reduction.  

Preventive Medicine Reports 33 (2023) 102227