Factors associated with daily use of benzodiazepines/tranquilizers and opioids among people who use drugs

Background: Co-use of benzodiazepines and opioids significantly increases fatal overdose risk, yet few studies have examined co-use of these drugs when obtained both with and without a prescription. We examined associations of daily co-use of prescribed benzodiazepines/tranquilizers (BZD/TRQ) and prescribed and nonprescribed opioids among people who use street opioids (PWUO).Methods: PWUO (N = 417) were recruited from Baltimore City and neighboring Anne Arundel County, Maryland, and surveyed on sociodemographic characteristics, structural vulnerabilities, healthcare access and utilization, substance use, and overdose experiences. Multivariable logistic regression was used to identify factors associated with self-reported co-use.Results: Participants were 46 years old on average, and predominantly Black (74%) males (62%). Daily co-use was reported by 22%. In multivariable analyses, odds of co-use were significantly higher among participants who did not have a high school degree/GED (adjusted odds ratio [aOR]: 1.71, 95% confidence interval [CI]: 1.02-2.88), endorsed receiving mental health treatment in the past 6 months (aOR: 2.13, 95% CI: 1.28-3.56), reported daily use of powdered cocaine (aOR: 3.57, 95% CI: 1.98-6.45), and synthetic cannabinoids (aOR: 3.11, 95% CI: 1.40-6.93). Odds of co-use were significantly lower among Black participants compared to white participants (aOR: 0.39, 95% CI: 0.19-0.82).Conclusions and Scientific Significance: Clinicians working with PWUO or who prescribe BZDs or opioids should screen patients who use cocaine or synthetic cannabinoids, have low level of educational attainment, or recently accessed mental health services, as these patients may be at higher risk for daily co-use of BZD/TRQ and opioids, and therefore lethal overdose.