Abstract
OBJECTIVE: Individuals in the United States with opioid use disorder (OUD) have high rates of co-occurring alcohol use disorder. However, there is limited research on co-use patterns among opioid and alcohol use. The present study examined the relationship between alcohol and opioid use in treatment-seeking individuals with an OUD. METHOD: The study used baseline assessment data from a multisite, comparative effectiveness trial. Participants with an OUD who had used nonprescribed opioids in the last 30 days (n = 567) reported on their alcohol and opioid use during the past 30 days using the Timeline Followback. Two mixed-effects logistic regression models were used to assess the effect of alcohol use and binge alcohol use (≥4 drinks/day for women and ≥5 drinks/day for men) on opioid use. RESULTS: The likelihood of same-day opioid use was significantly lower on days in which participants drank any alcohol (p < .001) as well as on days in which participants reported binge drinking (p = .01), controlling for age, gender, ethnicity, and years of education. CONCLUSIONS: These findings suggest that alcohol or binge alcohol use is associated with significantly lower odds of opioid use on a given day, which was not related to gender or age. The prevalence of opioid use remained high on both alcohol use and non-alcohol use days. In line with a substitution model of alcohol and opioid co-use, alcohol may be used to treat symptoms of opioid withdrawal and possibly play a secondary and substitutive role in individuals with OUD substance use patterns.