INTRODUCTION: Studying polysubstance use is a public health recommendation. In the United Arab Emirates, more than 80% of adults with opioid use disorder (OUD) use 2 or more nonopioid substances. This secondary analysis contrasts the characteristics of polysubstance users (OUD + ≥1 nonopioid) with OUD, explores the correlates and predictors of nonfatal overdose, and examines the impact of polysubstance use on OUD treatment outcomes using buprenorphine (BUP).
METHODS: This analysis uses data from a 16-week outpatient randomized controlled trial of 141 adults with OUD allocated to BUP + incentivized adherence and abstinence monitoring (n = 70) and BUP in usual care (control, n = 71). Outcomes were nonfatal overdose events over the preceding 12 months, positive drug screens, and treatment retention. Participant characteristics were contrasted, and bivariate statistical tests were conducted for simple associations followed by logistic regression.
RESULTS: Polysubstance use was reported by 117 participants (82.9%), the majority of whom used pregabalin 72.1% (n = 75). Compared with OUD, polysubstance users observed higher arrests (median, 1.0 [interquartile range, 0.0-3.0] vs 0.5 [interquartile range, 0.0-2.0]; P = 0.04]) and nonfatal overdose events (n = 33 [31.8%] vs 2 [10.8%], P = 0.003). Carisoprodol and injecting drug use independently predicted nonfatal overdose (adjusted odds ratio, 4.519 [95% confidence interval, 1.81-11.22] and 2.74 [95% confidence interval, 1.15-6.51], respectively). No significant difference was observed in opioid use and retention in treatment outcomes between groups.
CONCLUSION: Carisoprodol and injecting drug use increase the likelihood of nonfatal overdose in adults with OUD. Polysubstance use does not impact response to BUP treatment compared with OUD.