Mechanisms and Clinical Features of Co-occurring Opioid and Nicotine Use.

PURPOSE OF REVIEW: To review the literature addressing shared pathophysiological and clinical features of opioid and nicotine use to inform etiology and treatment, and highlight areas for future research. RECENT FINDINGS: Opioid and nicotine use co-occur at an alarmingly high rate, and this may be driven in part by interactions between the opioid and cholinergic systems underlying drug reward and the transition to dependence. Pain, among other shared risk factors, is strongly implicated in both opioid and nicotine use and appears to play an important role in their co-occurrence. Additionally, there are important sex/gender considerations that require further study. Regarding treatment, smoking cessation can improve treatment outcomes in opioid use disorder, and pharmacological approaches that target the opioid and cholinergic systems may be effective for treating both classes of substance use disorders. SUMMARY: Understanding overlapping etiological and pathophysiological mechanisms of opioid and nicotine use can aid in understanding their co-occurrence and guiding their treatment.