A Trial of Directly Observed and Long-term Varenicline

This 2 x 2 factorial, randomized, double-blind, placebo-controlled trial will test two interventions: directly observed medication therapy, and long-term therapy with varenicline among smokers with opioid use disorder recruited from community-based, outpatient opioid treatment programs. The analytic strategy will evaluate the milestones in smoking cessation-achieving initial abstinence, preventing lapse and preventing relapse--necessary for long-term cessation, and evaluate theoretically-guided psychological and social factors and pharmacogenetic factors that influence these cessation processes.