Varenicline versus nicotine patch with brief advice for smokers with substance use disorders with or without depression: effects on smoking, substance use and depressive symptoms.

Abstract

Varenicline was compared with transdermal nicotine (NRT) for smokers with current substance use disorders (SUD) for effects on 3-month smoking abstinence (primary outcome) and, secondarily, on 3- and 6month abstinence while adjusting for medication adherence, and on additional smoking and substance use outcomes. Moderation by major depressive disorder history (MDD) and adherence were investigated. Double-blind double-placebo-controlled randomized design, stratifying by MDD, gender and nicotine dependence, with 3 and 6months follow-up. University offices in Rhode Island, USA. Adult smokers (n=137), in SUD treatment, substance abstinent <12months (n=77 varenicline, 60 NRT). Twelveweeks of varenicline (2mg/day, after 1-week dose run-up) or NRT (21mg/day decreasing to 7mg/day). Primary: point-prevalence smoking abstinence (7-day, confirmed) at 3months. Secondary: point-prevalence abstinence at 6months, quantity and frequency of smoking and substance use at 3 and 6months, and within-treatment abstinence, medication adherence and depressive symptoms. Smoking outcome analyses were repeated controlling for adherence and investigating adherence as a moderator. Effects on 3-month abstinence were P<0.065 without a covariate (Bayes factor 3.35, supporting the effect strongly) and differed significantly when controlling for baseline smoking [varenicline: 13%, NRT: 3%; odds ratio (OR)=4.81, 95% confidence interval (CI) 1.00, 23.13, P<0.05]. The threefold difference at 6months was not significant. Medication effect on abstinence across time was significant (P<0.05) covarying adherence and baseline smoking (OR=6.40, 95% CI=1.00, 40.93). Medication differences in 3-month abstinence occurred among participants with ≥77% adherence (P<0.02). No significant medication effects on heavy drinking, drug use or depressive symptoms were found. Varenicline appears to improve the chances of achieving at least 3months of smoking abstinence in smokers with substance use disorders trying to stop, compared with transdermal nicotine patches, the effect being independent of history of depressive disorder.