Adjunctive varenicline treatment for smoking reduction in patients with schizophrenia: A randomized double-blind placebo-controlled trial

Abstract

Objectives: Smoking is more common among patients with schizophrenia than it is in the general population. Varenicline, a partial and full agonist at the α4β2 and α7 nicotine acetylcholine receptors, respectively, has been shown to be an effective anti-smoking treatment. This study examined the effects of varenicline treatment on smoking reduction in patients with schizophrenia.

Methods: Sixty smokers with schizophrenia were recruited and randomized to receive either varenicline or placebo. Smoking behavior was assessed with the Minnesota Nicotine Withdrawal Scale (mNWS), Brief Questionnaire of Smoking Urge (QSU-brief), and Modified Cigarette Evaluation Questionnaire (mCEQ). Exhaled carbon monoxide was also measured to assess smoking dependency and status. Data were analyzed with the two-tailed Student's t-test, χ(2) test, and repeated measures ANOVA.

Results: During the 8-week study, there was a significant time×group interaction, which showed that smoking decreased over time in the varenicline group. Expired CO levels also decreased in the varenicline group, showing a significant time effect, group effect, and time×group interaction. Total mCEQ scores decreased in the varenicline group, demonstrating a significant time×group interaction. Among the five domains of the mCEQ, the smoking satisfaction, psychological reward, and enjoyment of respiratory tract sensation domains showed significant time×group interactions in the varenicline group. The QSU-brief and mNWS demonstrated a significant time effect, but not significant time×group interactions. Adjunctive varenicline treatment with antipsychotics was generally well-tolerated and safe.

Conclusions: Varenicline showed significant efficacy in reducing smoking in people with schizophrenia.

Trial registration: ClinicalTrials.gov NCT00523445.

Keywords: Schizophrenia; Smoking; Varenicline.