A double-blind randomized placebo-controlled pilot study of neuropsychiatric adverse events in abstinent smokers treated with varenicline or placebo

Abstract

Background: Varenicline is an α4β2 partial nicotinic agonist approved for smoking cessation. There have been spontaneous postmarketing reports of neuropsychiatric adverse events (NPAEs) in smokers without a history of psychiatric illness quitting with varenicline.

Methods: One hundred ten smokers without history of psychiatric illness (screened by Structured Clinical Interview for DSM-IV) were randomized to 12 weeks of varenicline 1 mg twice daily (n = 55) or placebo. Adverse events were solicited systematically. Depressive symptoms, anxiety, aggression, and irritability were measured at baseline and weekly using the Montgomery-Åsberg Depression Rating Scale (MADRS), the Hamilton Anxiety Scale (HAM-A), and the Overt Aggression Scale-Modified (OAS-M). The Profile of Mood States (POMS) was administered daily. Mixed-model analysis of repeated measures was conducted to compare mean changes in scores between groups across study periods.

Results: Participants' mean baseline characteristics were 33 years of age, 22 cigarettes/day and Fagerström Test for Nicotine Dependence score > 7. Reported NPAEs were similar between groups. No suicidal events were reported. There were no significant differences between groups for the MADRS (treatment difference vs. placebo = .03, 95% confidence interval [CI] -.68-.73; NS), HAM-A (treatment difference [TD] = .14, 95% CI -.62-.90; NS), OAS-M Aggression subscale (TD = .5, 95% CI -1.18-2.18; NS), OAS-M Irritability subscale (TD = .08, 95% CI -.17-.34; NS), and the POMS total scores (TD = .5, 95% CI -.52-1.53; NS).

Conclusions: There were no significant differences between groups on measures of depressive symptoms, anxiety, or aggression/hostility. Systematically solicited NPAEs were similar between the varenicline and placebo groups.

Trial registration: ClinicalTrials.gov NCT00749944.