1. ¹Clinical Pharmacology, DecisionLine Clinical Research Corporation, Toronto, Ontario, Canada
2. ²Neurosciences Development, Pfizer Global Research and Development, Groton, Connecticut, USA
3. ³Neuroscience Statistics, Pfizer Global Research and Development, Groton, Connecticut, USA
4. ⁴Department of Pharmacology, University of Toronto, Toronto, Ontario, Canada
5. ⁵Department of Medicine, University of Toronto, Toronto, Toronto, Ontario, Canada
6. ⁶Department of Psychiatry,University of Toronto, Toronto, Toronto, Ontario, Canada

Correspondence: EM Sellers, (e.sellers@dlcrc.com)

Received 2 November 2007; Accepted 19 December 2007; Published online 20 February 2008.

Abstract

Varenicline is an ₄₂ nicotinic acetylcholine receptor partial agonist developed as an aid for smoking cessation.This study evaluated varenicline's potential for abuse by smokers (n = 23) and nonsmokers (n = 22). The study useda randomized, double-blind, placebo-controlled, double-dummy crossover design with five treatment periods: 15 and 30 mg amphetamine, 1 and 3 mg varenicline, and placebo. Following each treatment, the participants were assessedon aspects relating to potential abuse of the drug (e.g., drug liking, drug high, and drug monetary value).The positive effects measured for 3 mg varenicline were similar to those for the placebo, and significantly lower than those for amphetamine in both smokers and nonsmokers. Unpleasant effects were reported for 3 mg vareniclinein both participant groups. For 1 mg varenicline, the overall patterns were similar, with the exception that thenonsmokers group showed some small positive effects balanced by some negative effects when compared with the effects of placebo. These findings lead to the conclusion that varenicline is unlikely to be abused.