Effects of 21 days of varenicline versus placebo on smoking behaviors and urges
among non-treatment seeking smokers.
Author(s): Ashare RL, Tang KZ, Mesaros AC, Blair IA, Leone F, Strasser AA.
Affiliation(s): Department of Psychiatry, University of Pennsylvania Perelman School of Medicine,
Philadelphia, PA, USA.
Publication date & source: 2012, J Psychopharmacol. , 26(10):1383-90
Varenicline promotes smoking cessation and reduces urges to smoke. However, the
mechanisms associated with these effects and their time course are not well
characterized. One mechanism may be extinction, but the duration of the current
dosing protocol may not be sufficient. We examined the effect of extended
pre-treatment with varenicline on smoking behavior among 17 non-treatment seeking
adult smokers. Using a within-subjects, double-blind, placebo-controlled
crossover design, participants received standard dosing of varenicline for 21
days, followed by a 14-day washout period and 21 days of placebo; order
counterbalanced. Cigarettes per day (CPD), smoking topography, smoking urges
(QSU), and side effects were assessed every three days. Biomarkers (e.g. nicotine
metabolites) were collected on days 1, 7, and 21. There was a significant drug by
time interaction indicating a reduction in CPD during varenicline phase (between
days 10-21), but no reduction during placebo. Varenicline also led to reductions
in nicotine metabolites and urges to smoke. Among this sample of non-treatment
seeking smokers, varenicline significantly reduced smoking behavior. Results have
important treatment implications because changes in CPD and craving did not occur
until after the typical one-week run-up period. This suggests that a longer
duration of pre-treatment may be beneficial for some smokers.
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