Effects of Varenicline on Cigarette Self Administration
The investigators hypothesize that varenicline will dose dependently attenuate the subjective effects of cigarettes after a period of abstinence. Also, treatment with varenicline will dose dependently weaken the severity of nicotine withdrawal symptoms. Thirdly, we hypothesize that treatment with varenicline will dose dependently decrease cigarette self-administration in the model proposed.
|Study Design:||Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Single Group Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Treatment
|Official Title:||Effects of Varenicline on Cigarette Self Administration|
- Cigarette Choice [ Time Frame: During the experimental session (6 hours) repeated four times once a week over a four week period. ] [ Designated as safety issue: No ]Every 30 min participants had opportunity to make a choice of cigarettes or money. The outcome measure is a number of cigarette choices made during the experimental choices (out of 9 possible choices)
|Study Start Date:||February 2008|
|Study Completion Date:||May 2009|
|Primary Completion Date:||May 2009 (Final data collection date for primary outcome measure)|
Each participant participates in 4 consecutive interventions in random order.
4. 2 mg varenicline, 1 capsule before the session
4 doses of Varenicline. 1 capsule of either dose (0mg, 0.5mg, 1mg, 2 mg) in the morning on days at least 5 days apart.
Other Name: Chantix
Tobacco use is the leading preventable cause of death in the U.S.A. Every year 400,000 people die from cigarette smoking and in 2006, one out of every five deaths in the US were smoking related. Recent advances in laboratory studies of tobacco effects in humans and in understanding the effects of nicotine on the brain and behavior present an opportunity to advance medication development.
The addictive properties of nicotine are thought to be a result of nicotine triggering the acute release of dopamine, a pleasurable event that a person seeks to repeat. Varenicline is a partial agonist of the nicotine receptors, therefore also triggering the release of dopamine but in a more sustained and moderate manner, which could counter the low dopamine levels arising from a lack of nicotine and therefore aid craving. Also, by binding to these nicotine receptors in advance of smoking, it could stop nicotine from binding and creating pleasurable effects.
This study will assess the effect of acute treatment with varenicline and placebo on early tobacco withdrawal, acute effects of cigarettes and cigarette self-administration in cigarette-smoking volunteers. After overnight abstinence, participants will come into the lab and receive acute treatment with varying doses of varenicline or placebo and perform computer tests and fill out questionnaires. Then they will be given the opportunity to smoke under operational conditions (cigarette versus money choice). This study will employ a within-group, double-blind, randomized and counterbalanced design.
The main goal of this project is to improve the current laboratory model of smoking cessation and study the mechanism involved in smoking maintenance. We hypothesize that varenicline will dose-dependently: 1) decrease nicotine withdrawal symptoms, 2) decrease acute effects of cigarettes and 3) decrease self-administration of cigarettes in the laboratory paradigm. Showing the effectiveness of varenicline in the proposed laboratory model will confirm the model's predictive validity to detect clinically effective medication.
Please refer to this study by its ClinicalTrials.gov identifier: NCT00731055
|United States, New York|
|New York State Psychiatric Institute|
|New York, New York, United States, 10032|
|Principal Investigator:||Adam Bisaga, MD||New York State Psychiatric Institute|