Effect of Varenicline on Reactivity to Smoking and Drinking Cues
Condition: Tobacco Dependence; Alcohol Dependence
MeSH terms: Alcoholism; Tobacco Use Disorder
Study type: Interventional

Summary: 
      Alcohol and nicotine dependence are often co-morbid, with 85% of alcoholics also smoking.
      However, very little research has been conducted into the nature of this co-occurrence. Thus,
      the main aim of this study is to assess differences in alcohol and tobacco consumption and
      cue-induced craving in treatment-seeking smokers after two weeks treatment of varenicline.

      Hypotheses

        1. Two weeks of varenicline treatment will significantly decrease cue-induced tobacco
           craving compared to placebo (Due to the actions of varenicline on alpha-4-beta-2
           receptors and its downstream effect on dopamine release).

        2. Varenicline will decrease cue-induced alcohol craving compared to placebo.

        3. The impact of Varenicline on cue-induced alcohol craving will be greater in heavy
           drinkers compared to social drinkers.
    

Detailed description: 
      The relationship between alcohol and tobacco dependence needs to be addressed as such
      populations are generally excluded from clinical trials involving smoking cessation
      pharmacotherapy. Furthermore, the effect of Varenicline(Pfizer Pharmaceuticals)treatment on
      tobacco cue-induced craving has not been empirically measured, nor has the effect of
      varenicline on alcohol consumption. In addition to being an effective aid in smoking
      cessation, preliminary evidence has shown that Varenicline can decrease alcohol consumption
      in animal models.

      Varenicline is a partial agonist of the α4β2 nicotinic acetylcholine receptor. This drug's
      partial agonist effect allows for the activation of this receptor at a lesser degree than
      nicotine while simultaneously preventing nicotine binding due to the drugs high affinity
      (i.e.: antagonist effect) for this receptor subtype.

      Varenicline has recently been approved in Canada as an aid for smoking cessation. This study
      will be a double-blind, placebo-controlled randomized study. It will assess differences in
      alcohol and tobacco consumption and cue-induced craving in treatment-seeking smokers after
      two weeks of treatment with either varenicline or placebo.Ultimately This study may help to
      further understand the association between smoking and drinking alcohol.

      This study will consist of two study groups composed of 40 subjects each being randomized to
      receive either placebo or varenicline (0.5mg once daily for days 1-3, 0.5mg twice daily for
      days 4-7 followed by 1mg twice daily for days 8-14). One group will be heavy smokers and
      heavy drinkers while the other will be heavy smokers and social drinkers. Upon entering the
      study, subjects will undergo baseline cognitive and craving measures for both tobacco and
      alcohol associated cue presentations prior to randomization to varenicline or placebo.
      Subjects will be provided a 1-week supply of study medications and directions for use. During
      this period, subjects will be requested to complete a diary outlining their cigarette and
      alcohol craving and consumption each day and outline any adverse effects. Upon completion of
      this 1-week period, subjects will attend the Centre for Addiction and Mental Health (CAMH)
      where their old pill bottles and daily diaries will be collected and they will be supplied
      with study medication (1mg varenicline taken twice daily or placebo) and daily diary for an
      additional week. At this visit, subjects will complete the symptom checklist. At the end of
      the second week of treatment, subjects will be requested to return to CAMH where craving for
      tobacco and alcohol and cue-reactivity will be assessed in a similar manner as to study day
      After study completion, all subjects will be given the option to continue with varenicline in
      a 12-week treatment plan through the Nicotine Dependence Clinic.
    

Intervention name(s): Varenicline; Placebo
Intervention type(s): Drug; Drug
Intervention description(s): This group (N=40) will receive Varenicline (0.5mg once daily for days 1-3, 0.5mg twice daily for days 4-7 followed by 1mg twice daily for days 8-14). The group will consist of heavy smokers and heavy drinkers (N=20) and heavy smokers and social drinkers (N=20).; This group (n=40) will receive matching placebo capsules in the identical dosing regimen described for the Varenicline arm. The group will consist of heavy smokers who are heavy drinkers (n=20) and heavy smokers who are social drinkers (n=20).
Other intervention name(s): Chantix; Champix
Intervention MeSH terms: Varenicline
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Treatment
Keywords: Nicotine; Nicotine dependence; Smoking cessation; Alcohol; Alcohol dependence; Alcohol cessation; Treatment; Smoking; Cigarette; Heavy drinkers; Social drinkers; Co-morbidity of alcohol and nicotine dependence; Nicotine receptor; Nicotinic receptor; Nicotinic acetycholine receptor; Alpha-4-beta-2 nicotinic acetycholine receptor; Cholinergic receptor; Dopamine; Craving; Diary; Cue induced; Pharmacotherapy; Varenicline; Chantix; Champix