Conditions: Nicotine Dependence
Keywords: Nicotine addiction Cigarette smoking Smoking cessation Zyban Chantix Nicotine patches varenicline bupropion fMRI
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 282
Healthy volunteers: no

Brief summary:
The purpose of this study is to look at brain function in order to understand how different treatments work to help people quit smoking. In this study, the investigators will look at the effects of nicotine patches, Chantix alone or Chantix paired with Zyban.

Detailed description:

Arms:
arm 1: For the first 3 days after being switched from Nicotine Replacement Therapy (NRT) occurring at one week before the target quit date, smokers in this group will receive varenicline at a dose of 0.5 mg once per day followed by 0.5 mg twice a day for the remaining 4 days of that week. Subsequently, the dose will be 1 mg twice per day, and will remain at that dose for the remainder of the 12 weeks. During the time they receive varenicline, smokers in this group will also receive placebo bupropion and placebo patches. arm 2: 21 mg/24 h for 2 weeks before the quit date and 7 weeks after the quit date, 14 mg/24 h for 2 weeks, and 7 mg/ 24 h for 2 weeks. After the 1st week, smokers in this group will also receive placebo bupropion and placebo varenicline. arm 3: For the first 3 days after being switched from Nicotine Replacement Therapy (NRT) occurring at one week before the target quit date, smokers in this group will receive varenicline at a dose of 0.5 mg once per day followed by 0.5 mg twice a day for the remaining 4 days of that week plus bupropion at a dose of 150mg once per day. Subsequently, the dose of varenicline will be 1 mg twice per day and the dose of bupropion will be 150 mg twice per day, and will remain at that dose for the remainder of the 12 weeks. During the time they receive varenicline and bupropion, smokers in this group will also receive placebo patches. arm 4: Nicotine patches at 21 mg/24 h for 7 weeks after the quit date, 14 mg/24 h for 2 weeks, and 7 mg/ 24 h for 2 weeks. After the 1st week, smokers in this group will also receive placebo bupropion and placebo varenicline.

Interventions: intervention 1: Varenicline intervention 2: Bupropion intervention 3: Nicotine patches intervention 4: Placebo varenicline intervention 5: Placebo bupropion intervention 6: Placebo patch
Intervention descriptions: intervention 1: None intervention 2: None intervention 3: None intervention 4: None intervention 5: None intervention 6: None

Protocol document: