Conditions: Nicotine Dependence
Keywords: Nicotine addiction Cigarette smoking Smoking cessation Zyban Chantix Nicotine patches Nicotrol Inhaler varenicline bupropion
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 702
Healthy volunteers: no

Brief summary:
This study focuses on the first step in developing an algorithm for maximizing quit-smoking success based on an adaptive approach, which changes treatment from the initial nicotine replacement therapy (NRT) when that treatment alone may not be sufficient. These NRT "non-responders" are switched (in double-blind fashion) before the quit date to receive either varenicline alone or varenicline paired with bupropion. Some participants who would otherwise have failed at their quit smoking attempt could be "rescued" by switching to alternative pharmacotherapies. The proposed study will evaluate the combination treatment against varenicline alone in an adaptive trial design

Detailed description:

Arms:
arm 1: This group will consist of smokers who, based on smoking behavior, DO NOT respond favorably to pre-cessation nicotine patches (assessed at Session P2). They will receive varenicline. arm 2: This group will consist of smokers who, based on smoking behavior, respond favorably to pre-cessation nicotine patches(assessed at Session P2). They will continue to receive only nicotine patches. arm 3: This group will consist of smokers who, based on smoking behavior, respond favorably to pre-cessation nicotine patches (assessed at Session P2). They will continue to receive nicotine patches and will receive a nicotine inhaler to use as needed after their quit date. arm 4: This group will consist of smokers who, based on smoking behavior, DO NOT respond favorably to pre-cessation nicotine patches (assessed at Session P2). They will receive varenicline in combination with bupropion.

Interventions: intervention 1: Varenicline intervention 2: Bupropion intervention 3: Nicotine patches intervention 4: Nicotine Inhaler
Intervention descriptions: intervention 1: For the first 3 days after being switched from nicotine patches (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. intervention 2: For the first 3 days after being switched from nicotine patches (occurring at one week before the target quit date), smokers in this group will receive bupropion at a dose of 150mg once per day. Subsequently, the dose will be 150mg twice per day, and will remain at that dose for the remainder of the 12 weeks. intervention 3: Nicotine Replacement Therapy Groups:

1. For smokers with high baseline carbon monoxide (CO): 42 mg/24 h for 2 weeks before the quit date and 3 weeks after the quit date, 21 mg/24 h for 4 weeks, 14 mg/24 h for 2 weeks, and 7 mg/24 h for 2 weeks; or
2. For smokers with low baseline CO: 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.

Varenicline and varenicline in combination with bupropion groups:

1. For smokers with high baseline CO: 42 mg/24 h for 1 week
2. For smokers with low baseline CO: 21 mg/24 h for 1 week intervention 4: Nicotine inhaler to use as needed after quit date

Protocol document: