Study of Bupropion Versus Bupropion + Naltrexone for Smoking Cessation

The purpose of this study is to compare the effects of bupropion + placebo to bupropion + naltrexone as treatments to help smokers quit. Bupropion is an FDA-approved medication for smoking cessation that is believed to provide relief from craving and withdrawal through promotion of two neurotransmitter chemicals, dopamine and noradrenaline. Naltrexone is an FDA-approved medication for the treatment of opiate and alcohol dependence, that appears to function through blocking certain opiate receptors in the brain. It is expected that bupropion + naltrexone will produce higher smoking quit rates than bupropion + placebo. Bupropion alone is effective in alleviating some nicotine withdrawal complaints and craving for nicotine. However, bupropion does not reduce the rewarding effects of slips to smoking. Naltrexone alone is not generally effective as a smoking cessation medication, but it does help to reduce the rewarding effects of slips to smoking. Thus, it may help to prevent full relapse to smoking. In addition, naltrexone can help to reduce craving for cigarettes. It is hypothesized that the differing complementary actions of the two drugs will help smokers more than bupropion alone. In addition to examining smoking quit rates, the proposed study will also look at psychological processes that change during smoking cessation including, nicotine withdrawal, nicotine craving, mood, impulsivity, and attention