FDA-approved approaches for smoking cessation include nicotine replacement therapy (NRT), bupropion, and varenicline. NRTs include: transdermal patch, nicotine gum, inhalers, lozenges, and nasal spray. Meta-analyses of clinical trial efficacy data indicate that NRTs double the odds of successful quitting for at least 6 months compared to placebo (Moore et al. 2009; Stead et al. 2008). Bupropion, an anti-depressant medication, is a norepinephrine-dopamine reuptake inhibitor (Learned-Coughlin et al. 2003; Terry and Katz 1997) as well as a nicotinic acetylcholine receptor antagonist (Slemmer et al. 2000). Bupropion has similar efficacy to NRT and data from a meta-analysis revealed that bupropion doubles abstinence rates for at least 6 months compared to placebo (Hughes et al. 2007). Varenicline, an α4β2* nicotinic acetylcholine receptor partial agonist, was developed to mimic the effects of nicotine by stimulating a moderate amount of dopamine release to prevent craving and withdrawal, while reducing the reinforcing effects of nicotine from cigarette smoking (Rollema et al. 2007). Meta-analysis data indicate that varenicline improves the odds of abstinence two to three-fold, relative to placebo (Cahill et al. 2011). Varenicline is more effective
