One limitation of this study is that treatment took place in the context of a longitudinal study, which may have selected for participants with greater motivation to quit than smokers in the general population. In addition, treatment lasted only 8 weeks (with the exception of the nicotine lozenge, which lasted for 12 weeks). Future research will be needed to determine whether long-term usage of these pharmacotherapies improves efficacy (although some evidence suggests that longer use is not efficacious1). A final limitation is that the study did not include varenicline amongst the tested medications (varenicline was not FDA-approved at the time of study initiation), and therefore it is unknown how these agents would have fared relative to varenicline, the monotherapy designated as most effective by the 2008 PHS Guideline.1 The results do suggest the importance of testing varenicline against a combination of the nicotine patch and an ad libitum NRT medication because the current study identified this intervention as especially efficacious relative to placebo.
