Comparisons with other studies or reviews
This systematic review is different from other studies in that varying degrees of alcohol dependence were considered among smokers. This study found that the same drugs that have been used to explore smoking cessation treatments have also been used for treating other types of addiction, such as those who are dependent on alcohol. At the same time, many studies have paid attention to the smoking cessation effects of these drugs on different populations of smokers, such as pregnant women and people with schizophrenia. For example, Kishi et al.[38] conducted a systematic review to explore the effect of Varenicline on smoking cessation, and found that Varenicline was not superior to placebo for promoting smoking cessation in people with schizophrenia. Meanwhile, Oon-Arom[39] separately synthesized the evidence for Varenicline on alcoholism. These two studies show that Varenicline is a relatively important drug in the treatment of addictive behaviors. Moreover, Siskind[40] conducted a network meta-analysis to explore smoking cessation effects among people with schizophrenia spectrum disorders and pointed out that Varenicline might be superior to Bupropion. As for other drugs, Lotfy[41] and David[42] synthesized the effects of Topiramate and Naltrexone on smoking cessation, respectively, with both studies indicating that these drugs have no beneficial short-term or long-term effects on smoking abstinence. From these systematic reviews and meta-analyses, it can be seen that the populations studied were general smokers or smokers with schizophrenia. However, this study has found that some RCTs reported the smoking cessation effects of these drugs on alcohol-dependent people, but to date, there has been no relevant synthesis of this evidence.