Safety
As shown in table 2, the adverse events reported in some studies were used to assess the safety of specific drugs. From the results, three drugs (Varenicline, Topiramate, and Bupropion) reported the symptoms and cases of adverse reactions in different groups. These adverse symptoms mainly included nausea, insomnia, headache and depression, etc. From the statistical difference, paresthesia caused by Topiramate, mild nausea caused by Varenicline, and insomnia caused by Bupropion reported more cases than placebo group. For other symptoms, there was no obvious difference between drugs and placebo.