Cytisine increases the chances of quitting, although absolute quit rates were modest in two recent trials. Varenicline at standard dose increased the chances of successful long-term smoking cessation between two- and threefold compared with pharmacologically unassisted quit attempts. Lower dose regimens also conferred benefits for cessation, while reducing the incidence of adverse events. More participants quit successfully with varenicline than with bupropion. Two open-label trials of varenicline versus NRT suggested a modest benefit of varenicline but confidence intervals did not rule out equivalence. Limited evidence suggests that varenicline may have a role to play in relapse prevention. The main adverse effect of varenicline is nausea, but mostly at mild to moderate levels and tending to subside over time. Possible links with serious adverse events, including serious psychiatric or cardiovascular events, cannot be ruled out.

Future trials of cytisine may test extended regimens and more intensive behavioural support. There is a need for further trials of the efficacy of varenicline treatment extended beyond 12 weeks.
A randomized controlled open comparative trial of varenicline vs nicotine patch in adult smokers: efficacy, safety and withdrawal symptoms (the VN-SEESAW study).
It has been suggested that anti-smoking therapy gives encouraging results, but this has not been verified by well-randomized study protocols. The present study was a randomized controlled trial of varenicline vs nicotine patch in adult smokers for comparison of efficacy, safety and withdrawal symptoms.
                The 32 adult smokers were randomly divided into a varenicline group (VG, n=16) and a nicotine patch group (NG, n=16). The primary endpoints were the 12- and 24-week smoking-abstinence rates, safety and withdrawal symptoms including stress. No significant difference in abstinence rates was observed between the 2 groups over weeks 9-12 (71.4% vs 78.6% in the VG and NG, respectively), and weeks 9-24 (64.3% vs 71.4%, respectively). The frequencies of inability to concentrate at 2, 4, and 8 weeks, and wakeful nights at 2 weeks were higher in the VG than in the NG. Adverse side-effects associated with a gastrointestinal disorder occurred in 14 cases and 1 case in the VG and NG, respectively, and skin allergy was seen in 0 and 9 cases, respectively.
                The selection of treatment depends on the balance of desired acuteness of cessation of smoking and side-effects, such as psychiatric and gastrointestinal problems or skin allergy.