Efficacy and Safety of Vernonia cinerea for Smoking Cessation: An Open-Label Randomized Controlled Trial

This study aimed to compare the efficacy and safety of Vernonia cinerea (VC) and nortriptyline for smoking cessation. A randomized, active-comparator, open-label trial was conducted in 2019. A total of 84 patients participated in the study, and equally randomized with 42 participants in each group. Overall, there was no statistically significant difference of continuous abstinence rate (CAR) between VC and nortriptyline group (Odd ratio 0.68, 95%CI 0.25-1.85, P=0.451). After week 12, the end of treatment, CAR between both groups was not different (44.44% vs 45.95%, Odd ratio 0.77, 95%CI 0.23-2.54, P>0.999). After follow up by the end of research at week 24, the CAR in both groups was not different (41.67% vs 43.24%, Odd ratio 0.76, 95%CI 0.23-2.55, P>0.999). After week 24, relapse rate between VC and nortriptyline group was not different (13.89% vs 10.81%, P=0.923). In addition, both groups were effective in reducing the number of cigarettes per day compared to baseline. However, there was no difference between the groups. Overall, the VC group had an 8% smoking rate less than nortriptyline group, but not statistically significant (IRR 0.92, 95%CI 0.59-1.43, P=0.702). They also resulted in reducing the exhaled CO level at treatment period and wash out period (at week 12; 7(-17-20) vs 7(-12-16), mean difference 0.78, 95%CI -3.07-4.63, P>0.999, at week 24; 8(-5-22) vs 8.5(-5-17), mean difference 0.39, 95%CI -3.46-4.24, P>0.999). Overall, there was no difference between either group (mean difference -0.31, 95%CI -3.10-2.47). For safety data, adverse events including tongue bitter taste or numbness were found in VC group to be greater than in nortriptyline group (61.9% vs 30.95%, P=0.004), whereas dry mouth and drowsiness were greater found in nortriptyline group (35.71% vs 90.48%, P<0.001 and 16.67% vs 90.48%, P<0.001, respectively). Serious adverse events were not found. In smoking cessation, efficacy and safety of either VC or nortriptyline showed no difference.