Effect of MDR C3435T polymorphism on Varenicline treatment in quit smoking

Despite so many global efforts, smoking still remains to be one of the most common addictions worldwide. Even though most smokers wish to quit smoking, many of them fail. In this respect, genetic variants arc thought to be remarkable factors in nicotine dependence and in treatment of smoking cessation. This is a paper investigating a single variant p-glycoprotein (P-gp) polymorphisms and its effect on Varenicline efficacy in the smoking cessation. 158 smokers and 52 non-smoker healthy volunteers were included. We determined the P-gp C3435T gene polymorphisms in all subjects. Face to face interviews with smokers were performed for smoking cessation and Varenicline was given for smoking cessation. Cessation success was evaluated in the 6th month and success rates were compared according to the P-gp genotype distributions. In our study, smoking cessation rate by Varenicline was 57.0%. This rate was 55.0% in females, and 57.2% in males (p=0.85). The P-gp C3435T gene distribution was similar in control, quitters and not-quitter groups. Cessation rate was at highest point in genotype CT (62.2%) and at the lowest in TT (47.6%). It was 53.8% in genotype CC and there was no statistically significant difference (p=0.27). Our results suggest that genetic variants of P-gp C3435T did not significantly affect Varenicline treatment for smoking cessation.