CYP2B6 and bupropion's smoking-cessation pharmacology: the role of hydroxybupropion.

Bupropion is indicated to promote smoking cessation. Animal studies suggest that the pharmacologic activity of bupropion can be mediated by its major metabolite, hydroxybupropion. We measured plasma bupropion and its metabolite levels in a double-blind, placebo controlled, randomized smoking-cessation trial. Among the treatment-adherent individuals, higher hydroxybupropion concentrations (per µg/ml) resulted in better smoking-cessation outcomes (week 3, 7, and 26 odds ratio (OR) = 2.82, 2.96, and 2.37, respectively, P = 0.005-0.040); this was not observed with bupropion levels (OR = 1.00-1.03, P = 0.59-0.90). Genetic variation in CYP2B6, the enzyme that metabolizes bupropion to hydroxybupropion, was identified as a significant source of variability in hydroxybupropion formation. Our data indicate that hydroxybupropion contributes to the pharmacologic effects of bupropion for smoking cessation, and that variability in response to bupropion treatment is related to variability in CYP2B6-mediated hydroxybupropion formation. These findings suggest that dosing of bupropion to achieve a hydroxybupropion level of 0.7 µg/ml or increasing bupropion dose for CYP2B6 slow metabolizers could improve bupropion's cessation outcomes.

A randomized trial of targeted educational materials for smoking cessation in African Americans using transdermal nicotine

This study examines the efficacy of targeted versus standard care smoking cessation materials among urban African American smokers. Five hundred smokers (250 to each group) are randomized to receive a culturally targeted or standard care videotape and print guide. Both groups receive 8 weeks of nicotine patches and reminder telephone calls at Weeks 1 and 3. Process outcomes include material use and salience at 1 and 4 weeks postbaseline. Smoking outcomes include 7-day abstinence, smoking reduction, and readiness to quit at 4 weeks and 6 months postbaseline. Despite greater use of the targeted guide (68.8 per cent vs. 59.6 per cent, p < .05), intervention participants do not perceive the targeted materials as more salient, and no significant differences are found between groups on the smoking outcomes. Findings point to the importance of greater audience segmentation and individual tailoring to better match intervention materials to the needs of the priority population. (AU)

Regular and occasional smoking by college students: personality attributions of smokers and nonsmokers.

Recent reports show an increase in smoking among college students and suggest that occasional smoking is now initiated by previously nonsmoking students. This study evaluated whether this apparent increase in smoking by students is associated with positive self-images associated with smoking. Regular and occasional smokers rated how smoking "changes the way you feel about yourself" on 18 self-attributes that may be associated with smoking, e.g., from cigarette advertisements. Nonsmokers also rated smokers on the same 18 attributes. All three groups rated three attributes in the negative direction with at least a moderate effect size: that being a smoker was less healthy, that smokers were less desirable as a date and that smokers were less attractive while smoking. On only one other attribute regular smokers differed from neutral with at least a moderate effect size: that smoking made them feel less feminine. As hypothesized, the occasional smokers also rated some attributions positively with at least a moderate effect size: that smoking made them feel more daring and more adventurous and did not make them feel like an outcast. The nonsmokers rated a number of additional attributes about smokers negatively with at least a moderate effect size: that smokers are less sexy, less feminine, less sophisticated, less masculine, and less mature. Thus, the results suggest that smoking shows at best mixed associations with self-attributions of college students who smoke and is viewed negatively by those who do not smoke. Other results suggest that the recent increase in occasional smoking may be related to smoking with friends who smoke and smoking while drinking alcohol.