Bupropion for smoking cessation in African American light smokers: a randomized controlled trial

Abstract

Background: Previous research demonstrated the efficacy of sustained release bupropion (bupropion SR) for smoking cessation in whites as well as moderate to heavy (≥10 cigarettes per day [CPD]) African American smokers. We evaluated whether bupropion SR was effective for smoking cessation among African American light smokers (≤10 CPD).

Methods: A randomized, double-blind placebo-controlled trial was conducted from December 27, 2007, to May 13, 2010. All participants were African American light smokers (≤10 CPD), aged 18 years or older. Participants were randomly assigned to receive 300 mg bupropion SR (150 mg once daily for 3 days and then 150 mg twice daily) (n = 270 participants) or placebo (n = 270 participants) for 7 weeks, and up to six sessions of health education counseling. Serum cotinine was measured at baseline (week 0). The primary outcome was salivary cotinine-verified 7-day point prevalence smoking abstinence at week 26; a cut point of 15 ng/mL differentiated smokers from nonsmokers. Salivary cotinine-verified smoking abstinence at end of medication treatment at week 7 was also examined. Odds ratios (OR) for smoking abstinence and 95% confidence intervals (CIs) were calculated using logistic regression models. All statistical tests were two-sided.

Results: Participants at baseline visit (week 0) smoked an average of 8.0 CPD and had a mean serum cotinine level of 275.8 ng/mL (SD = 155.8 ng/mL); most used menthol cigarettes (83.7%) and smoked within 30 minutes of waking (72.2%). After imputing those lost to follow-up as smokers, no statistically significant difference in long-term smoking abstinence rates at week 26 was observed between bupropion SR and placebo groups (13.3% vs 10.0%, OR = 1.39, 95% CI = 0.82 to 2.35, P = .23). Cotinine-verified smoking abstinence rate at end of medication week 7 was higher in the bupropion SR vs placebo group (23.7% vs 9.6%, OR = 2.92, 95% CI = 1.78 to 4.77, P < .001).

Conclusions: Bupropion SR was effective in promoting smoking cessation during the medication phase of treatment but showed no effect on long-term smoking cessation among African American light smokers. More research is needed to identify strategies for sustaining abstinence among African American light smokers.

Figure 1

CONSORT diagram of Kick It at Swope III (KIS-III) screening, enrollment, and retention through 6-month follow-up. Participants were enrolled between December 27, 2007, and October 27, 2009, and randomly assigned to receive a 7-week supply of active bupropion SR or placebo. Follow-up was completed on May 13, 2010.

Figure 2

Changes in depression scores relative to baseline at weeks 3, 7, and 26. The 10-item Center for Epidemiological Studies Depression Scale (CESD-10) assessed distress associated with depressive symptoms. CESD-10 depression scores are presented showing changes in CESD-10 score compared with baseline (horizontal dotted line). Diamonds represent the sustained release bupropion (bupropion SR) treatment group. Circles represent the placebo treatment group. Error bars represent standard deviations.

Figure 3

Changes in withdrawal scores relative to baseline at weeks 3, 7, and 26. The eight-item Minnesota Withdrawal Scale (MNWS) assessed nicotine withdrawal. Change in withdrawal during the study period is presented showing the mean change in MNWS score compared with baseline (horizontal dotted line) for each treatment group. Diamonds represent the sustained release bupropion (bupropion SR) treatment group. Circles represent the placebo treatment group. Error bars represent standard deviations.