Placebo-controlled trial of bupropion for smoking cessation in pregnant women

Background: Although a relatively small proportion of women who become pregnant continue to smoke cigarettes, no smoking cessation medication has been shown to be effective for this subgroup of smokers. Bupropion, a nonnicotine-based medication, is approved for the promotion of smoking cessation in nonpregnant individuals. We chose to study it in pregnant smokers because, although pregnancy increases nicotine metabolism, it does not affect the metabolism of bupropion.

Objective: We evaluated the efficacy and safety of sustained-release bupropion for smoking cessation among pregnant women.

Study design: We conducted a multiple site, placebo-controlled, randomized clinical trial of bupropion for tobacco use among pregnant women (N=129) (clinical trial number NCT02188459). We enrolled women during the second trimester and randomly assigned them to receive 10 weeks of treatment with either bupropion or placebo, accompanied by a total of 6 smoking cessation counseling sessions (4 during treatment and 2 postpartum). The primary outcome was 7-day point prevalence smoking abstinence, confirmed with breath carbon monoxide measurements, at the end of treatment (week 10) and at week 24. Group differences were assessed as a binary abstinence outcome using a repeated measure generalized estimating equations model with a logit link. Prolonged abstinence and smoking rates were secondary outcomes. Safety measures included maternal treatment-related adverse events, gestational age, the rate of overall and spontaneous preterm births and infant birthweight and size for gestational age, head circumference, and 5-minute Apgar scores.

Results: There were no significant differences in the safety measures across the treatment arms and bupropion was not efficacious in promoting smoking cessation at the end of treatment (7-day point prevalence quit rates: bupropion, 11.0%; placebo, 18.5%) or week 24 (7-day point prevalence quit rates: bupropion, 9.4%; placebo, 21.5%) (P>.05). African American women and women with a lower severity of nicotine dependence had significantly higher quit rates overall and women with an opioid use disorder who were being treated with opioid agonist therapy had significantly lower quit rates overall, irrespective of the treatment group (all P values <.05).

Conclusion: Although bupropion use was not associated with an elevated risk for pregnancy complications when initiated in the second trimester, it did not increase the likelihood of smoking cessation in this cohort of pregnant women. Because smoking is the major preventable source of poor pregnancy outcomes and psychosocial interventions have only modest beneficial effects, additional studies are needed to identify safe and efficacious smoking cessation medications for pregnant women who continue to smoke.