Randomized, controlled pilot trial of bupropion for pregnant smokers: challenges and future directions

Electronic cigarettes versus nicotine patches for smoking cessation in pregnancy: a randomized controlled trial

Nicotine replacement therapy, in the form of nicotine patches, is commonly offered to pregnant women who smoke to help them to stop smoking, but this approach has limited efficacy in this population. Electronic cigarettes (e-cigarettes) are also used by pregnant women who smoke but their safety and efficacy in pregnancy are unknown. Here, we report the results of a randomized controlled trial in 1,140 participants comparing refillable e-cigarettes with nicotine patches. Pregnant women who smoked were randomized to e-cigarettes (n = 569) or nicotine patches (n = 571). In the unadjusted analysis of the primary outcome, validated prolonged quit rates at the end of pregnancy in the two study arms were not significantly different (6.8% versus 4.4% in the e-cigarette and patch arms, respectively; relative risk (RR) = 1.55, 95%CI: 0.95-2.53, P = 0.08). However, some participants in the nicotine patch group also used e-cigarettes during the study. In a pre-specified sensitivity analysis excluding abstinent participants who used non-allocated products, e-cigarettes were more effective than patches (6.8% versus 3.6%; RR = 1.93, 95%CI: 1.14-3.26, P = 0.02). Safety outcomes included adverse events and maternal and birth outcomes. The safety profile was found to be similar for both study products, however, low birthweight (<2,500 g) was less frequent in the e-cigarette arm (14.8% versus 9.6%; RR = 0.65, 95%CI: 0.47-0.90, P = 0.01). Other adverse events and birth outcomes were similar in the two study arms. E-cigarettes might help women who are pregnant to stop smoking, and their safety for use in pregnancy is similar to that of nicotine patches. ISRCTN62025374.

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.

Pharmacological interventions for promoting smoking cessation during pregnancy

BACKGROUND

Tobacco smoking in pregnancy causes serious health problems for the developing fetus and mother. When used by non-pregnant smokers, pharmacotherapies (nicotine replacement therapy (NRT), bupropion, and varenicline) are effective for increasing smoking cessation, however their efficacy and safety in pregnancy remains unknown. Electronic cigarettes (ECs) are becoming widely used, but their efficacy and safety when used for smoking cessation in pregnancy are also unknown.

OBJECTIVES

To determine the efficacy and safety of smoking cessation pharmacotherapies and ECs used during pregnancy for smoking cessation in later pregnancy and after childbirth, and to determine adherence to smoking cessation pharmacotherapies and ECs for smoking cessation during pregnancy.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (20 May 2019), trial registers, and grey literature, and checked references of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) conducted in pregnant women, comparing smoking cessation pharmacotherapy or EC use with either placebo or no pharmacotherapy/EC control. We excluded quasi-randomised, cross-over, and within-participant designs, and RCTs with additional intervention components not matched between trial arms.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methods. The primary efficacy outcome was smoking cessation in later pregnancy; safety was assessed by 11 outcomes (principally birth outcomes) that indicated neonatal and infant well-being. We also collated data on adherence to trial treatments. We calculated the risk ratio (RR) or mean difference (MD) and the 95% confidence intervals (CI) for each outcome for each study, where possible. We grouped eligible studies according to the type of comparison. We carried out meta-analyses where appropriate.

MAIN RESULTS

We included 11 trials that enrolled a total of 2412 pregnant women who smoked at enrolment, nine trials of NRT and two trials of bupropion as adjuncts to behavioural support, with comparable behavioural support provided in the control arms. No trials investigated varenicline or ECs. We assessed four trials as at low risk of bias overall. The overall certainty of the evidence was low across outcomes and comparisons as assessed using GRADE, with reductions in confidence due to risk of bias, imprecision, and inconsistency. Compared to placebo and non-placebo (behavioural support only) controls, there was low-certainty evidence that NRT increased the likelihood of smoking abstinence in later pregnancy (RR 1.37, 95% CI 1.08 to 1.74; I² = 34%, 9 studies, 2336 women). However, in subgroup analysis by comparator type, there was a subgroup difference between placebo-controlled and non-placebo controlled RCTs (test for subgroup differences P = 0.008). There was unclear evidence of an effect in placebo-controlled RCTs (RR 1.21, 95% CI 0.95 to 1.55; I² = 0%, 6 studies, 2063 women), whereas non-placebo-controlled trials showed clearer evidence of a benefit (RR 8.55, 95% CI 2.05 to 35.71; I² = 0%, 3 studies, 273 women). An additional subgroup analysis in which studies were grouped by the type of NRT used found no difference in the effectiveness of NRT in those using patches or fast-acting NRT (test for subgroup differences P = 0.08). There was no evidence of a difference between NRT and control groups in rates of miscarriage, stillbirth, premature birth, birthweight, low birthweight, admissions to neonatal intensive care, caesarean section, congenital abnormalities, or neonatal death. In one study infants born to women who had been randomised to NRT had higher rates of 'survival without developmental impairment' at two years of age compared to the placebo group. Non-serious adverse effects observed with NRT included headache, nausea, and local reactions (e.g. skin irritation from patches or foul taste from gum), but data could not be pooled. Adherence to NRT treatment regimens was generally low. We identified low-certainty evidence that there was no difference in smoking abstinence rates observed in later pregnancy in women using bupropion when compared to placebo control (RR 0.74, 95% CI 0.21 to 2.64; I² = 0%, 2 studies, 76 women). Evidence investigating the safety outcomes of bupropion use was sparse, but the existing evidence showed no difference between the bupropion and control group.

AUTHORS' CONCLUSIONS

NRT used for smoking cessation in pregnancy may increase smoking cessation rates in late pregnancy. However, this evidence is of low certainty, as the effect was not evident when potentially biased, non-placebo-controlled RCTs were excluded from the analysis. Future studies may therefore change this conclusion. We found no evidence that NRT has either positive or negative impacts on birth outcomes; however, the evidence for some of these outcomes was also judged to be of low certainty due to imprecision and inconsistency. We found no evidence that bupropion may be an effective aid for smoking cessation during pregnancy, and there was little evidence evaluating its safety in this population. Further research evidence on the efficacy and safety of pharmacotherapy and EC use for smoking cessation in pregnancy is needed, ideally from placebo-controlled RCTs that achieve higher adherence rates and that monitor infants' outcomes into childhood. Future RCTs of NRT should investigate higher doses than those tested in the studies included in this review.

Use of smoking cessation pharmacotherapies during pregnancy is not associated with increased risk of adverse pregnancy outcomes: a population-based cohort study

BACKGROUND

Varenicline, bupropion and nicotine replacement therapy (NRT) are three effective pharmacotherapies for smoking cessation, but data about their safety in pregnancy are limited. We assessed the risk of adverse perinatal outcomes and major congenital anomalies associated with the use of these therapies in pregnancy in Australia.

METHODS

Perinatal data for 1,017,731 deliveries (2004 to 2012) in New South Wales and Western Australia were linked to pharmaceutical dispensing, hospital admission and death records. We identified 97,875 women who smoked during pregnancy; of those, 233, 330 and 1057 were exposed to bupropion, NRT and varenicline in pregnancy, respectively. Propensity scores were used to match exposed women to those who were unexposed to any smoking therapy (1:10 ratio). Propensity scores and gestational age at exposure were used to match varenicline-exposed to NRT-exposed women (1:1 ratio). Time-dependent Cox proportional hazards models estimated hazard ratios (HR) with 95% confidence intervals (95% CI) for any adverse perinatal event (a composite of 10 unfavourable maternal and neonatal outcomes) and any major congenital anomaly.

RESULTS

The risk of any adverse perinatal event was not significantly different between bupropion-exposed and unexposed women (39.2% versus 39.3%, HR 0.93, 95% CI 0.73-1.19) and between NRT-exposed and unexposed women (44.8% vs 46.3%, HR 1.02, 95% CI 0.84-1.23), but it was significantly lower in women exposed to varenicline (36.9% vs 40.1%, HR 0.86, 95% CI 0.77-0.97). Varenicline-exposed infants were less likely than unexposed infants to be born premature (6.5% vs 8.9%, HR 0.72, 95% CI 0.56-0.92), be small for gestational age (11.4% vs 15.4%, HR 0.68, 95% CI 0.56-0.83) and have severe neonatal complications (6.6% vs 8.2%, HR 0.74, 95% CI 0.57-0.96). Among infants exposed to varenicline in the first trimester, 2.9% had a major congenital anomaly (3.5% in unexposed infants, HR 0.91, 95% CI 0.72-1.15). Varenicline-exposed women were less likely than NRT-exposed women to have an adverse perinatal event (38.7% vs 51.4%, HR 0.58, 95% CI 0.33-1.05).

CONCLUSIONS

Pregnancy exposure to smoking cessation pharmacotherapies does not appear to be associated with an increased risk of adverse birth outcomes. Lower risk of adverse birth outcomes in varenicline-exposed pregnancies is inconsistent with recommendations that NRT be used in preference to varenicline.

Smoking cessation in pregnancy: An update for maternity care practitioners

INTRODUCTION

This paper provides an up-to-date summary of the effects of smoking in pregnancy as well as challenges and best practices for supporting smoking cessation in maternity care settings.

METHODS

We conducted a qualitative review of published peer reviewed and grey literature.

RESULTS

There is strong evidence of the effects of maternal tobacco use and secondhand smoke exposure on adverse pregnancy outcomes. Tobacco use is the leading preventable cause of miscarriage, stillbirth and neonatal deaths, and evidence has shown that health effects extend into childhood. Women who smoke should be supported with quitting as early as possible in pregnancy and there are benefits of quitting before the 15th week of pregnancy. There are a variety of factors that are associated with tobacco use in pregnancy (socioeconomic status, nicotine addiction, unsupportive partner, stress, mental health illness etc.). Clinical-trial evidence has found counseling, when delivered in sufficient intensity, significantly increases cessation rates among pregnant women. There is evidence that the use of nicotine replacement therapy (NRT) may increase cessation rates, and, relative to continued smoking, the use of NRT is considered safer than continued smoking. The majority of women who smoke during pregnancy will require support throughout their pregnancy, delivered either by a trained maternity care provider or via referral to a specialized hospital or community quit-smoking service. The 5As (Ask, Advise, Assess, Assist, Arrange) approach is recommended for organizing screening and treatment in maternity care settings. Additionally, supporting smoking cessation in the postpartum period should also be a priority as relapse rates are high.

CONCLUSIONS

There have been several recent updates to clinical practice regarding the treatment of tobacco use in pregnancy. It is important for the latest guidance to be put into practice, in all maternity care settings, in order to decrease rates of smoking in pregnancy and improve pregnancy outcomes.

Smoking cessation in pregnancy: a continuing challenge in the United States

Despite significant population level declines, smoking during pregnancy remains a major public health issue in the United States (US). Approximately 360,000-500,000 smoke-exposed infants are born yearly, and prenatal smoking remains a leading modifiable cause of poor birth outcomes (e.g. birth < 37 gestational weeks, low birth weight, perinatal mortality). Women who smoke during pregnancy are more likely to be younger and from disadvantaged socioeconomic and racial and ethnic groups, with some US geographic regions reporting increased prenatal smoking rates since 2000. Such disparities in maternal prenatal smoking suggests some pregnant women face unique barriers to cessation. This paper reviews the current state and future direction of smoking cessation in pregnancy in the US. We briefly discuss the etiology of smoking addiction among women, the pathophysiology and effects of tobacco smoke exposure on pregnant women and their offspring, and the emerging issue of electronic nicotine delivery systems. Current population-based and individual smoking cessation interventions are reviewed in the context of pregnancy and barriers to cessation among US women. Finally, we consider interventions that are on the horizon and areas in need of further investigation.

Behavioral Counseling and Pharmacotherapy Interventions for Tobacco Cessation in Adults, Including Pregnant Women: A Review of Reviews for the U.S. Preventive Services Task Force

BACKGROUND

Tobacco use is the leading cause of preventable death in the United States.

PURPOSE

To review the effectiveness and safety of pharmacotherapy and behavioral interventions for tobacco cessation.

DATA SOURCES

5 databases and 8 organizational Web sites were searched through 1 August 2014 for systematic reviews, and PubMed was searched through 1 March 2015 for trials on electronic nicotine delivery systems.

STUDY SELECTION

Two reviewers examined 114 articles to identify English-language reviews that reported health, cessation, or adverse outcomes.

DATA EXTRACTION

One reviewer abstracted data from good- and fair-quality reviews, and a second checked for accuracy.

DATA SYNTHESIS

54 reviews were included. Behavioral interventions increased smoking cessation at 6 months or more (physician advice had a pooled risk ratio [RR] of 1.76 [95% CI, 1.58 to 1.96]). Nicotine replacement therapy (RR, 1.60 [CI, 1.53 to 1.68]), bupropion (RR, 1.62 [CI, 1.49 to 1.76]), and varenicline (RR, 2.27 [CI, 2.02 to 2.55]) were also effective for smoking cessation. Combined behavioral and pharmacotherapy interventions increased cessation by 82% compared with minimal intervention or usual care (RR, 1.82 [CI, 1.66 to 2.00]). None of the drugs were associated with major cardiovascular adverse events. Only 2 trials addressed efficacy of electronic cigarettes for smoking cessation and found no benefit. Among pregnant women, behavioral interventions benefited cessation and perinatal health; effects of nicotine replacement therapy were not significant.

LIMITATION

Evidence published after each review's last search date was not included.

CONCLUSION

Behavioral and pharmacotherapy interventions improve rates of smoking cessation among the general adult population, alone or in combination. Data on the effectiveness and safety of electronic nicotine delivery systems are limited.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality.

Estimating the Potential Impact of Tobacco Control Policies on Adverse Maternal and Child Health Outcomes in the United States Using the SimSmoke Tobacco Control Policy Simulation Model

INTRODUCTION

Numerous studies document the causal relationship between prenatal smoking and adverse maternal and child health (MCH) outcomes. Studies also reveal the impact that tobacco control policies have on prenatal smoking. The purpose of this study is to estimate the effect of tobacco control policies on prenatal smoking prevalence and adverse MCH outcomes.

METHODS

The US SimSmoke simulation model was extended to consider adverse MCH outcomes. The model estimates prenatal smoking prevalence and, applying standard attribution methods, uses estimates of MCH prevalence and relative smoking risks to estimate smoking-attributable MCH outcomes over time. The model then estimates the effect of tobacco control policies on adverse birth outcomes averted.

RESULTS

Different tobacco control policies have varying impacts on the number of smoking-attributable adverse MCH birth outcomes. Higher cigarette taxes and comprehensive marketing bans individually have the biggest impact with a 5% to 10% reduction across all outcomes for the period from 2015 to 2065. The policies with the lowest impact (2%-3% decrease) during this period are cessation treatment, health warnings, and complete smoke-free laws. Combinations of all policies with each tax level lead to 23% to 28% decreases across all outcomes.

CONCLUSIONS

Our findings demonstrate the substantial impact of strong tobacco control policies for preventing adverse MCH outcomes, including long-term health implications for children exposed to low birth weight and preterm birth. These benefits are often overlooked in discussions of tobacco control.