Risks and benefits of nicotine to aid smoking cessation in pregnancy

Benefits and risks of pharmacological smoking cessation therapies in chronic obstructive pulmonary disease

Smoking cessation is the most effective way to reduce the risk of developing chronic obstructive pulmonary disease (COPD) or to reduce its progression. However, little is known about the efficacy and safety of different pharmacological smoking cessation therapies used for the treatment of patients with COPD who smoke. The aim of this review was to evaluate the benefits and risks of pharmacological smoking cessation therapies in COPD. We conducted an extensive computer-aided literature search which resulted in the identification of four papers that met the inclusion criteria and contributed to this review. In two studies the efficacy of nicotine polacrilex (nicotine gum) was assessed. In one study, which did not have a control group, the efficacy of nicotine nasal spray was evaluated. The fourth study, a placebo-controlled trial, evaluated the efficacy of bupropion sustained release. The results of these studies indicated that nicotine gum, nicotine nasal spray and bupropion have a good safety profile and seem to increase abstinence rates in smokers with COPD. The incidence and nature of specific adverse effects occurring in patients with COPD seem to be comparable with the adverse effects reported by healthy smokers. However, the efficacy seems to depend on the follow-up period used to define success (i.e. abstinence rates decline with longer follow-up), as well as the intensity and duration of the concomitant psychosocial intervention. This review indicates that for a continuation of the effect of pharmacological smoking cessation therapies, the combination of pharmacotherapy (to reduce craving and withdrawal) and a relapse-prevention programme, in which attention is focused on the behavioural aspects of smoking and smoking cessation, seems to increase abstinence, especially when the psychosocial intervention is prolonged for a longer period. Also, the characteristics of the smokers who are motivated to quit must be taken into account in order to increase the number of successful attempts to quit smoking and prevent relapses. We therefore recommend using a holistic approach in which the possible coexistence of multiple problems (which are known to affect the success of smoking cessation strategies) is integrated.

Stopping smoking during pregnancy: are we on the right track?

BACKGROUND

Recent data suggest that although smoking during pregnancy has declined in North America, this has more to do with falling rates of smoking initiation among women of childbearing age than with increased rates of pregnancy-related smoking cessation. One possible explanation is poor exposure to effective stop-smoking strategies. Better information about women who smoke during pregnancy may help target these interventions more effectively.

METHODS

The study was a cross-sectional, self-administered survey of a consecutive sample of 916 (40.4% of eligible) women who delivered healthy babies in 1997-98 at a tertiary teaching hospital in Hamilton, Ontario. Our main focus was on health behaviours (smoking, drinking, eating, and exercise habits) before and during pregnancy; but we also included questions about the presence of (other) children and (other) smokers in the household, perceived health status, the subject's age and level of education, and whether or not the present pregnancy was planned. Factors associated with pregnancy-related smoking cessation were identified using multiple logistic regression.

RESULTS

Respondents were better educated and healthier, but smoked at rates similar to women of childbearing age in Hamilton at the time of the survey. Two thirds of prior smokers or 20% of respondents overall continued to smoke during pregnancy. After adjustment for other factors, three factors were associated with ongoing smoking during pregnancy: having other smokers in the household; having other children in the household; and not having post-secondary education.

CONCLUSIONS

Many pregnant smokers are not being reached by current stop-smoking strategies. New ways to help these women and their partners are needed.

[Individually tailored medical counseling for pregnant smokers]

OBJECTIVES

To identify the characteristics of smoking addiction in a group of pregnant women, to evaluate the efficacy of medical counseling tailored to the patient's stage in the cessation process and to examine factors that might affect the ability of a woman to quit smoking during pregnancy.

PATIENTS AND METHODS

One hundred sixteen women (mean age 29.71 5.44 years; range 15-41) were referred by obstetricians to a respiratory medicine specialist if they continued smoking after being advised to quit. The information each woman received was appropriate to her stage in the cessation process and covered the risks that smoking posed for her child and the benefits that would come from quitting. Each woman was provided with guidelines for quitting and helped to choose the first day to start the cessation process. The women received follow-up counseling sessions after the first and third months.

RESULTS

Twenty-seven women (23.3%) quit smoking, 18 (15.52%) advanced a stage in the cessation process and 30 (25.86%) smoked less. Overall, the program benefited 60 women (51.7%) who quit smoking, reduced the number of cigarettes they smoked or progressed to a new stage.

CONCLUSIONS

The results reveal that most pregnant smokers need the intervention of specialists with knowledge of smoking addiction to facilitate the cessation process.

Estimating the health consequences of replacing cigarettes with nicotine inhalers

BACKGROUND

A fast acting, clean nicotine delivery system might substantially displace cigarettes. Public health consequences would depend on the subsequent prevalence of nicotine use, hazards of delivery systems, and intrinsic hazards of nicotine.

METHODS

A spreadsheet program, DEMANDS, estimates differences in expected mortality, adjusted for nicotine delivery system features and prevalence of nicotine use, by extending the data and methods of the SAMMEC 3 software from the US Centers for Disease Control and Prevention. The user estimates disease risks attributable to nicotine, other smoke components, and risk factors that coexist with smoking. The public health consequences of a widely used clean nicotine inhaler replacing cigarettes were compared to historical observations and public health goals, using four different risk attribution scenarios and nicotine use prevalence from 0-100%.

MAIN OUTCOME MEASURES

Changes in years of potential life before age 85 (YPL85).

RESULTS

If nicotine accounts for less than a third of smokers' excess risk of SAMMEC diseases, as it most likely does, then even with very widespread use of clean nicotine DEMANDS predicts public health gains, relative to current tobacco use. Public health benefits accruing from a widely used clean nicotine inhaler probably equal or exceed the benefits of achieving Healthy People 2010 goals.

CONCLUSIONS

Clean nicotine inhalers might improve public health as much as any feasible tobacco control effort. Although the relevant risk estimates are somewhat uncertain, partial nicotine deregulation deserves consideration as part of a broad tobacco control policy.

Pharmacotherapies to enhance smoking cessation during pregnancy

Smoking during pregnancy is a significant public health concern. Maternal smoking increases the risk of spontaneous abortion, low birth weight, premature delivery, sudden infant death syndrome and learning and behavioral problems in the offspring. Unfortunately, the majority of pregnant women do not quit smoking during pregnancy. Although pharmacotherapy may improve smoking cessation rates in pregnancy, very few studies exist that have studied the safety and efficacy of medications to treat pregnant smokers. This article reviews the available safety and efficacy data for the use in pregnancy of the five first-line therapies and two second-line therapies that are recommended for smoking cessation in non-pregnant smokers. Other promising nicotine replacement therapies are also reviewed. Ultimately, the choice whether to use pharmacotherapy for smoking cessation should be made jointly by the pregnant smoker and her health care provider. This article reviews factors that may be considered when prescribing pharmacotherapy to pregnant smokers (i.e. the role of behavioral counseling, identification of appropriate patients, potential advantages and disadvantages of each of the pharmacotherapies, proposed monitoring strategies, dose and duration and goals of treatment). More research regarding the safety and efficacy of pharmacotherapy during pregnancy is needed to define the risk/benefit profile of each medication for use in smoking cessation in pregnant women.

The pharmacotherapy of smoking cessation

1. The great majority of smokers are chronically dependent on tobacco. This dependence arises from the rituals and sensory associations of smoking that are reinforced, within seconds, by a rapid burst of nicotine from the cigarette. 2. All forms of nicotine replacement therapy (NRT) -- gum, patches and inhaler -- and bupropion are safe and effective for increasing smoking cessation rates in the short and long terms. 3. Other than those who are minimally dependent, all patients willing to quit should be offered one of these therapies unless contraindications exist. The effectiveness of drug treatments is multiplied when associated with effective counselling or behavioural treatments. 4. While NRT is not recommended during pregnancy or in patients with cardiac disease, if the alternative is smoking NRT is almost certainly safe. 5. Combination NRT (more than one therapy) may be indicated in patients who have failed monotherapy in association with withdrawal symptoms. 6. There are some specific contraindications to the use of bupropion. Its subsidised availability should not influence prescribers to ignore these.

Prenatal nicotine exposure increases apnoea and reduces nicotinic potentiation of hypoglossal inspiratory output in mice

We examined the effects of in utero nicotine exposure on postnatal development of breathing pattern and ventilatory responses to hypoxia (7.4 % O2) using whole-body plethysmography in mice at postnatal day 0 (P0), P3, P9, P19 and P42. Nicotine delayed early postnatal changes in breathing pattern. During normoxia, control and nicotine-exposed P0 mice exhibited a high frequency of apnoea (f(A)) which declined by P3 in control animals (from 6.7 +/- 0.7 to 2.2 +/- 0.7 min(-1)) but persisted in P3 nicotine-exposed animals (5.4 +/- 1.3 min(-1)). Hypoxia induced a rapid and sustained reduction in f(A) except in P0 nicotine-exposed animals where it fell initially and then increased throughout the hypoxic period. During recovery, f(A) increased above control levels in both groups at P0. By P3 this increase was reduced in control but persisted in nicotine-exposed animals. To examine the origin of differences in respiratory behaviour, we compared the activity of hypoglossal (XII) nerves and motoneurons in medullary slice preparations. The frequency and variability of the respiratory rhythm and the envelope of inspiratory activity in XII nerves and motoneurons were indistinguishable between control and nicotine-exposed animals. Activation of postsynaptic nicotine receptors caused an inward current in XII motoneurons that potentiated XII nerve burst amplitude by 25 +/- 5 % in control but only 14 +/- 3 % in nicotine-exposed animals. Increased apnoea following nicotine exposure does not appear to reflect changes in basal activity of rhythm or pattern-generating networks, but may result, in part, from reduced nicotinic modulation of XII motoneurons.