Peter Hajek

Effects of Switching to Electronic Cigarettes with and without Concurrent Smoking on Exposure to Nicotine, Carbon Monoxide, and Acrolein

Concern has been raised about the presence of toxicants in electronic cigarette (EC) aerosol, particularly carbonyl compounds (e.g., acrolein) that can be produced by heating glycerol and glycols used in e-liquids. We investigated exposure to carbon monoxide (CO), nicotine (by measuring cotinine in urine), and to acrolein (by measuring its primary metabolite, S-(3-hydroxypropyl)mercapturic acid (3-HPMA) in urine) before and after 4 weeks of EC (green smoke, a “cig-a-like” EC, labeled 2.4% nicotine by volume) use, in 40 smokers. Thirty-three participants were using EC at 4 weeks after quitting, 16 (48%) were abstinent (CO-validated) from smoking during the previous week (EC only users), and 17 (52%) were “dual users.” A significant reduction in CO was observed in EC-only users [–12 ppm, 95% confidence interval (CI), –16 to –7, 80% decrease) and dual users (–12 ppm, 95%CI, –19 to –6, 52% decrease). Cotinine levels also declined, but to a lesser extent (EC-only users: –184 ng/mg creatinine; 95% CI, –733 to –365, 17% decrease; and dual users: –976 ng/mg creatinine; 95%CI, –1,682 to –270, 44% decrease). Mean 3-HPMA levels had decreased at 4 weeks by 1,280 ng/mg creatinine (95%CI, –1,699 to –861, 79% decrease) in EC-only users and by 1,474 ng/mg creatinine (95%CI, –2,101 to –847, 60% decrease) in dual users. In dual users, EC use significantly reduced exposure to CO and acrolein because of a reduction in smoke intake. EC may reduce harm even in smokers who continue to smoke, but long-term follow-up studies are needed to confirm this. Cancer Prev Res; 8(9); 873–8. ©2015 AACR.

Electronic cigarettes: review of use, content, safety, effects on smokers and potential for harm and benefit

AIMS We reviewed available research on the use, content and safety of electronic cigarettes (EC), and on their effects on users, to assess their potential for harm or benefit and to extract evidence that can guide future policy. METHODS Studies were identified by systematic database searches and screening references to February 2014. RESULTS EC aerosol can contain some of the toxicants present in tobacco smoke, but at levels which are much lower. Long-term health effects of EC use are unknown but compared with cigarettes, EC are likely to be much less, if at all, harmful to users or bystanders. EC are increasingly popular among smokers, but to date there is no evidence of regular use by never-smokers or by non-smoking children. EC enable some users to reduce or quit smoking. CONCLUSIONS Allowing EC to compete with cigarettes in the market-place might decrease smoking-related morbidity and mortality. Regulating EC as strictly as cigarettes, or even more strictly as some regulators propose, is not warranted on current evidence. Health professionals may consider advising smokers unable or unwilling to quit through other routes to switch to EC as a safer alternative to smoking and a possible pathway to complete cessation of nicotine use.

Randomised controlled trial of nasal nicotine spray in smoking cessation

Studies with nicotine chewing gum and nicotine skin patches indicate that nicotine replacement can help people to give up smoking. The rapidity with which nicotine is absorbed when given as a nasal spray suggests that it might be effective for those for whom the other means of replacement are too slow. The efficacy and safety of a nasal nicotine spray as an adjunct to group treatment for stopping smoking were assessed in a randomised, double-blind, placebo-controlled trial in which 227 cigarette smokers attending the Maudsley Hospital Smokers Clinic received 4 weeks of supportive group treatment plus active nicotine (0.5 mg per shot) or placebo nasal spray. The main end-point was biochemically validated complete abstinence from smoking from the third week of group treatment until the 12-month follow-up. Side-effects were assessed by self-reports and, where necessary, by physical examination. Of subjects assigned to active treatment 26% (n = 30) were validated abstinent throughout the year, compared with 10% (n = 11) of those assigned to placebo (relative abstinence rate 2.6, 95% CI 1.5-4.5, p less than 0.001). The advantage of the active spray was greatest in the heaviest smokers. Plasma nicotine concentrations from the spray were typically between one-half and three-quarters of baseline smoking levels. Tobacco-withdrawal symptoms, craving for cigarettes, and weight gain in abstinent subjects were reduced by the active spray. Minor irritant side-effects were frequent in both active and placebo sprays, but only 2 subjects had the spray discontinued as a result. No serious adverse effects were encountered. Nasal nicotine spray combined with supportive group treatment is an effective aid to smoking cessation.

Patterns of electronic cigarette use and user beliefs about their safety and benefits: an internet survey.

INTRODUCTION AND AIMS As the popularity of electronic cigarettes (e-cigarettes) increases, it is becoming important to find out more about the characteristics of e-cigarette users, why and how they use the product and whether e-cigarettes are used exclusively or in combination with conventional cigarettes. The objective of this study was to investigate patterns and effects of e-cigarette use and user beliefs about e-cigarette safety and benefits. DESIGN AND METHODS E-cigarette users in Poland were recruited online and asked to participate in a web-based survey. The participants provided information on their smoking history, patterns of e-cigarette use, beliefs and attitudes regarding the product and information on concurrent use of conventional cigarettes. RESULTS The survey was completed by 179 e-cigarette users. Almost all participants used e-cigarettes daily. E-cigarettes were primarily used to quit smoking or to reduce the harm associated with smoking (both 41%), and were successful in helping the surveyed users to achieve these goals with 66% not smoking conventional cigarettes at all and 25% smoking under five cigarettes a day. Most participants (82%) did not think that e-cigarettes were completely safe, but thought that they were less dangerous than conventional cigarettes. Sixty percent believed that e-cigarettes were addictive, but less so than conventional cigarettes. DISCUSSION AND CONCLUSIONS The participants primarily used e-cigarettes as a stop-smoking aid or as an alternative to conventional cigarettes, and the majority reported that they successfully stopped smoking. More data on e-cigarette safety and its efficacy in harm-reduction and smoking cessation are needed.

A comparison of the abuse liability and dependence potential of nicotine patch, gum, spray and inhaler

Abstract Rationale: Nicotine replacement therapy (NRT) in varying forms is becoming widely used. Clinicians, therapists and regulatory authorities are interested in the abuse liability and dependence potential of the different forms. Objectives: To compare the abuse liability and dependence potential of nicotine gum, transdermal patch, spray and inhaler. Methods: 504 male and female smokers seeking help with stopping smoking were randomly allocated to the four products. Measures were taken at the designated quit date, then 1 week, 4 weeks, 12 weeks and 15 weeks later. Smokers were advised to use the product for up to 12 weeks. Those still using the product at the 12-week visit were advised to cease use by week 14. Measures included: pleasantness and satisfaction ratings at weeks 1 and 4 (used as a marker of abuse liability); ratings of feeling dependent on NRT at weeks 1, 4, 12 and 15 (used as a marker of subjective dependence); mood and physical symptoms ratings at weeks 12 and 15 (the change being used to assess physical dependence on NRT), continued usage of NRT at week 15 (used as an marker of behavioural dependence). Results: Average ratings of pleasantness were low. The nicotine patch was rated as less unpleasant to use than all other products. There were no significant differences between the products in terms of satisfaction or subjective dependence except at week 15 when no patch users rated themselves as dependent. Continued use of NRT at week 15 was related to rate of delivery of nicotine from the products – 2% for patch, 7% for gum and inhaler, 10% for spray (P<0.05 for linear association). Among those abstinent for 15 weeks, the figures were: 8%, 25% and 37%, respectively. Stopping NRT use between weeks 12 and 15 was not accompanied by withdrawal discomfort or increased frequency of urges to smoke although subjects stopping inhaler use experienced a mild increase in strength of urges to smoke. We conclude that abuse liability from all four NRT products was low. Subjective dependence was moderate and did not differ across products. Behavioural dependence was modest and was positively related to rate of nicotine delivery. Physicians can reassure their patients that most are able to come off NRT as recommended without discomfort.

Nicotine content of electronic cigarettes, its release in vapour and its consistency across batches: regulatory implications.

BACKGROUND AND AIMS Electronic cigarettes (EC) may have a potential for public health benefit as a safer alternative to smoking, but questions have been raised about whether EC should be licensed as a medicine, with accurate labelling of nicotine content. This study determined the nicotine content of the cartridges of the most popular EC brands in the United Kingdom and the nicotine levels they deliver in the vapour, and estimated the safety and consistency of nicotine delivery across batches of the same product as a proxy for quality control for individual brands and within the industry. METHODS We studied five UK brands (six products) with high internet popularity. MEASUREMENTS Two samples of each brand were purchased 4 weeks apart, and analysed for nicotine content in the cartridges and nicotine delivery in vapour. RESULTS The nicotine content of cartridges within the same batch varied by up to 12% relative standard deviation (RSD) and the mean difference between different batches of the same brand ranged from 1% [95% confidence interval (CI) = -5 to 7%] to 20% (95% CI=14-25%) for five brands and 31% (95% CI=21-39%) for the sixth. The puffing schedule used in this study vaporized 10-81% of the nicotine present in the cartridges. The nicotine delivery from 300 puffs ranged from ∼2 mg to ∼15 mg and was not related significantly to the variation of nicotine content in e-liquid (r=0.06, P=0.92). None of the tested products allowed access to e-liquid or produced vapour nicotine concentrations as high as conventional cigarettes. CONCLUSIONS There is very little risk of nicotine toxicity from major electronic cigarette (EC) brands in the United Kingdom. Variation in nicotine concentration in the vapour from a given brand is low. Nicotine concentration in e-liquid is not well related to nicotine in vapour. Other EC brands may be of lower quality and consumer protection regulation needs to be implemented, but in terms of accuracy of labelling of nicotine content and risks of nicotine overdose, regulation over and above such safeguards seems unnecessary.

Stopping Smoking Shortly Before Surgery and Postoperative Complications A Systematic Review and Meta-analysis

OBJECTIVE To examine existing smoking studies that compare surgical patients who have recently quit smoking with those who continue to smoke to provide an evidence-based recommendation for front-line staff. Concerns have been expressed that stopping smoking within 8 weeks before surgery may be detrimental to postoperative outcomes. This has generated considerable uncertainty even in health care systems that consider smoking cessation advice in the hospital setting an important priority. Smokers who stop smoking shortly before surgery (recent quitters) have been reported to have worse surgical outcomes than early quitters, but this may indicate only that recent quitting is less beneficial than early quitting, not that it is risky. DESIGN Systematic review with meta-analysis. DATA SOURCES British Nursing Index (BNI), The Cochrane Library database, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Embase, Medline, PsycINFO to May 2010, and reference lists of included studies. STUDY SELECTION Studies were included that allow a comparison of postoperative complications in patients undergoing any type of surgery who stopped smoking within 8 weeks prior to surgery and those who continued to smoke. DATA EXTRACTION Two reviewers independently screened potential studies and assessed their methodologic quality. Data were entered into 3 separate meta-analyses that considered all available studies, studies with a low risk of bias that validated self-reported abstinence (to assess possible benefits), and studies of pulmonary complications only (to assess possible risks). Results were combined by using a random-effects model, and heterogeneity was evaluated by using the I(2) statistic. RESULTS Nine studies met the inclusion criteria. One found a beneficial effect of recent quitting compared with continuing smoking, and none identified any detrimental effects. In meta-analyses, quitting smoking within 8 weeks before surgery was not associated with an increase or decrease in overall postoperative complications for all available studies (relative risk [RR], 0.78; 95% confidence interval [CI], 0.57-1.07), for a group of 3 studies with high-quality scores (RR, 0.57; 95% CI, 0.16-2.01), or for a group of 4 studies that specifically evaluated pulmonary complications (RR, 1.18; 95% CI, 0.95-1.46). CONCLUSIONS Existing data indicate that the concern that stopping smoking only a few weeks prior to surgery might worsen clinical outcomes is unfounded. Further larger studies would be useful to arrive at a more robust conclusion. Patients should be advised to stop smoking as early as possible, but there is no evidence to suggest that health professionals should not be advising smokers to quit at any time prior to surgery.

Breath-holding endurance as a predictor of success in smoking cessation☆

A pretreatment test of breath-holding endurance predicted end-of-treatment outcome in 56 Smokers Clinic clients (r = .44; p less than .001). The cut off points derived by discriminant analysis were 32 seconds for men and 20 seconds for women, which correctly classified 78.6% of cases. The breath-holding test might sample the type of endurance necessary to withstand the discomfort associated with cigarette withdrawal and may also be relevant to success in quitting other addictive behaviours. However, alternative explanations are possible and more data are needed.

Individual differences in preferences for and responses to four nicotine replacement products

Abstract. Rationale: With several different forms of nicotine replacement therapy available for smokers, it is useful to know about factors that may influence choice of form. Objective: To examine factors associated with preference for different nicotine replacement products and effectiveness of these products. The simple comparison of success rates between the products has been reported previously. Methods: Five hundred and four smokers were invited to rank order four products (gum, patch, nasal spray and inhaler) in terms of preference and were then randomly allocated to receive one of the products for a smoking cessation attempt. They were followed up 1 week, 4 weeks, 12 weeks and 15 weeks later. Ratings of the products were repeated 1 week after the quit date. Mood and physical symptoms were assessed at baseline and at each follow-up visit. Urges to smoke were assessed at all post-quit date sessions. Abstinence was assessed by self-report with expired air carbon monoxide verification. Results: The patch was the most popular product initially, followed by the spray and inhaler and then the gum. The difference was greater for women than men. However, all smokers quickly came to like whichever product they had been allocated. Smokers who initially preferred the spray or inhaler were heavier smokers than those who preferred the gum or patch. Prior experience of the gum was associated with lower initial preference for it, but did not affect outcome. Prior experience with the patch had no effect on preference or outcome. Being allocated to the preferred product did not increase success at stopping smoking. Women were more successful at stopping smoking on the inhaler than the gum. Among highly dependent smokers, those on the inhaler had a lower relapse rate than those on the other products. Conclusions: Regardless of initial preferences, whether patients obtain their preferred form of NRT or one selected for them did not seem to affect outcome. This may be because smokers came to like particular products as they got used to them. Other things being equal, women may be better advised to use inhaler rather than gum and men vice versa.

TIME COURSE OF CIGARETTE WITHDRAWAL SYMPTOMS WHILE USING NICOTINE GUM

Ratings of withdrawal symptoms were provided at weekly intervals by 147 smokers clinic clients who managed complete abstinence for 4 weeks. The ratings followed a similar temporal pattern regardless of amount of nicotine gum used. Irritability, depression, difficulty concentrating and restlessness peaked in the 1 st week or two and returned to baseline by week 4. Hunger was more persistent. Craving was reported to be the most troublesome withdrawal symptom at first, although by the 4th week hunger was cited almost as often. Across all subjects,e venings were cited most often as the worst time of day for craving but among heavier smokers and those who used more nicotine gum mornings were considered worst.