Efficacious Smoking Cessation Research Articles

Sex Differences in Varenicline Efficacy for Smoking Cessation: A Meta-Analysis.

Women have lower rates of quitting than men with both bupropion and nicotine replacement. It is unknown whether varenicline demonstrates differential efficacy for men and women. The purpose of this study was to conduct the first comprehensive meta-analysis of clinical trial data examining sex differences in the efficacy of varenicline for smoking cessation. Searching MEDLINE, EMBASE, and PsychINFO, 17 of 43 clinical trials of varenicline for smoking cessation published through December 31, 2014 were low-bias randomized double-blind placebo-controlled trials. Data (n = 6710 smokers, 34% female, n = 16 studies, 96% of available data) was analyzed with Metafor program in R. Outcome endpoints were 7-day point-prevalence (PP) and continuous-abstinence (CA) at week 12 (end of treatment), week 24 (6-month follow-up), and week 52 (12-month follow-up). Using placebo, women were less likely than men to quit (PP-12, CA-24; P < .05 for sex). Using varenicline, similar rates of abstinence for men and women were demonstrated for all six outcomes (eg, PP-12 abstinence rates were 53% in both women and men). Varenicline versus placebo outcomes demonstrated that varenicline was more effective for women for short and intermediate outcomes (PP-12, CA-12, CA-24; P < .05 sex × medication interaction). For end-of-treatment PP, varenicline was 46% more effective for women. For continuous abstinence, varenicline was 34% (CA-12) and 31% (CA-24) more effective for women. Unlike other smoking cessation medications, varenicline demonstrated greater efficacy among women smokers for short and immediate-term outcomes and equal efficacy for 1-year outcomes. Varenicline may be particularly useful for reducing the sex disparity typically seen in rates of smoking cessation. Varenicline is currently the most effective FDA-approved smoking cessation medication and this is the first demonstration that women compared with men have a preferred therapeutic response for a smoking cessation medication when considering short-term outcomes. Importantly, this is also the first demonstration that women have similar rates of quitting to men when considering longer-term, 1-year outcomes.

Abstract CN02-03: Quitting or switching? Health benefits and risk of electronic cigarettes

Abstract Although the best way for smokers to avoid the health risks associated with smoking is to quit smoking altogether, for those who do continue to smoke the application of an exposure reduction (“harm reduction”) strategy could result in substantial reductions in mortality and morbidity. Many smokers are concerned about the health effects of smoking and might be interested in trying new products if they believed this would reduce their health risk. The concept of exposure reduction is based on the principle that if dangerous behavior, like smoking, is likely to continue, the harm caused should be minimized. One such approach for continuing smokers would be to promote the substitution of alternative, less toxic means of delivering nicotine, assuming that these were proven to be less hazardous than tobacco smoking and did not cause any additional health risks. Electronic nicotine inhalers, commonly called electronic cigarettes or “e-cigarettes”, represent a new stage in which nicotine is delivered in a method that simulates smoking but without involving a tobacco combustion process. E-cigarette are battery-powered devices that provide inhaled doses of nicotine by delivering a vaporized liquid nicotine solution, usually including propylene glycol or glycerin. The nicotine is extracted from tobacco leaves (in the same way the pharmaceutical industry obtains nicotine for NRT production), and is then diluted and introduced into the e-cigarette's cartridge. In addition to delivering nicotine, the vapor also provides a flavor and physical sensation similar to that of inhaled tobacco smoke, although no tobacco or combustion is actually involved in its operation. When a user initiates inhalation into the device, air flow is detected by a sensor, which activates a heating element that vaporizes the nicotine solution stored in the mouthpiece cartridge. It is this vapor that is inhaled by the user. On some models an LED on the opposite end of the device is activated during inhalation to serve as an indicator of use as well as simulating the glow of burning tobacco. E-cigarettes have been shown to reduce craving and withdrawal symptoms in abstinent smokers and, as nicotine is delivered without tobacco combustion, are thought to be substantially safer than cigarettes. While e-cigarette use is rapidly increasing, relatively little is known about their efficacy for smoking cessation, particularly compared with established nicotine-containing pharmacological aids. One randomized controlled trial by Bullen et al. showed that e-cigarettes are at least as effective as nicotine patches for smoking cessation. Interestingly, a substantial proportion of participants in this study engaged in harm reduction, becoming long-term e-cigarette users and reducing their conventional cigarette consumption. Thus, against the backdrop of ongoing debates on tighter regulation of e-cigarettes, a sole focus on smoking cessation may be misguided. From a public health perspective, the permanent switch from combustible to noncombustible products is an important endpoint in itself. Nonetheless, the finding that e-cigarettes are at least as effective as existing licensed, nicotine-containing smoking cessation products should go some way towards easing, if not completely allaying, the fears of many health professionals observing their fast uptake among smokers. Distributors of e-cigarettes promote the product as completely free of harmful substances. However, nicotine solutions used in e-cigarettes vary with respect to concentrations of toxicants, and the quality control in e cigarette manufacturing is questionable. Although a number of toxicants have been identified in e-cigarette vapors, the levels of these toxicants are orders of magnitude lower than those found in cigarette smoke, but higher than those found in Nicotine Replacement Therapy (NRT) products. Some studies suggest that vapor from e-cigarette is significantly less cytotoxic compared to tobacco smoke. One study found that after switching from tobacco to electronic cigarettes nicotine exposure is unchanged while exposure to selected toxicants is substantially reduced. Although it cannot be said that currently marketed e-cigarettes are safe, e-cigarette vapor is likely to be much less toxic than cigarette smoke. The devices likely pose less direct hazard to the individual smoker than tobacco cigarettes and might help smokers quit smoking or reduce harm by smoking fewer cigarettes. The use of e-cigarettes as a harm reduction strategy among cigarette smokers who are unable to quit, warrants further studies. Further research is needed to evaluate long term effects of switching, including the health effects of continued use of e-cigarettes. Citation Format: Maciej Lukasz Goniewicz. Quitting or switching? Health benefits and risk of electronic cigarettes. [abstract]. In: Proceedings of the Thirteenth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2014 Sep 27-Oct 1; New Orleans, LA. Philadelphia (PA): AACR; Can Prev Res 2015;8(10 Suppl): Abstract nr CN02-03.

A Systematic Review of Combination Therapies for Smoking Cessation

Introduction: The use of pharmacological and behavioural therapies has been shown to help smokers quit. However, the efficacy of combining smoking cessation therapies remains poorly understood. We conducteda systematic review of randomized controlled trials (RCTs) with factorial designs to assess the efficacy of combination smoking cessation therapies.Methods: We performed a systematic search of the Cochrane Library, EMBASE, PsycINFO, and PubMed databases for RCTs of combination therapies for smoking cessation. We included RCTs with factorial designs,reporting biochemically validated point prevalence or continuous abstinence outcomes at 6 or 12 months.Combination therapies were either two pharmacotherapies or apharmacotherapy with behavioural therapy.Pharmacotherapies included nicotine replacement therapies (NRTs), bupropion, and varenicline. Behavioural therapies included counselling and minimal intervention.Results: A total of 11 RCTs met our inclusion criteria: 4 combinations of pharmacotherapies and 7 combinations of a pharmacotherapy with behavioural intervention. Combinations were two NRTs (2 RCTs), bupropion with NRT (3 RCTs), bupropion with behavioural intervention (4 RCTs), and NRT with behavioural intervention (3 RCTs). No identified trials combined varenicline with other included pharmacotherapies. Combining pharmacotherapies did not increase smoking abstinence at 6 or 12 months, compared with pharmacologicalmonotherapies. Evidence suggests a modest yet inconsistent benefit from combining pharmacotherapy withbehavioural therapy.Conclusion: Evidence from RCTs with factorial designs does not conclusively show combination smoking cessation therapies to be superior to monotherapies. Pharmacotherapies could be prescribed without behavioural therapy, with minimal loss of treatment efficacy.Key words: Smoking cessation, combination therapy, systematic review

Genetic ancestry as an effect modifier of naltrexone in smoking cessation among African Americans: an analysis of a randomized controlled trial.

To determine whether there were differential quit rates between African Americans (AA) and European Americans with the experimental treatment naltrexone, and examine the role of genetic ancestry on these outcomes among AAs. Data from a previous randomized trial of 315 smokers to naltrexone versus placebo were reanalyzed using West African (WA) genetic ancestry to define subpopulations. Logistic regression models were used to estimate treatment effects on early and end of treatment quit rates, by race and WA ancestry. Among European Americans (n=136), naltrexone significantly increased quit rates at 4 weeks (62 vs. 43%, P=0.03) with directional, but not statistically significant effects at 12 weeks (30 vs. 18%, P=0.12). In contrast, among the AAs (n=95), quit rates did not differ between naltrexone and placebo groups at either interval (4 weeks: 43 vs. 32%, P=0.27; 12 weeks: 22 vs. 18%, P=0.60). A median split was conducted in AAs for WA ancestry. Among AAs with low WA ancestry, quit rates were significantly higher with naltrexone compared with placebo (60 vs. 27%, P=0.03). There was no advantage in quit rates with naltrexone for the high WA ancestry group. Naltrexone efficacy for smoking cessation varies across AA individuals with different levels of WA ancestry. These results suggest that genetic background may partially explain racial differences in drug response.

Smoking cessation in Asians: focus on varenicline.

Smoking is a modifiable risk factor for morbidity and mortality caused by cancer, cardiovascular diseases, respiratory diseases, and many other diseases. Given the large population size and high prevalence of smoking in Asia, successful smoking cessation could potentially prevent the large number of premature deaths in Asians. However, most dependent smokers cannot successfully quit smoking due to nicotine addiction, and they need professional help and smoking cessation therapies. Varenicline is a highly selective partial agonist for the nicotinic acetylcholine receptor α4β2 subtype, which is believed to be responsible for mediating the reinforcing properties of nicotine. This article is a narrative review, which summarizes the smoking cessation efficacy, side effects, and cost utilities of varenicline in Asians. From this review, we conclude that varenicline is an effective medication that could assist smoking cessation in the Asian populations. The adverse events of varenicline are tolerable, and the most common events were nausea and abnormal dreams. Both the efficacy and tolerance of varenicline in Asians are similar to that in Western populations. Considering the cost utilities, varenicline should be recommended for use in smoking cessation and be covered by medical insurance in most Asian countries.

Agreement between exhaled breath carbon monoxide threshold levels and self-reported cigarette smoking in a sample of male adolescents in Jordan.

This study aimed to measure the percent agreement between Exhaled Breath Carbon Monoxide (eBCO) measure using a piCO+ smokerlyzer® and self-reported cigarette smoking status and to determine the optimal thresholds for definite identification of cigarette smokers of male school students in Jordan. A descriptive, cross sectional, study of a random sample of male adolescents in grades 7 and 8 from four public high schools in Irbid, completed an adaptation of a standardized Arabic-language tobacco smoking questionnaire and an eBCO measure. Sensitivity and specificity of the eBCO were calculated against self-reported cigarette smoking. Participants (n = 439) had a mean age of 12.5 years (SD = 0.50) and 174 (39.9%) reported being an ever smoker of whom 59 (33.9%) reported being a recent (30-day) smoker. The optimal eBCO cut-off point for recent smoking was 4.5 ppm with a sensitivity of 84.7% and specificity of 65.5%. Overall, eBCO can accurately identify recent smokers and distinguish them from non-smokers. The eBCO use enables healthcare professionals and researchers to assess efficacy of smoking cessation and prevention programs without necessarily relying on self-report. Further research is indicated to validate our findings and should be expanded to include females, detailed characteristics of cigarette and waterpipe smoking.

Neurobiological Bases of Cue- and Nicotine-induced Reinstatement of Nicotine Seeking: Implications for the Development of Smoking Cessation Medications.

A better understanding of the neurobiological factors that contribute to relapse to smoking is needed for the development of efficacious smoking cessation medications. Reinstatement procedures allow the preclinical assessment of several factors that contribute to relapse in humans, including re-exposure to nicotine via tobacco smoking and the presentation of stimuli that were previously associated with nicotine administration (i.e., conditioned stimuli). This review provides an integrated discussion of the results of animal studies that used reinstatement procedures to assess the efficacy of pharmacologically targeting various neurotransmitter systems in attenuating the cue- and nicotine-induced reinstatement of nicotine seeking. The results of these animal studies have increased our understanding of the neurobiological processes that mediate the conditioned effects of stimuli that trigger reinstatement to nicotine seeking. Thus, these findings provide important insights into the neurobiological substrates that modulate relapse to tobacco smoking in humans and the ongoing search for novel efficacious smoking cessation medications.

Mediators of a smoking cessation intervention for persons living with HIV/AIDS

BackgroundCigarette smoking among persons living with HIV (PLWH) is a pressing public health concern, and efforts to evaluate cessation treatments are needed. The purpose of the present study was to assess potential mechanisms of a cell phone-delivered intervention for HIV-positive smokers. MethodsData from 350 PLWH enrolled in a randomized smoking cessation treatment trial were utilized. Participants were randomized to either usual care (UC) or a cell phone intervention (CPI) group. The independent variable of interest was treatment group membership, while the dependent variable of interest was smoking abstinence at a 3-month follow-up. The hypothesized treatment mechanisms were depression, anxiety, social support, quit motivation and self-efficacy change scores. ResultsAbstinence rates in the UC and CPI groups were 4.7% (8 of 172) and 15.7% (28 of 178), respectively. The CPI group (vs. UC) experienced a larger decline in depression between baseline and the 3-month follow-up, and a decline in anxiety. Self-efficacy increased for the CPI group and declined for the UC group. Quit motivation and social support change scores did not differ by treatment group. Only self-efficacy met the predefined criteria for mediation. The effect of the cell phone intervention on smoking abstinence through change in self-efficacy was statistically significant (p<0.001) and accounted for 17% of the total effect of the intervention on abstinence. ConclusionsThe findings further emphasize the important mechanistic function of self-efficacy in promoting smoking cessation for PLWH. Additional efforts are required to disentangle the relationships between emotional, distress motivation, and efficacious smoking cessation treatment.

Do electronic cigarettes help with smoking cessation?

Smoking causes around 100,000 deaths each year in the UK, and is the leading cause of preventable disease and early mortality.1,2 Smoking cessation remains difficult and existing licensed treatments have...

Varenicline for smoking cessation in bipolar disorder: a randomized, double-blind, placebo-controlled study.

Virtually no clinical trials for smoking cessation have been undertaken in bipolar disorder. Varenicline has shown efficacy for smoking cessation, but warnings about neuropsychiatric adverse events have been issued. We assessed the efficacy and safety of varenicline in euthymic bipolar subjects motivated to quit smoking. Clinically stable adult patients with DSM-IV bipolar disorder (n = 60) who smoked ≥ 10 cigarettes per day were randomized to a 3-month, double-blind, placebo-controlled varenicline trial and a 3-month follow-up. Study enrollment was completed from February 2010 through March 2013. Varenicline was dosed using standard titration, and smoking cessation counseling was provided to all patients. The primary outcome was defined as a 7-day point prevalence of self-reported no smoking verified by expired carbon monoxide level < 10 ppm at 12 weeks. Psychopathology and side-effects were assessed at each visit. At 3 months (end of treatment), significantly more subjects quit smoking with varenicline (n/n = 15/31, 48.4%) than with placebo (n/n = 3/29, 10.3%) (OR = 8.1; 95% CI, 2.03-32.5; P < .002). At 6 months, 6 of 31 varenicline-treated subjects (19.4%) remained abstinent compared to 2 of 29 (6.90%) assigned to placebo (OR = 3.2; 95% CI, 0.60-17.6; P = .17). Psychopathology scores remained stable. Ten serious adverse events occurred (n = 6, varenicline; n = 4, placebo). Abnormal dreams occurred significantly more often in varenicline-treated subjects (n/n = 18/31, 61.3%) than in those receiving placebo (n/n = 9/29, 31%; Fisher exact test, P = .04). Eight varenicline-treated and 5 placebo-assigned subjects expressed fleeting suicidal ideation, a nonsignificant difference. Varenicline shows efficacy for initiating smoking cessation in bipolar patients, but medication trials of longer duration are warranted for maintaining abstinence. Vigilance for neuropsychiatric adverse events is prudent when initiating varenicline for smoking cessation in this patient population. ClinicalTrials.gov identifier: NCT01010204.

Electronic nicotine delivery systems ("e-cigarettes"): review of safety and smoking cessation efficacy.

Cigarette smoking is common among cancer patients and is associated with negative outcomes. Electronic nicotine delivery systems ("e-cigarettes") are rapidly growing in popularity and use, but there is limited information on their safety or effectiveness in helping individuals quit smoking. The authors searched PubMed, Web of Science, and additional sources for published empirical data on safety and use of electronic cigarettes as an aid to quit smoking. We conducted a structured search of the current literature up to and including November 2013. E-cigarettes currently vary widely in their contents and are sometimes inconsistent with labeling. Compared to tobacco cigarettes, available evidence suggests that e-cigarettes are often substantially lower in toxic content, cytotoxicity, associated adverse effects, and secondhand toxicity exposure. Data on the use of e-cigarettes for quitting smoking are suggestive but ultimately inconclusive. Clinicians are advised to be aware that the use of e-cigarettes, especially among cigarette smokers, is growing rapidly. These devices are unregulated, of unknown safety, and of uncertain benefit in quitting smoking. In the absence of further data or regulation, oncologists are advised to discuss the known and unknown safety and efficacy information on e-cigarettes with interested patients and to encourage patients to first try FDA-approved pharmacotherapies for smoking cessation.

E-cigarettes--prevention, pulmonary health, and addiction.

E-cigarettes are coming into wider use. They are advertised as an aid to smoking cessation, but there is concern that they may also serve as a gateway drug for cigarette smoking. The authors systematically searched the PubMed database for relevant publications on the mechanism of action of e-cigarettes, the nature of their emissions, their assessment by potential users, their efficacy in smoking cessation, and their potential for addiction. There have been many reports of epidemiologically uninformative case series in which smokers were helped to stop smoking by the use of e- cigarettes. Only two controlled trials have shown that e-cigarettes have approximately the same effect as nicotine substitution therapy when used as an aid to smoking cessation. The effect is nearly independent of nicotine content. E-cigarettes are also consumed, to a small extent, by nonsmokers. As far as can be estimated toxicologically at present, the danger to active and passive smokers of e-cigarettes is presumably orders of magnitude less than that of tobacco smokers, although the variable composition of the fluids used in e-cigarettes introduces a degree of uncertainty. Preclinical and initial clinical data, including some data from randomized controlled trials, indicate that e-cigarettes may be useful as an aid to smoking cessation or as a means of lowering risk in high-risk groups. In contrast to the demonstrated efficacy of multimodal smoking-cessation programs with pharmacological and psychotherapeutic support, the efficacy of e-cigarettes in smoking cessation has not yet been satisfactorily shown. Valid and informative clinical trials are urgently needed. These should also be designed to determine what predisposition(s), if any, might make the use of e-cigarettes more or less successful than that of other aids to smoking cessation. Moreover, e-cigarettes might be a gateway drug for cigarette smoking; thus, no clear recommendation about their use can be made at present.

Involvement of neuronal β2 subunit-containing nicotinic acetylcholine receptors in nicotine reward and withdrawal: implications for pharmacotherapies.

Tobacco smoking remains a major health problem. Nicotine binds to nicotinic acetylcholine receptors (nAChRs), which can cause addiction and withdrawal symptoms upon cessation of nicotine administration. Pharmacotherapies for nicotine addiction target brain alterations that underlie withdrawal symptoms. This review will delineate the involvement of the β2 subunit of neuronal nAChRs in nicotine reward and in generating withdrawal symptoms to better understand the efficacy of smoking cessation pharmacotherapies. Chronic nicotine desensitizes and upregulates β2 subunit-containing nAChRs, and the prolonged upregulation of receptors may underlie symptoms of withdrawal. Experimental research has demonstrated that the β2 subunit of neuronal nAChRs is necessary for generating nicotine reward and withdrawal symptoms. Smoking cessation pharmacotherapies act on β2 subunit-containing nAChRs to reduce nicotine reward and withdrawal symptom severity.

Determinants of use of smoking cessation aids in 27 European countries

ObjectiveTo identify determinants of use of smoking cessation aids among current and former smokers in the European Union (EU). MethodsData from n=9921 current and ex-smokers from 27 European countries (Eurobarometer 77.1, February–March 2012) were analysed. Multivariate binary logistic regression was used to assess for correlates of use of any recommended aid with proven efficacy, defined as use of pharmacotherapy or psychosocial counselling (p<0.05). The regression analyses assessed for socio-demographic characteristics, EU region, as well as scope of national smoking cessation policies. ResultsAmong current smokers who had made a quit attempt and ex-smokers, 19.9% had used any recommended aid with proven efficacy. Respondents from Northern (adjusted odds ratio [aOR]=1.90), Western (aOR=3.21) and Eastern Europe (aOR=1.69) were more likely to have used an efficacious smoking cessation aid compared to respondents from Southern Europe (all p<0.05). Respondents in countries with comprehensive tobacco cessation programmes that offered cost-covered national quit lines, medication, and other cessation services had increased likelihood of using efficacious cessation aids (OR=1.29; 95% Confidence Interval: 1.07–1.55). ConclusionsThese findings underscore the need for enhanced and sustained efforts to ensure increased access to cessation services and aids as part of a comprehensive tobacco control programme.

Electronic cigarette awareness, use history, and expected future use among hospitalized cigarette smokers.

E-cigarette use has surged during the past few years while the debate about the product's safety and efficacy for smoking cessation continues. Little is known about the characteristics that distinguish users from nonusers; in this study, we aimed to elucidate these characteristics among hospitalized smokers, a heretofore unstudied population. Cross-sectional data were collected from cigarette smokers via hospital bedside interviews. Participants reported e-cigarette use status, reasons for use (if used), e-cigarette advertising exposure, expected likelihood of future e-cigarette use, desire to quit smoking, and demographic characteristics. Of the 657 English-speaking hospitalized smokers who provided data, 97% reported awareness of e-cigarettes and 46.4% reported e-cigarette use, with 20% reporting use in the previous 30 days. Previous e-cigarette use was significantly more likely among those who were White (odds ratio [OR] = 4.7; confidence interval [CI] = 3.2-6.7), were married/had a domestic partner (OR = 1.5; CI = 1.0-2.2), had more than a high school education (OR = 1.7; CI = 1.1-2.7), had e-cigarette advertising exposure (OR = 1.6; CI = 1.1-2.4), and were younger (OR = 1.3; CI = 1.1-1.5). Expected likelihood of future e-cigarette use was high and positively correlated with desire to quit smoking (Spearman's ρ = .18, p < .0001). Rates of awareness and use of e-cigarettes may be elevated among hospitalized smokers, with more use reported among those who were White, younger, more educated, in a relationship, and exposed to e-cigarette advertising. The association between desire to quit smoking and expected likelihood of future e-cigarette use suggests that cigarette smokers may perceive e-cigarettes as a useful cessation aid.

Abstract P135: Varenicline and the Risk of Adverse Cardiovascular Events: A Population-Based Cohort Study

Background: Clinical trial results suggest that varenicline is the most efficacious smoking cessation therapy. However, its cardiovascular safety is controversial, with recent meta-analyses providing conflicting results. Our objective was to compare the effect of varenicline to that of bupropion on the risk of cardiovascular events. Methods: We conducted a population-based cohort study of new users of varenicline or bupropion using data extracted from the UK’s Clinical Practice Research Datalink (CPRD) and Hospital Episode Statistics. Our primary endpoint was a composite of myocardial infarction, coronary revascularization, stroke, and all-cause mortality. An ‘as-treated’ analysis with a Cox proportional hazards model was used, with patients censored 7 days after the end of their last prescription or upon switching smoking cessation drugs. In secondary analyses, we compared varenicline and bupropion to nicotine replacement therapy (NRT) in pairwise comparisons. All analyses used high-dimensional propensity scores to adjust for potential confounding. Results: Our primary cohort included 90,522 varenicline users and 12,640 bupropion users. The mean age was 44 years, and 48% were men. The mean treatment duration was 45 days. A total of 128 events occurred among varenicline users, and 15 occurred among bupropion users. Although estimates suggest that varenicline may modestly increase the risk of cardiovascular events compared to bupropion, they were accompanied by wide 95% CIs (Table). Both varenicline and bupropion users had significantly lower risks of cardiovascular events than NRT users (Table). Conclusions: While we cannot exclude a modestly increased risk of cardiovascular events with varenicline relative to bupropion, such events remain rare, and both varenicline and bupropion are associated with a decreased risk of cardiovascular events compared with NRT. The long-term benefits obtained due to the increased smoking abstinence with varenicline likely outweigh any increased cardiovascular risk.

Electronic Cigarettes. Potential Harms and Benefits

Use of electronic cigarettes, devices that deliver a nicotine-containing vapor, has increased rapidly across the country and globally. Perceived and marketed as a "healthier alternative" to conventional cigarettes, few data exist regarding the safety of these devices and their efficacy in harm reduction and treatment of tobacco dependence; even less is known about their overall impact on population health. This review highlights the recent data regarding electronic cigarette toxicity, impact on lung function, and efficacy in smoking reduction and cessation. Studies show that the vapor generated from electronic cigarettes has variable amounts of nicotine and potential harmful toxins, albeit at levels lower than in conventional cigarettes. The long-term carcinogenic and lung function effects of electronic cigarettes are not known. Although some data demonstrate that electronic cigarettes may be effective in reducing conventional cigarette consumption, there are no data demonstrating the efficacy of electronic cigarettes as a tool to achieve cessation. Until robust longitudinal evaluations demonstrate the safety of electronic cigarettes and efficacy in treatment of tobacco dependence, their role as a harm reduction tool is unclear.

Electronic cigarettes: patterns of use, health effects, use in smoking cessation and regulatory issues.

BackgroundElectronic cigarettes (e-cigarettes) are battery-powered devices that vaporize a liquid solution to deliver a dose of inhaled nicotine to the user. There is ongoing debate regarding their regulation.ObjectivesThis comprehensive narrative review aimed to discuss key issues including usage patterns, health effects, efficacy in smoking cessation and regulatory concerns with a view to informing future regulation and research agendas.MethodsPubMed, Scopus and Web of Science databases were searched using the terms (electronic cigarettes OR e-cigarettes) for articles in English, relevant to humans and published during January 2009-January 2014.ResultsThe literature search revealed 37 relevant articles. Findings suggest that e-cigarettes are mostly used by middle-aged current smokers, particularly males, to help them for quitting or for recreation. E-cigarettes contain very low levels of multiple toxic substances such as formaldehyde and acrolein, but these levels are many times lower than those found in cigarettes. They were found to have effectiveness in aiding smoking cessation to a limited degree. Debate continues regarding regulating their use for cessation versus heavy restrictions to control recreational use on the basis that it perpetuates nicotine addiction.ConclusionsThe cytotoxicity and long term health effects of e-cigarettes are unknown. Nevertheless the e-cigarette market continues to expand, largely driven by middle-aged smokers who claim to be using e-cigarettes in an attempt to reduce or quit smoking. E-cigarettes may have some potential as smoking cessation aids and, in the researchers’ view, should therefore be subject to further research and regulation similar to other nicotine replacement therapies.

E-cigarettes: online survey of UK smoking cessation practitioners.

BackgroundUse of e-cigarettes (inhalable vapour producing battery powered devices that aim to simulate tobacco cigarettes), is rising in a number of countries, but as yet none of these products are regulated as medicinal devices or available as smoking cessation treatments. Smokers seeking support from health professionals to stop smoking are interested in e-cigarettes and may be buying them to aid a quit attempt. Determining what smokers are asking, and what health professionals think about these products may have implications for smoking treatment services in a number of countries.MethodsStop smoking service advisors, managers and commissioners in the United Kingdom were asked to take part in two surveys on e-cigarettes. Data was analysed from 587 practitioners who completed a survey in 2011 and 705 practitioners who completed a repeat survey in 2013. Responses to multiple choice questions and free text comments were analysed.ResultsResponding practitioners reported that interest in, and use of, e-cigarettes is growing among adults seeking help to stop smoking in the UK. In 2013 91% of respondents reported that interest in e-cigarettes had grown in the past year and whilst in 2011, 2% of respondents reported a ‘quarter to a half’ of their clients saying that they were regularly using e-cigarettes, by 2013 this had increased to 23.5% (p < .001). Responding practitioners’ views towards e-cigarettes became more positive between the first and second surveys (15% strongly agreed/agreed in 2011 that ‘e-cigarettes are a good thing’ rising to 26% in 2013). However, they continued to have concerns about the products. In particular, analysis of free text responses suggested practitioners were unsure about safety or efficacy for smoking cessation, and were worried that smokers may become dependent on the products. Practitioners were also aware of the potential of e-cigarettes to undermine smokers’ willingness to use evidence-based methods to stop, and to challenge policies aiming to denormalise tobacco smoking.ConclusionsHealth professionals are asking for reliable and accurate information on e-cigarettes to convey to smokers who want to quit. Randomized controlled trials and ongoing surveillance of e-cigarette use and its consequences for smoking cessation rates and smoking treatment services are required.

Electronic cigarette: A review

The principal addictive component of tobacco smoke is nicotine. The mechanisms of nicotine addiction are highly complex and are responsible for maintenance of smoking behaviour. Use of electronic cigarettes (E-cigarettes), devices that deliver a nicotine containing vapor has increased rapidly across the world. They are marketed as a healthier alternatives to conventional cigarettes. There is extensive debate over long-term safety and efficacy of these devices on public health. Studies show that the vapor generated from the E-cigarettes has a variable amount of nicotine and potential harmful toxins. Until robust research demonstrates the safety of E-cigarettes and efficacy in the treatment of tobacco dependence, their role as safe smoking cessation tool is unclear. This review highlights the recent data regarding E-cigarettes toxicity, impact on lung function, and efficacy in smoking reduction and cessation.