Electronic Cigarettes: No Such Thing as a Free Lunch…or Puff

Abstract

As practitioners of pulmonary and cardiac medicine, many of us have no doubt been asked by our patients who smoke about so-called “electronic cigarettes” (e-cigarettes). These devices, termed electronic nicotine delivery systems (ENDS) by the World Health Organization, have been available in the US market since 2007. Our patients have likely heard far more about these devices through marketing, chat rooms, and word of mouth, than we as physicians have through the medical literature. Because ENDS are not currently regulated by the US Food and Drug Administration (FDA) as medical devices— recent court decisions, denied the agency the right to such oversight—manufacturers of ENDS have not been required to establish either safety or efficacy, and we have had few data with which to answer our patients' queries about these products. Are e-cigarettes a smoking cessation tool? Are they a harmless alternative to cigarettes, as manufacturers claim?In this issue of CHEST (see page 1400), Vardavas et al1Vardavas CI Anagnostopoulos N Kougias M Evangelopoulou V Connolly GN Behrakis PK Short-term pulmonary effects of using an electronic cigarette: impact on respiratory flow resistance, impedance, and exhaled nitric oxide.Chest. 2012; 141: 1400-1406Abstract Full Text Full Text PDF PubMed Scopus (387) Google Scholar evaluated the immediate effect of e-cigarette vapors on airway mechanics. Subjects, healthy smokers without chronic lung disease, inhaled the vapors of a commercially available e-cigarette for 5 min. A comprehensive analysis of lung function, including oscillometry and spirometry, revealed that after inhaling e-cigarette vapors, subjects had a significant increase in airway resistance. There were no significant effects on FEV1, FVC, or FEV1/FVC ratio. Subjects also had measurable, significant decreases in fraction of exhaled nitric oxide (Feno). Control subjects inhaling vaporless control cigarettes did not have any changes in airway resistance or Feno. This pattern of changes in airway mechanics and Feno experienced by subjects using e-cigarettes is very similar to that seen shortly after inhalation of tobacco smoke.2Karrasch S Ernst K Behr J KORA Study Group et al.Exhaled nitric oxide and influencing factors in a random population sample.Respir Med. 2011; 105: 713-718Abstract Full Text Full Text PDF PubMed Scopus (20) Google Scholar The implication is that with long-term exposure to ENDS, it is plausible that, as with cigarette smoking, there is the potential for more permanent changes in lung function. The study's authors correctly point out that this is conjectural and that further research on the long-term effects of ENDS is needed.Numerous manufacturers market ENDS, but the devices share key design features. They use a battery-operated heating device that vaporizes a nicotine-containing solution from a replaceable cartridge in a process triggered by the pressure drop that occurs when the user inhales from the device. They resemble cigarettes, and, in addition to providing nicotine in inhaled form, replicate some of the behavioral aspects of cigarette smoking. Cartridges come with various concentrations of nicotine, and refill solutions containing large amounts of nicotine are available.3Cobb NK Abrams DB E-cigarette or drug-delivery device? Regulating novel nicotine products.N Engl J Med. 2011; 365: 193-195Crossref PubMed Scopus (131) Google Scholar The most common vehicle in which the nicotine in such cartridges is contained is propylene glycol, though other chemicals may be used. The efficiency of systemic nicotine delivery with the e-cigarette is highly variable,4Eissenberg T Electronic nicotine delivery devices: ineffective nicotine delivery and craving suppression after acute administration.Tob Control. 2010; 19: 87-88Crossref PubMed Scopus (159) Google Scholar and the pharmacokinetics of nicotine delivery appear to more closely resemble those of nicotine replacement therapies than that of cigarettes.5Bullen C McRobbie H Thornley S Glover M Lin R Laugesen M Effect of an electronic nicotine delivery device (e cigarette) on desire to smoke and withdrawal, user preferences and nicotine delivery: randomised cross-over trial.Tob Control. 2010; 19: 98-103Crossref PubMed Scopus (428) Google Scholar Marketing materials for ENDS commonly emphasize the safety of the devices in comparison with cigarettes, claiming that the aerosols or vapors delivered by the devices are “tar free” and lack the carcinogens and other chemicals found in cigarette smoke. Because of concerns about running afoul of the FDA, ENDS are not specifically marketed as smoking cessation aids.Users of ENDS tend to be former or current smokers who choose ENDS for a variety of reasons, including the markedly reduced cost compared with cigarettes, the ability to use the devices in settings in which cigarette smoking is prohibited, the curbing of nicotine cravings, and the perceived lower toxicity compared with traditional tobacco cigarettes.6Etter JF Bullen C Electronic cigarette: users profile, utilization, satisfaction and perceived efficacy.Addiction. 2011; 106: 2017-2028Crossref PubMed Scopus (557) Google Scholar No randomized controlled clinical trials have evaluated ENDS as smoking cessation tools. ENDS appear to be most commonly used by current smokers as an alternative to cigarettes rather than as cessation tools, although some ENDS users do reduce or eliminate cigarette use.7Polosa R Caponnetto P Morjaria JB Papale G Campagna D Russo C Effect of an electronic nicotine delivery device (e-cigarette) on smoking reduction and cessation: a prospective 6-month pilot study.BMC Public Health. 2011; 11: 786Crossref PubMed Scopus (336) Google Scholar Given the relatively short time that ENDS have been available, long-term patterns of use are not clear, and it is plausible that, as with cigarettes and other forms of nicotine, some users will use the devices for prolonged periods. We as physicians, and they as our patients, need and deserve the information necessary to make informed choices and recommendations about the safety of these devices as alternatives to cigarettes and other available therapies for smoking cessation. Although the FDA has pledged to regulate these devices as tobacco products, it is unclear what this will entail and how it will change the availability, marketing, manufacturing, and quality control of these devices.The study by Vardavas and colleagues,1Vardavas CI Anagnostopoulos N Kougias M Evangelopoulou V Connolly GN Behrakis PK Short-term pulmonary effects of using an electronic cigarette: impact on respiratory flow resistance, impedance, and exhaled nitric oxide.Chest. 2012; 141: 1400-1406Abstract Full Text Full Text PDF PubMed Scopus (387) Google Scholar although modest in its size, scope, and conclusions, provides some much needed data on the potential harm of e-cigarettes. Clearly, more studies are needed on the long-term effects of these devices, especially in patients with chronic airways disease. In the interim, we now have enough information to state that the use of the ENDS does cause at least short-term adverse effects that are similar to those of cigarettes, and to tell our patients that there is no such thing as a free lunch…or, in the case of ENDS, a (harm-) free puff. As practitioners of pulmonary and cardiac medicine, many of us have no doubt been asked by our patients who smoke about so-called “electronic cigarettes” (e-cigarettes). These devices, termed electronic nicotine delivery systems (ENDS) by the World Health Organization, have been available in the US market since 2007. Our patients have likely heard far more about these devices through marketing, chat rooms, and word of mouth, than we as physicians have through the medical literature. Because ENDS are not currently regulated by the US Food and Drug Administration (FDA) as medical devices— recent court decisions, denied the agency the right to such oversight—manufacturers of ENDS have not been required to establish either safety or efficacy, and we have had few data with which to answer our patients' queries about these products. Are e-cigarettes a smoking cessation tool? Are they a harmless alternative to cigarettes, as manufacturers claim? In this issue of CHEST (see page 1400), Vardavas et al1Vardavas CI Anagnostopoulos N Kougias M Evangelopoulou V Connolly GN Behrakis PK Short-term pulmonary effects of using an electronic cigarette: impact on respiratory flow resistance, impedance, and exhaled nitric oxide.Chest. 2012; 141: 1400-1406Abstract Full Text Full Text PDF PubMed Scopus (387) Google Scholar evaluated the immediate effect of e-cigarette vapors on airway mechanics. Subjects, healthy smokers without chronic lung disease, inhaled the vapors of a commercially available e-cigarette for 5 min. A comprehensive analysis of lung function, including oscillometry and spirometry, revealed that after inhaling e-cigarette vapors, subjects had a significant increase in airway resistance. There were no significant effects on FEV1, FVC, or FEV1/FVC ratio. Subjects also had measurable, significant decreases in fraction of exhaled nitric oxide (Feno). Control subjects inhaling vaporless control cigarettes did not have any changes in airway resistance or Feno. This pattern of changes in airway mechanics and Feno experienced by subjects using e-cigarettes is very similar to that seen shortly after inhalation of tobacco smoke.2Karrasch S Ernst K Behr J KORA Study Group et al.Exhaled nitric oxide and influencing factors in a random population sample.Respir Med. 2011; 105: 713-718Abstract Full Text Full Text PDF PubMed Scopus (20) Google Scholar The implication is that with long-term exposure to ENDS, it is plausible that, as with cigarette smoking, there is the potential for more permanent changes in lung function. The study's authors correctly point out that this is conjectural and that further research on the long-term effects of ENDS is needed. Numerous manufacturers market ENDS, but the devices share key design features. They use a battery-operated heating device that vaporizes a nicotine-containing solution from a replaceable cartridge in a process triggered by the pressure drop that occurs when the user inhales from the device. They resemble cigarettes, and, in addition to providing nicotine in inhaled form, replicate some of the behavioral aspects of cigarette smoking. Cartridges come with various concentrations of nicotine, and refill solutions containing large amounts of nicotine are available.3Cobb NK Abrams DB E-cigarette or drug-delivery device? Regulating novel nicotine products.N Engl J Med. 2011; 365: 193-195Crossref PubMed Scopus (131) Google Scholar The most common vehicle in which the nicotine in such cartridges is contained is propylene glycol, though other chemicals may be used. The efficiency of systemic nicotine delivery with the e-cigarette is highly variable,4Eissenberg T Electronic nicotine delivery devices: ineffective nicotine delivery and craving suppression after acute administration.Tob Control. 2010; 19: 87-88Crossref PubMed Scopus (159) Google Scholar and the pharmacokinetics of nicotine delivery appear to more closely resemble those of nicotine replacement therapies than that of cigarettes.5Bullen C McRobbie H Thornley S Glover M Lin R Laugesen M Effect of an electronic nicotine delivery device (e cigarette) on desire to smoke and withdrawal, user preferences and nicotine delivery: randomised cross-over trial.Tob Control. 2010; 19: 98-103Crossref PubMed Scopus (428) Google Scholar Marketing materials for ENDS commonly emphasize the safety of the devices in comparison with cigarettes, claiming that the aerosols or vapors delivered by the devices are “tar free” and lack the carcinogens and other chemicals found in cigarette smoke. Because of concerns about running afoul of the FDA, ENDS are not specifically marketed as smoking cessation aids. Users of ENDS tend to be former or current smokers who choose ENDS for a variety of reasons, including the markedly reduced cost compared with cigarettes, the ability to use the devices in settings in which cigarette smoking is prohibited, the curbing of nicotine cravings, and the perceived lower toxicity compared with traditional tobacco cigarettes.6Etter JF Bullen C Electronic cigarette: users profile, utilization, satisfaction and perceived efficacy.Addiction. 2011; 106: 2017-2028Crossref PubMed Scopus (557) Google Scholar No randomized controlled clinical trials have evaluated ENDS as smoking cessation tools. ENDS appear to be most commonly used by current smokers as an alternative to cigarettes rather than as cessation tools, although some ENDS users do reduce or eliminate cigarette use.7Polosa R Caponnetto P Morjaria JB Papale G Campagna D Russo C Effect of an electronic nicotine delivery device (e-cigarette) on smoking reduction and cessation: a prospective 6-month pilot study.BMC Public Health. 2011; 11: 786Crossref PubMed Scopus (336) Google Scholar Given the relatively short time that ENDS have been available, long-term patterns of use are not clear, and it is plausible that, as with cigarettes and other forms of nicotine, some users will use the devices for prolonged periods. We as physicians, and they as our patients, need and deserve the information necessary to make informed choices and recommendations about the safety of these devices as alternatives to cigarettes and other available therapies for smoking cessation. Although the FDA has pledged to regulate these devices as tobacco products, it is unclear what this will entail and how it will change the availability, marketing, manufacturing, and quality control of these devices. The study by Vardavas and colleagues,1Vardavas CI Anagnostopoulos N Kougias M Evangelopoulou V Connolly GN Behrakis PK Short-term pulmonary effects of using an electronic cigarette: impact on respiratory flow resistance, impedance, and exhaled nitric oxide.Chest. 2012; 141: 1400-1406Abstract Full Text Full Text PDF PubMed Scopus (387) Google Scholar although modest in its size, scope, and conclusions, provides some much needed data on the potential harm of e-cigarettes. Clearly, more studies are needed on the long-term effects of these devices, especially in patients with chronic airways disease. In the interim, we now have enough information to state that the use of the ENDS does cause at least short-term adverse effects that are similar to those of cigarettes, and to tell our patients that there is no such thing as a free lunch…or, in the case of ENDS, a (harm-) free puff. Supplementary Material/cms/asset/3304ad77-3b9e-40cd-946a-75c9ecb61304/mmc1.mp3Loading ... Download .mp3 (18.43 MB) Help with .mp3 files Supplementary audioEffects of Using Electronic CigarettesDuration: 40:14 minModerator: D. Kyle Hogarth, MD, FCCP, Podcast Editor, CHESTParticipants: Constantine I. Vardavas, MD, MPH, PhD; Susan Murin, MD, FCCP; Mark V. Avdalovic, MD /cms/asset/3304ad77-3b9e-40cd-946a-75c9ecb61304/mmc1.mp3Loading ... Download .mp3 (18.43 MB) Help with .mp3 files Supplementary audioEffects of Using Electronic CigarettesDuration: 40:14 minModerator: D. Kyle Hogarth, MD, FCCP, Podcast Editor, CHESTParticipants: Constantine I. Vardavas, MD, MPH, PhD; Susan Murin, MD, FCCP; Mark V. Avdalovic, MD