Electronic Cigarettes a summary of the current evidence Hayden McRobbie Clinical Director – The Dragon Institute for Innovation Professor of Public Health Interventions – Wolfson Institute of Preventive Medicine, Queen Mary University of London

In the past 5 years have received honoraria for speaking at smoking cessation meetings that have been organized by J&J and Pfizer I believe that electronic cigarettes have a role to play in helping people to stop smoking Disclosure

A question for you The long-term use of non-combustible nicotine (as in e-cigarettes) is an acceptable, if not ideal, alternative to continued cigarette smoking. A.Strongly agree B.Somewhat agree C.Neither agree or disagree D.Somewhat disagree E.Strongly disagree

Across the Atlantic At the Global Tobacco Dependence Treatment Summit only 33% of attendees agreed Clive Bates. Are they nuts? The dysfunction and decadence of tobacco control in one chart. 24 May

Rule Britannia

EC use in Great Britain ASH Fact Sheet on the use of electronic cigarettes among adults in Great Britain, May 2016

Nicotine delivery Early studies showed EC available at the time (2007) delivered very little nicotine Newer devices, in the hands of experienced users, can deliver nicotine in a similar way to cigarettes St Helen et al Addiction Oct 2. doi: /add [Epub ahead of print]Addiction.

Device is important Nicotine delivery is generally better from newer (e.g. 2 nd & 3 rd ) generation devices Source: RCP Tobacco Harm Reduction adapted from Farsalinos et al. Scientific Reports 2014;4:4133

Practice is probably important N=6 EC naïve smokers Provided pharmacokinetic data after their first use (5 mins) of EC and again following 4 weeks of use 79% increase in overall nicotine intake –AUC 0→inf increased from 115 to 206 ng*min/ml; p <.05 Hajek et al Nicotine Tob Res 2015;17:175–9.

Do EC help people quit? E-cigarettes show efficacy when used by smokers as an aid to quitting smoking. StudyNicotine ECPlacebo ECRR (95% CI) Bullen 20137% (21/289) 4% (3/73) 1.77 (0.54 – 5.77) Caponnetto % (22/200) 4% (4/100) 2.75 (0.97 – 7.76) Total9% (43/489) 4% (7/173) 2.29 (1.05 – 4.96) StudyNicotine ECNicotine PatchRR (95% CI) Bullen 20137% (21/289) 6% (17/295) 1.26 (0.68 – 2.34) McRobbie H, Bullen C, Hartmann-Boyce J, Hajek P. Electronic cigarettes for smoking cessation and reduction. Cochrane Database Syst Rev 2014;12:CD

EC for stopping smoking E-cigarettes are proving much more popular than NRT as a substitute for tobacco cigarettes.

Estimated population impact million 3.16 million Smokers Made a quit attempt 37.3% 0.89 million Used EC 28.2% 22,000 Quit 2.5% West et al. Addiction Jun;111(6):1118-9Addiction. According to the Smoking Toolkit Study, some 0.56 million EC users have stopped smoking so far.

The opposing view Kalkhoran & Glantz. Lancet Respir Med Feb;4(2):116-28

Toxicants in EC vapour Toxicants including acrolein and acetaldehyde, metal and silicate particles, and tobacco-specific nitrosamines (TSNAs) have been found in vapour In general these are at much lower levels than in cigarette smoke

Formaldehyde PowerFormaldehyde (μg/10 puffs) n = 3 Atomiser 1Atomiser watts watts6.1ND 9 watts* watts* Formaldehyde (and other aldehydes) –High levels can be generated when e- cigarettes are operated at high temperatures –Users notice this as an unpleasant taste (known as a ‘dry puff’) and avoid it Atomiser 1 had a double wick, resulting in high liquid supply and lower chance of overheating at high power levels Atomiser 2 was a conventional setup (single wick). *Dry puff conditions Farsalinos et al. Addiction 2015;110:1352–6.

Cardiovascular system No adverse effects of short- term e-cigarette use have been found Some anti-vaping advocates pick up on particle size in EC vapour, but it’s not just size that matters but what they are made of Royal College of Physicians. Nicotine without smoke: Tobacco harm reduction. London: RCP, 2016

Respiratory system EC vapour may have an irritant effect on the airways However, smokers who switch to an e-cigarette are likely to experience improvements in respiratory symptoms Royal College of Physicians. Nicotine without smoke: Tobacco harm reduction. London: RCP, 2016

Flavours Flavours are important to vapers No study so far shows any clear hazards of flavours in e-cigarette vapour, but some may yet emerge

Level of risk We cannot be certain on the exact degree of risk However, an estimate can be based on the facts that the constituents of cigarette smoke that harm health are either –absent in e-cigarette vapour, or –if present, are mostly at levels significantly below 5% of doses from smoking (mostly below 1%) At least 95 % Safer Nutt et al. Estimating the harms of nicotine-containing products using the MCDA approach. Eur Addict Res 2014;20:218–25. McNeill et al. E-cigarettes: an evidence update. A report commissioned by Public Health England. London: PHE, 2015.

Perception of harm is going the wrong way ASH Fact Sheet on the use of electronic cigarettes among adults in Great Britain, May 2016

Perceptions of nicotine ASH Fact Sheet on the use of electronic cigarettes among adults in Great Britain, May 2016

Lower addiction potential than cigarettes Very few never smokers who try EC become regular users EC users report that they feel less dependent on them than on cigarettes Possible reasons for this include: –pulmonary absorption from currently available EC is likely to be low, especially with first time use –The addictiveness of cigarettes is likely to also be related to other substances in tobacco smoke This may change in the future as EC technology evolves

Other Concerns? That e-cigarettes will: –renormalising the act of smoking –acting as a gateway to smoking in young people –being used for temporary, not permanent, abstinence from smoking

Dual use Around two-thirds of EC users also smoke Concern that dual use might –Expose users to increased toxins –People may not stop smoking conventional cigarettes Brose et al. Addiction 2015;110:1160–8; Hitchman et al. Nicotine Tob Res 2015;17:1187–94

Reduction in acrolein exposure p<0.001 McRobbie et al. Effects of Switching to Electronic Cigarettes with and without Concurrent Smoking on Exposure to Nicotine, Carbon Monoxide, and Acrolein. Cancer Prev. Res , 873–878

Tobacco control & regulation Smoked tobacco is the most harmful form of tobacco use Nicotine use is associated very few adverse health risks

Policy and public health Policies should aim to: –Discourage EC use by non-smokers who would not have smoked otherwise –Encourage innovations in EC that promote smoking cessation

Making sense of the evidence

Conclusions There is growing evidence that electronic cigarettes can help people stop smoking Long-term health effects are unknown, however any risks are likely to be many times less than risks associated with smoking tobacco Unnecessary regulation will threaten potential benefits Ongoing monitoring is needed to assess emerging problems and benefits

THE END