Electronic Cigarettes a summary of the current evidence

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

Disclosure • 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

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. B. C. D. E. Strongly agree Somewhat agree Neither agree or disagree Somewhat disagree Strongly disagree https: //www. mentimeter. com/s/0 de 387 b 0 fd 53 ed 8 e 8729 c 8882 d 8 a 7 d 6 d/bde 97329 cad 2

Across the Atlantic At the Global Tobacco Dependence Treatment Summit 2016. . . only 33% of attendees agreed Clive Bates. Are they nuts? The dysfunction and decadence of tobacco control in one chart. 24 May 2016. www. clivebates. com/? p=4124

Rule Britannia

EC use in Great Britain Electronic cigarette use in adult current smoker, ex-smokers and never smokers in Great Britain (2012 – 2015) 70 % adults in Great Britain 60 50 Current smoker - tried EC Current smoker - current EC use 40 Ex-smoker - tried EC Ex-smoker - current EC use 30 Never smoker - tried EC 20 Never smoker - current EC use 10 0 2012 2013 2014 2015 2016 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. 2015 Oct 2. doi: 10. 1111/add. 13183. [Epub ahead of print]

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. Study Nicotine EC Placebo EC RR (95% CI) Bullen 2013 7% (21/289) 4% (3/73) 1. 77 (0. 54 – 5. 77) Caponnetto 2013 11% (22/200) 4% (4/100) 2. 75 (0. 97 – 7. 76) Total 9% (43/489) 4% (7/173) 2. 29 (1. 05 – 4. 96) Study Nicotine EC Nicotine Patch RR (95% CI) Bullen 2013 7% (21/289) 6% (17/295) 1. 26 (0. 68 – 2. 34) Mc. Robbie H, Bullen C, Hartmann-Boyce J, Hajek P. Electronic cigarettes for smoking cessation and reduction. Cochrane Database Syst Rev 2014; 12: CD 010216.

EC for stopping smoking Cessation method used by smokers trying to quit 50 40 30 20 E-cigs NRT OTC Champix Beh'l supp 2015 -1 2014 -3 2014 -1 2013 -3 2013 -1 2012 -3 2012 -1 2011 -3 2011 -1 2010 -3 0 2010 -1 10 2009 -3 % smokers trying to stop • E-cigarettes are proving much more popular than NRT as a substitute for tobacco cigarettes. NRT Rx www. smokinginengland. info/latest-statistics

Estimated population impact 2014 Smokers Made a quit attempt 37. 3% 8. 46 million Used EC 28. 2% 3. 16 million 2. 5% 0. 89 million According to the Smoking Toolkit Study, some 0. 56 million EC users have stopped smoking so far. West et al. Addiction. 2016 Jun; 111(6): 1118 -9 Quit 22, 000

The opposing view Kalkhoran & Glantz. Lancet Respir Med. 2016 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 Power Formaldehyde (μg/10 puffs) n = 3 Atomiser 1 Atomiser 2 6. 5 watts 6. 5 3. 7 7. 5 watts 6. 1 ND 9 watts* 9. 5 119. 2 10 watts* 11. 3 344. 6 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 • Formaldehyde (and other aldehydes) – High levels can be generated when ecigarettes are operated at high temperatures – Users notice this as an unpleasant taste (known as a ‘dry puff’) and avoid it Farsalinos et al. Addiction 2015; 110: 1352– 6.

Cardiovascular system • No adverse effects of shortterm 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 At least 95% Safer • 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%) Nutt et al. Estimating the harms of nicotine-containing products using the MCDA approach. Eur Addict Res 2014; 20: 218– 25. Mc. Neill 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 % of adults in GB Perception of harm relative to cigarettes 45 40 35 30 25 20 15 10 5 0 35 34 22 25 39 30 22 30 21 15 28 23 17 19 15 10 7 2 2 1 More or equally harmful Less harmful 2013 (n=8936) 2014 (n=11307) Lot less harmful 2015 (n=11340) Completely harmless Don't know 2016 (n=11489) ASH Fact Sheet on the use of electronic cigarettes among adults in Great Britain, May 2016

http: //www. health. state. mn. us/nicotine

% of adult current smokers Perceptions of nicotine What proportion of the risk from smoking comes from nicotine? 50 41 40 30 20 10 27 22 44 33 25 23 18 15 19 25 8 0 None or very small Some but well Around half of the under half the risk or more EC user Ex-EC user Don't know Never EC user 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: This may change in the future as EC technology evolves – 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

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 Urinary 3 -HPMA levels (ng/mg creatinine) 3000 2500 2000 Baseline 1500 p<0. 001 4 -weeks 1000 p<0. 001 500 0 EC only (n=16) Dual users (n=17) Mc. Robbie et al. Effects of Switching to Electronic Cigarettes with and without Concurrent Smoking on Exposure to Nicotine, Carbon Monoxide, and Acrolein. Cancer Prev. Res. 2015 8, 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 http: //www. ncsct. co. uk/usr/pub/e-cigarette_briefing. pdf

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

hayden@thedragon. institute www. thedragon. institute THE END