Harm reduction in nicotine addiction - Tobacco Dependence Clinic

252 Pages·2007·1.82 MB·English

Harm reduction in
nicotine addiction
Helping people who
can't quit
A report by the Tobacco Advisory Group of the Royal College
of Physicians, October 2007
Acknowledgements
The members of the Tobacco Advisory Group acknowledge with thanks Diana
Beaven, Hannah Thompson and Joanna Reid of the RCP Publications Department
for the editing and production of the book.
Citation of this report: Royal College of Physicians. Harm reduction in nicotine
addiction: helping people who can’t quit. A report by the Tobacco Advisory Group of the
Royal College of Physicians. London: RCP, 2007.
Royal College of Physicians of London
11 St Andrew’s Place, London NW1 4LE
www.rcplondon.ac.uk
Registered Charity No 210508
Copyright
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the publisher.
Copyright © 2007 Royal College of Physicians
ISBN 978-1-86016-319-7
Coverphotograph:Brenda Ann Kenneally
Design:Suzanne Fuzzey
Typeset by Dan-Set Graphics, Telford, Shropshire
Printed in Great Britain by The Lavenham Press Ltd, Suffolk
Contents
Contributors vii
Members of the Tobacco Advisory Group of the Royal College of Physicians viii
Foreword ix
Preface xi
1 Use of tobacco in society 1
1.1 Introduction 1
1.2 The history of tobacco use 1
1.3 The smoking epidemic 6
1.4 The health impacts of tobacco smoking 12
1.5 Conclusions 18
2 Nicotine and nicotinic receptors, and their role in smoking 23
2.1 Chemical and pharmacokinetic aspects of nicotine 23
2.2 The physiological functions of nicotinic receptors 25
2.3 Brain nicotinic receptors and cigarette smoking 27
2.4 Insights into nAChR activation, desensitisation and
resensitisation from in vivostudies 31
2.5 Regulation of nicotinic receptor expression and function by
chronic nicotine exposure 31
2.6 Acute actions of nicotine maintained in habitual cigarette smokers 34
2.7 Effects of nicotine on release of brain dopamine in smokers 35
2.8 Contribution of nicotinic receptor subtypes to the reinforcing
effects of nicotine in animal models 37
2.9 Conclusions 38
3 The neurobiological mechanisms underlying nicotine dependence 45
3.1 Introduction 45
3.2 Nicotine self-administration in experimental animals 46
3.3 Neurobiology underlying the reinforcing properties of nicotine 47
3.4 The role of the accumbal shell 48
3.5 The role of the accumbal core 50
3.6 The role of conditioned stimuli in nicotine reinforcement 51
3.7 Desensitisation and the neurobiology of addiction 52
3.8 The effects of nicotine withdrawal 53
3.9 The putative role of paracrine dopamine 54
iv Contents
3.10 A unifying hypothesis 57
3.11 Inhibition of monoamine oxidase 59
3.12 Conclusions 60
4 Mechanisms of tobacco addiction in humans 65
4.1 Background and perspective 65
4.2 The addictiveness of tobacco products 65
4.3 The role of nicotine as the addictive drug in tobacco 66
4.4 The cycle of human tobacco use and addiction 67
4.5 Developments in imaging and cognitive assessment 76
4.6 Insights from new pharmacological developments 78
4.7 Conclusions 79
5 Sources of nicotine for human use 88
5.1 Available sources of nicotine for human use 88
5.2 Dose and delivery kinetics of nicotine from different sources 92
5.3 Contaminants and additives 97
5.4 Addiction potential of alternative nicotine products 98
5.5 Use of alternative nicotine sources as substitutes for cigarettes 99
5.6 Conclusions 100
6 The risk profile of smoked tobacco 104
6.1 Introduction 104
6.2 Population trends in smoking prevalence in the United Kingdom 104
6.3 Trends in prevalence in other countries 105
6.4 Health risks associated with active smoking 107
6.5 Health risks associated with passive smoking 113
6.6 Effects of smoking cessation 115
6.7 Conclusions 117
7 The risks of medicinal nicotine 119
7.1 Introduction 119
7.2 Local effects 119
7.3 Systemic adverse effects of nicotine replacement therapy 121
7.4 Conclusions 126
8 The risk profile of smokeless tobaccos 129
8.1 Introduction 129
8.2 Common types of smokeless tobacco used around the world 131
Contents v
8.3 Potentially harmful constituents 134
8.4 Overview of health effects of smokeless tobacco products 142
8.5 Health effects of smokeless tobacco compared with cigarettes 155
8.6 Conclusions 161
9 Current nicotine product regulation 167
9.1 Introduction 167
9.2 Smoked tobacco products 168
9.3 Smokeless tobacco products 174
9.4 New tobacco product formulations and potential reduced
exposure products 176
9.5 Medicinal nicotine products 177
9.6 Regulatory imbalance 180
9.7 Approaches to nicotine and tobacco product regulation in
different countries 181
9.8 Future regulatory options 183
9.9 Conclusions 185
10 Current nicotine product use and socioeconomic deprivation 189
10.1 Introduction 189
10.2 Tobacco use among disadvantaged groups 189
10.3 Consumption of tobacco and levels of nicotine dependence 192
10.4 Costs of smoking 194
10.5 Inequalities in the burden of ill health caused by smoking 194
10.6 Disadvantage and smoking uptake 195
10.7 Smoking cessation in disadvantaged groups 195
10.8 Exposure to second-hand smoke at work 196
10.9 Exposure to second-hand smoke in the home 198
10.10Smoking and pregnancy 198
10.11Conclusions 200
11 Ethics, human rights and harm reduction for tobacco users 203
11.1 Background to the harm reduction approach 203
11.2 Components of the harm reduction argument 204
11.3 Harm reduction options for tobacco use 206
11.4 Approaches to rebalancing the nicotine product market 215
11.5 Conclusions 215
vi Contents
12 Reducing the harm from nicotine use: implications for health
policy and nicotine product regulation 218
12.1 Introduction 218
12.2 The importance of nicotine in smoking behaviour 220
12.3 The relative harm of different nicotine products 220
12.4 The effectiveness of medicinal nicotine products as an alternative
to smoking 221
12.5 Smokeless tobacco products as an alternative to smoking 222
12.6 Harm reduction strategies 222
12.7 Current nicotine product regulation and health 224
12.8 How should nicotine products be regulated to improve public health? 225
12.9 The consequences of a failure to act 227
12.10Conclusions 229
13 Key conclusions and recommendations 232
Contributors
Deborah Arnott Director, Action on Smoking and Health, London
Richard Ashcroft Professor of Bioethics, School of Law, Queen Mary, University of
London
David Balfour Professor of Behavioural Pharmacology, Division of Pathology and
Neuroscience, University of Dundee
Neal Benowitz Professor of Medicine, Psychiatry and Biopharmaceutical Sciences,
University of California, San Francisco
John Britton Professor of Epidemiology, University of Nottingham
Paul Clarke Professor of Pharmacology, McGill University, Montreal
Richard EdwardsSenior Lecturer in Epidemiology, Department of Public Health,
University of Otago, Wellington, New Zealand
Jonathan Foulds Professor of Health Education and Behavioral Science and
Director, Tobacco Dependence Program, UMDNJ School of Public Health, New
Brunswick
Anna Gilmore Reader in Public Health, University of Bath
Allan Hackshaw Deputy Director, Cancer Research UK and UCL Cancer Trials
Centre, University College London
Jack Henningfield Professor of Behavioral Biology, Johns Hopkins University
School of Medicine; Consultant, Pinney Associates
Richard Hubbard Professor of Respiratory Epidemiology, University of Nottingham
Lynn Kozlowski Professor of Health Behavior, University at Buffalo, State
University of New York
Ann McNeill Professor of Health Policy and Promotion, University of Nottingham
Members of the Tobacco Advisory Group of
the Royal College of Physicians
John Britton (Chair)
Deborah Arnott
Tim Coleman
Linda Cuthbertson
Richard Edwards
Anna Gilmore
Christine Godfrey
Allan Hackshaw
Martin Jarvis
Ann McNeill
Jennifer Percival
Mike Ward
Foreword
I am proud that the Royal College of Physicians remains at the forefront of policy
development in the field of smoking 45 years after our influential intervention of
1962. John Britton and his team have produced another stimulating and radical
report that faces up to the issue of nicotine addiction and challenges the current
position on alternative nicotine products. I congratulate them on this
comprehensive, carefully argued report and commend it to you.
October 2007 Ian Gilmore
President, Royal College of Physicians
Preface
Cigarette smoking is powerfully addictive, and caused 100 million deaths in the
20th century. In the 21st century, if smoking trends persist as expected, one
billion people will die from smoking tobacco. All of these deaths are preventable.
Current national and international tobacco control policies focus, quite
rightly, on measures that help to prevent people from starting smoking, and help
existing smokers to quit. However, once established, smoking is a very difficult
addiction to break, and millions of people smoking today will never succeed. At
present rates of progress it will take over two decades for the prevalence of
smoking in the UK to halve from current levels, such that by 2025 there will
probably still be over five million smokers in the UK. Preventing harm to the
health of these smokers is a vital priority in this country, and in all countries
where the smoking epidemic is established.
The Royal College of Physicians first called for radical policies to reduce the
prevalence of smoking in 1962. Several of the policies we recommended then
have since become established international practice. However, those measures,
then and now, do not address the problem of smokers who cannot quit. The
majority of the 150 million deaths from smoking expected worldwide in the next
20 years will occur in people who are smoking today. These people need help.
In this report we make the case for harm reduction strategies to protect
smokers. We demonstrate that smokers smoke predominantly for nicotine, that
nicotine itself is not especially hazardous, and that if nicotine could be provided
in a form that is acceptable and effective as a cigarette substitute, millions of lives
could be saved. We also argue that the regulatory systems that currently govern
nicotine products in most countries, including the UK, actively discourage the
development, marketing and promotion of significantly safer nicotine products
to smokers.
Harm reduction is a fundamental component of many aspects of medicine
and, indeed, everyday life, yet for some reason effective harm reduction
principles have not been applied to tobacco smoking. This report makes the case
for radical reform of the way that nicotine products are regulated and used in
society. The ideas we present are controversial, and challenge many current and
entrenched views in medicine and public health. They also have the potential to
save millions of lives. They deserve serious consideration.
October 2007 John Britton
Chair, Tobacco Advisory Group of the Royal College of Physicians