Smoking and health

1. Smoking and health Robert West University College London 2010

2. Outline • Smoking and health • The tobacco industry • The process of smoking cessation • Cigarette addiction • Effective interventions to promote and aid smoking cessation

3. Importance of early smoking cessation • After 40 years of age, each year of continued smoking loses an average of 3 months of life • Smokers who do not stop lose 10 years of life on average • Stopping smoking at: • 60 loses 6 years • 50 loses 4 years • 40 loses 1 year • The prognosis is worse for: • heavy smokers • smokers who experienced smoking-related disease

4. Health consequences of smoking • Lung cancer: the ‘escalator of death’ – smokers need to get off as young as possible • The risk never goes down in absolute terms

5. Health consequences of smoking • COPD: the only major disease category that is growing in the UK • Stopping smoking immediately normalises the decline in lung function

6. Health consequences of smoking • CHDrisk starts to reduce immediately and the excess risk is halved after 12 months • This is probably because a large part of the risk is due to acute increase in MI risk from inhaling smoke particles, similar to effect of air pollution

7. Disabling conditions caused or made worse by smoking • Dementia • Blindness (macular degeneration) • Deafness • Peripheral vascular disease (leading to amputations) • Stroke

8. The tobacco industry • Knew: • from 1960s that smoking caused lung cancer • from 1970s that cigarettes were addictive because of nicotine • Covered up, fought and lobbied against any attempts to educate or protect the public • Were forced to admit this when a court settlement in the US led to disclosure of secret documents • But they are still at it ...

9. Tobacco industry and ‘impact assessments’ • Impact assessments are mandatory now for all EU policies • These favour corporate interests by overemphasising economic impact on industry and failing adequately to assess health impacts • New research shows how British American Tobacco, through an aggressive lobbying campaign, helped to: • “secure binding changes to the EU Treaty via the Treaty of Amsterdam that required EU policy makers to minimise legislative burdens on businesses. Efforts subsequently focused on ensuring that these Treaty changes were translated into the application of a business orientates form of IA.” Smith et al (2010 PloS Medicine

10. The process of smoking cessation • The process of smoking cessation involves a number of events: • the ‘quit attempt’ • initiation of arulethat smoking is not permitted • arises at a moment when the desire to stop now is greater than the desire to carry on • lapse • smoking a cigarette butkeeping or suspending the no-smoking rule • arises when the desire to smoke is greater than the desire not to • relapse • abandoning the no smoking rule • arises when the desire to abandon the no-smoking rule is greater than the desire to keep it

11. Quit attempts and relapse Quit attempts • In UK and US 40% of smokers report having made a quit attempt in the past year • 50% of quit attempts involve no pre-planning: the attempt starts the moment the decision is made • Making a quit attempt in the next 6 months is: • predicted by lower enjoyment of smoking and higher concern • not predicted by measures of addiction (e.g. time to first cig of day) Relapse • 75% of quit attempts fail in the first week • Success of a quit attempt is: • predicted by measures of addiction • not predicted by higher previous enjoyment of smoking or higher concern

12. Cigarette addiction and nicotine dependence • Smokers experience powerful feelings of urge or need to smoke which overwhelm and undermine their resolve not to • This is because nicotine acts as both a positive and negative reinforcer: • Positive reinforcement: • nicotine acts on the reward pathways in the brain generating urges to smoke in the presence of smoking cues • Negative reinforcement • nicotine causes chronic changes to the brain resulting in a need to smoke to alleviate: • ‘nicotine hunger’ when CNS concentrations are depleted • aversive withdrawal symptoms

13. Nicotine and the central reward pathway • Nicotine binds to nicotinic acetylcholine receptors in the Ventral Tegmental Area • This increases NDMA-initiated burst firing of the mesolimbic dopamine pathway • This increases release of dopamine in the Nucleus Accumbens

14. Usually strongest in 1 week Usually last between 1 and 4 weeks Usually last at least 12 weeks Usually last between 1 and 4 weeks Usually permanent Problems experienced during cessation • Urges to smoke • Mood disturbance • Irritability • Depression • Anxiety • Restlessness • Difficulty concentrating • Increased appetite • Physical symptoms • Increased cough • Constipation • Mouth ulcers • Weight gain (mean 6-8kg)

15. Unaided cessation

16. Rate of use of aids to cessation • In the UK • 40% of quit attempts involve use of medication, mostly nicotine replacement therapy • 5% involve use of face-to-face behavioural support • 2% involve use of telephone support

17. Principles underlying effective interventions • Promoting a quit attempt • increase desire to stop now by • increasing feelings of concern • boosting confidence in success • providing a route for immediate action • Effective methods of quitting • minimise desire to smoke • maximise desire not to smoke • increase self-regulatory capacity and skills • promote optimal use of medications

18. Brief advice from a physician • Target group • All smokers attending surgeries • The intervention • Ask about smoking and history or quitting; Advise to stop; Assist by referring to Stop Smoking Service or giving prescription • Type of evidence • Multiple randomised controlled trials • Effect • Increases the rate at which smokers try to stop and the success rates in those that try • Causes 2% of smokers to stop >6 months

19. Behavioural support for quit attempts • Advice, discussion and exercises designed to: • maximise and sustain motivation not to smoke • minimise motivation to smoke • increase self-regulatory capacity and skills • optimise use of smoking cessation medications

20. Modes of delivery • Face-to-face sessions • individual • group • Telephone

21. Face-to-face: Individual and group • Target group • Smokers wanting to stop and willing to use support • The intervention • Multi-session advice, discussion and exercises • Type of evidence • multiple randomised controlled trials and case-control studies • Effect • Causes 5% of smokers to stop for > 6 months • Comment • Not clear what are active ingredients • Not clear whether more sessions results in larger effect • Appears to be important that is delivered by specialist • No proven methods for preventing late relapse

22. Telephone • Target group • Smokers wanting to stop and willing to use support • The intervention • Multi-session, pro-active advice, discussion and exercises • Type of evidence • Multiple randomised controlled trials • Effect • Appears to cause 5% of smokers to stop for > 6 months • Comment • Studies not used biochemical verification • Uptake is currently very low

23. Nicotine Replacement Therapies 1 of 2 • Target group • smokers wanting to stop and use medication to assist • The intervention • products the delivery nicotine into the bloodstream other than by smoking without additional toxins for 8-12 weeks (transdermal patch, chewing gum, lozenge, sublingual tablet, inhaler, nasal spray) • Type of evidence • multiple randomised controlled trials supplemented by observational data • Effect • causes 5-10% of smokers to stop >6 months

24. Nicotine Replacement Therapies 2 of 2 • Comment • Not clear whether some forms are more effective than others • Evidence indicates • starting patch before the quit date improves success rates • using different forms in combination improves success rates • the effect is both in preventing lapses and in preventing lapses turning into relapse

25. Bupropion 1 of 2 • Target group • smokers wanting to stop and use medication to assist • Intervention • sustained release bupropion 300 mg b.i.d. for 7-9 weeks starting one week before target quit date • Type of evidence • multiple randomised controlled trials • Effect • causes 10% of smokers to stop >6 months

26. Bupropion 2 of 2 • Comment • not clear whether 300 mg is more effective than 150mg • contraindicated in pregnant smokers and teenagers • combining it with NRT does not appear to increase chances of success • mode of action appears to be in preventing lapses and reducing the chances of lapses turning into relapse • most important common side effect is sleep disturbance • most important rare side effects are seizure and allergic reactions

27. Nortriptyline 1 of 2 • Target group • smokers wanting to stop and use medication to assist • Intervention • 75-150 mg nortriptyline b.i.d. for 8+ weeks • Type of evidence • multiple placebo controlled randomised trials • Effect • causes 10% of smokers to stop >6 months

28. Nortriptyline 2 of 2 • Comment • most important common side effects are dry mouth and sleep disturbance • can be fatal in overdose • much cheaper than other smoking cessation medications

29. Varenicline 1 of 2 • Target group • smokers wanting to stop and use medication to assist • Intervention • varenicline tablet 1 mg b.i.d. for 12 weeks optionally followed by a further 12 weeks in those abstinent after initial course • Type of evidence • multiple placebo-controlled and comparative randomised controlled trials • Effect • causes 15% of smokers to stop >6 months

30. Varenicline 2 of 2 • Comment • most important common side effects are sleep disturbance and nausea • reports of possible rare side effect of neuropsychiatric disturbances are unsubstantiated • more effective than bupropion • almost certainly more effective than NRT when used in single forms • additional 12 weeks of use in those abstinent at end of first course increases long-term abstinence

31. Summary of treatment effectiveness

32. Optimal treatment to promote and aid cessation • Repeated brief advice to all smokers • ask about smoking and quitting history • advise to stop and link to current medical condition where possible • assist with stopping through referral or brief advice plus medication • Assistance • ‘optimised NRT’ (2 week patch preload then ‘patch plus’ or varenicline) and • specialist-delivered behavioural support • consider: nortriptyline or bupropion

33. Key points • Every year that quitting is delayed after the age of 30-40 loses an average of 3 months of life • Smoking causes major disabling conditions, such as dementia, as well as premature death • Most attempts to stop smoking fail because nicotine dependence generates powerful urges to smoke and adverse withdrawal symptoms • Treating cigarette addiction involves reducing the powerful motivations to smoke and maximising motivation to remain abstinent to give the brain a chance to recover • The optimal treatment involves a combination of behavioural support and medication • The optimal medication involves varenicline or a combination of different forms of NRT