Transcript The PRIME Theory of motivation and its application to smoking

What if anything to do about smoking
and oral tobacco use in your patients
Robert West
University College London
October 2013
1
Declaration of competing interest
• I undertake research and consultancy for companies that
develop and manufacture smoking cessation medicines
and licensed nicotine products
• I am a trustee of the charity, QUIT
• I am an honorary co-director of the National Centre for
Smoking Cessation and Training
• My salary and most of my research is funded by Cancer
Research UK
2
Aim
To provide ‘state of the science’ guidance on the best way
of approaching the issue of smoking and oral tobacco use
in dental patients
3
Objectives
To describe
1. when and how best to raise the topic of tobacco use
2. latest evidence on best ways of quitting cigarettes and
oral tobacco including consideration of electronic
cigarettes and the safety and effectiveness
of varenicline
3. optimal referral options
4
Poll
What is your current practice when it comes to smoking and tobacco
use in your patients? (Multiple response)
1. I don’t do anything
2. I make sure I have an up to date record of whether they smoke or
use tobacco
3. I have leaflets which smokers can pick up if they want
4. I occasionally raise the topic with patients if it seems right
5. I try and make a point of talking about it and advising them to stop
6. I try and make a point of talking about it and advising them on the
best ways of stopping
7. I have a system in place for referring patients who smoke or use
tobacco to the local stop-smoking service
5
Poll
On average how many hours of healthy life do smokers lose each day
they continue to smoke after their 30s? (One response)
1.
2.
3.
4.
5.
6.
1
2
3
4
5
6
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Smoking and mortality
Source: Doll et al (2004) BMJ, 328, 1519.
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Poll
Which of the following is true? (One response)
1.
2.
3.
4.
Cigarettes are much more harmful than oral tobacco
Cigarettes are slightly more harmful than oral tobacco
Cigarettes and oral tobacco are equally harmful
Oral tobacco is more harmful than cigarettes
8
Smokeless tobacco and oropharyngeal
cancer
Relative risks from smoking:
Lung cancer: 9.0
Laryngeal: 7.0
Pharyngeal: 6.8
Digestive tract: 3.6
Oral: 3.4
Gandini et al (2008) In J Cancer,
122, 155
Lee et al (2009) BMC Medicine, 7, 36
9
Poll
Which of the following are true? (Multiple response)
1. Smokers who can go on a long flight without experiencing strong
cravings can’t be addicted
2. Most smokers could easily stop if they tried hard
3. Addiction to cigarettes is mainly psychological
4. Nicotine from cigarettes trains the brain to light up in situations
where smoking normally occurs
5. Smokers who light up soon after waking find it harder to stop than
those who typically wait longer
6. Headaches are a common nicotine withdrawal symptom
10
Addiction to cigarettes
• Cigarettes deliver nicotine rapidly to the brain via the
pulmonary circulation in a form that is convenient and
palatable
• Nicotine delivered in this way is highly addictive
• The primary mechanism is ‘operant learning’
– Smoking is rewarded (‘positive reinforcement’)
– Abstinence is punished (‘negative reinforcement’)
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Positive reinforcement
• Nicotine binds to nicotinic
acetylcholine receptors in
the Ventral Tegmental
Area
12
Positive reinforcement
• This increases NDMAinitiated burst firing of the
mesolimbic dopamine
pathway
13
Positive reinforcement
• This increases release of
dopamine in the Nucleus
Accumbens
• Nicotine also affects the
operation of metabotropic
glutamate receptors 5
(mGluR5) found in the nucleus
accumbens and may play a
role in modulating the postsynaptic response to both
glutamate and dopamine
14
Positive reinforcement
• The dopamine release ‘teaches’ the smoker to repeat
the action of puffing on a cigarette just like feeding a dog
teaches it to sit up and beg
15
Negative reinforcement
• Prolonged exposure to nicotine results in neural
adaptation
• Nicotine is rapidly removed from the body by metabolism
and excretion with a half life of about 120 minutes
• Even short periods of abstinence lead to ‘withdrawal
symptoms’
• Smoking a cigarette alleviates these symptoms
• This ‘teaches’ the smoker to smoke when symptoms of
this kind occur
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Negative reinforcement
Withdrawal
discomfort,
craving
Puff on a
cigarette
Withdrawal
relief
More
puffs
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Nicotine withdrawal symptoms
Symptom
Irritability/aggression
Depression
Restlessness
Poor concentration
Increased appetite/weight gain
Light-headedness
Night-time awakenings
Constipation
Coughs/colds/mouth ulcers
Urges to smoke
Duration
< 4 weeks
< 4 weeks
< 4 weeks
< 2 weeks
>10 weeks
<48 hours
< 1 week
>2 weeks
>2 weeks
>2 weeks
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The double ‘whammy’
• Smoking is rewarded and abstinence is punished
• Both of these processes tap into ancient motivational
systems that evolved millions of years before humankind
• When a smoker ‘decides’ to try to stop, he or she is
fighting these processes
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Addiction to cigarettes
I really want to stop
smoking: it’s costing
me money and it will
probably kill me
Just
smoke
20
Poll
Which of the following has been found in general practice to be most
effective in prompting smokers to try to stop? (One response)
1. Giving strongly worded advice to stop for health reasons
2. Encouraging smokers to reflect on why they smoke and whether
they might want to stop
3. Offering support with stopping to all smokers without first asking
whether they want to stop
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GP advice to stop smoking
Did not see GP
Saw GP but no mention of
smoking
11%
8%
39%
7%
Smoking mentioned but not
advised to stop
Advised to stop but not
offered help
11%
Offered medication
5%
19%
Advised to see practice nurse
Referred to Stop Smoking
Service
Percentage of smokers and recent ex-smokers for whom …; data
from Smoking Toolkit Study, N=7611
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0
N=7611, p<0.001 for difference between offer of support/prescription and others
Refer to
SSS
Recommend
to see
practice
nurse
Prescription
only
Advised to
stop but no
offer
Mentioned
but not
advised to
stop
No advice or
not seen
Not seen
GP
% tried to stop in past year
Attempts to stop according to GP advice to
stop smoking
70
60
50
40
30
20
10
23
Poll
Which of the following have been shown in randomised controlled trials
to help smokers to stop? (Multiple response)
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Varenicline (Champix)
Bupropion (Zyban)
Nicotine replacement therapy (NRT)
Fluoxetine (Prozac)
Cytisine (Tabex)
Acupuncture
Individual counselling (behavioural support)
Group-based behavioural support
Telephone support
Electronic cigarettes
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Poll
Which two of the following have been found in randomised controlled
trials to be most effective in helping smokers to stop? (Multiple
response)
1. Varenicline
2. Bupropion
3. A combination of nicotine patches and a faster acting nicotine
product
4. A combination of bupropion and nicotine patches
5. High dose nicotine patches
6. Electronic cigarettes
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Poll
What is the best advice for a patient who is not ready to stop smoking
right now? (One response)
1. Do nothing until they feel ready to stop
2. Try and cut down
3. Try and cut down and use one of the licensed nicotine products to
help them
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Hughes et al 2008, Cahill et al
2012, Cochrane
• Bupropion: 11,440
• Nortripyline: N=975
• Cytisine: N=937
• 95% confidence intervals from
meta-analyses
20
15
10
5
0
Varenicline Single form Dual form
NRT
NRT
↑ % abstinent >6m
Stead et al 2008, Cahill et al 2012,
Cochrane
• Varenicline: N=6,166
• Single NRT: N=51,265
• Dual NRT: 4,664
• NRT for ‘reduce to quit’: N=3,429
• 95% confidence intervals from
meta-analyses
↑ % abstinent >6m
Medications: efficacy
NRT for
'reduce to
quit'
20
15
10
5
0
Bupropion Nortriptyline
Cytisine
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Stead et al 2012, Cochrane1
• Pro-active telephone vs reactive:
N=24,994
• Individual vs brief advice: N=7,855
• Group vs self-help: N=4,375
• Internet vs nothing: N=2,960
• Text messaging versus control
messages: N=9,110
• Written materials: N=15,117
• 95% confidence intervals from
meta-analyses
↑ % abstinent >6m
Behavioural support: efficacy
10
8
6
4
2
0
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Poll
Newspaper reports have claimed that varenicline increases risk of
depression and suicide. What is the truth behind these reports?
1. A small increase in risks of both has been found in patients with
depression
2. A small increase in risk has been found regardless of pre-existing
depression
3. No increased risk has been found in any patient group
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Varenicline and suicide risk
Gunnell et al (2009) BMJ, 339, 3805
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Poll
Newspaper reports have claimed that varenicline increases risk of
cardiovascular events. What is the truth behind these claims? (One
response)
1. One meta-analysis of RCTs found a significant increase in risk but
later ones have not
2. Three meta-analyses have now shown a small but significant
increase in risk of non-fatal MIs
3. There is a slight increase in risk of fatal MIs but the risk is far less
than from continuing to smoke
31
Varenicline and cardiovascular events
Prochaska et al (2012) BMJ, 344, 2856
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Poll
Which of the following is true? (One response)
1. Electronic cigarettes are almost as harmful to health as tobacco
cigarettes
2. Electronic cigarettes carry about half the risk to health as tobacco
cigarettes
3. Electronic cigarettes carry very little risk to health compared with
conventional cigarettes
4. We do not know yet whether electronic cigarettes are less
hazardous than smoking
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Carcinogen levels in e-cigarette vapour
Goniewicz et al (2013) Tob Control, Online early 34
Referral options
• The goal
– to encourage tobacco use cessation attempts in
patients
– to encourage use of optimal methods of stopping
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Helping smokers to help themselves by
bring the science of stopping to smokers
www.smokefreeformula.com
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Poll
What do you plan to do about smoking and tobacco use in your
patients in the future? (Multiple response)
1. Nothing
2. I will make sure I have an up to date record of whether they smoke
or use tobacco
3. I will have leaflets which smokers can pick up if they want
4. I will occasionally raise the topic with patients if it seems right
5. I will try and make a point of talking about it and advising them to
stop
6. I will try and make a point of talking about it and advising them on
the best ways of stopping
7. I will have a system in place for referring patients who smoke or
use tobacco to the local stop-smoking service
37