3' Nicotine addiction

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3. Nicotine addiction

• Royal College of Physicians of London
• Tobacco Advisory Group

2
Nicotine addiction

• Nicotine receptors present in the brain
• Stimulation of dopamine release in the nucleus
  accumbens
• Reinforcing through reward and withdrawal
• Cigarettes deliver rapid doses of nicotine
• Animal studies provide strong and consistent
  evidence that nicotine is addictive

3
Nicotine delivery
Royal College of Physicians, Nicotine in Britain,
2000
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Classification of dependence
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Fagerström test for nicotine dependence
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Simplified addiction test
This gives a scale from 1-12
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Withdrawal effects

• Light-headedness
• Sleep disturbance
• Poor concentration
• Craving for nicotine
• Irritability/aggression
• Depression
• Restlessness
• Increased appetite

• lt48 hrs 10
• lt 1 wk 25
• lt2 wks 60
• gt 2 wks 70
• lt 4 wks 50
• lt 4 wks 60
• lt 4 wks 60
• gt 10 wks 70

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Low tar cigarettes
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What are low-tar cigarettes?
Low tar yield when measured on a smoking
machine
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Ventilation holes
Ventilation holes in the filter of a 'low tar'
cigarette, designed to reduce machine-smoked tar
yield
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Why low-tar is misleading

• Machine smoking
• Fixed to ISO standards
• 2 sec
• 35ml puff
• once a minute
• To a predetermined butt length

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Why low-tar is misleading

• Machine smoking
• Fixed to ISO standards
• 2 sec
• 35ml puff
• once a minute

• Human smoking
• Compensates to achieve desired nicotine dose
• Longer, deeper, more puffs
• More of the rod smoked
• Ventilation holes blocked by fingers, lips or
  saliva

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Brand yield and nicotine intake in smokers
Cotinine173.5138.7 (nicotine yield) r.19,
r².034
Health survey for England 1998
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Predicted nicotine intake per cigarette
1.6
Predicted
1.4
1.2
1.0
Nicotine intake per cigarette (mg)
0.8
0.6
0.4
0.2
0 - .1
.1-
.2-
.4-
.5-
.6-
.7-
.8-
.9-
1.0
Cigarette nicotine yield (mg)
Health survey for England 1998
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Predicted and actual nicotine intake per cigarette
1.6
1.4
1.2
1.0
Nicotine intake per cigarette (mg)
0.8
0.6
0.4
0.2
0 - .1
.1-
.2-
.4-
.5-
.6-
.7-
.8-
.9-
1.0
Cigarette nicotine yield (mg)
Predicted
Actual
Health survey for England 1998
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Tar reduction effect of smoker compensation
400
350
300
250
Plasma cotinine (ng/ml)
200
1.5
1.3
Nicotine yield (mg) .
1.1
0.9
0.7
0.5
Frost et al, Thorax 1995501038
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Switching to lights