Nicotine
Tobacco Overview
60 species of tobacco; primarily Nicotiana tabacum used in the US.
Consumed as cigarettes, cigars, snuff, chewing tobacco, and pipe tobacco.
Nicotine identified as the main active ingredient.
History of Tobacco Use
Introduced to the West in late 15th century via Columbus and Native Americans.
Increased popularity in Europe; by mid-1600s, widespread use across central Europe.
Medical use declined after nicotine's toxic properties were understood (1828).
Prevalence of Tobacco Use
2015 Smoking Statistics:
Males aged 12-17: 4.6%, 18-25: 30.7%, 26+: 22.5%.
Females aged 12-17: 3.8%, 18-25: 22.7%, 26+: 17.7%.
Education and employment linked to lower prevalence of smoking.
Initiation of Smoking
Majority of smokers start in adolescence; 90% of smoking-related deaths in adults started as teens.
Influences include biological, psychological, and environmental factors.
E-Cigarette Use (2011-2015): Notable increase among teens.
Pharmacology of Nicotine
Sites of Action: Acts as a cholinergic agonist on acetylcholine receptors.
Physiological Effects: Increases dopamine, blood pressure, heart rate; releases adrenaline.
Pharmacokinetics
Absorption: Rapid from lungs (7 seconds to brain).
Metabolism: Primarily in the liver; eliminated in urine.
Tolerance and Dependence
Quick development of nicotine tolerance; leads to physical dependence;
Withdrawal symptoms: cravings, irritability, anxiety, etc.
Acute Effects of Nicotine
Nicotine has biphasic effects; stimulant properties weaker than other amphetamines.
Effects of Chronic Tobacco Use
Linked to serious diseases: lung cancer, heart disease, respiratory issues.
CDC: approx. 480,000 deaths annually due to smoking-related causes.
Passive Smoking
Recognized as a serious health risk; identified as a carcinogen.
Significant health impacts, including increased heart disease risks.
Treatment of Cigarette Smoking
Intrinsically Motivated: Health concerns; Extrinsically Motivated: Social pressures.
Strategies for quitting include behavioral programs and nicotine replacement therapies (NRTs).
Success rates higher with formal treatment.
Nicotine Replacement Therapies
Increase quit rates; types include gum, patches, and inhalers.
Additional options: Bupropion and varenicline.
Tobacco Overview
60 species of tobacco; primarily Nicotiana tabacum used in the US.
Nicotine identified as the main active ingredient.
1. History and Origin Source
Introduced to the West in late 15th century via Columbus and Native Americans.
Increased popularity in Europe; by mid-1600s, widespread use across central Europe.
Medical use declined after nicotine's toxic properties were understood (1828).
2. Production Uses and Administration
Consumed as cigarettes, cigars, snuff, chewing tobacco, and pipe tobacco.
Administered through various routes, primarily inhalation (smoking), oral (chewing tobacco), or nasal (snuff).
Absorption of nicotine is rapid, especially from the lungs.
3. Lack of Health Benefits
No known health benefits; associated with significant and wide-ranging health risks.
4. Pharmacology of Nicotine (Mechanism of Action)
Sites of Action: Acts as a cholinergic agonist on acetylcholine receptors in the central and peripheral nervous systems.
Physiological Effects: Increases dopamine release (contributing to its addictive properties), elevates blood pressure and heart rate, and causes the release of adrenaline.
5. Pharmacokinetics
Absorption: Rapid from lungs (approximately 7 seconds to reach the brain) when smoked; absorbed more slowly through mucous membranes (e.g., mouth, nose).
Metabolism: Primarily in the liver by the enzyme cytochrome P450 2A6 (CYP2A6).
Elimination: Nicotine and its metabolites (primarily cotinine) are eliminated in urine.
6. Acute Effects of Nicotine
Nicotine has biphasic effects, meaning it can act as both a stimulant and a depressant depending on the dose and individual.
Stimulant properties are generally weaker compared to other amphetamines, but it can enhance alertness, concentration, and memory at lower doses.
7. Effects of Chronic Tobacco Use
Linked to serious diseases including lung cancer, heart disease, stroke, chronic obstructive pulmonary disease (COPD), emphysema, and other respiratory issues.
CDC estimates approximately 480,000 deaths annually in the US due to smoking-related causes, making it a leading cause of preventable death.
8. Tolerance and Dependence
Quick development of nicotine tolerance, leading to a need for increased doses to achieve desired effects.
Leads to strong physical and psychological dependence.
Withdrawal symptoms: Include intense cravings, irritability, anxiety, difficulty concentrating, depressed mood, increased appetite, and sleep disturbances.
9. Trends and Prevalence of Tobacco Use
2015 Smoking Statistics: (Note: These statistics represent the prevalence in 2015 and may have changed since then).
Males aged 12-17: 4.6%
Males aged 18-25: 30.7%
Males aged 26+: 22.5%
Females aged 12-17: 3.8%
Females aged 18-25: 22.7%
Females aged 26+: 17.7%
Initiation Trends: The majority of smokers start in adolescence; 90% of smoking-related deaths in adults began smoking as teens.
E-Cigarette Use (2011-2015): Showed a notable increase among teens during this period, affecting overall tobacco product use trends.
10. Variables Impacting Use and Initiation
Influences on Initiation: Complex interaction of biological predispositions, psychological factors (e.g., stress, mood), and environmental factors (e.g., peer pressure, parental smoking, media influence, accessibility).
Socioeconomic Factors: Lower educational attainment and unemployment are generally linked to a higher prevalence of smoking.
11. Passive Smoking
Recognized as a serious health risk, also known as secondhand smoke, containing numerous known carcinogens.
Significant health impacts on non-smokers, including increased risks of heart disease, lung cancer, respiratory infections, and sudden infant death syndrome (SIDS).
12. Treatment and Cessation Strategies
Motivation for Quitting: Can be intrinsically motivated (e.g., health concerns, desire for self-improvement) or extrinsically motivated (e.g., social pressures, financial cost, family influence).
Strategies for Quitting: Include behavioral programs (e.g., counseling, support groups) and pharmacological interventions.
Success rates for quitting are significantly higher with formal treatment and support.
13. Nicotine Replacement Therapies (NRTs)
Designed to deliver nicotine without the harmful chemicals found in tobacco smoke, increasing quit rates.
Types include nicotine gum, patches, lozenges, nasal sprays, and inhalers.
Additional pharmacological options for cessation include non-nicotine medications like Bupropion (an antidepressant) and Varenicline (a partial nicotinic receptor agonist).