Tobacco & Nicotine

How much actual nicotine does something like a cigar contain?

160 mg of nicotine

Related to above – is nicotine considered toxic (in sufficient dose)? Where does most nicotine come from?

1. Found naturally only in the tobacco plant Nicotiana tabacum (mostly leaves)  

2. One of the most toxic of all drugs  

3. More deadly than arsenic

4. It is considered toxic in sufficient doses

What about Menthol? Does it affect risk, addictiveness? Are there demographic/race differences in who uses menthol cigarettes? initially promoted as healthier but is it?

1. Marketed to African Americans

2. Originally claimed to be “healthier”

   1. May be more addictive

What things influence absorption of nicotine?

1. Cigarettes better absorbed in lungs  

2. Pipes, cigars, smokeless products better absorbed in mouth  

3. Rapidly absorbed into the bloodstream  

   1. Easily crosses blood–brain barrier

4. Absorption affected by:  

   1. PH, filter, volume of smoke inhaled

What are the negative effects of tobacco use (what negative health effects can it cause)? What about for pregnant women?

1. Life-threatening conditions

   1. Cardiovascular disease, cancer, and chronic obstructive pulmonary disease (COPD)

2. Also causally associated with

   1. Type 2 diabetes, Crohn’s disease, tuberculosis, rheumatoid arthritis, impaired reproductive function, and impaired immune function

   2. #1 cause of preventable disease, disability, death in the US

3. Secondhand smoke

   1. Class A carcinogen, associated with a higher incidence of heart disease and lung cancer

4. Prenatal and postnatal effects

   1. Higher risk of miscarriage, stillbirth, premature birth, low infant birth weight, SIDS, cleft palate, depression, ADHD

What are some ways that help people to quit smoking?  What are the effects of nicotine withdrawal?

1. Nicotine replacement therapies

   1. Gum, patches

   2. Vaping (efficacy not proven)

2. Pharmacological treatments that don’t replace nicotine

   1. Bupropion, Varenicline, hallucinogens?

3. Behavioral and psychological treatments

4. Withdrawal

   1. Can occur fairly rapidly (hours, days) and last for weeks or months

   2. Psychological vulnerability to relapse for years

   3. Most prominent withdrawal symptoms:

      1. Concentration

      2. Headache

      3. GI disturbance

      4. Increase in appetite

How quickly is nicotine metabolized (i.e. what is its half life)? How quickly do people develop tolerance? How long does it stay in one’s system?

1. CY450 system of the liver

   1. Nicotine metabolized more slowly in men (probably), newborns, and the elderly

2. Very short half life of two hours

3. Tolerance develops at different speeds to different effects (but overall very fast, sometimes just hours)

What makes nicotine so addictive and why so hard to quit?

1. Accessibility and Ritual

2. Reward pathway and Acetylcholine (arousal, attention, memory)

3. Both biologically and psychologically addictive

   1. Drug-related cues induce nicotine cravings

   2. Social factors enhance addictive properties

Is having a mental health diagnosis correlated with smoking?

Tobacco use more common in people with mental illness

How might smoking affect an adolescent’s developing brain?

1. Nicotine exposure during adolescence negatively impacts learning, memory, attention, behavior

2. Increases the risk of addiction and mental health issues

What are the acute effects of nicotine use? In other words, what does nicotine do to the brain and body, blood, cardiovascular system, etc.? 

1. Brain

   1. Increased alertness, arousal, memory, vigilance, and concentration

   2. Headache, dizziness, sleep disturbances, and irritability

   3. Suppressed appetite

   4. Heightening tension in non-smokers, while smokers calmed

   5. Stimulated brain areas related to pleasure and reinforcement

2. Respiratory

   1. Constricted bronchi, so decreased amount of air entering lungs

   2. Decreased lung capacity

3. GI

   1. Increased nausea and vomiting

   2. Increased gastric HCl secretion

   3. Decreased GI tone and muscle contraction, can lead to diarrhea

4. Mouth

   1. Dry mouth

   2. Possible changed shape and reduced function of taste buds

5. Endocrine

   1. Increased release of epinephrine, norepinephrine, vasopressin, cortisol, prolactin, growth hormone, and insulin

6. Cardiovascular

   1. Increased heart rate and blood pressure

   2. Decreased ability to carry oxygen to tissues

   3. Increased blood clotting

   4. Constricted blood vessels of hands, feet, and skin

   5. Increased risk of heart attack and stroke