Chapter 7 - Nicotine and Caffeine

Question 1

What is nicotine?

Answer 1

leaves of tobacco plants; Nicotiana tabacum is most commonly used (highest nicotine content); absorbed when smoked or chewed

Question 2

Nicotine content of popular tobacco products

Answer 2

cigarettes (10mg, 1-2mg gets absorbed); cigars and pipes (amount varies, 5mg to 350mg)

Question 3

What are some smokeless tobacco products?

Answer 3

chewing and dipping tobacco, snuff

Question 4

What are E-cigarettes?

Answer 4

involves inhaling vaporized nicotine; vegetable glycerin added to make “smoke” visible, can cause lipid related lung injury; 0.3-4mg of nicotine in 15 puffs

Question 5

despite a decrease in ____, there has been a significant increase in ____

Answer 5

smoking cigarettes; vaping

Question 6

Tobacco use can cause…

Answer 6

cancer (lung, mouth); cardiovascular issues (heart attack, stroke); pulmonary disease (emphysema)

Question 7

Secondhand smoke risks

Answer 7

cancer; heart disease
in kids: bronchitis, pneumonia, ear infections, SIDS

Question 8

Thirdhand smoke risks

Answer 8

remnants of tobacco smoking on material in the smoker’s local environment (skin, hair, clothing, walls); risk to young kids

Question 9

History of tobacco

Answer 9

concerns as early as 17th century; early 20th century research focused on adverse effects

Question 10

Absorption (pharmacokinetics of smoking)

Answer 10

enters from mucous membranes (mouth, nose, throat) and lungs; tar sticks to mouth, nose, throat, and lungs– nicotine leaches from the tar

Question 11

Flue Curing (of cigarettes)

Answer 11

treat leaves with vented heat; produces neutral pH of tobacco smoke (7); allows smoke to be inhaled (cigarettes)

Question 12

The large surface area of the lungs provides a…

Answer 12

very effective route for nicotine to be absorbed into blood stream

Question 13

Best pH for absorption in the mouth is ____

Answer 13

pH 8.2
-sometimes chemicals are added to e-cigs to increase their pH

Question 14

Most products yield blood concentrations of ____

Answer 14

12 to 16 mg of nicotine per ml of blood

Question 15

Approximate absorption time for tobacco products

Answer 15

smoking 7mins, oral products 20 mins, vaping 20-30 mins

Question 16

Nicotine can readily cross the ____

Answer 16

blood brain barrier

Question 17

Nicotine metabolization

Answer 17

mostly in liver by CYP-2A6 enzymes; produces active metabolite cotinine

Question 18

Nicotine elimination

Answer 18

half life of about 2 hours; 30% faster in smokers (pharmacokinetic tolerence)

Question 19

Nicotine is an agonist for the ____

Answer 19

nicotinic ACH receptor
– Ionotropic receptor
– When bound to receptor site, positive ions flow into the neuron: Ca2+, Na+, K+
– depolarizations
-Each nicotinic ionotropic receptor comprises a configuration of α & β subunits

Question 20

What does it mean to have biphasic effects (nicotine)?

Answer 20

It first activates receptor by opening channel (agonist)
-Then, receptor enters desensitized state: the channels close and the receptor cannot be activated (functional antagonism)
-Occurs when nicotine is still bound to the receptor
-In time, desensitized state ends and receptors can be activated again

Question 21

Upregulation of ACH receptors

Answer 21

brain compensates for the repeated closing of nicotinic receptor channels by upregulating nicotinic receptor numbers; end up with more nicotinic ACH receptors expressed on post
synaptic neurons

Question 22

Peripheral NS (dist. of nicotinic receptors)

Answer 22

in ganglia of the ANS (symp and parasymp.); overall activation increases sympathetic NS; neuromuscular joints (voluntary muscle contractions)

Question 23

Central NS (dist. of nicotinic receptors)

Answer 23

receptors are found in structures important for arousal and cognitive functioning (ex. hippocampus and cerebral cortex); motor functioning (basal ganglia); reward circuitry where they increase DA (VTA and NA)

Question 24

What are some other NTs that nicotine effects?

Answer 24

ACH, glutamate, GABA; other constituents of tobacco smoke may enhance these effects

Question 25

physiological effects of nicotine

Answer 25

HR and BP: first cig of the day incr HR and BP then becomes desensitized (acute tolerance); reduces appetite

Question 26

movement (behavioural effects of nicotine)

Answer 26

depends on use (naive vs users); hand tremors in naive users; increased purposeless behaviours in chronic users

Question 27

cognition (behavioural effects of nicotine)

Answer 27

NAIVE ONLY (tolerance effect)
improves attention, vigilance, information processing speeds (e.g. Stroop Test); improved memory (word recall)

Question 28

subjective effects on naive users

Answer 28

negative subjective effects; nausea, disequilibrium, tension, jitteriness, confusion; acute tolerance to these effects

Question 29

subjective effects on chronic users

Answer 29

positive subjective effects; feelings of vigor, arousal, reduced fatigue; habitual users likely to become addicted

Question 30

Nicotine abstinence syndrome

Answer 30

includes craving, irritability, anxiety, hostility, concentration difficulties, impatience, insomnia

Question 31

How do some people smoke but don’t get addicted?

Answer 31

can be psychosocial factors (coping skills, less stress, better social support); can be genetic factors (Differ in gene expression for α5, α3, β4 receptor subunits, which are found on chromosome 15)

Question 32

Some ways that smokers quit

Answer 32

Cold turkey; Nicotine replacement (e.g., nicotine patches, gum); Varenicline (Chantix): a partial agonist of nicotinic ACH receptor
- less activation of nicotinic receptors (reduces
effectiveness of nicotine); Bupropion (antidepressant): increases DA which may
compensate for reduced DA in reward pathway with nicotine withdrawal

Question 33

Research suggests that making it to ____ of nicotine abstinence is best predictor of success

Answer 33

two weeks
-the problem seems to be that most cessation
strategies do not work and smokers do not make it to two weeks

Question 34

What is caffeine?

Answer 34

Mild psychostimulant of the xanthine family (includes theobromine and theophylline)

Question 35

oral administration of caffeine

Answer 35

food, drink, pills

Question 36

pharmacokinetics of caffeine

Answer 36

absorption across intestinal walls; peak concentrations at around 40mins; penetrates brain and placental blood barriers

Question 37

caffeine is metabolized in the ____

Answer 37

liver

Question 38

what is the half life of caffeine?

Answer 38

varies widely (3-10hrs); decreased by nicotine; increased by antidepressants

Question 39

caffeine is what kind of agonist?

Answer 39

adenosine receptor agonist
-Adenosine: primary role in the control of
sleep

Question 40

effects of caffeine

Answer 40

Increases heart rate, blood vessel constriction,
increases breathing rate, reduces appetite,
increases attention and alertness, and produces
positive mood

Question 41

What causes caffeinism?

Answer 41

high doses; agitation, anxiety, insomnia, negative mood, rapid heart rate and high blood pressure
-recommended no more than 400 mg per day
(adults); 100 mg in adolescents