Nicotine

Question 1

Is nicotine addictive?

Answer 1

Yes, highly

Question 2

What was nicotine originally used for?

Answer 2

it was an insecticide

Question 3

What plant does nicotine come from?

Answer 3

Tobacco plant

Question 4

What is the #1 killer in the world?

Answer 4

Smoking

Question 5

What did cigarette ads target?

Answer 5

they targeted kids to get addicted and continue using when they got older

Question 6

How fast does nicotine reach the brain after inhaling it?

Answer 6

7 seconds (as fast as if injected)

Question 7

How does time of effect, change addiction?

Answer 7

The less time it takes to get to the brain the more addictive a drug is

Question 8

The cigarette is a delivery system for more than 7,000 other chemicals in cigarette smoke, how many are carcinogens, what type of toxins?

Answer 8

• Carcinogens (70), ciliotoxins (paralyse cilia in lungs, can’t move mucus out), inhibitors

Question 9

What diseases can be caused by smoking?

Answer 9

Heart disease, stroke, gum infections, bladder cancer

Question 10

what happens to mucociliary clearance when smoking?

Answer 10

it is decreased, can’t get mucous out of lungs

Question 11

Smoking combined with asbestos causes?

Answer 11

50-90 times more risk, increase lung cancer deaths.
Asbestos has small fibers that when breathed in can get into the lungs and cause cancer

Question 12

How many deaths from coronary heart disease are due to smoking

Answer 12

1/3

Question 13

What is nicotine’s effect on the skin, eyes, hair (does it vasoconstrict or vasodilate)

Answer 13

Nicotine – vasoconstriction
Skin – wrinkles (smoking + sun damage)
Eyes – cataracts
Hair – thinning

Question 14

20% of smokers die from what lung conditions?

Answer 14

Bronchitis + emphysema

Question 15

How many people die from second hand smoke each year?

Answer 15

900,000 people

Question 16

Children exposed to smoke are more at risk of developing what diseases?

Answer 16

Children exposed to smoke have an increased rate of brain tumors, cancers, asthma, infections SIDS

Question 17

Types of nicotine absorption/administration?

Answer 17

Mouth, lungs, skin (patch)

Question 18

Does nicotine have a first pass inactivation?

Answer 18

No, bypasses the liver, when inhaled

Question 19

How do smokers control nicotine bioavailability?

Answer 19

The smoker controls the bioavailability
- If nicotine is higher than 6%, then the smoker puffs less
- If the nicotine level is less than 6%, then the smoker puffs more
- The smoker controls the level of nicotine to be about the same

Question 20

Nicotine gum (oral administration) causes?

Answer 20

Nicotine gum – rate of absorption is slower less concentration in blood

Question 21

Why can children die from eating a cigarette?

Answer 21

Nicotine is absorbed very well in the GI tract, so if a child swallows/ eats a cigarette they will get nicotine poisoning and can die

Question 22

Where is nicotine distributed in the body?

Answer 22

• Everywhere
• Chemoreceptor trigger zone (triggers vomiting before enough gets absorbed, kids) – no blood brain barrier
• Smokers build up tolerance to vomiting, need more nicotine to have the same effect

Question 23

Which cytochrome P450 metabolizes nicotine?

Answer 23

CYP2A6, CYP2A6 activates procarcinogens that form cytotoxic and genotoxic metabolites (urine is carcinogenic)

Question 24

What is nicotine’s half life?

Answer 24

2 hours

Question 25

What effect does a defective CYP2A6 cause?

Answer 25

- Slower removal of nicotine - Therefore, a smoker needs to smoke less cigarettes to maintain the same blood nicotine levels - (They can smoke, but end up smoking less)

Question 26

Excretion of Nicotine?

Answer 26

- Urine is carcinogenic, which is probably why bladder cancer is more common in smokers - Alkaline urine decreases the excretion of nicotine

Question 27

What type of receptor is the nicotinic receptor, how many subunits does it have?

Answer 27

it is a ligand gated ion channel, (sodium/calcium channel), it has 5 subunits, alpha (9) or beta (3), receptors in the neurons differ from those in the muscles

Question 28

What is the effect of acetylcholine binding to nicotinic receptors?

Answer 28

- Ach binds, opens channel – sodium/calcium can now flow through - Ach comes off, receptor is desensitized for a bit and then regenerates

Question 29

What is the effect of nicotine binding to nicotinic receptors?

Answer 29

- Nicotine binds – opens channel - The receptor is desensitized for longer - More ions get into the brain (Na+, Ca2+)

Question 30

What cardiovascular effects does nicotine cause?

Answer 30

- Change blood flow, heart rate (increases) - Hunger contractions of the stomach decrease, less hungry

Question 31

Is nicotine excitatory or inhibitory?

Answer 31

excitatory

Question 32

Effects of Nicotine poisoning?

Answer 32

CNS: excitation followed by inhibition Tremor, convulsions… Paralysis Death from respiratory failure

Question 33

what type of receptors are necessary for dopamine release?

Answer 33

Beta 2 and alpha 4 ach receptors

Question 34

What is menthol?

Answer 34

It is a channel modulator

Question 35

What effect does menthol have on smoking?

Answer 35

- Increases the addictive property - Decreases the ability to stop smoking - Now banned as an addition in cigarettes

Question 36

How does nicotine alter dopamine levels in the brain causing addiction?

Answer 36

Nicotine decreases the GABA inhibition (desensitize) Nicotine stimulates receptors on glutamate excitation - Increases the amount of dopamine released

Question 37

What are some withdrawal symptoms from smoking nicotine?

Answer 37

- Depressed mood, steep trouble, irritable, difficulty concentrating, restless, increased appetite, weight gain - Craving for nicotine peaks at 3 days and then goes down - Initial distress in first 5 days - Later there is a sense of well being, but the cravings don’t go away - Excess nicotinic receptors slowly decline, up to 6-12 weeks for them to go away

Question 38

Types of nicotine treatments?

Answer 38

- Replacement therapy – patch - Block nicotinic receptors in the reward pathway – BUP (drug), varenicline, partial agonist, lower effect of dopamine - Block CYP2A6 - Decrease dopamine release (topiramate tablet - Nicotine vaccine – being tested, nicotine would have no effect

Question 39

What are the effects of e-cigarettes?

Answer 39

e-cigarettes have small particles that are absorbed into the lungs and get into the blood, the magnitude of the risk for vaping is not known yet - Disruption to lung function and gas exchange - Impaired respiratory immunity and host defence systems - Respiratory inflammation and injury