Nicotine Flashcards
1
Q
Tabacco plant
A
- Tobacco plant only natural source of nicotine
- Belongs to genus Nicotiana
- Rustica: bad taste, planted in Virginia
- Tabacum: spaniards had monopoly
2
Q
History
A
- Columbus given tobacco by inhabitants of San Salvador
- British were against it bc it was Spanish
- 1600 got their first shipment of tobacco from Virginia
- End of Spanish monopoly
- 1700s tobacco was sniffed
- Russia punished smoking with torture exile to Siberia and death (same in Turkey China and Japan) did not stop spread of smoking
- Chewing tobacco was american and patriotic
- Never adapted by british
- Advantage: free hands
- Disadvantage: health problems (TB), spit everywhere (even in the courts)
3
Q
20th century
A
- 1963 peak of sales: 4300 cigarettes/year, half that today
- 1964 First surgeon report that smoking was bad for you
- Decrease in smoking
- 1994: nicotine declared addictive (but the senate still did not think it was addictive)
- FDA could have declared a drug but they didn’t (there’s money in cigarettes)
- 1996 benzopyrene first chemical found w direct link to cancer
- 1998 first Big tobacco settlement 4 billion dollars against the company
- They increased the price of cigarettes and just made people pay for the lawsuit
- Commericials banned from selling cigarettes to kids
4
Q
What is in tobacco
A
- 1700 degree farenheit: 4,000 compounds oxidised and released in the smoke
- Two components in smoke
- Particle phase:
- Water
- Nicotine
- Tar -> carcinogenic -> taste and smell
- Gaseous phase
- CO2
- CO
- Ammonia
- Hydrogen Cyanide
- Acetone
- Particle phase:
5
Q
Toxic compounds
A
- CO
- Odorless, colorless & tasteless
- Extremely toxic
- Attaches to hemoglobin -> CO has a higher affinity than Oxygen
- Deprives tissues of oxygen (asphyxiation)
- Leads to cardiovascular disease
- Tar
- 6-16 mg/cigarette
- Sticky tar clogs cilia so they can’t filter lungs -> carcinogenic products can settle on tissue
- Nicotine
- 8-10 mg/cigarette (only 20-25% enters bloodstream)
- Toxic
- Psychoactive drug and dependence producing
- Used in insecticides
- Smokers get 2-8 mg a day (per one pack, LD= 60 mg)
- Ammonia: increases nicotine absorption
6
Q
Route of administration: Orally
A
- Nicotine absorbed through membranes in mouth
- Chewing: put between cheek and gum
- Snuff: lower lip and gum
7
Q
Route of administartion: smoked
A
- Cigarettes: tobacco burned, nicotine vaporizes -> lungs -> heart -> brain in a bolus (intense and all at once)
- Pipes and cigars -> absorbed from the mouth
- E-cigarettes
8
Q
Metabolism and Elimination
A
- Broken down by liver: cotinine by cytochrome P450 2A6 -> excreted in the urine
- Some have low levels of CYP P450 2A6 -> less likely to become smokers bc negative reaction
- Methoxsalen: prevents the breakdown of nicotine
- Halflife: 2 hours makes you wanna smoke again
9
Q
Mechanism of Action
A
- Nicotine (agonist) binds to Nicotinic Cholinergic Receptor all over the body (brain and muscle): a subtype of ACh receptor
- Opens Na+ Channels
- Neuron depolarizes: fast excitatory response
- Release of serotonin, endorphin, vasopressin, growth hormone adrenalin and prolactin
10
Q
Physiological effects
A
- Relaxes smokers, stimulates non-smokers
- Increases blood preassure
- Constricts blood vessels in skin -> cold hands
- Adrenal Glands: E and NE
- Tachycardia (heartbeats way faster)
- increase in blood pressure
- Medulla -> increase in respiration
- Stimulates vomiting center (first time
11
Q
Behavioral effects
A
- Mood
- Smokers: Relaxing, reduce tension when needed, stimulates when bored
- Non-smokers: arousal, more tension
- Cognitive factors: Ach
- increases memory in abstinent smokers (partially relief from withdrawal)
- Nonsmokers also increase performances
- Increased attention in EEG
12
Q
Withdrawal and tolerance
A
- Tolerance to nausea/dizziness
- No tolerance to
- Increase in HR
- Changes in Skin temp
- Acute tolerance: happens during the day
- Withdrawal
- Within 6 hours of the last cigarette: HR and blood pressure decreases
- 24 hours
- irritability
- Fatigue
- Drowsiness
- Insomnia
- Craving for cigarettes
13
Q
Treatments
A
- 2/3 of smokers say they want to quit
- only 3% successful first attempt
- 50% eventually quit
- 90% who quit do it without help
- Women have a harder time quitting than men (easier when ovulating though)
14
Q
Prescription drugs
A
- Chantix:
- reduces cravings
- a partial agonist to nACh: mimics effects of nicotine without hight
- Zyban: reduces withdrawal symptoms (DA and NE reuptake inhibitor, the antagonist of nAChR)
- Methoxalen: inhibits cytochrome P450 2A: makes smoking unpleasant
15
Q
Quitting
A
- Within 8 hours: CO levels are normal
- 24 hours: risk of heart attack decreases
- 2 weeks to 3 months: circulation improves lung functioning increases by 30%
- 1-9 months:
- Cilia go back to normal: can clean lungs
- Sinus congestion fatigue and shortness of breath decrease
- 1-year: coronary heart disease risk decreases by half
- 10-years: lung cancer death is half of a smokers
- 15 years: risk of coronary heart disease = same as non smoker
