Transcript Nicotine - People Server at UNCW

Nicotine
Chapter 7
History of Tobacco
History of Tobacco &
Nicotine
• Smoking practiced
among the early Mayas,
probably in the district
of Tabasco, Mexico, as
part of their religious
ceremonies 86-161 AD
• Europeans’ first
exposure from
Columbus 1492.
Exposure was not
widespread. Tobacco
was not well thought of
at first
History of Tobacco
1560 - Marked as 1st
yr tobacco officially
introduced to
Europe
Proponents of tobacco
• Sir Francis Drake
• Sir Walter Raleigh
– Led to the
fashionability of pipe
smoking of tobacco
History of Tobacco
King James I of England
• 1604 - Pamphlet condemning tobacco
– “bewitching of tobacco”
Early 1700s Russia
– “Westernization” of people
– penalties for smoking (torture, Siberian exile,
death)
History of Tobacco
By 17th century
• Tobacco here to stay
– In Western Europe, used as treatment for
migraines
– Japan & China stop enforcing prohibition of use
– Russia opens door to West
– Sultan of Turkey begins to smoke
History of Tobacco
• 1828 - Nicotine was isolated
• Cigarettes first appeared in 1850s, but
chewing still more popular
Tobacco & Nicotine In US
• In U.S., tobacco became major commodity
in early 1600s, used as currency
• Financed Revolutionary War
– Ben Franklin promised Virginia's tobacco to
France
– Had it not been for tobacco, no French
assistance & no USA
Tobacco Use in 20th Century
Future favored cigarettes over other usage
• New emphasis on social manners
• Public health issues of infectious disease
– decrease in chewing except in small rural towns of U.S.
• Women began smoking
– But, 1904 NYC woman arrested for smoking in public
• 1920s - “reach for a Lucky instead of a sweet”
– Promoted weight loss effects
• Also cigarettes in WWI
Tobacco & Nicotine In US
• 1890s - no medicinal value for nicotine
– dropped from U.S. pharmacopia
• 1925 - 14 states banned smoking
• 1938 - study linking cigarettes & lung cancer
• 1954 - more stats relating smoking to lung cancer
& cardiovascular disease
• 1964 - first Surgeon General's report
– advised smoking shortens life expectancy
• 1986 - Surgeon General's report on passive
smoking
• Use continued to decline over past twenty years
• 2000 – Worldwide consumption still on increase
Nicotine Forms
• Tobacco
– Smokeable
• Cigarette
• Pipe
• Cigar
– Leaf (Chewing)
– Leaf (Dip)
– Snuff (powdered)
• Transdermal Patch
Snuff
• Grind tobacco into fine powder
• Pinch into nose & exhale with sneeze
(cleared head of “superfluous humours”)
• 1700s – snuff overtook smoking as
method of choice
– Started in France & spread through rest of
Europe
Chewing
In U.S., snuffing replaced by chewing
• Freed hands for working
• Low cost - democratic custom all could have
• “spitting” seen as nasty habit, also health
issue
– Major cause of spread of infectious disease (TB)
Cigar Smoking
• Tight rolls of tobacco leaves
• Flue-curing - process of heating tobacco
leaves
– to cure them, makes milder smoke
• Also new type of leaf
– North Carolina #1 tobacco-growing center
• Mixed effects of chewing with ingestion of
smoke
Cigarettes
• Rolls of shredded tobacco wrapped in paper
• 1614 – Invented by beggars in Seville, Spain
from scrap of cigars
• 1856 - Became popular with English soldiers in
Crimean War - Spread throughout Europe
U.S, not inclined to use it
– Public image
– Rumors of opium, arsenic laced paper, & camel dung,
– Also image:
cigarette - dainty & “sissy”
vs. cigars - fat, long & dark
Cigarettes
1881 - James Bonsack patented cigarettemaking machine
• Made cigarettes even more low-cost
• Revolutionized tobacco industry
- From 300 cigarettes per hour by hand
to 3 machines producing 200 cigarettes
per minute
Cigarette Smoking
Nicotine in a cigarette – 8 to 10
mg
Smoking – delivers about 1-3 mg
to the smoker
Technique of smoker can increase
nicotine (time smoke is in lungs, rapid
puffing)
Nicotine Pharmacology
• Biphasic actionnicotinic acetylcholine
receptors
– Agonist – low doses
– Antagonist – high doses
• Although a stimulant, it
is often used to relax
• Works in CNS and PNS
• One of the most toxic
dependence-producing
psychoactive
compounds overall
– Nicotine acts to stimulate
dopamine release in
mesolimbic dopamine
pathway (reward center).
Nicotine Pharmacology
•
One of most powerful poisons ingested
by Americans
– LD50 60 mg
•
•
Can't happen via inhalation
Orally, two protections against death
1. quick first pass metabolism through
liver
2. activation of vomiting center
Peripheral Effects
• A sympathomimetic
– Increases heart rate, blood pressure,
respiration
• A parasympathomimetic
– Increases smooth muscle (GI tract) activity
– Increases HCL production in stomach
Central Effects
• Arousal
• Improves vigilance & rapid information
processing
• Improves mental performance &
memory
• Stimulates adrenalin and ADH release
• Nicotine may reverse some deficits
caused by alcohol
Biotransformation/Excretion
• Broken down by lung and liver
– >90% in liver
• Metabolization of nicotine and other
toxins in cigarette smoking lowers blood
levels of many important drugs.
• Excreted through kidneys (urine)
• Lungs do some excretion
Tolerance
• Develops rapidly
– Within the first exposure for some effects
• Area Postrema
– Can build up and dissipate over the course
of a day
– Chronic tolerance happens as well
• Dispositional Tolerance
– Some smokers clear nicotine faster
Dependence
• One of the most dependence-producing
drugs
– Pharmacology – Stimulates reward center
influences ANS
– Function – Weight control, coping with
negative affect/stress, cognitive
enhancement
– Social Factors – Friends, habit, context
Withdrawal Symptoms
of Nicotine
•
•
•
•
•
•
Lethargy, decreased arousal
Constipation
Headaches
Disrupted sleep cycles
Irritability/anxiety
Excessive hunger (blood sugar drop)
Compounds in Tobacco
• Tar - sticky substance
– Amount varies from 12 - 16mg to 6mg
– Last 3rd of cigarette contains 50% of
tar (final puffs more hazardous)
– Prevents cilia from working, decreases
cilia escalator
– Increases carcinogens compounds to
settle on tissue rather than being
expelled
Compounds in Tobacco
Carbon Monoxide
• Odorless & tasteless, but extremely toxic
• Attaches to hemoglobin
– Hemoglobin has greater affinity for CO than
oxygen
• Accumulation of CO occurs
• Leads to asphyxiation of body
Health Effects of Nicotine Addiction
• Cardiovascular Disease
– Most likely killer
• Cancer
– Approx 90% of all lung cancer
• Chronic Obstructive Pulmonary Disease
– All long-term smokers get some level of
COPD
– Emphysema most serious
Approaches to Treatment
• Self-help
• Behavioral intervention
• Pharmacotherapy
• Combined strategies
Nicotine Replacement
• Nicotine gum
• Transdermal nicotine
• Nicotine aerosols
Pharmacotherapy
• Clonidine
• SSRIs
• Zyban
Quitting Overall
• Combination of strategies works best
• Behavioral + replacement +
pharmacotherapy
• Quitting reduces risk of all-cause
mortality among other diseases
• Risk of lung cancer remains elevated
but drops significantly