340 likes | 990 Views
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
E N D
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 cigarette-making 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 action- nicotinic 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 • quick first pass metabolism through liver • 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 Symptomsof 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