Exam 2: Nicotine Flashcards
what is nicotine
an alkaloid found in tobacco leaves
- large and small leaf varieties
- nicotine content for commercially grown tobacco leaves is as much as 6% for addictive part of tobacco
some history of nicotine
-indigenous people smoked it for religion
-1st encountered by European when Columbus came
-europe commercialized growh of it in virginia colony
-firt medical concern - 17th century
-in 1828 nicotine isolated from tobacco by french chemist
-mainly chewing tobacco before 1900s
-smoking inc
negative ehalth consequences by surgeon general in 11960s
2003-ecigs
legal status 1994-200s
1994- FDA requested to regulate them - not approved
1996-FDA approved to limit access and ads to kids and adolescents
2000-FDA cannot regulate tobacco products unless granted authority by congress
2009-tobacco products under FDA control
can FDA ask companies to remove nicotine from their products
no
- can only regulate if there is a concern
reasons people may use nicotine
- establish feelings of independence
- improve self image
- enhance social acceptance
- counteract stress and boredom
- curiosity
factors that predict smoking
- poor academic performance
- rebelliousness
- sensation seeking
- smoking by family/friends
stages in developing a smoking habit
1a: nonsmoking-precontemplation - does not intend to start
1b: nonsmoking-contemplation or preparation-thinking about starting
2: initiation or tried
3: experimentation
4: regular smoker- on regular basis, at parties, weekends
5: established smoker - nicotine dependent
what is smoking a major cause of
illness and premature death
tobacco use counts for 1/3 of all _______
cancers
- mouth, pharynx, laryna, esophagus, stomach, lung, cervix, kidney, bladder, throat, pancreas
linked to 90% lung cancer causes
secondhand smoke
inhalation of tobacco smoke by people other than the “active” smoker
- causes 3000 lung cancer death amongst nonsmokers
what does secondhand smoke increase people’s risk for
- cardiovascular disease
- childhood asthma
- sudden infant death syndrome
pharmokinetics
ADME - what the body does to the drug
routes of administration for nicotine
-buccal (chew), intranasal (snuff), oral (losenge), transdermal patch, nasal spray, inhalation (cigs, vapes)
oral, transdermal, nasal spray are used when people are trying to stop smoking
where is it uncommon for nicotine to be absorbed in the body
GI tract
nicotine absorption is dependent on what
pH
nicotine is a weak base pH= 8
in acidic environment: ionized- poorly absorbed across membrane
in alkaline: nonionized: well absorbed
at physiological pH, what percent of nicotine is non-ionized
31%
what is the most common method for getting nicotine into the bloodstream
inhalation
inhalation of nicotine
- nicotine distilled from burning tobacco and caries droplets containing water, tar, and nicotine into the lungs (high SA)
- nicotine rapidly absorbed across respiratory epithelium
what has cancer causing agent in nicotine
tar
a typical cigarette has how much nicotine?
How much does it take to kill you?
6-20mg
30-60mg is a lethal dose for 150lb person
so 2 cigarettes has enough to kill you
why don’t people di from acute cigarette smoking if it only takes 2 cigarettes to kill you?
only 1-3mg of nicotine is absorbed
amount available depends on number and length of puffs
may have developed tolerance
Buccal absorption
pH in mouth = 7
acidic media - cigarettes
alkaline media-pipes, cigars, snuff, chews, nicotine gums, lozenges
How can beverages alter pH and affect absorption
coffee and alcohol are acidic
- if drinking at same time as smoking, pH will be adjusted, there is less ionization and it will absorb better into the system with cigarettes
- with chews and alkaline substances the coffee would make it harder to be absorbed into the system
absorption: skin and GI tract
nicotine readily absorbed through intact skin - transdermal patched
nicotine absorbed into SI BUT has low bioavailability due to 1st pass metabolism
- sublingual tablets and lozenges avoid 1st pass metabolism
route of administration effects
nicotine blood concentration levels
distribution of nicotine
- BBB permeable
- reaches brain in 7-20s following inhalation
- peak levels in lungs, blood, brain in 10 min
peaks in brain quickly even though slow inc in blood concentration
nicotine use higher in e cigs than cigs
metabolism of nicotine- liver
removed from brain within 30 min
-70% broken down into active metabolite cotinine by cytochrome p450 2A6!!!!
metabolism of nicotine: lungs
metabolized to cotinine and nicotine-N-oxide
excretion of nicotine
10-20% excreted unchanged in the urine
what is detected in drug test for nicotine
cotinine is detected
can be in urine for several days
people with low cytochrome p450 2A6 activity _______
are less likely to become smokers, and if they do they have a greater success in stopping bc it builds in their system longer - get neg effects and not pleasurable ones
genetic polymorphisms play role
half lives of nicotine and cotinine
nicotine: 2hrs
cotinine: 19 hrs
to avoid withdrawal they continue smoking throughout day
ways to excrete nicotine
urine
breastmilk - can give to baby
