Nicotine Flashcards
What happens when someone smokes? (process in body)
- smoke containing nicotine inhaled, carried into lungs, absorbed into pulmonary venous circulation (quickly b/c large SA), moves to brain (quickly), nicotine binds to and activates nicotinic acetylcholine receptors
- either relaxes or stimulates depending on environment
- some report euphoria esp with 1st cig of day
Smoking market
-more men
-changing from industrialized nations to developing nations
(more info in notes)
Tobacco (plant? what does it contain?)
- most north american products are form Nicotiana tabacum species
- Contains: nicotine, carotenoids, compounds produced from curing process (take leaves dry out, get new chemicals that were not present in plant), 599 compounds added during processing, 4000 new chemicals created by burning tobacco (linked to cancer)
What are some intentional additives used?
-mostly for flavour, modify burn rate,ability to release nicotine (change ph to change way absorbed)
-additives thought to be safe but when burned can form carcinogenic chemicals
-simple sugars converted into acetaldehyde when burned
->thought to perhaps inhibit monoamine oxidases and boost NT levels
(more in notes)
What are some of the unintentional additives?
- from growing , handling and processing
- conveyor belt fragments, insect parts, pesticide, herbicide, heavy metals, bacterial toxins, mold toxins, radioactive elements from soil
- often fertilized with mineral called apatite to starve plants of nitrogen (to get certain flavour) but it contains radium and radioactive isotopes of lead and polonium
Cigars vs cigarettes
(more in notes)
cigarette: maltch of tobacco and additives, # inhalations=11, 26mg tar (unfiltered), 16mg tar (filtered), less smoke, less nicotine, 20 mg of BaP (causes cancer)
- cigar is pure tobacco: 8X mass, 120 inhalations, 44 mg tar, more smoke, more nicotine, 100 mg BaP
Smokeless tobacco
- some claim to be safer than smoking
- amount of nicotin absorbed 3-4x greater than cigs but process slow (membranes of mouth
- at least 28 carcinogens (curing)
- not as addictive but still addictive
- increased risk of oral cancers (inflammatory process that leads to cancer)
Electronic cigs
- do not contain tobacco, no combusion
- nicotine and inhalation, heats up and vaporizes nicotine-containing liquid
- > don’t know if some absorbed in mouth or GI or if all in lungs
- idea safe alternative to cigs and provide behavioural cues that satisfy some cravings
Concerns of electronic cigs
- inhalation of some of the liquid propylene glycol which nicotine dissolved in (irritates lungs, induce asthma)
- nitrosamines (cause cancer)
- children break and swallow nicotine
- BUT newer models use distilled waterand gycol, less nitrosamines than in other therapies to quit, cigs contain just as much nicotine as e-cigs
Can e-cigs aid in cessation?
- several studies say can be successful component of cessation
- not same levels of plasma nicotine buthave bahavioural aspects (throat catch)
- help with craving better then other therapies
Is Hooka a healthier alternative?
- shisha used in hookas (water pipes)
- heated not burned and smoke cooled as passes through water (a lot of toxins get caught in the water
- 1 gram of tobacco shisha produces 11 times more CO than cigs (ties to hemoglobin and prevents from transporting oxygen)
- lots of carginogens, increases heart rate and bp and leads to lung disease, increased risk of oral and lung cancer
Nicotine
- facilitates addictions
- mimicks acetylcholine at acetylcholine receptors (agonist) ->same site
- charged at low pH (pick up excess H+, protenated)
- tar, carbon monooxide, metals, hydrocarbons are primary causes of cancer
Nicotine and pH
- charge depends on pH
- diprotonated (low pH) form does not occur when smoking
- monoprotonated med pH
- freebase (nonprotonated) high pH, is volatile, more easily released from tobacco and increases ease of absorption (companies want this), absorbed into blood quickly b/c not charged once in blood forms back to monoprotonated so can bind to receptors
What are the 2 components of cig smoke?
1) particulate phase: volatile and non-volatile nicotine, water, tar, metals, radioactive compounds
2) gaseous phase: volatile nicotine, carbon monoxide, carbon dioxide, nitrogen oxide, volatile notrisamines, ammonia, nitrites, sulfur, alcohols, ketones, aldehydes, volatile hydrocarbons
Administration
- few drops of nicotine would kill person (60mg), one cig=0.5-2mg
- smoker gets fraction due to side stream smoke, pyrolysis (break down of nicotine during cumbustion), filter
- most people smoke in same way (increase nicotine less puffs visa versa), 1-2micrograms per kg
