Caffeine Flashcards
Caffeine Products
Coffee Tea Soft Drinks Ice Cream Chocolate Fortified Water
US Beverage Consumption
28- Soft Drink 18- Bottled Water 13- Beer 13- Milk 12- Coffee
Caffeine Intro
Most widely used stimulant
Over 80% of world drink daily
Coffee most prevalent form
Caffeine Pharmacokinetics
Rapidly and completely absorbed when consumed
Significant blood levels reached 30-45 min
Peak plasma levels in 90 minutes
Half Life 3.5-6 hours, but longer in infants, elderly, and pregnant women
Freely basses through blood brain barrier and placenta
Metabolized by liver enzymes
SSRIs are major inhibitors of these enzymes, so patients can have toxic reactions to high levels of caffeine
Caffeine Metabolism
Metabolized into theobromine, paraxanthine and theophylline
theobromine- Increases O2 flow
Paraxanthine- Increases fat breakdown to enhance athletic performance
Theophylline- Increases heart rate, open airways and improves concentration
Tobacco shortens caffeine half life,
quitters- caffeine can contribute to withdrawal symptoms as high levels of caffeine causes anxiety
Adenosine
Purine nucleotide
Plays role in energy transfer through ATP and ADP
Plays a neuromodulatory role in promoting sleep and suppressing arousal
Four known adenosine receptors, A1, A2A, A2B, A3 which are G protein coupled
Inhibitory effect on the CNS
Caffeine Mechanism of Action
Caffeine acts as an antagonist to adenosine receptors
Blocks adenosine from binding and having an effect on sleep
- Primary site are adenosine receptors on GABAergic neurons
Also influences dopaminergic, glutaminergic cholinergic and noradrenergic neurons
Does not result in DA release in nucleus accumbens, but does release it in prefrontal cortex
Causes arousal with profound reinforcing effects
Adenosine –> GABA –> Dopamine–> DA
Mild Dose- Caffeine
Brain Activity is increased- causing an alerting effect
Heart rate increase- both direct on the brain center and in heart
Breathing rate increases and smooth muscle relaxes- good for asthma
Constricts blood vessels in brain, but dilates vessels in peripheral system– Brain blood flow is decreased
Increases “bad cholesterol” and LDL
Increases urine production and inhibits antidiuretic hormone
Oil, acids and caffeine irritate stomach lining
Mild analgesic
High Dose- Caffeine
Tremors, nausea, vomiting, irregular, or very rapid heart beat confusion
Panic attacks and seizures at very high doses
Physical Performance Caffeine
Slight enhancement of physical performance
Delays fatigue
However, excessive urination can cause dehydration
Increased heart rate can cause irregular arrhythmias
Caffeine Dependence and Withdrawal
Chronic use as little as 100 mg/day can cause withdrawal when use is abruptly ended
Headache, drowsiness, difficulty concentrating, impaired motor performance, and dysphoric mood all occur when consumption is stopped
Effects appear slowly and are maximum at 1-2 days
Energy Drink
Beverage that contains mild stimulant drug, most commonly caffeine
Also contains a sugar or sweetener
Abuse Potential- Energy Drink
Combination with alcoholic beverages is popular practice
Caffeine can make depressant effects of alcohol, but has no effects on alcohol metabolism
Mask sensory cues used to regulate drinking
- 3 times more likely to binge drink
- 2 times more likely to be sexually assaulted and drink and drive
Four Loko
Product containing alcohol, caffeine, taurine, guarana
Originally introduced as an “energy drink”– ethical and legl implication of marketing to younger students
Masked the alcohol induced intoxication, thus causing individuals to black out
Resonsible for many hospitalizations on college campuses
MythBusting Caffeine
People metabolize caffeine at different rates- some fast, some slow
Drinking coffee does not make you sober- can cover some of the depressant effects
Coffee shops have different levels of caffeine in same drink– temperature, bean composition, and acidity all play a role
Addictive for some individuals, abrupt abstinence can cause withdrawal symptoms- headache, fatigue, dysphoric mood
Does not increase the risk for cancer or heart disease
