CNS stimulant   Alkaloid from a chemical

group called Xanthines   Found in 63 species of

plants   Everyday 90% of

Americans consume caffeine in some form

  Caffeine (1, 3, 7-trimethylxanthine) – found in coffee, sodas and some OTC medicine

  Theophylline (1, 5-dimethylxanthine) – found in tea

  Theobromine (3, 7-dimethylxanthine) – found in chocolate

  Plants evolve caffeine to protect themselves from attack by bacteria, fungi and insects.   1st use of caffeine as early as 600,000

BCE   First historical record of caffeine use

from Aztec records.   Homer makes reference to a

mysterious black bitter beverage with the power to ward off sleep.

1475 - The worlds first coffee shop opens in Constantinople

1821 - Pure caffeine extracted from coffee

1880's - Caffeinated soft drinks appear 1903 - Researchers remove

caffeine from beans ‘without destroying the flavor’

1923 - Decaffeinated coffee is introduced to the United States

1940 - The US imports 70 percent of the world coffee crop.

1962 - American per-capita coffee consumption peaks at more than three cups a day.

1971 - First Starbucks opens in Seattle.

1995 - Coffee becomes the worlds most popular beverage (overtaking tea).

  ‘Tweenagers’ consisting of 8 to 14 year olds are heavily targeted by marketers

  Why do so many young tweenagers drink caffeinated beverages? –  Coffee bars are often the only place for young

people to hang out –  Marketing of ‘cold-sweet’ coffee drinks and

high caffeine sports/energy drinks

  In Canada, adding caffeine to citrus drinks has not been allowed. The company that produces Mountain Dew has been fighting to add caffeine to Canadian Mountain Dew claiming to improve taste.

  The Do the Dew ad campaign shows frenzied lifestyle

7-Up 0 mg Root Beer (non-Barq’s) 0 mg Tea, the elegant option 30-60 mg Coke 45.6 mg Mountain Dew 55 mg JOLT 71.2 mg of caffeine Coffee 80-135 mg Excedrin 130 mg per tablet No Doz 200 mg a pill In 1998 Americans guzzled 15 billion gallons of sodas, the equivalent of 585 cans for every man woman and child in America.

 Soda companies pay school districts for exclusive selling rights (Coke vs Pepsi) and for the right to put ads on the gym walls and school buses –  1997 in West Virginia a state law

prohibiting the sale of soda in schools was overturned after extensive lobbying by soft-drink companies

  mixture of energy drinks and alcohol sold as expensive cocktails in many clubs –  100mg of caffeine --

often sold without labels

– Dangerous when combined with alcohol

Anheuser-Busch’s ‘BE’ Takes Beer to a New Level

ST. LOUIS (Oct. 4, 2004) – B-to-the-E (BE), Budweiser's newest

entry in a long line of innovative beers by Anheuser-Busch, is a distinctive new product for contemporary adults who are looking for the latest beverage to keep up with their highly social and fast-paced lifestyles.

54 mg of caffeine (plus guarana and ginseng)

Absorption through:   Stomach   Small intestine   Large intestine

Effects of caffeine Depends on:

  Food in the body   Caffeine in the

substance

  Throughout the body and the brain

  Water soluble   Crosses blood brain

barrier   Reaches the fetus   No accumulation

within body

Dose: 100 mg = 1 Cup of Arabica Coffee (8oz) Route: Taken Orally Onset: 30-60 Minutes Peak At: 2 Hours Half-life: Approximately 3-7 hours

The enzyme CYP1A2 is responsible for the metabolism of caffeine in the liver. One form of the enzyme, produced by the gene variant 1A, metabolizes caffeine

rapidly while another form, 1F, metabolizes it slowly.

Shorter/Faster Metabolism if:

  Cigarettes   Caucasians   Women   Child

Longer/Slower Metabolism if:

  Alcohol   Asians   Men   Newborn   Liver Damage   Pregnant

 Smoking Will Metabolize Twice as Fast

•  Alcohol Will Metabolize Slowly

 Metabolized by liver (first-order kinetics)

•  Excreted by kidney via urine (diuretic)

  Main mechanism of action: direct competitive antagonist of adenosine receptors - A1 and A2a

  Effects on Monoamines:

-Elevates levels of 5-HT in the brain

-Stimulates NE neurons

-Increases rate of DA formation →However, this may be quickly followed by a

decrease →Yet, injection of caffeine usually increases

locomotor activity, an effect supposedly blocked by a DA receptor antagonist

•  Multiple mechanisms

•  Adenosine antagonist - both A1 and A2 sites

•  2nd messenger theory - Phosphodiesterase inhibition

- cAMP, AMP, intracellular calcium

  50-200 mg - Sleepy first 5 minutes - Blood levels peak at 30 min. - Stimulant effects

  300-1000 mg –  Prolonged ability to perform –  Exaggeration of side effects –  Pronounced insomnia –  Nervousness –  Irritability –  Tremor –  Restlessness

  1000+ mg –  “Caffeinism” –  All of the above worsen –  GI disturbances –  Cardiac arrhythmias

A. Recent consumption of caffeine B. Five (or more) of the following develop shortly after caffeine use

restlessness nervousness excitement insomnia flushed face diuresis GI disturbances muscle twitching rambling flow of speech tachycardia periods of inexhaustibility psychomotor agitation

•  Central Nervous System - stimulant

•  Autonomic Nervous System - change in EMG activity

•  Cardiovascular System - heart and blood vessels - blood platelets

•  Gastrointestinal System - cause for ulcers?

•  Respiratory - increases blood and air to lungs

•  Skeletal Muscles - contraction (contrarily)

•  Energy Metabolism - basal metabolic rate, free fatty acids, oxidation of fats in exercise

•  Neurotransmitters - norepinephrine in CNS, norepinephrine and epinephrine in blood, seratonin in brain

•  Neuroendicrine effects - stress (high doses)

  Increases wakefulness, alleviates fatigue, facilitates concentration

  Can also produce: elevated mood, shaky/jittery feeling

  ↑ time to fall asleep,↓ amount and quality of sleep

  ↑ attention/vigilance, ability to sustain performance

  ↑ work capacity/speed,↓ # of errors

Fig. 3-d: Percent change on a repeated acquisition test, which assesses motor learning and memory

  Decreased A2a receptor expression   Increased A1 receptor expression   Tolerance to respiratory effects after 8

consecutive days of daily administration   Cross-tolerance   Caffeine tolerance is pharmacodynamic

 Very rare but deadly occurrence  LD50= 150mg/kg

–  70 kg (154 lbs) person’s lethal dose is 10.5 grams

–  In 1986, of 2709 cases of caffeine “exposure” registered with Poison Control Centers, 0.1% or 3 cases resulted in death.

 Withdrawal has been reported after stopping a dose as low as 100 mg/day

 40-70% of people who attempt to quit caffeine experience withdrawal

 Withdrawal can be totally incapacitating  Onset: 12-24 hours  Peak: 20-48 hours  Duration: 2-7 days

  Withdrawal can occur by abstaining from a dose as low as 100mg/day –  equivalent to a cup of coffee or

2-3 caffeinated soft drinks.

  Telephone survey shows 40-70% of consumers trying to quit reported experiencing withdrawal symptoms

The most commonly reported symptoms of withdrawal are:

•  Headache

•  Fatigue

•  Sleeplessness/Drowsiness

•  Difficulty Concentrating

•  Work Difficulty

•  Irritability

•  Depression

•  Anxiety

•  Flu-like symptoms

•  Impairment in psychomotor, vigilance, and cognitive performances

 Not included in DSM IV – While caffeine produces physical

dependence, there is insufficient information on whether it causes inability to stop use or cause use despite harm.

  Treatment of migraine headaches, caused by dilation of blood vessels –  Mixed with ergotamine tartrate (vasoconstrictor) –  Increases the power of aspirin and other

painkillers by about 40% –  has also been used to treat:

• chronic obstructive pulmonary disease • asthma • breathing problems in newborns • overdoses with opioid drugs

  Weight Loss Effects   Increased Alertness   Enhanced

Concentration   Enhance Physical

Endurance and Delay Fatigue

  5 or more cups of coffee daily can increase the risk of heart disease due to:

- ↑ heart rate - ↑ blood pressure - ↑ blood cholesterol levels

  Drinking coffee may cause increase of stress hormones

- adrenal gland produces adrenaline until no more can be produced - leads to chronic fatigue, constant exhaustion and susceptibility to disease

  Diuresis   Gastritis   Heartburn   Lower birth weights   Pregnancy risks   Panic Attacks   Jitters   Anxiety   Raised Blood Pressure   Insomnia

  Because of risk of increased blood pressure, caffeine should be used cautiously by patients who take other drugs that raise bp –  Anti-Depressants that are MAO inhibitors

  Marplan, Nardil, and Parnate

–  High doses of cold medicine   Phenylpropanolamine

  Adds to the effects of other stimulants –  Cocaine, amphetamines, metamphetamines

  Sodas are aggressively marketed for kids

  Marketers focus on children starting at the age of 18 months

  In order to establish consumer loyalty to their brand, advertisers try to appeal to younger and younger customers –  Mountain Dew, the preferred soda of

children under 6, distributed a half million free pagers to children in 1998 in an ad campaign