Caffeine

1
Caffeine

• Chapter 8

2
Caffeine

• Most used drug in the world
• An alkaloid belonging to a class of compounds
  called METHYLXANTHINES
• Caffeine
• Theophylline
• Theobromine

3
History of Caffeine

• Huge history of use
• Tea dates back to 2737 B.C. in Chinese legend
• Coffee uncertain, but cultivated in Ethiopia in
  575 A.D.
• clearly beans chewed probably brewed way before
• Tea comes from Far East
• Coffee from the Middle East/North Africa

4
History

• Both coffee and tea historically used as
  religious drinks
• Over time, became widely consumed throughout all
  levels of society
• Played invaluable role in history of world
• importance in European commerce and colonial
  development

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COFFEE

• 1st coffeehouse in Constantinople in 1554
• England
• First coffee house Oxford - 1650
• 1700s London - 2000 coffee houses
• Heavy association with political turmoil
• Governments frequently tried to ban coffee
  houses, thinking they could suppress revolution

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COFFEE

• Growth of coffee houses in 1700s played role in
  reducing gin epidemic
• 17th 18th century - Europeans shipped
  cultivated coffee throughout colonial
  landholdings
• Along with tea, was primary commodity of the
  European colonies

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TEA

• Used in China for thousands of years before
  spreading throughout East
• Medicinal use (3000 BC)
• headaches
• to keep awake during prayer
• 1st brought to England by Dutch East India
  Company in 1657
• Spread throughout Europe by 1700

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Tea East India Company

• In 1773, East India Tea Company was granted
  permission by English Government to sell tea to
  American Colonies tax free
• Gave them a way to bypass American merchants
• So when first tea shipment arrived
• Dressed up as Indians dumped tea in sea
• Boston Tea Party
• One of precipitating events in American
  Revolution also reason U.S. primarily coffee
  drinking nation - became politically incorrect to
  drink tea

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Today

• All forms of caffeine legal and fully integrated
  into most all societies
• Most widely used psychotropic drug
• HUGE industry
• No illegal market

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Sources of Methylxanthines

• Naturally Occurring Sources
• Coffee
• Tea
• Chocolate
• Kola Nut
• Synthetic Sources
• Cola
• Pharmaceutical Preparations (alone and in combo)

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Sources of Methylxanthines

• Chocolate - Little caffeine (less than 20 mg)
• Little effect in producing arousal
• Theobromine not very effective
• Coffee (5 oz cup) 80-150 mg caffeine
• Freeze dried - less
• Drip - more
• Decaffeinated - pretty much cleared out
• Tea
• Has half caffeine of coffee plus theophylline
• Theophylline more potent than caffeine
• Produces some of actions of tea not found in
  coffee

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Sources Methylxanthines

• Soda Originally from Kola Nut
• Limited by law to 50 mg caffeine
• Drugs
• No Doz 100 mg
• Vivarin 200
• Anacin 32
• Excedrin 65
• Caffeine aspirin together make absorption much
  better
• increases effectiveness
• caffeine changes blood flow - helps headaches

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Route of Administration

• Oral administration
• Beverages Coffee, tea, cocoa, chocolate milk,
  cola (fortified)
• Chocolate
• OTC preparations
• Stimulants
• Pain-killers (caffeine synergizes acetylsalicylic
  acid)
• Diuretics and cold preparations

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Mechanisms of Action

• Some blockade of GABA receptors
• Effects are mediated by the blockade of ADENOSINE
  receptor
• Adenosine is a neuromodulator.
• Adenosine receptors coupled to other NT receptors
  to modulate effects of that NT.
• Adenosine is an inhibitory NM.
• Adenosine acts to modulate NE, DA, ACh,
  glutamate, and GABA.
• Also leads to increased calcium in axon terminal

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CNS Effects

• Normal doses (100-200 mg)
• Alertness, sustained attention, faster thought
• Reduced fatigue, lower need for sleep
• Fine motor coordination, timing accuracy, and
  arithmetic may be impaired
• Heavy dosing (1.5 grams a day) may produce
  agitation, anxiety, tremors, panting, and insomnia

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PNS Effects

• Coronary artery vasodilator bronchodilation
  (smooth muscle relaxer)
• Increase HR (striated muscle constrictor)
• Constricts cerebral arteries
• Acts as diuretic (Gotta go pee)

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Side Effects of Caffeine

• Indigestion, palpitations, tremor, insomnia,
  headache
• Conflicting data on reproductive effects
• May slow growth in utero, especially high dose
• Caffeine may be harmful prior to conception
• May increase the risk of spontaneous abortion
• gt 4 cups/day
• Osteoporosis
• Cholesterol increases

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Interactions

• People smoke fewer cigarettes after drinking
  coffee
• Smokers metabolize caffeine quicker
• Caffeine only makes drunk people more awake
• IT DOES NOT INCREASE TIME TO SOBRIETY

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Toxicity

• Caffeinism - 10 cups or more per day
• Initial signs insomnia, restlessness
• muscle tension shaking, tachycardia
• sensory disturbances may also occur (ears
  ringing, light flashes)
• Mild delirium anxiety attacks may occur in
  predisposed individuals
• Cardiac arrhythmias at 10 - 20 grams
• Lethal Dose around 10 grams

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Tolerance

• Probably does develop
• Dispositional Tolerance?

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Dependence

• Caffeine is dependence producing (2 weeks at
  600mg/day)
• Withdrawal effects due to increased adenosine
  receptor density and thus increased adenosine
  sensitivity
• Withdrawal Not fatal
• Depression
• Fatigue
• Irritability
• Muscle aches
• Headaches