Caffeine Chapter 8. Caffeine Most used drug in the world An alkaloid belonging to a class of...
-
Upload
bernard-eaton -
Category
Documents
-
view
225 -
download
0
Transcript of Caffeine Chapter 8. Caffeine Most used drug in the world An alkaloid belonging to a class of...
Caffeine
Most used drug in the world An alkaloid belonging to a class of
compounds called METHYLXANTHINES Caffeine Theophylline Theobromine
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
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
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
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
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
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
Today All forms of caffeine legal and fully
integrated into most all societies Most widely used psychotropic drug HUGE industry No illegal market
Sources of Methylxanthines
Naturally Occurring Sources Coffee Tea Chocolate Kola Nut
Synthetic Sources Cola Pharmaceutical Preparations (alone and in
combo)
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
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
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
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
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
PNS Effects
Coronary artery vasodilator & bronchodilation (smooth muscle relaxer)
Increase HR (striated muscle constrictor)
Constricts cerebral arteries Acts as diuretic (Gotta go pee)
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
• > 4 cups/day
Osteoporosis Cholesterol increases
Interactions People smoke fewer cigarettes after
drinking coffee Smokers metabolize caffeine quicker Caffeine only makes drunk people
more awakeIT DOES NOT INCREASE TIME TO SOBRIETY
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