Lecture 17- Caffeine

Question 1

What is the most widely consumed psycho-tropic drug in the world?

Answer 1

• Caffeine (>90%)
• Cheap and legal

Question 2

Caffeine origin

Answer 2

• mild stimulant (but w different mech of action)
• naturally occuring, but synthetic versions in pill form are available
• origin of caffeine use in history not well understood

Question 3

Caffeine sources

Coffee beans

Answer 3

grown along equator in bean-growing belt

Question 4

Sources

Cacao pod

Answer 4

• Cocoa/chocolate products
• varies between 5 and 60 mg

Question 5

sources

Kola nuts

Answer 5

cola drinks about 35 mg

Question 6

sources

tea

Answer 6

around 30 mg but large range (10-90 mg)

Question 7

sources

headache pills

Answer 7

30-63 mg

Question 8

sources

stay awake pills

Answer 8

100-200 mg

Question 9

Caffeine Amounts

Answer 9

• 150-200 mg: strong coffee, espresso
• 54 mg: high caffeine soda like mtn dew
• 38 mg: normal soda, tea (Coke, pepsi)
• <25 mg: chocolate

member of the methylxanthine family

caffeine, theophyline, theobromine

Question 10

most common caffeine sources

Answer 10

• coffee, tea, soft drinks (followed close by chocolate)
• concentrations of each methylxathine may vary widely

Question 11

Ubiquitous Use

Answer 11

• “Cradle to Grave”: used non-medically by all ages

Question 12

Where is the highest consumption rate of caffeine and how does that compare to the US?

Answer 12

• Scandinavian countries have the highest consumption rates at around 414 mg/day
• the US average is 170 mg/day (primarily coffee)

Question 13

Who consumes the highest dose/weight of caffeine?

Answer 13

• Children (soft drinks)
• 2nd highest dose/weight is in 18 years and older
• use declines in the elderly

Question 14

Caffeine therapeutic uses: excedrin

Answer 14

• Headache medication (Excedrin)
• Relieves headache
• caffeine withdrawal
• helps analgesics do their work better

Question 15

Caffeine therapeutic uses: Dristan

Answer 15

• Stimulates breathing
• treatment of apnea (cessation of breathing) in newborn babies

Question 16

ADMET: A

Answer 16

• rapidly absorbed from gut
• crosses BBB
• peaks in 15-45 minutes
• depends on the source at low to moderate levels

Question 17

ADMET: ME

Answer 17

• Metabolized via liver and excreted through urine (90%)
• Half-life ranges form 3-7 hours
• factors that influence the rate of metabolism include: liver disease, pregnancy, contraceptive use… increased by smoking…age (due to immature metabolism)

Question 18

Mechanism of Action

Answer 18

• Caffeine acts as a competitive antagonist at adenosine receptors
• Caffeine blockade of adenosine receptors leads to stimulant-like effects (increases epinephrine secretion and enhances neural activity in many brain regions)

Question 19

Adenosine receptors info

Answer 19

• inhibitory metabotropic receptors
• found in CNS and PNS
• Activation= sedation, regulation of oxygen to cells, dilation of cerebral and coronary blood vessels, production of asthma