Caffeine Flashcards
Disclaimer: The caffeine flashcards are derived from the textbook, not the lectures.
Caffeine
- Mild psychostimulant of the xanthine family
- Found in certain plants
- The most widely used drug internationally
Which plants are xanthines found in?
- Kola nuts
- Cocoa tree nuts
- Tea leaves
- Coffee beans
Energy drinks (8oz) contain around ____mg of caffeine
75mg
A 10 oz cup of coffee contains approx. [answer] mg of caffeine, a 10 oz cup of tea contains approximately [answer] mg of caffeine.
10 oz cup of coffee: 200 mg
10 oz cup of tea: 100 mg
Brewed coffee became popular around:
1000 C.E.
Who identified caffeine’s chemical properties?
Emil Fischer
Caffeine products are administered [answer]
Orally
100% of caffeine is absorbed across ____
Intestinal walls
The acids that caffeine contain are called
Cholorogenic acids
Caffeine is metabolized in the ____
Liver
CYP-1A2
The main caffeine-metabolizing enzyme
CYP-2E1
A caffeine-metabolizing enzyme (secondary to CYP-1A2)
What are two types of substances that affect the metabolization of caffeine?
Antidepressants: Are CYP-1A2 (caffeine metabolizing enzyme) inhibitors, reducing the metabolization of caffeine
Smoking (not the nicotine itself): Enhances CYP-1A2, increases the metabolism of caffeine
The metabolism of caffeine produces these active metabolites:
Theophylline, theobromine, and paraxanthine (the latter of which occurs only when metabolically converted from caffeine).
The body primarily eliminates caffeine through the
Kidneys
The rate of elimination of caffeine varies widely, from approximately [answer] to [answer] hours.
Three to ten hours
Depends on the individual. Smoking cigars or cigarettes doubles the rate of caffeine elimination.
Caffeine’s primary mechanism of action
Antagonism of adenosine A1 and A2 receptors
Adenosine
A neuromodulator that has inhibitory effects on neurons throughout the central and peripheral nervous system. Adenosine specifically has inhibitory effects on cholinergic neurons in the cerebral cortex, and on dopamine neurons in the basal ganglia.
Physiological, behavioural and subjective effects of caffeine
List some of these effects
Increased heart rate, blood vessel constriction, increased breathing rate, reduced appetite, increased attention, alertness and positive mood
Tolerance for caffeine can occur with many of its [answer] effects, but may not occur with its [answer] effects.
Tolerance for caffeine can occur with many of its subjective effects, but may not occur with its physiological effects.
Can excessive daily caffeine intake cause withdrawal when the person stops consuming caffeine?
Yes. This is called caffeine withdrawal and can cause headaches, fatigue, irritability and low mood.
Is caffeine addictive?
This is controversial, but caffeine is not usually considered addictive, considering “that caffeine appears neither irresistible nor a cause of social disruption” (Satel, 2006).