Caffeine

Question 1

Which of the following regarding people who are tolerant and/or dependent on caffeine in coffee is false?
a) They are considered addicted to caffeine
b) They may develop a headache if they miss their morning cup of coffee
c) They may exhibit no trouble sleeping after consuming coffee right before bedtime
d) They may develop an intense craving for coffee if they try to stop drinking it

Answer 1

a)
They are considered addicted to caffeine

Question 1

In lab animals, the effect of increasing doses of caffeine causes:
a) reduced activity, followed by increased activity
b) dose dependent increases in activity
c) increased activity, followed by decreased activity
d) dose dependent decreases in activity

Answer 1

c)
increased activity, followed by decreased activity

Question 2

In addition to coffee and tea, caffeine is found in all of the following except:
a) analgesic drugs
b) cough suppressants
c) OTC stimulants
d) diet soda

Answer 2

b)
cough suppressants

Question 3

Caffeine
a) is rapidly and completely absorbed through the gastrointestinal tract, primarily the small intestine
b) has a half-life that averages about 8 hours
c) accumulates over the day, with significant amounts remaining the following morning in the blood stream
d) is metabolized more slowly in smokers

Answer 3

a)
is rapidly absorbed through the gastrointestinal tract, primarily the small intestine

Question 4

At high doses, caffeine:
a. stimulates Ca2+ release
b. inhibits cAMP phosphodisterase
c. blocks GABAA receptors
d. All of the above

Answer 4

d)
all of the above

Question 5

In animals, caffeine has a biphasic effect whereby:
a. low doses stimulate sleeping behavior and high doses are without effect.
b. low doses stimulate locomotion and high doses produce sedation.
c. low doses produce sedation and high doses stimulate locomotion.
d. low doses have a stimulant effect and high doses produce agitation.

Answer 5

d)
low doses have a stimulant effect and high doses produce agitation

Question 6

Which of the following is NOT one of the major metabolites of caffeine?
a. paraxanthine
b. cotinine
c. theophylline
d. theobromine

Answer 6

b)
cotinine

Question 7

Caffeine is useful for treating headaches because it:
a. increases blood flow in the brain, but not in the periphery.
b. dilates blood vessels by about 30%.
c. increases blood pressure and therefore decreases tension in head muscles.
d. constricts blood vessels in the brain.

Answer 7

d)
constricts blood vessels in the brain

Question 8

At low doses, caffeine primarily
a. acts as an agonist at adenosine A1 receptors
b. acts as an agonist at adenosine A2A receptors
c. Both A and B
d. None of the above

Answer 8

d)
none of the above

Question 9

Caffeine is
a. a weak acid with a pKa = 8.0
b. a weak base with a pKa = 10.6
c. a weak base with a pKa = 0.5
d. a weak acid with a pKa = 5.9

Answer 9

c)
a weak base with a pKa = 0.5