Opioids

Question 1

Tolerance to opiate effects:
a) is primarily due to increased rate of metabolism
b) develops quite gradually over time
c) is not specific to a given receptor type
d) occurs rapidly for analgesic effects, and slowly for constipating effects

Answer 1

d)
occurs rapidly for analgesic effects, and slowly for constipating effects

Question 2

Which of the following pieces of evidence suggests that NMDA receptors play a role in opiate tolerance and dependence?
a) MK801 increases PKC activity and as a result increases tolerance
b) increased nitric oxide activity decreases tolerance
c) MK801 blocks morphine tolerance
d) NMDA receptor antagonists induce opiate dependence

Answer 2

c)
MK801 blocks morphine tolerance

Question 3

The opioid pro peptides:
a) are made in the terminal button and cleaved by enzymes into the opiate peptides
b) are referred to as the “enkephalins”
c) are processed by proteases into both opiate and nonopioid peptides
d) include the endorphins and the endomorphins

Answer 3

c)
are processed by proteases into both opiate and nonopioid peptides

Question 4

At low doses, opiates exert all of the following effects except for:
a) pain relief
b) pupil dilation
c) drowsiness
d) reduced sex drive

Answer 4

b)
pupil dilation

Question 5

Which of the following about the effects of opiates on synaptic transmission is false?
a) they act on receptors that are couple to inhibitory G proteins
b) they affect endorphin autoreceptors and reduce the amount of transmitter released
c) they cause postsynaptic depolarization by opening potassium channels
d) they cause less transmitter to be released via axoaxonic inhibition

Answer 5

c)
they cause postsynaptic depolarization by opening potassium channels

Question 6

A model of the neurobiology of opiate reinforcement suggests that opiates produce their effects by inhibiting:
a) dopamine
b) GABA
c) dynorphin
d) betaendorphin

Answer 6

b)
GABA

Question 7

Compared with a pure opiate agonist, a partial opiate agonist has:
a. higher efficacy.
b. lower efficacy.
c. effects opposite to the agonist.
d. a partial effect at Cl- channels.

Answer 7

b)
lower efficacy

Question 8

Which of the following is a metabolite of morphine that is significantly more potent as an
analgesic than morphine is?
a. oxycontin
b. heroin
c. morphine hydroxylase
d. morphine-6-glucoronide

Answer 8

d)
morphine-6-glucoronide

Question 9

At low to moderate doses, opiates produce:
a. loss of consciousness.
b. intense euphoria.
c. cough suppression.
d. diarrhea.

Answer 9

c)
cough suppression

Question 10

Which of the following is a semi-synthetic opiate drug?
a. morphine
b. heroin
c. thebaine
d. methadone

Answer 10

b)
heroin

Question 11

Historically, the term “narcotic” defines a class of drugs that
a. reduces pain.
b. is illegal to possess.
c. causes sleep.
d. binds to opioid receptors.

Answer 11

c)
causes sleep

Question 12

Which of the following is a classic symptom of opiate overdose?
a. pinpoint pupils
b. increased respiration
c. diarrhea
d. None of the above.

Answer 12

a)
pinpoint pupils

Question 13

Opiate receptors are coupled to:
a. Cl- channels.
b. Na+ channels.
c. Gi.
d. Gs.

Answer 13

c)
Gi

Question 14

Name the three classic subtypes of opioid receptors and the one, more recently
discovered, novel subtype of opioid receptor

Answer 14

µ (mu), δ (delta), κ (kappa), Nociceptin receptor (NOP)