Module 1: Pharmacodynamics

Question 1

Which one of the following statements best reflects a key principle of pharmacodynamics?

a. drugs can often have several different actions on the body which are governed by the drug concentration achieved.
b. drugs must be highly selective to be useful medicines.
c. drugs must be highly potent, and therefore used at lower doses, to be useful medicines.
d. drugs must bind to a receptor to have an effect on the body.

Answer 1

a. drugs can often have several different actions on the body which are governed by the drug concentration achieved.

Question 2

which one of the following receptors requires an agonist to cross the plasma cell membrane in order to activate a response?

a Nicotinic ACh receptor

b. GABAA receptor
c. B-adrenoreceptor
d. Oestrogen receptor

Answer 2

d. Oestrogen receptor

Question 3

Which of the following statements about agonists is correct?

a. partial agonists have lower affinity for receptors than full agonists
b. a partial agonist has lower clinical efficacy than a full agonist
c. a full agonist needs to activate all receptors to produce a maximal response
d. a partial agonist has lower pharmacological efficacy than a full agonist.

Answer 3

d. a partial agonist has lower pharmacological efficacy than a full agonist.

Question 4

which one of the following statements about antagonists is INCORRECT?

a. antagonism means that less agonist binds to the receptor
b. some antagonists compete with the binding of an endogenous agonist to a receptor
c. antagonists can reduce cell activity by inhibiting intracellular pathways downstream of a receptor
d. it is possible for a drug to act as an agonist and antagonist in different locations.

Answer 4

a. antagonism means that less agonist binds to the receptor