Deck 3: Pharmacodynamics

Question 1

In what way is the log-concentration effect (dose response) curve of an agonist drug modified in the presence of a competitive receptor antagonist?

A) shifted to the right without a change in slope or maximum effect
B) shifted to the left without a change in slope or maximum effect
C) shifted to the right with a decreased slope and maximum effect
D) shifted to the left with a decreased slope and maximum effect
E) not shifted right or left but shows a decreased maximum effect

Answer 1

shifted to the right without a change in slope or maximum effect

Question 2

A patient exhibits a rapid loss of responsiveness to a drug during the first several hours of drug administration. Which event is most likely responsible for this effect?

A) up-regulation of drug metabolizing enzymes
B) down-regulation of drug metabolizing enzymes
C) internalization of cell membrane receptors
D) formation of receptor antibodies
E) phosphorylation of G protein-coupled receptors

Answer 2

phosphorylation of G protein-coupled receptors