Pharmacodynamics

Question 1

what are the features of drug receptors?

Answer 1

1. recognize and bind other molecules (ligands)
2. propagate regulatory signals following ligand binding
3. modulate ongoing cellular functions

Question 2

estrogen receptor and vitamin A receptor are what types of receptors?

Answer 2

intracellular

Question 3

what are two examples of intracellular receptors?

Answer 3

estrogen and vitamin A

Question 4

EGFR, IR, and TGF-BR are what types of receptors?

Answer 4

intrinsic enzymatic activity

Question 5

what are the typical targets for receptors with intrinsic enzymatic activity?

Answer 5

signal transduction - protein and lipid kinase cascades, protein phosphatases

Question 6

what are examples of receptors with intrinsic activity?

Answer 6

EGFR, IR, TGF-BR

Question 7

nicotinic Ach receptor is what type of receptor?

Answer 7

ligand gated ion channel

Question 8

IL-3r, EPOr, and leptin receptor are what type of receptors?

Answer 8

directly associate with intracellular enzymes

Question 9

which receptors directly associate with intracellular enzymes?

Answer 9

IL-3r, EPOr, and leptin receptor

Question 10

B-adrenergic, rhodopsin, frizzled, and Smo receptors are what type of receptors?

Answer 10

GPCRs

Question 11

what is the dissociation constant for drug binding affinity?

Answer 11

Kd = [R][L] / [RL]

or, Koff / Kon

Question 12

what is the dissociation constant Kd equal to when the free receptor concentration equals the concentration of bound receptor?

Answer 12

ligand concentration (when half the receptors are occupied and half are free)

Question 13

how does a small Kd value relate to binding affinity?

Answer 13

small Kd = greater binding affinity

Question 14

definition: potency

Answer 14

measurement of drug dose used to compare the relative affinity and effectiveness of two or more drugs - done by comparing EC50s (more potent = more to the left)

Question 15

definition: efficacy

Answer 15

the maximal effect a drug can induce

Question 16

definition: competitive antagonist

Answer 16

1. agonist and antagonist compete for same binding site
2. shift to the right in the EC50
3. maximal effect is still achievable

Question 17

definition: noncompetitive antagonist

Answer 17

1. agonist and antagonist bind to different sites
2. decrease in maximal effect
3. agonist’s affinity for receptor may not change in presence of noncompetitive antagonist

Question 18

definition: partial agonist

Answer 18

drug that produces a lower maximal response as compared to the agonist

Question 19

definition: therapeutic index

Answer 19

1. indicator
2. ratio of TD50 / ED50
3. the greater the ratio / window between the TD50 and ED50, the safer the drug is for a patient

Question 20

how does tolerance affect the dose-response curve?

Answer 20

shift to right

Question 21

how does sensitization affect the dose-response curve?

Answer 21

shift to left