lecture 2 - intro to pharmacodynamics

Question 1

What are the 4 proteins types that act as sites of drug action?

Answer 1

receptors, enzymes, transporters/carrier molecules, ion channels

Question 2

What are the most common protein drug target?

Answer 2

Receptors

Question 3

What are the 4 types of receptors?

Answer 3

Ligand-gated ion channels, G-protein couple receptors, kinase-linked receptors, nuclear receptors

Question 4

What is drug affinity?

Answer 4

The tendency of a drug to bind to a receptor/protein

Question 5

What is the relative affinity of drug which bind at low concentration?

Answer 5

High affinity

Question 6

How is affinity numerically defined?

Answer 6

The concentration of drug required to occupy 50% of receptors - AKA the Kd (dissociation constant)

Question 7

What is drug potency?

Answer 7

A measure of drug activity expressed in terms of the amount of drug required to produce an effect of given intensity.

Question 8

How is potency measured?

Answer 8

EC50 - the effective concentration of an agonist required to product 50% of the maximal drug response.

Question 9

What is the relative potency of a drug with a low EC50 value?

Answer 9

High potency - low concentration required to reach 50% of maximal response.

Question 10

What is drug efficacy?

Answer 10

The ability of a drug to bind to a receptor and cause a change in receptor action.

Question 11

How is efficacy measured?

Answer 11

Emax - the maximal effect

Question 12

What class of drug has positive efficacy?

Answer 12

agonist

Question 13

What class of drug has negative efficacy?

Answer 13

inverse agonist

Question 14

What class of drug has no efficacy?

Answer 14

antagonist

Question 15

What are drug agonists?

Answer 15

drugs with positive efficacy that will activate a receptor to promote cellular response

Question 16

What are drug inverse agonists?

Answer 16

drugs with negative efficacy that will bind to receptors to decrease basal receptor activity

Question 17

What are drug antagonists?

Answer 17

A drug with no efficacy that will bind to receptors but have no effect on activity - thereby preventing native ligands from binding.

Question 18

What are full agonists?

Answer 18

Drugs that elicit the maximum tissue response

Question 19

What are partial agonists?

Answer 19

Drugs tat produce less than the maximum tissue response.

Question 20

Which type of agonist will produce a maximal response at 100% receptor occupancy?

Answer 20

Full agonists

Question 21

What is reversible competitive antagonism?

Answer 21

When a drug binds to a receptor in a reversible manner to compete directly with agonist binding

Question 22

What shift is observed in a concentration response curve when a reversible competitive antagonist is used?

Answer 22

Rightward - more agonist must be added to reach maximum response

Question 23

What type of bonding is used in reversible competitive antagonism?

Answer 23

non-covalent

Question 24

What is irreversible competitive antagonism?

Answer 24

Drug binds covalently to receptor’s orthosteric site, reducing the number of receptors available to agonist permanently.

Question 25

What is the site of a receptor where endogenous agonists bind?

Answer 25

Orthosteric binding site

Question 26

What is constitutive activity of a receptor?

Answer 26

When a receptor has activity despite not having an agonist bound.

Question 27

How do inverse agonists alter constitutive activity?

Answer 27

The prevent it - turn receptor off. useful in preventing over activity of a receptor

Question 28

What is allosteric binding?

Answer 28

The binding of an agonist to a site other than the orthosteric binding site (where endogenous ligands bind). This results in an increase or decrease in the affinity or efficacy of the orthosteric ligand.

Question 29

What are the non-receptor mechanisms of drug antagonism?

Answer 29

chemical, pharmacokinetic, interrupt receptor response, physiological

Question 30

What is chemical antagonism?

Answer 30

When two substances combine in solution to prevent an action occurring.

Question 31

What is pharmacokinetic antagonism?

Answer 31

When the concentration of a drug at the active site is reduced .

Question 32

What is interrupt receptor-response antagonism?

Answer 32

When sites downstream of a receptor are blocked, preventing downstream effects of receptor activation.

Question 33

What is physiological antagonism?

Answer 33

When two drugs with opposing action “cancel each out”

Question 34

What are the 2 types of ion channel?

Answer 34

Ligand gated, voltage gated

Question 35

How does blocking Na+ channels prevent pain?

Answer 35

Blocking voltage gated Na+ channels prevent pain signals from being transducted in neurons.

Question 36

What is the effect of blocking Ca2+ voltage gated channels on neurotransmitter release?

Answer 36

Stops the release of neurotransmitter in neurons

Question 37

What are the 2 types of enzyme inhibition?

Answer 37

Non-competitive, competitive