Receptors and Dose-Response

Question 1

Drug

Answer 1

A substance that interacts with specific molecular components of an organism to produce a biochemical and physiological response

Question 2

Pharmacology

Answer 2

The study of drugs

Question 3

Toxicology

Answer 3

The branch of pharmacology that deals with undesirable effects of chemicals on living systems

Question 4

Pharmacogenomics

Answer 4

The relation of one’s genetic makeup to the response to a drug - genetically determined differences in drug response

Question 5

Allosteric modulators

Answer 5

Bind to sites on a receptor but do not prevent the

binding of the agonist

Question 6

Constituitive activity

Answer 6

Receptor pool that produces similar effect of an agonist

Question 7

Pharmacodynamics

Answer 7

Actions of the drug on the body

Question 8

Pharmacokinetics

Answer 8

Actions of the body on the drug

Question 9

Equilibrium dissociation constant Kd

Answer 9

Represents the concentration for a drug at which half-maximal binding is observed- that is half the receptors are occupied

Question 10

Potency

Answer 10

The agonist concentration required to elicit a half-maximal effect

Question 11

Efficacy

Answer 11

The maximal effect of the agonist

Emax

Question 12

Agonist

Answer 12

Binds to a receptor and stabilizes the receptor in a particular conformation

Question 13

Antagonist

Answer 13

Binds to the receptor but has no effect in the absence of the agonist

Question 14

Competitive antagonism

Answer 14

Receptor antagonism which is surmountable, where increasing the agonist concentration restores agonist occupancy

Question 15

Partial agonist

Answer 15

Produces only a submaximal response due to less than 100% occupancy of receptors

Question 16

Constituitive activation

Answer 16

An appreciable level of activation existing even when no receptor ligand is present

Question 17

Inverse agonism

Answer 17

Decreases the level of activation in the presence of constitutive receptor activation

Question 18

Covalent

Answer 18

Strongest and longest-lasting drug-receptor interaction

Question 19

Lock-And-Key model

Answer 19

Refers to drugs binding to specific sites on receptors to elicit their effects

Question 20

Enantiomers

Answer 20

Optical isomers of a drug where often one isomer is more active

Question 21

Racemic mixture

Answer 21

Commercial preparation of a drug that contains both enantiomers

Question 22

Therapeutic response

Answer 22

The desired effect of a drug without side effects or toxic effects

Question 23

Idiosyncratic response

Answer 23

Rare and unpredictable responses, typically not showing a concentration dependence and may be observed at low doses

Question 24

Receptor

Answer 24

The component of a cell that interacts with a drug and initiates the chain of events leading to the drug’s observed effects

Question 25

7 TM receptor

Answer 25

Prominent receptor class activating G-proteins to elicit a cellular response

Question 26

Receptor binding curves

Answer 26

Comparisons among drugs made more readily using a semi-logarithmic scale for the x-axis

Question 27

High affinity- what happens to Kd?

Answer 27

Lower Kd

Question 28

Low affinity- what happens to Kd?

Answer 28

Higher Kd

Question 29

Spare receptors

Answer 29

Maximal effect is obtained at a lower dose than is required for receptor saturation (EC50

Question 30

Therapeutic index

Answer 30

The relationship between ED50 and TD50

Question 31

Therapeutic window

Answer 31

Margin of safety of the drug in a population based on TI

Question 32

When do you only get Kd?

Answer 32

at equilibrium | -the concs of all species are set by the equilibrium

Question 33

Ro

Answer 33

total conc of occupies and unoccupied Rs | -so total number of receptors

Question 34

[LR]/ [Ro]

Answer 34

fraction of total receptors occupied by bound L

Question 35

EC50

Answer 35

potency

Question 36

E

Answer 36

quantifiable response of a drug

Question 37

E/Emax

Answer 37

response over max resonse

Question 38

Example of a system with spare receptors

Answer 38

histamine induced contraction of guinea pig ileum

Question 39

If ED99 overlaps with LD1 then is the margin of safety low or high?

Answer 39

low