Unit 4 Pharmacology: Pharmacodynamics

Question 1

Pharmacodynamics is the study of

Answer 1

the drugs effect on the body (relationship between effect site concentration and clinical effect)

Question 2

On the dose response curve, the x axis (bottom axis) corresponds with

Answer 2

potency

Question 3

define potency

Answer 3

dose required to achieve a given clinical effect.

Question 4

define efficacy

Answer 4

intrinsic ability of a drug to elicit a given effect

Question 5

On the dose response curve, the y axis (left) corresponds with

Answer 5

efficacy. the height of the plateau represents this.

Question 6

what does the slope of the dose response curve tell us

Answer 6

how many receptor must be occupied to elicit a clinical effect

Question 7

what is potency of a drug affected by

Answer 7

absorption, distribution, metabolism, elimination, and receptor affinity

Question 8

what does a left shifted curve on the dose response curve represent

Answer 8

increased affinity for receptor, higher potency, lower dose required

Question 9

what does a light shifted curve on the dose response curve represent

Answer 9

increased affinity for the receptor, lower potency, higher dose required

Question 10

define ED50

Answer 10

dose required to achieve a given effect on 50% of the population. a measure of potency

Question 11

define ED90

Answer 11

dose required to achieve a given effect on 90% of the population. a measure of potency

Question 12

once the plateau is reached for efficacy, does additional drug produce any additional effect?

Answer 12

no

Question 13

the higher the plateau, the _____ the efficacy

Answer 13

greater

Question 14

what does a steep slope imply

Answer 14

that most of the receptors must be occupied before we observe the clinical response

Question 15

name two categories of drugs that have a steep slope

Answer 15

volatile anesthetics and NMB’s

Question 16

drugs that produce the same clinical effect but with different dosages have different

Answer 16

potencies

Question 17

what does a full agonist mimic

Answer 17

an endogenous ligand

Question 18

continuous administration of an agonist may do what to receptors

Answer 18

cause down regulation

Question 19

examples of full agonist drugs include (4)

Answer 19

norepinephrine
propofol
dopamine
alfentanil

Question 20

when a partial agonist binds to a receptor, does it active a full cellular response

Answer 20

no, it only partially activates a cellular response

Question 21

a partial agonist is also called

Answer 21

an agonist antagonist

Question 22

example of a partial agonist drug includes

Answer 22

nalbuphine

Question 23

what happens when an antagonist binds to a receptor

Answer 23

it prevents an agonist from binding to it. does not tell the cell to do anything

Question 24

do antagonist drugs have efficacy

Answer 24

by definition, they do not have efficacy

Question 25

continuous administration of an antagonist may do what to receptors?

Answer 25

cause up regulation

Question 26

if a patient receives a competitive antagonist, the dose response curve for the agonist shifts to the

Answer 26

right

Question 27

define the effect of an inverse agonist at the receptor site

Answer 27

binds to the receptor and causes an opposite effect to that of a full agonist

Question 28

define the efficacy of an inverse agonist

Answer 28

it has negative efficacy

Question 29

give an example of a drug that is an inverse agonist

Answer 29

propanolol (binds to and activates B1 but decreases cAMP)

Question 30

administering drugs together: addition

Answer 30

effects of two drugs given at same time are added to each other. (morphine and hydromorphone, ASA and ibuprofen)

Question 31

administering drugs together: synergism

Answer 31

effect of two drugs given at same time is greater than the sum of the individual effects (prop and midaz, levodopa and carbidopa)

Question 32

administering two drugs together: potentiation

Answer 32

effect of one drug is enhanced by a drug that has no effect on its own (probenecid and PCN)

Question 33

administering two drugs together: antagonism

Answer 33

simultaneous administration of one drug negates the effect of a second drug (midaz and flumazenil, fentanyl and naloxone)

Question 34

how to calculate therapeutic index

Answer 34

divide LD50 by ED50
ex)LD1500mg, ED125mg. 1500/25= TI 12

Question 35

define TD50

Answer 35

dose that will produce toxicity in 50% of the population

Question 36

a racemic mixture contains how many enantiomers

Answer 36

2 enantiomers in equal amounts

Question 37

define stereochemistry

Answer 37

study of the three dimensional structure of molecules

Question 38

define chirality

Answer 38

a division of stereochemistry. deals with molecules that have a center of 3D asymmetry.

Question 39

a molecule with one chiral carbon will exist as how many enantiomers

Answer 39

two

Question 40

define enantiomer

Answer 40

chiral molecules that are non superimposable mirror images of one another