Pharm 2060B Module 8

Front 1

what are the two tenets of the simple occupancy theory?

Back 1

1. the intensity of a drug's response is proportional to the number of receptors occupied

2. the maximal response occurs when all the receptors are occupied

Front 2

Which theory implies that two drugs that act at the same receptor should have the same efficacy?

Back 2

simple occupancy theory

Front 3

what are the three tenets of the modified occupancy theory?

Back 3

1. the intensity of a drug's response is proportional to the number of receptors occupied by the drug

2. different drugs that bind to the same receptor may have different binding strengths/affinities for that receptor

3. different drugs binding to the same receptor may have difference receptor activating abilities (i.e. intrinsic activities)

Front 4

define affinity

Back 4

the attraction a drug has for its receptor

Front 5

affinity is associated with potency/efficacy?

Back 5

potency. drugs with high affinity are more potent for a certain effect than drugs with low affinity

Front 6

define intrinsic activity

Back 6

ability of a drug to activate the receptor

Front 7

intrinsic activity is associated with potency/efficacy?

Back 7

it is associated with efficacy. specifically, maximal efficacy

Front 8

drugs with a high intrinsic activity have high maximal efficacy

Back 8

know urself

Front 9

t/f agonists, antagonists and partial agonists all produce some sort of pharmacological effect

Back 9

true.

Front 10

which of these do agonists have?

affinity

intrinsic ability

Back 10

both

Front 11

what are the 3 receptors dopamine binds to at the 3 different dose levels, and what is the effect?

Back 11

1. at low doses dopamine binds to the dopamine receptor. This causes renal artery vasodilation, increased renal blood flow, increased urinary output

2. at medium doses dopamine binds to the beta adrenergic receptor. this causes increased cardiac output

3. at high doses dopamine binds to the alpha adrenergic receptor. this causes increased renal vasoconstriction, increased renal blood flow, and increased urinary output

Front 12

which of these two do antagonists have?

affinity

intrinsic activity

Back 12

they only have affinity

Front 13

t/f antagonists effect is based on the presence of the corresponding agonist

Back 13

true. antagonists won't do anything unless there's an agonist there too

Front 14

describe the function of beta blockers

Back 14

they block the binding of epinephrine beta 1 receptors, ultimately decreasing cardiac output

Front 15

describe the functions of antihistamines

Back 15

block the binding of histamines to H1 histamine receptors, preventing allergic symptoms

Front 16

describe functions of gastric acid reducers

Back 16

block the binding of histamine to histamine H2 receptors, decreases gastric acid secretion

Front 17

describe the function of opiod receptor blockers

Back 17

blocks binding of opiates to opioid receptors, useful for drug overdoses

Front 18

Name and describe the three types of antagonists

Back 18

1. competitive antagonists - binding occurs at the same site as the agonists, and binding is reversible

2. irreversible antagonists - binding occurs at the same site as the agonists, binding is irreversible

3. allosteric antagonists - binding occurs at a different site than the agonists, binding is reversible

Front 19

what will happen to the DRC of an agonist, if the amount of competitive antagonist present is lowered?

Back 19

the DRC will shift to the left.

Front 20

how does the max efficacy of a drug change when a competitive antagonist is added, and then the same amount of agonist is added?

Back 20

it doesnt

Front 21

how can the effect of a competetive antagonist be overcome?

Back 21

by adding more agonist

Front 22

name an example of a competitive antagonist

Back 22

naloxone

Front 23

what will happen to the DRC of an agonist, if the amount of irreversible antagonist present is increased?

Back 23

the efficacy of the drug is lowered (specifically, max efficacy)

Front 24

how can the effect of a non-competetive antagonist be overcome?

Back 24

it cannot. it is non-competitive.

Front 25

how long do irreversible agonist effects last?

Back 25

until the receptor is replaced. for this reason, these antagonists are rarely used in clinical settings

Front 26

describe the function of allosteric antagonists

Back 26

they bind to different sites on the receptor than the agonist. the binding of which changes the conformation of the receptor, preventing agonists from binding to them. binding is reversible, but not competitive (they are not competing for the same sites)

Front 27

What are the effects of allosteric antagonists on the DRC of an agonist? how can these effects be overcome?

Back 27

an increase in the amount of allosteric antagonists decreases the maximal efficacy of the agonist. these effects cannot be overcome as the AA is non-competitive.

Front 28

do partial agonists lower maximal efficacy or potency of the agonist?

Back 28

maximal efficacy

Front 29

for most drugs, their action depends on the specific location of their receptor. where should it be, and what is the exception?

Back 29

receptors should be on the cell membrane surface. the exception to this is intracellular receptors/transcription factors

Front 30

describe desensitization

Back 30

when a receptor has been exposed to a certain agonist for a prolonged period of time, the receptor may become destroyed, or internalized by the cell. this will lead to a decrease in the number of receptors on the cell membrane surface, causing a greater amount of drug necessary to produce the same effect

Front 31

describe metabolic tolerance

Back 31

increased exposure to a certain agonism may cause the induction of drug metabolizing enzymes, which will lead to greater metabolic capacity, and lower free drug concentrations. more dope is needed to get the same kick

Front 32

describe tachyphylaxis

Back 32

a rapid decrease in response to a drug. in the case of transdermal patches, drug free periods must be enforced so tachyphylaxis does not occur.

Front 33

describe receptor upregulation/sensitization

Back 33

when a receptor has been exposed to an antagonist for a prolonged period of time, the opposite of desensitization may occur. the cell will synthesize more receptor and move it to the cell membrane. in this case the cell is said to become supersensitive/hypersensitive. WHen an agonist is added, then the cell goes off bang bang.