Pharmacodynamics

Question 1

The vast majority of drugs have MW values between

Answer 1

100 and 1,000

Question 2

Drug-receptor binding initiates a chain of events leading to the drug’s
observed effect or

Answer 2

Response

Question 3

Drugs can show a differential capacity for initiating a pharmacologic response upon binding to a

Answer 3

Receptor

Question 4

What are the three models linking drug binding to a pharmacologic response?

Answer 4

1. ) Agonism
2. ) Partial Agonism
3. ) Antagonism

Question 5

Drugs that mimic actions of endogenous compounds (e.g., neurotransmitters or hormones) are called

Answer 5

Agonists

Question 6

Some bind to a given receptor and produce a maximal response, while others bind to the same receptor and produce only a partial response

Answer 6

Agonists

Question 7

An agonist that produces a partial response when the receptor is fully saturated is considered a

Answer 7

Partial Agonist

Question 8

Interferes with the action of an agonist by binding to receptors

Answer 8

Antagonist

Question 9

Although antagonists bind to receptors, they do not produce

Answer 9

Pharmacological responses

Question 10

Determine the quantitative relationship between drug dose and pharmacologic response

Answer 10

Receptors

Question 11

Determines the maximal effect a drug may produce

Answer 11

Total number of receptors

Question 12

A measure of how much drug is required to elicit a response, and is reflected in the EC50 value

Answer 12

Potency

Question 13

Highly potent drugs have

Answer 13

Low EC50 values

Question 14

High concentrations of a drug with low potency are required to achieve

Answer 14

Emax

Question 15

The value of Emax determines the drugs

Answer 15

Efficacy

Question 16

In a clinical setting, drug selection is typically based on

Answer 16

Efficacy and potential side effects

Question 17

Once a drug is chosen, the amount of drug to be administered is determined by the drugs

Answer 17

Potency

Question 18

Drugs that work by blocking the actions of endogenous agonists

Answer 18

Antagonists

Question 19

By definition, antagonists have no

Answer 19

Activity

Question 20

Typically, one would plot the dose-response curve of an agonist and determine how the curve is affected by differing concentrations of

Answer 20

Antagonists

Question 21

An antagonist whose effects can be overcome by adding more agonist

Answer 21

Competitive antagonist

Question 22

Competitive antagonism is typically observed with antagonists that bind receptors

Answer 22

Reversibly

Question 23

Binds B-adrenoreceptors and competitively inhibits the actions of the endogenous B-agonists norepinephrine and epinephrine

-example of competitive antagonism

Answer 23

Propanolol

Question 24

The degree of inhibition produced by a competitive antagonist depends on the concentration of the

Answer 24

Antagonist

Question 25

The clinical response to a competitive antagonist depends on the concentration of endogenous agonist competing for binding to

Answer 25

Receptors

Question 26

Episodic increases in endogenous agonist levels may reduce the therapeutic response of the administered

Answer 26

Antagonist

Question 27

Prevents an agonist from producing a maximal effect

Answer 27

Noncompetitive antagonist

Question 28

No amount of agonist can overcome the addition of a

Answer 28

Noncompetitive antagonist

Question 29

In such a case, antagonist-bound receptors are essentially removed from the pool of agonist targets

Answer 29

Noncompetitive antagonist

Question 30

Binds covalently to and irreversibly inactivates the proton pump in the stomach lining, preventing acidification

Answer 30

Omeprazole

Question 31

Omeprazole is an example of a

Answer 31

Noncompetitive antagonist

Question 32

What is the therapeutic advantage of a non-competitive irreversible antagonist?

Answer 32

Antagonist will maintain blockade even when concentration of endogenous agonist episodically increases

Question 33

What is the therapeutic disadvantage to non-competitive irreversible antagonist?

Answer 33

If overdose occurs, antagonist-induced blockade is difficult to overcome

Question 34

One drug may antagonize the actions of a second drug by binding to and inactivating the second drug

Answer 34

Chemical antagonism

Question 35

Antagonizes the anticoagulant actions of heparin by binding to heparin in an electrostatically driven manner

Answer 35

Protamine

Question 36

Protamine is an example of a

Answer 36

Chemical antagonist

Question 37

The actions of glucocorticoids lead to increased blood sugar, an effect that can be countered through use of insulin is an example of

Answer 37

Physiologic antagonism

Question 38

Some drugs induce the metabolism of other drugs, thereby antagonizing the actions of the metabolized drugs. This is called

Answer 38

Pharmacokinetic antagonism

Question 39

Induces the metabolic clearance of the anticoagulant warfarin

Answer 39

Phenobarbital

Question 40

Phenobarbital is an example of a

Answer 40

Pharmacokinetic antagonist

Question 41

Drug specificity for a given receptor depends on factors like

Answer 41

Molecular size, shape, and electrical charge

Question 42

Tissue selectivity can also arise from over-expression of a given receptor. In such a scenario, the tissue is said to have

Answer 42

Spare receptors

Question 43

Means that an agonist can induce a maximal response in a tissue without binding to all of the available receptors

Answer 43

Presence of spare receptors

Question 44

Spare receptors increase the likelihood of a drug being bound when present at low concentrations, and thereby increase tissue

Answer 44

Sensitivity

Question 45

Spare receptors are demonstrated by using

Answer 45

Noncompetitive irreversible antagonists

Question 46

They are difficult to construct when the pharmacological response is an “eitheror” (i.e., a quantal) event

Answer 46

Dose-response curves

Question 47

A quantitative dose-response relationship in a single individual may have limited applicability to other individuals, due to inter-individual

Answer 47

Variability

Question 48

Such limitations may be circumvented by determining the dose of drug required to produce a specified response in a large number of

Answer 48

Individuals

Question 49

Provide a convenient way for comparing the potencies or effective doses (i.e., ED50 values) of drugs in a clinical setting

Answer 49

Quantal dose-response curves

Question 50

Analogous to ED50, the dose required to produce a particular toxic response in 50% of the individuals is termed the

Answer 50

Median toxic dose

Question 51

The margin of safety of a drug is typically given by its

Answer 51

Therapeutic index