Deck 2: Pharmacodynamics: How Drugs Act

Question 1

New advances in pharmacology enable,for the first time,the development of drugs that bind to:

A)more than one receptor.
B)one receptor only.
C)more than one neurotransmitter.
D)one neurotransmitter only.

Answer 1

B

Question 2

Remarkably,molecular biological techniques such as receptor "cloning" have allowed for the development of drugs that are more selective than endogenous:

A)receptors.
B)ligands.
C)neurotransmitters.
D)ligands and neurotransmitters.

Answer 2

D

Question 3

Based on the concept of homeostatic control,you might expect drugs that block the action of

A)decrease; decrease
B)increase; increase
C)increase; decrease
D)decrease; increase

Answer 3

D

Question 4

A ________ usually binds to only one ________.

A)receptor; neurotransmitter
B)neurotransmitter; receptor
C)ligand; neurotransmitter
D)neurotransmitter; ligand

Question 5

G proteins can control the following cellular function(s):

A)opening and closing of ion channels.
B)energy metabolism of the neural cell.
C)neural cell division and differentiation.
D)All of the answers are correct.

Question 6

Acetylcholine esterase and monoamine oxidase are examples of:

A)G-protein-coupled receptors.
B)carrier/transport proteins.
C)directly gated ion channels.
D)enzyme receptor proteins.

Question 7

G protein-coupled receptors respond to binding of a neurotransmitter by altering :

A)ion channel function.
B)energy metabolism of the neural cell.
C)cell division
D)All of the answers are correct.

Question 8

A drug that blocks the effect of,and occupies the same receptor site as,the naturally occurring compound is termed:

A)a mimicker.
B)an antagonist.
C)an agonist.
D)a facilitator.

Question 9

The anxiolytic (anxiety-reducing)effect of benzodiazepines such as diazepam occurs through:

A)antagonist action at the serotonin receptor.
B)agonist action at the serotonin receptor.
C)antagonist action at the GABA receptor.
D)agonist action at the GABA receptor.

Question 10

Drugs that block the action of carrier proteins would be expected to __________; drugs that facilitate the action of carrier proteins would be expected to ____________.

A)decrease the level of neurotransmitter in the synapse; decrease the level of neurotransmitter in
B)increase the level of neurotransmitter in the synapse; increase the level of neurotransmitter in
C)increase the level of neurotransmitter in the synapse; decrease the level of neurotransmitter in
D)decrease the level of neurotransmitter in the synapse; increase the level of neurotransmitter in

Question 11

A ________ can usually bind to many ________.

A)receptor; neurotransmitters
B)neurotransmitter; receptors
C)ligand; neurotransmitters
D)neurotransmitter; ligands

Question 12

The benzodiazepines (such as diazepam)bind at:

A)the same site on the receptor as the endogenous neurotransmitter and mimic the action
B)the same site on the receptor as the endogenous neurotransmitter and block the action
C)a different site on the receptor as the endogenous neurotransmitter to facilitate the
D)a different site on the receptor as the endogenous neurotransmitter to inhibit the action

Question 13

The naturally occurring compounds that bind to receptors are termed:

A)transmitters.
B)drugs.
C)pharmaceuticals.
D)second messengers.

Question 14

"Isomers" represent forms of a molecule that are:

A)identical in all respects.
B)identical save for a handful of different atoms.
C)charged versus uncharged.
D)mirror images of one another.

Question 15

A drug that exerts an effect similar to,and occupies the same receptor site as,the naturally occurring compound is termed:

A)a mimicker.
B)an antagonist.
C)an agonist.
D)a facilitator.

Question 16

The benzodiazepine antagonist flumazenil binds at the same site on the receptor as the:

A)endogenous neurotransmitter to mimic the action of the neurotransmitter.
B)endogenous neurotransmitter to block the action of the neurotransmitter.
C)benzodiazepines to mimic the action of the benzodiazepines.
D)benzodiazepines to block the action of the benzodiazepines.

Question 17

Exposure to a drug that inhibits the breakdown of a neurotransmitter (NT):

A)increases the level of NT by inhibiting breakdown in the synapse; an example of such a
B)increases the level of NT by inhibiting breakdown mainly in the presynaptic terminal; an
C)increases the level of NT by inhibiting breakdown in the synapse; an example of such a drug is
D)increases the level of NT by inhibiting breakdown in the presynaptic terminal; an example of

Question 18

An ion channel within a postsynaptic receptor responds to binding of a neurotransmitter by altering:

A)both its permeability to,and selectivity for,ions.
B)its permeability to,but not selectivity for,ions.
C)its selectivity for,but not permeability to ions.
D)neither its permeability to,nor selectivity for,ions.

Question 19

In metabotropic receptors:

A)G proteins activate the extracellular recognition site.
B)the associated ion channel activates the G protein.
C)the associated ion channel activates the receptor recognition site.
D)the activated extracellular receptor in turn activates the G protein.

Question 20

Membrane-spanning receptor proteins include:

A)G-protein-coupled receptors,but not carrier/transport proteins.
B)carrier/transport proteins,but not G-protein/coupled receptors.
C)both G-protein-coupled receptors and carrier/transport proteins.
D)neither G-protein-coupled receptors nor carrier/transport proteins.

Question 21

The variability and slope of the dose-response curve refer to:

A)the number of molecules of drug required to elicit a response.
B)the maximum effect obtainable with the drug.
C)whether the drug acts on presynaptic or postsynaptic receptors.
D)individual differences in response to the drug.

Question 22

The therapeutic index refers to the:

A)absolute number of molecules of drug required to elicit a response.
B)maximum effect obtainable.
C)individual differences in drug response.
D)relative safety of the drug.

Question 23

The location of the dose-response curve along the horizontal axis reflects:

A)the therapeutic index of a drug.
B)the efficacy of a drug.
C)individual differences in drug response.
D)the potency of a drug.

Question 24

The intensity of a drug's effect is proportional to:

A)the "fit" of the drug to the receptor and the percentage of receptors occupied by the drug.
B)the "fit" of the drug to the receptor but not the percentage of receptors occupied by the drug.
C)neither the "fit" of the drug to the receptor nor the percentage of receptors occupied by the
D)the percentage of receptors occupied by the drug but not the "fit" of the drug to the receptor.

Question 25

The fact that caffeine cannot exert as much central nervous system stimulation as amphetamine indicates that caffeine:

A)is less potent than amphetamine.
B)is less efficacious than amphetamine.
C)has a lower therapeutic index than amphetamine.
D)has a steeper slope than amphetamine on a dose-response curve.

Question 26

A drug that is more efficacious than another drug has:

A)a larger maximum effect.
B)a larger ED50.
C)a larger TI.
D)a smaller LD50.

Question 27

A drug that is more potent than another drug has:

A)a larger maximal effect.
B)a larger ED50.
C)a larger LD50.
D)a smaller ED50.

Question 28

The term placebo is best described as:

A)a pharmacologically active substance that elicits a significant therapeutic response.
B)a pharmacologically inactive substance that elicits a significant therapeutic response.
C)a pharmacologically active substance that fails to elicit a significant therapeutic response.
D)a pharmacologically inactive substance that fails to elicit a significant therapeutic response.

Question 29

Potency refers to:

A)the absolute number of molecules of drug required to elicit a response.
B)the maximum effect obtainable.
C)the individual differences in drug response.
D)the relative safety of the drug.

Question 30

The peak of the dose-response curve indicates:

A)the therapeutic index of a drug.
B)the efficacy of a drug.
C)individual differences in drug response.
D)the potency of a drug.

Question 31

The therapeutic index is defined as the ratio of:

A)efficacy to potency.
B)potency to efficacy.
C)ED50 to LD50.
D)LD50 to ED50.

Question 32

An antagonist binds to the same receptor site as the endogenous compound but produces an effect opposite to the endogenous compound.

Question 33

Possible mechanisms for the placebo effect include:

A)biological action of the active ingredient in the placebo.
B)a clearly defined set of traits in the patient.
C)side effects of the placebo.
D)genetics of the patient.

Question 34

A given receptor is usually capable of binding to more than one neurotransmitter.

Question 35

An antagonist binds to the same receptor site as the endogenous compound but prevents the endogenous compound from acting.

Question 36

Side effects of a drug are usually:

A)not apparent until the maximum effect of the drug is observed and are independent
B)not apparent until the maximum effect of the drug is observed and are dependent
C)apparent well before the maximum effect of the drug is observed and are
D)apparent well before the maximum effect of the drug is observed and are

Question 37

With rare exception,the binding of a drug to a receptor is irreversible.

Question 38

The dose of drug that produces the effect desired in half of subjects is called the drug's:

A)half-life.
B)therapeutic index.
C)ED50.
D)LD50.

Question 39

In a given population,the dose-response curve for the dose of drug that produces the desired effect may overlap with the dose response curve for the lethal dose of the drug.For this reason,a more useful index of the margin of safety for a drug is the ratio of the:

A)LD50 to ED50.
B)ED50 to LD50.
C)ED99 to LD1.
D)LD1 to ED99.

Question 40

A given neurotransmitter is usually capable of binding to more than one receptor.

Question 41

Drug A and Drug B are equally efficacious.

Question 42

The double-blind randomized clinical trial without placebo is currently the gold standard for studying the effectiveness and safety of drugs in humans.

Question 43

Drug A is 10 times more potent than Drug B.

Question 44

The two dose-response curves represent drugs that are equipotent.

Question 45

Drug A is more efficacious than Drug B.

Question 46

Drug B is 10 times more potent than Drug A.

Question 47

Drug B is more potent that Drug A.

Question 48

Drug B is five times more efficacious than Drug A.

Question 49

Drug A is five times more potent than Drug B.

Question 50

Drug A and Drug B each have a different ED₅₀.

Question 51

Metabotropic receptors form a membrane-spanning pore through which ions pass.

Question 52

Ionotropic and metabotropic receptors mediate the effect of the steroid hormones.

Question 53

Drug A is 10 times more efficacious than Drug B.

Question 54

Two enantiomers of a given drug are almost always roughly equal to each other in biological activity.

Question 55

The G protein can directly,as well as indirectly,activate an ion channel.