Deck 3: Pharmacodynamics: How Drugs Act

Question 1

Barbiturates,like benzodiazepines,_____ the effect of GABA on the _____ channel within the GABA receptor.

A) decrease; potassium
B) decrease; chloride
C) increase; sodium
D) increase; chloride

Answer 1

D

Question 2

Based on the concept of homeostatic control,you might expect drugs that block the action of carrier proteins to _____ the number of postsynaptic receptors for the endogenous neurotransmitter; further,you might expect drugs that facilitate the action of carrier proteins to _____ the number of postsynaptic receptors for the endogenous neurotransmitter.

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

Answer 2

D

Question 3

Drugs that block the action of presynaptic carrier proteins would be expected to ______ the level of neurotransmitter in the synapse ; drugs that facilitate the action of presynaptic carrier proteins would be expected to _____ the level of neurotransmitter in the synapse _____.

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

Answer 3

C

Question 4

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

A) the external domain of the ion channel.
B) enzymes in the postsynaptic cell.
C) DNA replication.
D) chloride influx into the cell.

Question 5

The study of how a drug interacts with a receptor is termed:

A) pharmacology.
B) pharmacokinetics.
C) pharmacodynamics.
D) molecular physiology.

Question 6

All of the following are considered primary intracellular pathways for modulation of synaptic transmission,EXCEPT:

A) cyclic guanosine monophosphate (cGMP).
B) inositol triphosphate (IP3).
C) diacylglycerol (DG).
D) cyclic adenosine monophosphate (cAMP).

Question 7

Ionotropic receptors consist of _____ subunits.

A) three
B) four
C) five
D) six

Question 8

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.

Question 9

Transport proteins are thought to exist in all of the following ionic states,EXCEPT:

A) open to cytoplasm of the presynaptic cell.
B) open to the synapse.
C) open to the calcium channels of the presynaptic neuron.
D) blocked,but with the transmitter "trapped" inside.

Question 10

The primary advantage of G protein-coupled receptors over ionotropic receptors is that they:

A) amplify cellular signal by stimulating many second messenger molecules to be produced.
B) work more rapidly.
C) enhance cellular metabolism.
D) inhibit the formation of second messengers.

Question 11

A _____ can usually bind to many _____.

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

Question 12

A _____ usually binds to only one _____.

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

Question 13

The anxiolytic (anxiety-reducing)effect of benzodiazepines such as diazepam occurs through _____ receptor.

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

Question 14

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 15

The benzodiazepines (such as diazepam)bind at _____ site on the receptor as the endogenous neurotransmitter _____ of the neurotransmitter.

A) the same; and mimic the action
B) the same; and block the action
C) a different; to facilitate the action
D) a different; to inhibit the action

Question 16

Exposure to a drug that inhibits the breakdown of a neurotransmitter (NT)increases the level of NT by inhibiting breakdown:

A) in the synapse; an example of such a drug is acetylcholine esterase.
B) mainly in the presynaptic terminal; an example of such a drug is monoamine oxidase.
C) in the synapse; an example of such a drug is an acetylcholine esterase inhibitor.
D) in the presynaptic terminal; an example of such a drug is an acetylcholine esterase inhibitor.

Question 17

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 18

Some drugs are more selective than the endogenous:

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

Question 19

Benzodiazepines are _____ agonists that _____ the conductance of chloride ions into the neuron.

A) allosteric; inhibit
B) allosteric; increase
C) inverse; facilitate
D) inverse; enhance

Question 20

The naturally occurring compounds that bind to receptors are termed:

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

Question 21

The placebo response appears to be related to:

A) the genetic make-up of individuals.
B) supersensitivity to experimental instructions.
C) situational factors related to a drug trial.
D) unknown variables.

Question 22

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 23

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 24

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 25

Bill has been taking Prozac (fluoxetine),a selective serotonin reuptake inhibitor,for his depression for some time now.However,he has found that the drug has become less effective over time.This effect may be due to receptor:

A) up regulation.
B) sensitization.
C) adaptation.
D) desensitization.

Question 26

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

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

Question 27

In the context of a dose-response curve,the relationship between a drug dosage and the effect observed is referred to as:

A) efficacy.
B) slope.
C) potency.
D) variability.

Question 28

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

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

Question 29

A new nerve gas,Agousin,has been developed that acts on the cholinergic system; this gas would likely work as a(n)_____ inhibitor._____

A) reversible acetylcholine esterase
B) reversible monoamine oxidase
C) irreversible monoamine oxidase
D) irreversible acetylcholine esterase

Question 30

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 31

A drug that is more potent than another drug has a:

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

Question 32

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 33

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 34

"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 35

Potency 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 36

A drug that is more efficacious than another drug has a:

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

Question 37

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

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

Question 38

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 39

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 40

Side effects of a drug include those related to:

A) the primary mechanism of the drug such as blocking 5-HT receptors.
B) the secondary mechanism of the drug such as blocking cholinergic receptors.
C) both primary and secondary mechanisms of the drug.
D) neither of these mechanisms-side effects are unrelated to drug action.

Question 41

Affinity refers to the strength of binding between a neurotransmitter and a receptor.

Question 42

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

Question 43

Drug A is more efficacious than Drug B.

Question 44

Drug B is 10 times more potent than Drug A.

Question 45

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

Question 46

Drug A is 10 times more potent than Drug B.

Question 47

Fundamentally,drugs produce novel effects in the brain that would not be seen under normal circumstances.

Question 48

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

Question 49

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

Question 50

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

Question 51

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

Question 52

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

Question 53

Drug B is five times more efficacious than Drug A.

Question 54

Drug A and Drug B are equally efficacious.

Question 55

Drug A and Drug B each have a different ED₅₀.

Question 56

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 57

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

Question 58

Drug A is five times more potent than Drug B.

Question 59

Drug A is 10 times more efficacious than Drug B.

Question 60

Drug B is more potent that Drug A.

Question 61

Receptors that consist of an attachment site and a pore that allows specific ions to enter the cell are referred to as _____ receptors.

A) metabotropic
B) trophic
C) G-protein-coupled
D) ionotropic

Question 62

The binding of drugs to receptors involves _____ bonds that are ______.

A) weak; irreversible
B) ionic; irreversible
C) ionic; reversible
D) covalent; reversible

Question 63

Molecular isomers of drugs are _____ similar but are not _____active.

A) chemically; biologically
B) chemically; behaviorally
C) biologically; chemically
D) biologically; behaviorally

Question 64

In the context of polypharmacy,doses may be selected that are ineffective due to side effects- a phenomenon referred to as:

A) pharmacodynamic redundancy .
B) pharmacokinetic dosing.
C) inadequate dosing.
D) clinical dosing.

Question 65

Normal side effects to a drug may take all of the following forms EXCEPT:

A) fatal shock.
B) constipation.
C) dry mouth.
D) sleepiness.

Question 66

Pharmacodynamics is about:

A) what the body does to a drug.
B) how cells bind to drugs.
C) where drugs bind to cells in the body.
D) what a drug does to the body.

Question 67

Janette has been prescribed an antidepressant; over time,she may have to increase her dose due to receptor:

A) upregulation.
B) supersensitivity.
C) desensitization.
D) over production.

Question 68

Richard is participating in a research study involving a new pain medication.However,he is not actually receiving the biologically active medication.Research suggests that he:

A) is most likely to fall into the group of participants that sometimes respond to placebo.
B) is likely to always respond to placebo.
C) will not respond at all to the placebo.
D) he is more likely to respond to placebo because he is male.

Question 69

G-protein-coupled receptors are considered to be _____ while ionotropic are _____ receptors.

A) slow; fast
B) fast; direct
C) direct; fast
D) indirect; slow

Question 70

Ionotropic receptors consist of _____ coils embedded in the membrane with an attachment site(s)_____ the membrane.

A) spring; outside
B) spring; inside and outside
C) helical; outside
D) helical; beside

Question 71

The relative safety of a drug can be determined from the ratio of the LD₅₀ to the ED₅₀.

Question 72

Within the context of the dose-response curve,the _____ of the curve describes the association between the dose of the drug and its overall effect.

A) variability
B) height
C) slope
D) potency

Question 73

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

Question 74

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

Question 75

All of the following are types of receptors EXCEPT:

A) carrier proteins.
B) enzymes.
C) ion channel receptors.
D) cyclic AMP.

Question 76

If simultaneous administration of an agonist and antagonist cause a downward shift in the maximal effect of an agonist's response,the antagonist would be considered:

A) allosteric.
B) competitive.
C) noncompetitive.
D) reversible.

Question 77

The amount of drug that must be given to produce a given effect is called the drug:

A) efficacy.
B) potency.
C) intensity.
D) affinity.

Question 78

A drug that binds to a receptor site that elicits an opposite effect to that observed when an endogenous neurotransmitter binds is referred to as a(n):

A) partial antagonist.
B) allosteric agonist.
C) competitive antagonist.
D) inverse agonist.

Question 79

The _____ of a drug refers to how strongly it attaches to the receptor.

A) fit
B) affinity
C) binding
D) ionic nature

Question 80

G-protein-coupled receptors:

A) are sometimes referred to as ionotropic receptors.
B) possess a pore that opens allowing ions to enter the cell.
C) typically are made up of five helical,membrane-spanning coils.
D) involve the release of an attached intracellular protein after a drug binds.