WK1 QUIZ NR565 QUESTIONS WITH ACCURATE
ANSWERS
Absorption: correct answer Absorption is the process whereby a substance
entering the body is assimilated by it. For proper pharmacokinetics study, it is
necessary to know both the rate and the extent to which the active substance or
therapeutic moiety are absorbed. They include substances intended to produce /
not produce systematic effects.
Agonist correct answer A drug that binds to and activates a receptor. Can be full,
partial or inverse. A full agonist has high efficacy, producing a full response while
occupying a relatively low proportion of receptors. A partial agonist has lower
efficacy than a full agonist. It produces sub-maximal activation even when
occupying the total receptor population, therefore cannot produce the maximal
response, irrespective of the concentration applied. An inverse agonist produces
an effect opposite to that of an agonist, yet it binds to the same receptor binding-
site as an agonist.
Antagonist correct answer A drug that attenuates the effect of an agonist. Can be
competitive or non-competitive, each of which can be reversible or irreversible. A
competitive antagonist binds to the same site as the agonist but does not activate
it, thus blocks the agonist's action. A non-competitive antagonist binds to an
allosteric (non-agonist) site on the receptor to prevent activation of the receptor.
A reversible antagonist binds non-covalently to the receptor, therefore can be
"washed out". An irreversible antagonist binds covalently to the receptor and
cannot be displaced by either competing ligands or washing.
BMax correct answer The maximum amount of drug or radioligand, usually
expressed as picomoles (pM) per mg protein, which can bind specifically to the
receptors in a membrane preparation. Can be used to measure the density of the
receptor site in a particular preparation.
, Define pharmacodynamics. correct answer The nature and intensity of the
response that the drug has on the body
Define the four phases of pharmacokinetics. correct answer Absorption,
distribution, metabolism, and excretion.
Desensitization correct answer A reduction in response to an agonist while it is
continuously present at the receptor, or progressive decrease in response upon
repeated exposure to an agonist.
Distribution: correct answer Distribution is the dispersion or dissemination of
substances throughout the fluids and tissues of the body.
Duration of Action correct answer The duration of action of a drug is the length of
time that particular drug is effective. Duration of action is a function of several
parameters including plasma half-life, the time to equilibrate between plasma
and target compartments, and the off rate of the drug from its biological target.
Efficacy correct answer Describes the way that agonists vary in the response they
produce when they occupy the same number of receptors. High efficacy agonists
produce their maximal response while occupying a relatively low proportion of
the total receptor population. Lower efficacy agonists do not activate receptors to
the same degree and may not be able to produce the maximal response.
EXAMPLES OF GRADED RESPONSES TO DRUGS correct answer • Blood pressure
• Heart rate
• Diuresis
ANSWERS
Absorption: correct answer Absorption is the process whereby a substance
entering the body is assimilated by it. For proper pharmacokinetics study, it is
necessary to know both the rate and the extent to which the active substance or
therapeutic moiety are absorbed. They include substances intended to produce /
not produce systematic effects.
Agonist correct answer A drug that binds to and activates a receptor. Can be full,
partial or inverse. A full agonist has high efficacy, producing a full response while
occupying a relatively low proportion of receptors. A partial agonist has lower
efficacy than a full agonist. It produces sub-maximal activation even when
occupying the total receptor population, therefore cannot produce the maximal
response, irrespective of the concentration applied. An inverse agonist produces
an effect opposite to that of an agonist, yet it binds to the same receptor binding-
site as an agonist.
Antagonist correct answer A drug that attenuates the effect of an agonist. Can be
competitive or non-competitive, each of which can be reversible or irreversible. A
competitive antagonist binds to the same site as the agonist but does not activate
it, thus blocks the agonist's action. A non-competitive antagonist binds to an
allosteric (non-agonist) site on the receptor to prevent activation of the receptor.
A reversible antagonist binds non-covalently to the receptor, therefore can be
"washed out". An irreversible antagonist binds covalently to the receptor and
cannot be displaced by either competing ligands or washing.
BMax correct answer The maximum amount of drug or radioligand, usually
expressed as picomoles (pM) per mg protein, which can bind specifically to the
receptors in a membrane preparation. Can be used to measure the density of the
receptor site in a particular preparation.
, Define pharmacodynamics. correct answer The nature and intensity of the
response that the drug has on the body
Define the four phases of pharmacokinetics. correct answer Absorption,
distribution, metabolism, and excretion.
Desensitization correct answer A reduction in response to an agonist while it is
continuously present at the receptor, or progressive decrease in response upon
repeated exposure to an agonist.
Distribution: correct answer Distribution is the dispersion or dissemination of
substances throughout the fluids and tissues of the body.
Duration of Action correct answer The duration of action of a drug is the length of
time that particular drug is effective. Duration of action is a function of several
parameters including plasma half-life, the time to equilibrate between plasma
and target compartments, and the off rate of the drug from its biological target.
Efficacy correct answer Describes the way that agonists vary in the response they
produce when they occupy the same number of receptors. High efficacy agonists
produce their maximal response while occupying a relatively low proportion of
the total receptor population. Lower efficacy agonists do not activate receptors to
the same degree and may not be able to produce the maximal response.
EXAMPLES OF GRADED RESPONSES TO DRUGS correct answer • Blood pressure
• Heart rate
• Diuresis
