Test 4 Old Test Questions Flashcards
in areas where dopamine are low drug increases dopamine by activating the receptors. where dopamine levels are high, it causes a dose-dependent, reversible decrease in dopaminergic activity by blocking the receptors. this drug is best characterized by
partial agonist,
intrinsic activity between 0-1
term used to describe the response or effect of a drug can elicit is called
efficacy
the _______ the drug concentration needed to produce __________, the _______ the drug
the lower the drug concentration needed to produce a desired effect, the more potent the drug
T/F efficacy of agonist is partly dependent on the total number of target receptors on the tissue/organ of interest
True
which of the following will promote the greatest effect with the least amount of drug
high intrinsic activity, high receptor number, high affinity
T/F partial agonists, by definition, have low affinity
True
what type of drug would have 0 maximal effect as there is an increase of receptors bound by this drug
antagonist
Kd is to _____ as EC50 is to _____
Kd is to affinity as EC50 is to potency
as kd (inc/dec), affinity (inc/dec)
increases, decreases
an antagonist is administered to a patient that results in a dose ratio of 4. this means that
4 times the concentration of the agonist is now required to produce the same response compared to if the antagonist were absent
kd definition
ligand concentration which half of the target receptor population is occupied at equilibrium
fractional receptor occupancy is dependent on _____ of the drug
affinity and concentration
which curves have the highest efficacy when looking at a graph
the ones with the largest Emax
drug A has a kd of 0.1 microM, drug B has a kd of 30 microM. Why might this be?
drug A has a higher affinity for the receptor than drug B
as EC50 increases, Emax _____
remains the same
as kd increases, Bmax ______
remains the same
equation for finding kd
koff/kon
L * R / (LR)
EC50 is defined as
the ligand concentration at which half of the maximum reaction response is achieved
if compound A and compound B have the same Emax and Compound B is more potent than compound A what must be true
Compound B has a lower EC50 than compound A
the ED50 for a receptor agonist is 40mg. this means that
40mg is needed to effectively treat half of the study population
T/F partial agonists have a low affinity
false
what is the primary purpose of a drug-receptor binding curve
to describe receptor binding as a function of drug concentration
a graded dose response tells us about the _____ and ______ of a drug while a quantal dose response curve tells us about _______
a graded dose response tells us about the efficacy and potency of a drug while a quantal dose response curve tells us about safety
intrinsic activity is:
the relative ability of a ligand-receptor complex to produce a biological response
T/F when dosed at high enough concentration a partial agonist can exhibit the same maximal efficacy as a full agonist
False
more potent drugs have ____ kd and ____ affinity
more potent drugs have lower kd and higher affinity
the presence of a competitive agonist along with a full agonist has what effect
reduces the potency but not the efficacy of the agonist
the clinical effectiveness of a drug depends on the drug’s
maximal efficacy
T/F drug potency is related to the drugs affinity for a receptor while efficacy is related to the proportion of receptors activated
True
T/F the efficacy of an antagonist is decreased in the presence of a noncompetitive antagonist
True
T/F a partial agonist can reach 100% max effect of a full agonist only at 100% receptor occupancy
False
T/F the difference between two different drugs can be obtained from a quantal response curve
False
what best describes a quantal dose response curve
population of subjects increasing doses of drug to determine the dose needed to produce a desired effect
down-regulation is:
usually prolonged agonist exposure, likely lead to a decrease in maximal attainable response, will require a greater dose of agonist in order to achieve the same response prior to down regulation
the graph will shift right when drug A is a full agonist and drug B is added that is _____
- a partial agonist for the receptor
- an antagonist for the drug for the receptor
- a full agonist for the receptor
T/F drug x and drug y have the same affinities for the receptor so they will have the same effect
False
T/F drug x and drug y both require the same dose for a specific response, therefore they have equivalent potencies for this response
True
T/F drug X has a lower EC50 than Drug y, therefore Drug Y has a greater efficacy than Drug X
False
the graph will shift right when drug A is a full agonist and drug B that is added is____
enhances the ability of the initial drug to activate the receptor
T/F a partial agonist can be more potent than a full agonist in producing a specific response
True
If compound A and compound B have the same Emax, compound B is more potent than compound B, which must be true?
compound B must have a lower EC50 than compound A
what is true if two drugs have equal affinities for the same target receptor
both drugs will occupy the same percentage of receptors at identical concentration
