pcol/medchem 1 exam 1 – pcol-Graded A
agonist - correct answer-drug which causes specific physiological effect due to direct
interaction with a receptor
-has efficacy
antagonist - correct answer-compound which is devoid of intrinsic pharmacological
activity but blocks the action of a specific agonist
-does NOT have efficacy
addition - correct answer-when two agonists which product same effect are
administered together, they produce an effect EQUAL to the sum of the effects of
individual drugs
synergism - correct answer-when two agonists which product same effect are
administered together, produce an effect GREATER in magnitude than the sum of
effects of individual drugs
potentiation - correct answer-drug doesnt have effect on its own but when administered
with second drug, INCREASES effect of second drug
tolerance - correct answer-repeated administration of given dose produces decreased
effect
tachyphylaxis - correct answer-very rapidly developing tolerance
-ex. amphetamine
supersensitivity - correct answer-a heightened state of pharmacological responsiveness
of a tissue or organ, leading to an exaggerated effect of an agonist
desensitization - correct answer-reduced state of pharmacological responsiveness of a
receptor due to continuous presence of agonist at receptor
upregulation - correct answer-increase in receptor count
may lead to supersensitivity
downregulation - correct answer-decrease in receptor number
may lead to desensitization
ED50 - correct answer-smallest dose which is effective in 50% of individuals receiving
the drug
, LD50 - correct answer-smallest dose which is lethal in 50% of individuals receiving the
drug
therapeutic index (TI) - correct answer-LD50/ED50
larger # = safer
margin of safety - correct answer-LD0.1/ED99.9
larger # = safer
quantal dose-response curve - correct answer-relates dose to frequency of response
"all or none"
graded dose-response curve - correct answer-relates dose to size of response
when KD for a drug is small its affinity for the receptor is - correct answer-high
when KD for a drug is large its affinity for the receptor is - correct answer-low
KD = - correct answer-[D][R]/[DR] = k2/k1
occupancy theory - correct answer-KD = ED50 if the % occupancy of the receptor is
directly proportional to the % response (there are no spare receptors)
efficacy - correct answer-degree of effect obtainable for a given level of receptor
occupancy
-independent of slope
-measured along y axis
potency - correct answer-used in comparing two or more drugs when specifically
referring to the doses of each required to produce same effect
-must have same slope
-measured along x axis
-less drug used --> more potent
physiological antagonism - correct answer-when two agonists act upon a tissue to
produce OPPOSING responses --> cancel out effect
-act upon different receptors
antagonism by neutralization - correct answer-2 drugs combine with one another to form
an inactive compound
-no possible effect
pharmacological antagonism - correct answer-when the antagonist prevents an agonist
from acting upon its receptor to produce a response
-competitive, reversible
-irreversible
agonist - correct answer-drug which causes specific physiological effect due to direct
interaction with a receptor
-has efficacy
antagonist - correct answer-compound which is devoid of intrinsic pharmacological
activity but blocks the action of a specific agonist
-does NOT have efficacy
addition - correct answer-when two agonists which product same effect are
administered together, they produce an effect EQUAL to the sum of the effects of
individual drugs
synergism - correct answer-when two agonists which product same effect are
administered together, produce an effect GREATER in magnitude than the sum of
effects of individual drugs
potentiation - correct answer-drug doesnt have effect on its own but when administered
with second drug, INCREASES effect of second drug
tolerance - correct answer-repeated administration of given dose produces decreased
effect
tachyphylaxis - correct answer-very rapidly developing tolerance
-ex. amphetamine
supersensitivity - correct answer-a heightened state of pharmacological responsiveness
of a tissue or organ, leading to an exaggerated effect of an agonist
desensitization - correct answer-reduced state of pharmacological responsiveness of a
receptor due to continuous presence of agonist at receptor
upregulation - correct answer-increase in receptor count
may lead to supersensitivity
downregulation - correct answer-decrease in receptor number
may lead to desensitization
ED50 - correct answer-smallest dose which is effective in 50% of individuals receiving
the drug
, LD50 - correct answer-smallest dose which is lethal in 50% of individuals receiving the
drug
therapeutic index (TI) - correct answer-LD50/ED50
larger # = safer
margin of safety - correct answer-LD0.1/ED99.9
larger # = safer
quantal dose-response curve - correct answer-relates dose to frequency of response
"all or none"
graded dose-response curve - correct answer-relates dose to size of response
when KD for a drug is small its affinity for the receptor is - correct answer-high
when KD for a drug is large its affinity for the receptor is - correct answer-low
KD = - correct answer-[D][R]/[DR] = k2/k1
occupancy theory - correct answer-KD = ED50 if the % occupancy of the receptor is
directly proportional to the % response (there are no spare receptors)
efficacy - correct answer-degree of effect obtainable for a given level of receptor
occupancy
-independent of slope
-measured along y axis
potency - correct answer-used in comparing two or more drugs when specifically
referring to the doses of each required to produce same effect
-must have same slope
-measured along x axis
-less drug used --> more potent
physiological antagonism - correct answer-when two agonists act upon a tissue to
produce OPPOSING responses --> cancel out effect
-act upon different receptors
antagonism by neutralization - correct answer-2 drugs combine with one another to form
an inactive compound
-no possible effect
pharmacological antagonism - correct answer-when the antagonist prevents an agonist
from acting upon its receptor to produce a response
-competitive, reversible
-irreversible
