Pharmacodynamics Flashcards
What is the relationship between the drug dose and plasma concentration?
pharmacokinetics
What is the relationship between the effect site concentration and clinical effect?
pharmacodynamics
What theory unities kinetics and dynamics by examining plasma concentration and effect site concentration?
pharmacobiophasics
What affects pharmokinetics?
absorption, distribution, metabolism, and elimination
Vd, half lives, metabolism, enzyme induction and inhibition, clearance, steady state, context sensitive half life, degree of ionization, protein binding, ion trapping are all part of what pharmacology theory?
pharmacokinetics
Rate constants between the plasma and effect site make up what theory?
pharmacobiophysics
Potency, efficacy, dose response curve slope, agonist, antagonist, partial agonist, inverse agonist, ED50, LD50, therapeutic index and stereochemistry all make up what theory?
pharmacodynamics
What the body does to the drug?
pharmacokinetics
What the drug does to the body?
pharmacodynamics
What does slope on a dose response curve tell us?
how many receptors need to be occupied to elicit a clinical effect
What does a steep dose response curve tell us?
most receptors need to be occupied to create a response
What medications have a steep dose response curve?
inhaled anesthetics and NMB
What is potency on a dose response curve?
the dose required to achieve a clinical effect
What affects drug potency?
absorption, distribution, metabolism, elimination, and receptor affinity
What are two measures of potency?
ED50 and LD50
What does a left shift on the dose response curve indicate?
increased affinity for receptor-> increased potency, lower dose required for a clinical effect
What does a right shift on the dose response curve indicate?
decreased affinity for the receptor -> decreased potency, higher dose required for a clinical response
What is efficacy on a dose response curve?
a measure of the intrinsic ability of a drug to elicit a given clinical effect
What does the height on a dose response curve indicate?
efficacy
Once a drugs efficacy is reached what can occur if more drug is administered?
toxic levels, not additional effects
What type of agonist binds to a receptor and turns on a specific response?
full agonist
What does a full agonist tell the receptor to do?
produce its maximal response
Continuous administration of a full agonist causes up/down regulation of target receptors?
down regulation
What type of agonist binds to a receptor but is only capable of partially turning on a cellular response?
partial agonist
What is another name for a partial agonist?
agonist-antagonist
What does a partial agonist do at receptor sites?
competes for receptor sites and blocks the agonist
What kind of drug sits in the receptor and prevents the agonist from binding?
antagonist
Does an antagonist have efficacy?
no
Continuous infusion of an antagonist causes up/down regulation of target receptors?
up regulation
What type of antagonist is reversible? Non reversible?
competitive antagonism is reversible
non-competitive antagonism is not reversible
How does a competitive antagonist shift the dose response curve? What does this mean?
Right. increasing concentration of the agonist can overcome the antagonist, but it less potent.
What is an example of a competitive antagonist?
Rocuronium and Ach receptors
Describe non-competitive antagonism.
The drug binds to the receptor and does not unbind. New receptors must be made.
How does a non-competitive antagonist shift the dose response curve?
down. like a partial agonist
What is an example of a non-competitive antagonist
aspirin
What is an inverse agonist?
binds to the receptor and causes the opposite effect as agonist. Negative efficacy
Match the following. 1+1=2. potentiation 1+1=3 addition 1+0=3 antagonism 1+1=0 synergism
1+1=2 addition
1+1=3 synergism
1+0=3 potentiation
1+1=0 antagonism
What term describes two drugs given at the same time?
addition
What term describes two drugs given produce greater effect together?
synergism
What term describes when one drug is enhanced by another with no effect on its own?
potentiation
What term describes when one drug cancels the other?
antagonism
What is ED50?
the dose produces the expected clinical response in 50% of the population.
What is ED50 a measure of?
potentcy
What is LD50?
the dose that produced death in 50% of the population
What is therapeutic index and how is it calculated?
measure of drug safety. LD50/ED50
Drug A has a therapeutic index of 10, Drug B has a therapeutic index of 50. Which drug is safer?
drug B
What is chirality?
molecules with a center of 3 dimensional asymmetry. Carbon bound to 4 different atoms.
What is enantiomerism?
chiral molecules that are non-superimposable mirror images of each other.
How to dextrorotatory and levorotatory molecules rotate?
dextrorotatory: clockwise
levorotatory: counter-clockwise
What drugs are enantiomers in clinical practice?
(Kids Today May Illegally Drink My Parents Beer Maybe Monday If Kept
ketamine, thiopental, methohexital, isoflurane, desflurane, mepivicaine, prilocaine, bupivicaine, morphine, methadone, ibuprofen, ketorolac
What are racemic mixtures?
two enantiomers in equal amounts
What are examples of racemic mixtures in practice?
levobupivicaine, ketamine
What is special about ketamine?
it is a enantiomer and racemic mixture
Label as antagonist, partial agonist, inverse agonist, full agonist
What is the dose required to achieve a given clinical effect? Depicted on the x-axis
Potency
What is the intrinsic ability of a drug to elicit a given clinical effect? Depicted on the y-axis?
efficacy
