Pharmacodynamics Flashcards
Pharmacodynamics is the study of:
a. plasma concentration and effect-site concentration
b. drug dose and plasma concentration
c. effect site concentration and clinical effect
d. tissue concentration and efficacy
c. effect site concentration and clinical effect
Pharmacodynamics describes the relationship between
the effect-site concentration and the clinical effect
Pharmacokinetics describes the relationship between
drug dose and plasma concentration
Pharmacobiophasics unites PK and PD by examining the relationship between
plasma concentration and effect-site concentration
__________ explains “what the body does to the drug”
Pharmacokinetics
__________ explains “what the drug does to the body”
Pharmacodynamics
Pharmacokinetics includes these 4 processes.
absorption, distribution, metabolism, and elimination
On the dose-response curve, the x-axis correlates with:
a. individual variability
b. efficacy
c. percentage of receptors occupied
d. potency
d. potency
_________ is the dose required to achieve a given clinical effect.
Potency
_______ is depicted on the x-axis of a dose-response curve.
Potency
________ is the intrinsic ability of a drug to elicit a given clinical effect.
Efficacy
_______ is depicted on the y-axis of a dose-response curve.
Efficacy
The ________ tells us how many receptors must be occupied to elicit a clinical effect.
slope
We can compare the dose-response curves from multiple patients to learn about the ________ of each patient.
individual variability
The dose-response curve illustrates the relationship between
the drug dose and its clinical effects
The ______ & _______ are measures off potency.
ED50 & ED90
ED50 & ED90 represent the
dose required to achieve a given effect in 50% and 90% of the population, respectively
Once a drug reaches maximum efficacy, additional administration of the drugs increases
the risk of toxicity
Individual variability is defined as
differences between pharmacokinetics and pharmacodynamics between patients
Potency is affected by the
absorption, distribution, metabolism, elimination, and receptor affinity
A higher plateau implies a ______ efficacy, while a lower plateau reflects a ______ efficacy
higher; lower
A steep slope implies that
most of the receptors must be occupied before we observe the clinical response
These drugs have a steep slope
neuromuscular blockers & volatile anesthetics
A ______ instructs the receptor to produce its maximal response.
A full agonist
Examples of a full agonist include
norepinephrine, dopamine, propofol, and alfentanil
A _____ is only capable of partially activating a cellular response.
Partial agonist
An example of a partial agonist includes
nalbuphine
A ______ binds to a receptor and prevents an agonist from binding to it.
antagonist
________ antagonism is reversible.
Competetive
Examples of competitive antagonism include
atropine & nondepolarizing neuromuscular blockers
_________ antagonism is not reversible.
Noncompetitive
Examples of noncompetitive antagonism include
aspirin & phenoxybenzamine
A _______ binds to the receptor and causes an opposite effect to that of a full agonist.
inverse agonist
An example of an inverse agonist includes
propranolol
Describe how drugs can react when administered together.
synergism
addition
otentiation
antagonism
Describe synergism.
1+1= 3
Describe addition.
1+1=2
Describe potentiation.
1+0=3
effect of one drug is enhanced by a drug that has no effect of its own
Describe antagonism.
1+1=0
simultaneous administration of one drug negates the effect of a second drug like giving fentanyl and naloxone at the same time
A full agonist instructs the receptor to
produce its maximal response
Different drugs may produce the same clinical effect, but each may require a different dose to do so. This is a difference in
potency.
Continuous administration of an agonist may cause
down-regulation of the target receptors
A partial agonist may also be referred to as an
agonist-antagonist
Continuous administration of an antagonist may cause
up-regulation of the target receptors
