Pharmacology: Pharmacodynamics Flashcards
what the body does to the drug is known as?
Pharmacokinetics
Explanation of the relationship between the dose you administer and the drugs plasma concentration over time is known as?
pharmacokinetics
Pharmacokinetics relationship is affected by what four variables?
absorption
distribution
metabolism
elimination
Does plasma concentration always correlate to clinical effect?
No
Biophase is also known as?
effect site
What determines the clinical effect of a drug?
The drug concentration in biophase (not plasma)
What the drug does to the body represents what?
Pharmacodynamics
Pharmacodynamics describes the relationship between what two things?
effect site concentration and the clinical effect
Units PK and PD by examining the relationship between plasma concentration and effect site concentration, is known as?
Pharmacobiophasics
What does the dose response curve illustrate?
relationship between the drug dose and its clinical effects.
It tells us about potency, efficacy, and slope
Where is potency represented on the dose response curve?
x-axis
dose required to achieve a given clinical effect is known as?
Potency
What affects potency?
absorption distribution metabolism elimination receptor affinity
What are measures of potency? (2)
ED50
ED90
What causes a left shift on the dose response curve?
increased affinity for the receptor
higher potency
lower dose required
increased affinity for the receptor leading to a higher potency and ultimately a lower dose required
What cause a right shift on the dose response curve?
decreased affinity for the receptor
lower potency
higher dose required
decreased affinity for the receptor leads to a lower potency and a higher dose is then required
explain efficacy, what does it measure?
efficacy is a measure of the intrinsic ability of a drug to elicit a given clinical effect
Where is efficacy represented on the dose response curve?
The y axis represents efficacy, it is the height of the plateau
Once the plateau phase is reached (max efficacy) for a given drug, what will giving more drug do?
More drug administration once plateau phase is reached (efficacy) will increase the risk of toxicity.
It will NOT produce additional effect.
What does the slope of a drug on the dose response curve tell you?
The slope tells us how many of the receptors must be occupied to elicit a clinical effect
What does a steep slope on the dose response curve tell you?
A steep slope implies that most of the receptors must be occupied before we observe the clinical response.
Name two types of drugs that have steep slopes?
NMB and inhaled anesthetics
How would you learn about individual variability of each patient?
compare the dose response curves from multiple patients
On graph of agonists, partial agonists, antagonists and inverse agonist. (looks like a head scratcher)
Which curve represents each drug classification?
A (Top curve) - Full Agonist
B (Second curve) - Partial Agonist
C (middle/straight line from 0 on y-axis) - Antagonist
D (bottom curve) - Inverse Agonist
a drug that binds to a receptor follows what law?
law of mass action
There is a rate constant for drug ___.
binding.
There is a rate constant for drug dissociation from ____.
the receptor
Drugs may be classified based on their degree of
efficacy.
On the dose response curve. the Y-Axis represents?
Efficacy — it is measured by the height of the y-axis
Full agonist binds to a receptor and turns on a specific cellular
response
Full agonist mimic what?
endogenous lignads