9.7 Pharmacology 3 Flashcards
(19 cards)
dose-response curve
dosage range over which the drug is effective, including peak response
threshold dose
beginning of therapeutic response
ceiling effect
no further increase in response
What does the dose-response give indication of?
binding to cellular receptors
potency
dose that produces a given response in a specific amplitude
Drug A may have an effect at 10 mg, Drug B may require 80 mg to achieve same effect.
Which is more potent?
Drug A
less needed to provide the same response
Potency does NOT predict
therapeutic effect
quantal dose-response curve
percentage of the population that exhibits a specific response as the dosage is increased
grading of quantal dose-response curve
not graded
either present or absent in each member of the population
dose at which 50% of the population responds to the drug in a specified manner
median effective dose (ED_50)
dose at which 50% of the population exhibits an adverse effect
median toxic dose (TD_50)
dose which causes death of 50% of the animal test population
median lethal dose (LD_50)
What is a major indicator of drug safety?
therapeutic index
Large TI indicates:
a much larger dose is needed to evoke a toxic effect than it does to cause a therapeutic effect
TI =
TI = (TD_50)/(ED_50)
TI does not take these effects into account
long term
Tylenol has a TI of
27
*shows liver toxicity with prolonged use
diazepam (valium) has a TI of
3
Drugs with a (low/high) TI are riskier
low
