Dose-Response Curves Flashcards
The intrinsic activity of agonists is _____. The intrinsic activity of antagonists is ________.
1;0
NOTE: Both agonists and antagonists can bind to the receptor competitively and noncompetitively.
What is a chemical antagonist?
An agent that interacts directly with the drug, to remove it or prevent it from binding its receptor
NOTE: A chemical antagonist does not depend on interaction with the agonist’s receptor
Protamine sulfate acts as a chemical antagonist of what drug?
Heparin
NOTE: Protamine sulfate forms a stable inactive complex with heparin and inactivates it.
Define threshold
The lowest dose to elicit an effect
Define Emax
Ceiling effect, which is the dse that produces the maximal effect
EC50
Effective concentration that produces half of the maximal effect
The peak time to effect is the time it takes to get the _________.
Maximal effect (Emax)
How is the drug effect (E) calculated?
Emax x [D]
__________
[D] + EC50
NOTE: [D]= Drug concentration (mg/L)
What is the amount of bound drug calculated?
Bmax x [D]
_________
[D] + KD
NOTE: KD represents the concentration of free drug at which half-maximal binding is observed
Potency can be determined by examining the differences in ______among drugs.
EC50
Why do spare receptors increase the sensitivity of a tissue?
Spare receptors can increase the sensitivity of a tissue because less drug would be necessary to promote the significant # of drug-receptor interactions required for the desired effect.
_________ takes into account the maximal effect that a drug can achieve not its concentration or dose.
Efficacy
NOTE: A full agonist (A) will achieve a larger maximal effect than a partial agonist (B).
What effect would a competive antagonist have on potency and efficacy?
Decrease potency and no effect on efficacy
What effect does an irreversible antagonist have on efficacy and potency?
Efficacy decreases and potency is unaffected
What effect does a positive allosteric modulator have on potency and efficacy?
Both can increase
