04 - Antagonists and Dose Response Curves (pharmacodynamics) Flashcards
Pure antagonists don’t cause any…
Action by binding to the receptor (they just block it) 🙅♂️
3 Classes of antagonist…
- Chemical
- Physiological
- Pharmacological
Chelating agents are examples of which type of antagonist?
Chemical
Pharmacological (drug) antagonists can be divided into 2 categories based on binding site…
- Active site binding
* Allosteric site binding
Pharmacological (drug) antagonists can be divided into 2 categories based on the nature of the binding…
- Reversible
* Irreversible
Reversible active site antagonists are ( competitive / non-competitive )
Competitive
Irreversible active site antagonists are ( competitive / non-competitive )
Non-competitive
Both reversible and irreversible allosteric site antagonists are ( competitive / non-competitive)
Non-competitive
as they do not bind at the active site
Competitive antagonists will shift the response curve to the…
Right
as it will decrease the response at a given dose or concentration
The effectiveness of a competitive antagonist can be quantified with the…
Dose ratio
Schild equation
r - 1 = [B] / Kb
Where r - 1 is the dose ratio and [B] is concentration of antagonist
The Schild plot only works for…
Competitive active site antagonists (because the slope = 1, linear)
pA2 =
-log Kb
Irreversible antagonists decrease…
EC50
Which type of antagonism is most common, competitive or irreversible?
Competitive
