Pharmacodynamics & kinetics Flashcards
Definition of affinity
The tendency of a ligand to bind to a receptor
Definition of efficacy
The ability of a ligand to produce a biological response.
What is Intrinsic efficacy?
The ability of a ligand to generate the active form of the receptor.
What is an agonist?
Ligand that creates a response in the receptor
What is an antagonist?
Ligand that binds to the receptor but doesn’t create a response.
What is Bmax?
The maximum binding capacity.
What is Kd?
Concentration of ligand required to occupy 50% of available receptors.
How does Kd relate to affinity?
The lower the Kd the higher the affinity.
What is Emax?
The maximum response that can be measured.
What is EC50?
Concentration of agonist required to produce half of the maximal response
Definition of agonist potency
The concentration of a drug that creates 50% of it’s maximal response.
The lower the value of EC50 the more potent the drug.
What is a partial agonist?
An agonist that produces a response that is lower than that produced by a full agonist.
What is reversible competitive antagonism?
The antagonist binds to the orthosteric site (competitive).
It binds with weak (non-covalent bonds) hence reversibility.
What is Irreversible competitive antagonism?
Antagonist binds to orthosteric site.
With strong bonds which are hard to break. (Possibly covalent bonds)
What is non-competitive antagonism?
Binding occurs on the allosteric site.
Interaction could be either low or high affinity.
