1.2 - Drug-Receptor Interaction Flashcards
Features
- Affinity
* Intrinsic Activity
Ability of the ligand to BIND to receptors
Affinity
Ability of the ligand to ACTIVATE the receptors
Intrinsic Activity
Classification of Ligands
- Agonist
- Antagonist
- Allosteric Interaction
Affinity with Intrinsic Activity (IA)
Agonist
– Full
– Partial
– Inverse
— IA = 1
— Produces ALL of the expected effects
Full Agonist
— IA > 0 but < 1
— Produces SOME of the expected effects
— mixed effect
Partial Agonist
NOTE:
A partial agonist in the presence of full agonist will act as an ——
Antagonist
– Morphine + Nalbuphine = ⬇️ Analgesia
— IA < 0
Inverse Agonist
Affinity WITHOUT Intrinsic Activity
Antagonist
Types of Antagonism
- Based on MOA
- Based on the type of Interaction
- Based on Surmountability of Interaction
Based on MOA
- Functional Antagonism
- Receptor Antagonism
- Chemical Antagonism
– Physiologic Antagonism
– DIFFERENT receptors
– EPI + Histamine
Functional Antagonism
– Pharmacologic Antagonism
– SAME receptors
– EPI + B-blockers
Receptor Antagonism
– Chemical Reaction
– Protamine + Heparin
– DFO + Fe
Chemical Antagonism