3 Drug-Receptor Interactions

Pharmacodynamics

Study of physiological & biochemical interactions of drug molecules with cell receptors in target tissue

What biomolecule are receptors?

Proteins

Agonist receptors

Cause a drug action & then cause a drug effect

High affinity & efficacy, attaches readily & provides significant biological effect

Receptor antagonist

Also fit receptor but produce no cellular effect (low efficacy)

Partial agonist

Intermediate efficacy

Inverse agonist

Binds just as well have an affinity but biological action is opposite to what agonist normally creates

Do receptors have a life-span? And what is up and down regulation

Yes, receptors have a life-span

Up-regulation: # of receptors increase

Down-regulation: # receptors reduced, system less sensitive, happens in low amount of ligands or chronic activation