Pharmacodynamics, Definitions and Nomenclature

Question 1

Define Drug Action

Answer 1

A drug must bind to one or more cell constituents to produce a pharmacological response.

Question 2

The ligand and the binding site must be ____?

Answer 2

Complimentary

Question 3

Define Intrinsic Efficacy

Answer 3

The ability of a drug to elicit a response.
Defined as the maximal effect a drug can produce on a specific tissue, expressed as a proportion of the maximal effect of a full agonist on that tissue.

full agonists: intrinsic efficacy = 1
antagonists: intrinsic efficacy = 0
partial agonists: intrinsic efficacy between 0 and 1

Question 4

Define Affinity

Answer 4

A drugs ability to bind to the target

Question 5

Define Specificity and Selectivity

Answer 5

A drug is specific if it binds to its receptor directly, and non-specific if it acts at a different target.

A drug is selective if it binds to one receptor only, and non-selective if it binds to multiple receptors.

Question 6

Define Receptors

Answer 6

A receptor is a macromolecular complex that binds a ligand with high selectivity causing an effect.

Question 7

What are the 3 stages of Binder-Receptor Interactions

Answer 7

1. Binding
2. Conformational Change and transduction
3. Response

Question 8

Define Ligand

Answer 8

A molecule that binds to an active site on a macromolecule

Question 9

Define Agonist

Answer 9

a ligand that binds to and activates a receptor to produce a response in the cell/tissue e.g. acetylcholine

Question 10

Define Antagonist

Answer 10

a ligand that binds to a receptor but does not activate it.

Question 11

Define Allosteric Modulators

Answer 11

A molecule that binds to an active (allosteric) site on a macromolecule to enhance/reduce response to an agonist.