TEST 1 Drugs and Receptors

Question 1

Define Pharmacokinetics

Answer 1

• What the biological system does to the drug
• Absorption, Distribution, Biotransformation & Excretion of drugs

Question 2

Define Pharmacodynamics?

Answer 2

• Study of biochemical & physiological effects of drugs & mechanisms of action
• Includes dose-response relationships
• Levels of drug action
  
  • Molecule
  • Cell
  • Tissue
  • System
• Mechanisms of action and effects of drugs

Question 3

Define Therapeutics

Question 4

Define and describe drug receptor?

Answer 4

• Functional macromolecule to which a drug binds, to produce or inhibit a biological response.

Question 5

What is the fundamental principle of pharmacodynamics?

Answer 5

Drugs only modulate intrinsic biochemical or physiological function, they do not create effects de novo.

Question 6

Define Affinity?

Answer 6

Tenacity or persistent ability with which the drug binds to the specific receptors on the cell membrane.

Question 7

Define Intrinsic Activity?

Answer 7

Inherent property of the drug to impart a cellular response.

Question 8

Define Agonist? and give 2 examples?

Answer 8

• Binds to and stimulates a receptor (affinity + intrinsic activity)
• Examples
  
  • Muscarine - muscarinic acetylcholine receptor
  • Isoproterenol - beta adrenergic receptor.

Question 9

Define Antagonist? and give two examples?

Answer 9

• Binds to but does not stimulate a receptor (no intrinsic activity)
• Examples:
  
  • Atropine - antagonist for the muscarinic acetylcholine receptor
  • Propanolol - antagonist for the beta adrenergic receptor

Question 10

Define partial agonist, and give one example

Answer 10

• Agents that are only partly as effective as agonists no matter the amount employed.
• Example:
  
  • Buspirone - serotonin receptor partial agonist

Question 11

Define inverse agonist, and give two examples?

Answer 11

• Agents which stabilize the receptor in its inactive conformation are termed inverse agonist
• Example:
  
  • Losartan - Angll receptor blocker
  • Famotidine - H2 receptor blocker

Question 12

Define Signal transduction

Answer 12

The process by which the binding of a drug to the receptor initiates a cascade of biochemical events that leads to a physiological response.