Your SlideShare is downloading. ×
General principles of drug action
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

General principles of drug action

7,904
views

Published on

uploaded by : Morteza Parmis

uploaded by : Morteza Parmis

Published in: Health & Medicine

2 Comments
2 Likes
Statistics
Notes
No Downloads
Views
Total Views
7,904
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
123
Comments
2
Likes
2
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. Chapter 2 General Principles of Drug Action
  • 2. General Factors that Characterize the action of all Drugs and that Determine the effective level of any Therapeutic agent at its site of action
    • Route of administration
    • Passage across body membrane
    • Absorption
    • Transport and distribution
    • Molecular mechanism of drug action
    • Drug metabolism
    • excretion
  • 3. A. Route of administration
    • General Routes of Drug Administration
    • I. Enteral- (Oral and Rectal)
    • Oral
    • Dosage forms: tablet, capsule, suspension,
    • solution, pills etc.
    • Area of Absorption: gastric and intestinal mucosa
  • 4. oral
    • Advantages
    • - Safest
    • - Most convenient
    • - Cheapest
    • Disadvantages
    • Irritation of the gastric mucosa
    • Destruction of some drugs by the gastric acid
    • Variable rate of absorption
    • Slow rate of absorption
  • 5. II. Parenteral ( IV, IM, SC ID)
  • 6. Intravenous
    • Advantages
    • Most rapid and uniform response
    • More predictable response
    • Useful for administering drugs that poorly absorbed by other routes
    • Disadvantages
    • Produces more side effects
    • Drugs can not be withdrawn once injected
  • 7. Sublingual routes
    • Area of absorption : oral mucous membrane
    • Drug is placed under the tongue
    • By- Passed effect
    • Example of drug: Nitroglycerine
  • 8. B. Passage Across Body Membrane
    • Types of Body Membrane
      • Cell membrane
      • Intracellular membrane
      • Blood capillaries
  • 9.
    • Composition
        • Phospholipid (40%)
        • Protein (50-60%
  • 10.
    • Physiochemical properties
        • Lipid solubility
        • Molecular size and shape
        • Degree of ionization
          • pH
          • Pka
  • 11. Types of Passage ( Transport)
    • I. Passive transport
        • Simple diffusion
        • filtration
    • II Specialized transport
        • Active transport
        • Facilitated diffusion
        • Pinocytocis
  • 12. C. Absorption
    • movement of molecules from the site of administration to the blood stream
  • 13. Factors Affecting Absorption
    • Physiochemical factors that affect passage
    • Dosage form (bioavailability)
    • Drug solubility
    • Area of absorbing surface
    • Drug concentration
    • Blood flow
  • 14. D. Distribution
    • Movement of molecules from the blood stream to the different tissues of the body
  • 15. Factors Contributing to the unequal rate of Distribution
    • Plasma protein binding
    • Cellular binding
    • Storage in body fats
    • Blood-Brain Barrier
  • 16. E. Molecular Mechanism of Drug action
    • Receptors
    • Affinity
    • Agonist
    • Antagonist
  • 17. Factors affecting Drug activity
    • Antagonism
    • a. pharmacologic
    • e.g. histamine + antihistamine
    • b. physiologic
    • e.g. diuretics + sympathomimetic amide
    • c. chemical
    • e.g. heparin + protamine
    • 2. Additve effect
    • 3. Potentiation
    • 4. Cummulation
    • 5. Tolerance /tachyphylaxis
    • 6. Variation in drug response
  • 18. Drug Termination
    • Redistribution
    • Excretion (kidney)
    • Amount of drug excreted by the kidney depends on the following process
    • 1. passive tubular diffusion ( reabsorption)
    • 2. active tubular secretion
    • 3. filtration
    • * Metabolism
  • 19. Chapter 3 Adverse Drug Reactions
  • 20.
    • Classification
    • 1. Toxic
    • a. exaggerated effect on target organ
    • b. effects on non target organ (side effect)
    • c. effects on fetal development ( terratogenic)
    • d. local reaction
    • e. drug interactions
    • 2. Allergic reactions
    • 3. Idiosyncrasy
    • 4. Interference in natural defense mechanism