Introduction to Pharmacology

Introduction to Pharmacology

• Definition: Pharmacology is the science of drugs, derived from the Greek words:
  • Pharmacon = drug
  • Logos = discourse or study
• It is a branch of biomedical science that studies drugs and their interactions with living systems.

Components of Pharmacology

Pharmacology encompasses the study of:

1. History of Drugs
   • Evolution of drug discovery and usage through time
   • Traditional vs. modern drug development
2. Sources of Drugs
   • Natural Sources: Plants (e.g., atropine), animals (e.g., insulin), minerals (e.g., iron supplements)
   • Synthetic Sources: Chemically synthesized drugs
   • Biotechnological Sources: Recombinant DNA products, monoclonal antibodies
3. Properties of Drugs
   • Physical Properties: Solubility, state (solid, liquid, gas), molecular weight
   • Chemical Properties: Functional groups, pKa, stability, molecular structure
4. Drug Effects on Living Systems
   • Biochemical Effects: Influence on metabolic pathways, enzyme activities
   • Physiological Effects: Changes in blood pressure, heart rate, respiration, CNS activity
   • Therapeutic and Adverse Effects
5. Mechanism of Action
   • The biological process through which a drug exerts its effects
   • Involves receptor binding, enzyme inhibition, ion channel modulation, etc.
6. Pharmacokinetics(What the body does to the drug)
   • Absorption: Entry of drug into bloodstream (oral, IV, IM, etc.)
   • Distribution: Dispersion through tissues and organs
   • Biotransformation / Metabolism:
     • Mainly occurs in liver
     • Converts drug into active/inactive forms
   • Excretion:
     • Elimination from body through kidneys (urine), bile, lungs, sweat, saliva
7. Drug-Organ/Tissue Interactions
   • Drug behavior in healthy organs/tissues
   • Understanding normal physiology is essential to predict drug actions