Core Concepts: Drugs - Definition and Classification

Pharmacology

• Pharmacology is the science of drug action.
• A drug is a chemical entity (not a nutrient) causing a biological effect.
• A medicine is a regulated preparation of one or more drugs, used therapeutically.
• A pharmaceutical is a regulated product, usually containing one or more drugs.
• Drugs can be:
  • Small organic molecules
  • Peptides (<40 residues)
  • Oligonucleotides
  • Proteins
• Biologics are made in/extracted from cells

Drug Classification

• Drugs can be classified by:
  • Molecular structure (e.g., catecholamines, opioids)
  • Mode of action (e.g., muscarinic antagonists, beta-blockers)
  • Therapeutic use (e.g., bronchodilators, antihypertensives)

Drug Names

• Drugs can be identified by:
  • Chemical name
  • Generic name
  • Proprietary/trade name
• Example:
  • Salbutamol (Ventolin)
  • Chemical Name: 4-[2-(tertiary butylamino)-1-hydroxyethyl]-2-(hydroxymethyl) phenol

Proprietary vs Generics

• Proprietary drugs are under patent; generics are not (patent expired).
• Example:
  • Ibuprofen (patent approved in 1962, expired in the 1980s)
  • Atorvastatin (Lipitor)