Introduction to Pharmacology

Introduction to Pharmacology

• Pharmacology is the biomedical science focused on chemical substance interactions with living cells, tissues, and organisms.
• The term originates from Greek: "Pharmacon" (Drug) and "logos" (study).

Clinical Pharmacology

• Involves materials used for disease prevention, diagnosis, and treatment.
• Toxicology is a branch focusing on harmful effects of chemical agents on living systems.

Drug Nomenclature

• Chemical name example: (RS)-2-(4-(2-methylpropyl)phenyl)propanoic acid.
• Scientific name example: Ibuprofen.
• Trade or Brand name example: Advil.

Side Effects and Adverse Effects

• Side effects are unintended effects besides the original therapeutic effect.
  • Example: Diphenhydramine can cause sedation, urinary retention, dry mouth.
• Adverse effects require monitoring through pharmacovigilance, which assesses and prevents short-term and long-term adverse effects.

Drug Interactions

• Example of interactions:
  • Enalapril and Spironolactone.
  • Ketoconazole can enhance warfarin's effectiveness.
  • Antacids may inhibit ciprofloxacin absorption.

Timing and Duration of Action

• Onset of action refers to the time required for a medicine to take effect.
• Duration of action refers to how long the drug remains effective.

Contraindications

• Specific situations where a drug should not be used due to potential harm.
  • Example: Isotretinoin is contraindicated in pregnancy due to risk of birth defects.

Drug Tolerance and Types

• Drug tolerance is the reduced response to a drug with repeated use, requiring higher doses for the same effect.
• Cross-tolerance occurs when tolerance to one drug results in tolerance to another with similar effects.
  • Example: Morphine and Pethidine.
• Tachyphylaxis is rapid diminished response after repeated doses in a short time frame.
  • Example: Nitroglycerin and Ephedrine.

Drug Idiosyncrasy

• Abnormal or unexpected reactions to drugs, not related to the usual dosage.
  • Example: Sulfonamide can cause Stevens-Johnson syndrome; Ceftriaxone can cause agranulocytosis.

Sources of Drugs

• Plant sources: Aspirin, Digoxin, Morphine, Vinblastine.
• Animal sources: Heparin, Insulin, L-Thyroxine.
• Microorganisms: Penicillin, Polymyxin B.
• Mineral sources: Sodium bicarbonate (NaHCO3), Iodide.
• Synthetic drugs: Ciprofloxacin.
• Recombinant DNA technology: Human Insulin, growth hormone, interferons.

Pharmacodynamics and Pharmacokinetics

• Pharmacodynamics studies the biochemical and physiological effects of drugs and their mechanisms of action (what the drug does to the body).
• Pharmacokinetics examines processes that determine drug concentration in body fluids and tissues over time, including absorption, distribution, metabolism, and excretion (ADME).

This quiz covers fundamental concepts of pharmacology, including the interaction of chemical substances with living organisms. It references key texts such as Lippincott's Illustrated Reviews and RANG AND DALE’S Pharmacology. Test your knowledge of drug mechanisms and classifications.