Understanding Drug Interactions

📋 Course Outline

1. Drug Interaction Types
2. Pharmacokinetic Mechanisms
3. Pharmacodynamic Mechanisms
4. Absorption Factors
5. Distribution Factors
6. Metabolism Factors
7. Excretion Factors
8. Patient Factors
9. Drug Factors
10. Adverse Drug Reactions
11. ADR Classification
12. Risk Management

📖 1. Drug Interaction Types

🔑 Key Concepts & Definitions

• Pharmacokinetic Interaction: A type of drug interaction where one drug alters the absorption, distribution, metabolism, or excretion of another, affecting its concentration and efficacy.
• Pharmacodynamic Interaction: An interaction where drugs influence each other's effects at their site of action, either enhancing (synergism) or diminishing (antagonism) therapeutic effects.
• Enzyme Induction: The process by which certain drugs increase the activity of metabolic enzymes (e.g., cytochrome P450), leading to faster drug metabolism and reduced drug levels.
• Enzyme Inhibition: The process where drugs decrease enzyme activity, resulting in slower metabolism and increased plasma concentrations of other drugs.
• Protein Binding Displacement: When a drug displaces another from plasma protein binding sites, increasing free (active) drug levels and potential toxicity.
• Narrow Therapeutic Index: A small margin between effective and toxic drug doses, making interactions more clinically significant (e.g., warfarin, lithium).

📝 Essential Points