| Sub‑topic | Core Points | |-----------|-------------| | Definition & Scope | Pharmacology = study of drug action on animals; Toxicology = study of adverse effects of chemicals, poisons, and drugs. | | Historical Perspective | Early herbal remedies → development of synthetic drugs → modern rational drug design. | | Principles of Drug Therapy | Selectivity, potency, efficacy, safety, therapeutic index, dose‑response relationships. | | Pharmacokinetics vs. Pharmacodynamics | • Pharmacokinetics (PK): absorption, distribution, metabolism, excretion (ADME). • Pharmacodynamics (PD): receptor binding, signal transduction, dose‑effect relationship. | | Species Differences | Metabolic enzyme variations (e.g., CYP450), gastrointestinal flora, plasma protein binding, renal vs. hepatic clearance. | | Regulatory & Ethical Issues | Drug residues in food‑producing animals, withdrawal periods, licensing, adverse‑event reporting. | 2. Fundamentals of Pharmacokinetics | Chapter | Highlights | |---------|------------| | Absorption | • Oral, parenteral, topical, and intramammary routes. • Factors affecting oral absorption (pH, gastric emptying, first‑pass metabolism). | | Distribution | • Volume of distribution (Vd). • Plasma protein binding (albumin, α‑1‑acid glycoprotein). • Blood‑brain barrier, placenta, milk transfer. | | Metabolism | • Phase I (oxidation, reduction, hydrolysis) and Phase II (conjugation) reactions. • Species‑specific enzyme activity (e.g., cats lack glucuronidation). | | Excretion | • Renal clearance (glomerular filtration, tubular secretion/reabsorption). • Biliary excretion and enterohepatic recycling. • Role of lungs and skin in some species. | | Pharmacokinetic Modeling | • One‑compartment vs. multi‑compartment models. • Parameters: half‑life (t½), clearance (Cl), mean residence time (MRT). | | Special Considerations | • Age (neonates, geriatric), pregnancy, disease states (renal/hepatic impairment). | 3. Fundamentals of Pharmacodynamics | Sub‑topic | Key Concepts | |-----------|--------------| | Drug‑Receptor Interactions | Agonist, partial agonist, antagonist, inverse agonist. | | Dose‑Response Relationships | • Graded (continuous) vs. Quantal (all‑or‑none). • EC₅₀ , ED₅₀ , LD₅₀ , Therapeutic Index (TI) . | | Mechanisms of Action | • Enzyme inhibition/activation. • Ion‑channel modulation. • Hormone receptor agonism/antagonism. • Signal‑transduction interference. | | Tolerance, Dependence & Addiction | • Pharmacokinetic tolerance (enhanced clearance) vs. pharmacodynamic tolerance (receptor down‑regulation). | | Drug Interactions | • Synergism , antagonism , potentiation . • Enzyme induction/inhibition (CYP450). | | Adverse Drug Reactions (ADRs) | • Type A (dose‑related, predictable) vs. Type B (idiosyncratic). | 4. Major Classes of Veterinary Drugs Below is a concise “cheat‑sheet” of the major therapeutic groups covered in the book, with representative drugs, mechanisms, and typical veterinary uses.