Pharmacology: An Introduction Eighth Edition Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. Chapter 1 Pharmacology: An Introduction Dr. Ahmed © McGraw Hill 2 Learning Outcomes 1.1 List and define the major areas of pharmacology. 1.2 Describe what a drug is and explain the differences between therapeutic effect, side effect, and toxic effect. 1.3 Understand the terms site of action and mechanism of action, and how agonist and antagonist drugs interact at drug receptor sites. 1.4 Characterize the relationship between drug dosage and drug response, and the relationship between drug response and time. © McGraw Hill 3 Pharmacology Study of drugs. Drug sources. • Plants. • Animals. • Bacteria. • Chemical synthesis. © McGraw Hill 4 Table 1.1 - Major Areas of Pharmacology Area Description Pharmacodynamics Study of the action of drugs on living tissue Pharmacokinetics Study of the processes of drug absorption, distribution, metabolism, and excretion Pharmacotherapeutics Study of the use of drugs in treating disease Pharmacy Science of preparing and dispensing medicines Posology Study of the amount of drug that is required to produce therapeutic effects Toxicology Study of the harmful effects of drugs on living tissue © McGraw Hill 5 Terminology Related To Drug Effects • Drug effects. Desired Effects Undesired Effects • Therapeutic Effect. • Side Effect. • Adverse Effect. • Toxic Effect. © McGraw Hill 6 Undesired Drug Effects Side effects. • Causes slight discomfort. • Not harmful. Adverse effects. • Potentially harmful. Toxic effects. • Extremely harmful. © McGraw Hill 7 Concepts in Pharmacology 1 Site of action. • Location where a drug exerts its effect. Mechanism of action. • How a drug produces its effects. Receptor site. • Site on a cell where a drug exerts its effects. © McGraw Hill 8 Concepts in Pharmacology 2 Agonists and antagonists: • Agonists produce drug action. • Antagonists inhibit drug action. © McGraw Hill 9 Figure 1.1 - Competitive Antagonism at Work Access the text alternative for slide images. © McGraw Hill 10 Dose Response and Time-Plasma Drug Concentration Curves Dose response curve. • Response of a drug proportional to dose. • Dose: Exact amount of a drug administered in order to produce a specific effect. Time-plasma drug concentration curve. • Shows the relationship between time and plasma drug concentration. © McGraw Hill 11 Figure 1.2 - A Typical DoseResponse Curve Access the text alternative for slide images. © McGraw Hill 12 Figure 1.3 - A Typical Time-Plasma Drug Concentration Curve Access the text alternative for slide images. © McGraw Hill 13 Drug Safety 1 Medications must be proven safe and effective. Therapeutic index (TI). • Ratio of lethal dose 50 (LD50) to effective dose (ED50). • Gives an estimate of a drug’s relative safety. • TI = LD50/ED50. © McGraw Hill 14 Drug Safety 2 Adverse drug effects: • May or may not depend on the dose. • Dose dependent effects can be caused by teratogens and carcinogens. • Examples of dose independent effects - Drug idiosyncrasy and drug allergy. © McGraw Hill 15 Drug Nomenclature Drugs have chemical, generic (non-proprietary), and trade (brand) names. Drug classifications. • Prescription. • Nonprescription (over-the-counter). © McGraw Hill 16 Drug References 1 Drug reference books provide information on medications. • United States Pharmacopeia/National Formulary (USP/NF). • Physicians’ Desk Reference. • Drug Facts and Comparisons. • Drug Information - American Hospital Formulary Service. © McGraw Hill 17 Drug References 2 United States Pharmacopeia Dispensing Information. • Volume I - Drug Information for the Health Care Professional. • Volume II - Advice for the Patient. © McGraw Hill 18 Drug Legislation Acts Federal Pure Food and Drug Act (1906) Federal Food Drug and Cosmetic Act (1938) Amendment to the Federal Food Drug and Cosmetic Act (1962) Federal Comprehensive Drug Abuse Prevention and Control Act (1970) © McGraw Hill 19 End of Main Content Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.
