© 2012 The McGraw-Hill Companies, Inc. All rights reserved. 1 Pharmacology: An Introduction CHAPTER

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Learning Outcomes 1.1Define pharmacology and its major subdivisions. 1.2Describe what a drug is, and explain the differences between a therapeutic effect, side effect, and toxic effect. 1.3Explain the terms site of action, mechanism of action, receptor site, agonist, and antagonist. 1-2

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Learning Outcomes 1.4Explain the relationship between drug dosage and drug response, and the relationship between drug response and time. 1.5Recall the guidelines for drug safety and drug approval by the FDA. 1.6Identify drug nomenclature and the different terminology used in naming drugs. 1-3

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Learning Outcomes 1.7Recognize the drug references, and understand the information they provide. 1-4

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Major Areas of Pharmacology Pharmacodynamics –The study of the action of drugs on living tissue Pharmacokinetics –The study of the processes of drug absorption, distribution, metabolism, and excretion 1-5

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Major Areas of Pharmacology Pharmacotherapeutics –The study of the use of drugs in treating disease Pharmacy –The science of preparing and dispensing medicines 1-6

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Major Areas of Pharmacology Posology –The study of the amount of drug that is required to produce therapeutic effects Toxicology –The study of the harmful effects of drugs on living tissue 1-7

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Drug Sources Where do drugs come from? –Plants –Animals –Synthesized in a Lab Chemistry Biotechnology 1-8

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Drug Effects Therapeutic Effect Desired Effects Side Effect Adverse Effect Toxic Effect Undesired Effects 1-9

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Basic Concepts in Pharmacology Site of Action –Location where drug exerts its effect Mechanism of Action –How a drug produces its effects 1-10

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Basic Concepts in Pharmacology Receptor Site –Site on a cell where a drug exerts its effects Agonists produce drug action. Antagonists inhibit drug action. 1-11

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Basic Concepts in Pharmacology Dose-Response Curve Shows response of drug proportional to dose Time-Plasma Drug Concentration Curve Shows relationship of time and drug concentration 1-12

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Drug Safety Medications must be proven safe and effective –Therapeutic Index The ratio of LD50 to ED50 Gives an estimate of relative safety –Adverse Drug Effects May be dose dependant or dose independent 1-13

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Drug Nomenclature Drugs have three different names: –Chemical –Generic –Brand or Trade Drugs are also divided into the following classifications: –Prescription –Nonprescription (OTC) 1-14

© 2012 The McGraw-Hill Companies, Inc. All rights reserved. Drug References There are several drug reference books that provide information on medications: –United States Pharmacopeia/National Formulary –Physicians’ Desk Reference –Drug Facts and Comparisons –United States Pharmacopeia Dispensing Information –Drug InformationSAmerican Hospital Formulary Service 1-15