© 2012 The McGraw-Hill Companies, Inc. All rights reserved.

1Pharmacology: An Introduction

CHAPTER

© 2012 The McGraw-Hill Companies, Inc. All rights reserved.

Learning Outcomes

1.1 Define pharmacology and its major subdivisions.

1.2 Describe what a drug is, and explain the differences between a therapeutic effect, side effect, and toxic effect.

1.3 Explain the terms site of action, mechanism of action, receptor site, agonist, and antagonist.

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Learning Outcomes

1.4 Explain the relationship between drug dosage and drug response, and the relationship between drug response and time.

1.5 Recall the guidelines for drug safety and drug approval by the FDA.

1.6 Identify drug nomenclature and the different terminology used in naming drugs.

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Learning Outcomes

1.7 Recognize the drug references, and understand the information they provide.

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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

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Major Areas of Pharmacology

• Pharmacotherapeutics – The study of the use of drugs in treating

disease

• Pharmacy – The science of preparing and dispensing

medicines

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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

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Drug Sources

• Where do drugs come from?

– Plants

– Animals

– Synthesized in a Lab

• Chemistry

• Biotechnology

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Drug Effects

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Basic Concepts in Pharmacology

• Site of Action– Location where drug exerts its effect

• Mechanism of Action– How a drug produces its effects

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Basic Concepts in Pharmacology

• Receptor Site– Site on a cell where a drug exerts its effects

• Agonists produce drug action.• Antagonists inhibit drug action.

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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

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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

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Drug Nomenclature

• Drugs have three different names:– Chemical– Generic– Brand or Trade

• Drugs are also divided into the following classifications:– Prescription– Nonprescription (OTC)

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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

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