Principles of Pharmacology Chapter 30 Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 1

Chapter 30 Lesson 30.1 Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 2

Learning Objectives Pronounce, define, and spell the Key Terms. Differentiate a drug’s chemical, generic, and brand or trade name. Define the Drug Enforcement Administration (DEA) and explain why drugs are categorized in five schedules of the Controlled Substance Act. List each part of a prescription. Describe the use of drug reference materials. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 3

Introduction Pharmacology is the science of researching and developing drugs and studying their uses. What is the definition of “drug”? What is an ethical drug? Who recognizes and defines all of the drugs in the United States? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 4

Overview of Drugs Drug derivatives Identifying drugs Organic: drugs derived from living organisms such as plants or animals Inorganic: drugs synthesized in the laboratory Identifying drugs Chemical name: drug’s chemical formula Generic name: name that any business firm may use Brand or trade name: registered trademark Where do most drugs come from today? What is the chemical name for aspirin? (Acetylsalicylic acid.) What is the generic name for aspirin? (Aspirin.) What are some brand names for aspirin? (Bayer, St. Joseph’s.) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 5

Dispensing of Drugs Drugs are classified in two categories: Patent medicines (over-the-counter) Drugs that can be obtained without a prescription Prescription drugs Also referred to as “ethical drugs” Supplied by a pharmacist who has received a prescription Who is allowed to write prescriptions in the dental office? Give an example of an OTC and a prescription drug to treat the same illness (such as sore throat, allergy, pain). Why is the term “ethical” used for drugs that need a prescription? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 6

The Prescription Written order by a physician or dentist for the preparation and administration of a medicine by the pharmacist Prescription terminology Superscription: patient name, address, date, Rx Inscription: name and quantity of the drug Subscription: directions for mixing the drug Signature: instructions to the patient on how to take the drug What part of the prescription includes the name and quantity of the drug? What part of the prescription includes the instructions for the patient on how to take the drug? What part of the prescription includes the directions for mixing the drug? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 7

Fig. 30-1 Example of a prescription pad Fig. 30-1 Example of a prescription pad. (Courtesy of Colwell, a division of Patterson Companies, Inc, 800-637-1140) Can a dental assistant prescribe medication to a patient? What is the role of the dental assistant with regard to prescriptions? What does it mean to dispense “50”? What does “prn” mean for the patient as it relates to pain? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 8

Table 30-1 Common Prescription Abbreviations What does the abbreviation “b.i.d.” stand for? How does that compare with “t.i.d.” or “q.i.d.”? How is a drug prescription documented in the dental office? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 9

Drug-Reference Materials Physicians’ Desk Reference Also referred to as the “PDR” Updated source of information supplied by drug companies about their products Available as a bound text or a CD-ROM Package inserts Information sheet describing a drug for the patient Side effects Adverse and long-term effects Precautions Contraindications Dosage and route Have you ever looked through the PDR? Do you look at the package insert before using a drug? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 10

Chapter 30 Lesson 30.2 Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 11

Learning Objectives Cite the factors in determining the dosage of a drug. Describe how mediations are administered. Describe the stages a drug goes through in the body. Define the DEA and explain why drugs are categorized in five schedules of the Controlled Substance Act. Describe the classification of prescription drugs and their effects. Describe the effects of drug use. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 12

Drug Dosage Dosage is the amount of a drug that a patient takes. Specific factors in determining the dosage are: Age Weight Time of day at which the drug is taken Drug form Patient tolerance of the drug Other drugs the patient is taking What are the guidelines with respect to the telephone interaction of a dental assistant with a pharmacy? What should a dental assistant do when a pharmacist calls? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 13

Fig. 30-2 Routes of drug administration Fig. 30-2 Routes of drug administration. (From Young A, Procter D: Kinn’s the medical assistant: an applied learning approach, ed 9, Philadelphia, 2003, Saunders; Chester GA: Modern medical assisting, Philadelphia, 1998, Saunders; and Daniel SJ, Harfst SA: Mosby’s dental hygiene: concepts, cases, and competencies, 2004 update, St Louis, Mosby 2004) A, Oral route. B, Topical route. What are three of the five ways in which drugs are administered? Oral route (in the form of pills, tablets, capsules, or liquids). Topical route (applied to the mucosa or skin). Transdermal route (applied with the use of a patch that continuously releases a controlled quantity of a medication through the skin). (Cont’d) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 14

Fig. 30-2 Routes of drug administration Fig. 30-2 Routes of drug administration. (From Young A, Procter D: Kinn’s the medical assistant: an applied learning approach, ed 9, Philadelphia, 2003, Saunders; Chester GA: Modern medical assisting, Philadelphia, 1998, Saunders; and Daniel SJ, Harfst SA: Mosby’s dental hygiene: concepts, cases, and competencies, 2004 update, St Louis, 2004, Mosby 2004.) (Cont’d) C, Transdermal route. D, Inhalation route. (Cont’d) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 15

Fig. 30-2 Routes of drug administration Fig. 30-2 Routes of drug administration. (From Young A, Procter D: Kinn’s the medical assistant: an applied learning approach, ed 9, Philadelphia, 2003, Saunders; Chester GA: Modern medical assisting, Philadelphia, 1998, Saunders; and Daniel SJ, Harfst SA: Mosby’s dental hygiene: concepts, cases, and competencies, 2004 update, St Louis, Mosby 2004) (Cont’d) F, Injection route. E, Transdermal route. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 16

Table 30-2 Stages of Drug Action in the Body Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 17

Controlled Substances Act DEA Scheduled drugs: Schedule I: no current accepted medical usefulness and a high potential for abuse Schedule II: high potential for abuse but accepted medical usefulness as well Schedule III: less abuse potential and accepted medical uses Schedule IV: low abuse potential and accepted medical uses. Schedule V: not required to be prescribed What is a DEA identification number? Give examples of a Schedule I drug. Give examples of a Schedule II drug. Give examples of a Schedule IV drug. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 18

Classification of Drugs Why do I need to know different drug classifications? Helpful when reviewing a patient’s drug history Gives knowledge of patients requiring premedication Useful in dental procedures requiring different types of pain control Assistance in a medical emergency What can the dental assistant do if a patient does not know what drugs he or she is taking? What type of drug slows the clotting of blood? Why would a dentist prescribe an antibiotic? How would an antianxiety drug be used in a dental setting? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 19

Antibiotic Prophylaxis Antibiotics are prescribed to an uninfected patient to prevent bacterial colonization. The most common application is the prevention of infective endocarditis. Bacteria are abundant in the oral cavity. The antibiotic decreases the bacterial colonization or adherence. What is infective endocarditis, and who is at risk for it? What is the main bacteria involved in infective endocarditis? How can dental-office prevent endocarditis in patients who are at risk? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 20

Antibiotic Prophylaxis Recommendations Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 21

Table 30-3 Recommended Doses and Regimens for Common Antibiotics What are the three drugs used for antibiotic prophylaxis? Why do patients need to take another drug besides amoxicillin if they are allergic to penicillin as an antibiotic premedication? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 22

Adverse Drug Effects Side effects Allergic reactions Anaphylaxis Body’s reaction to a drug Allergic reactions Increased sensitivity to a substance Anaphylaxis Sudden onset of an allergic reaction to a drug Drug tolerance Loss of effectiveness of a drug Drug addiction Physical dependence on a certain drug What does it mean for a drug to have adverse effects? What is the drug that most commonly causes anaphylaxic reactions? (Penicillin.) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 23

Common Side Effects of Medications How can these side effects alter dental treatment? Can they increase the risk of an emergency situation? Should a dental assistant evaluate a patient’s reaction to a drug? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 24