Copyright C 2005, 2002, 1999, 1995, 1990, 1985, 1980, 1976 by Elsevier Inc. Principles of Pharmacology Chapter 30

Copyright C 2005, 2002, 1999, 1995, 1990, 1985, 1980, 1976 by Elsevier Inc. Introduction Pharmacology is the science that conducts research and develops the use and effects of drugs.

Copyright C 2005, 2002, 1999, 1995, 1990, 1985, 1980, 1976 by Elsevier Inc. Overview of Drugs Drug Derivatives –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

Copyright C 2005, 2002, 1999, 1995, 1990, 1985, 1980, 1976 by Elsevier Inc. 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

Copyright C 2005, 2002, 1999, 1995, 1990, 1985, 1980, 1976 by Elsevier Inc. Prescriptions 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 for the patient on how to take the drug

Copyright C 2005, 2002, 1999, 1995, 1990, 1985, 1980, 1976 by Elsevier Inc. Fig Example of a prescription pad. (Courtesy Colwell Systems, Champaign, IL.)

Copyright C 2005, 2002, 1999, 1995, 1990, 1985, 1980, 1976 by Elsevier Inc. Table 30-1 Common Prescription Abbreviations

Copyright C 2005, 2002, 1999, 1995, 1990, 1985, 1980, 1976 by Elsevier Inc. Drug Reference Materials Physicians’ Desk Reference –Also referred to as the “PDR” –An updated source of information supplied by drug companies about their products –Available as a bound text or CD-ROM Package Inserts –Information sheet describing the drug for the patient Side effects Adverse or long-term effects Precautions Contraindications Dosage and route

Copyright C 2005, 2002, 1999, 1995, 1990, 1985, 1980, 1976 by Elsevier Inc. Fig Mosby's Drug Consult

Copyright C 2005, 2002, 1999, 1995, 1990, 1985, 1980, 1976 by Elsevier Inc. 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 the drug is taken –Drug form –Patient tolerance to drug –Other drugs the patient is taking

Copyright C 2005, 2002, 1999, 1995, 1990, 1985, 1980, 1976 by Elsevier Inc. Fig 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: Mosby’s dental hygiene: concepts, cases, and competencies, 2004 Update, St. Louis, Mosby 2004)

Copyright C 2005, 2002, 1999, 1995, 1990, 1985, 1980, 1976 by Elsevier Inc. Stages of Drug Action in the Body

Copyright C 2005, 2002, 1999, 1995, 1990, 1985, 1980, 1976 by Elsevier Inc. Controlled Substance Act Drug Enforcement Agency (DEA) Scheduled Drugs: –Schedule I drugs have no current accepted medical usefulness and have a high potential for abuse. –Schedule II drugs have a high potential for abuse but have accepted medical usefulness. –Schedule III drugs have less abuse potential and do have accepted medical usefulness. –Schedule IV drugs have low abuse potential and have accepted medical use. –Schedule V drugs are not required to be prescribed.

Copyright C 2005, 2002, 1999, 1995, 1990, 1985, 1980, 1976 by Elsevier Inc. Classification of Drugs Why do I need to know different drug classifications? –Helpful when reviewing a patient’s drug history –Have the knowledge of patients requiring premedication –Assist in dental procedures requiring different types of pain control –Assist in a medical emergency

Copyright C 2005, 2002, 1999, 1995, 1990, 1985, 1980, 1976 by Elsevier Inc. Antibiotic Prophylaxis Antibiotic prescribed to an uninfected patient to prevent bacterial colonization. –Most common application is for the prevention of infective endocarditis. –Bacteria is abundant in the oral cavity The antibiotic decreases the bacterial colonization or adherence.

Copyright C 2005, 2002, 1999, 1995, 1990, 1985, 1980, 1976 by Elsevier Inc. Antibiotic Prophylaxis Recommendations

Copyright C 2005, 2002, 1999, 1995, 1990, 1985, 1980, 1976 by Elsevier Inc. Table 30-2 Recommended Doses and Regimens for Common Antibiotics

Copyright C 2005, 2002, 1999, 1995, 1990, 1985, 1980, 1976 by Elsevier Inc. Adverse Drug Effects Side Effects –Body's reaction to a drug Allergic Reactions –The body has an 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

Copyright C 2005, 2002, 1999, 1995, 1990, 1985, 1980, 1976 by Elsevier Inc. Common Side Effects of Medications