Chapter 21 Pharmacology Lesson 1 Pharmacodynamics Pharmacokinetics Chemical Name Generic Name Brand Name (FDA) (USP) (PDR®) Receptor Idiosyncrasy Iatrogenic Side effects Contraindications Journal Question: Maria has a school-age child who has been told that she is hyperkinetic in school and must be prescribed stimulants. Maria is very confused because she knows that caffeine is a stimulant and she uses it everyday to be more alert and increase her energy level in the morning. Has her school psychologist made a mistake? Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 1

Chapter Goals Learn the various subspecialty areas of pharmacology. Identify the various routes of drug administration.

Introduction Drugs: medicines/substances used to prevent or treat a condition or disease Obtained from various sources: plants: for example, digitalis animals: for example, hormones synthesized in lab: for example, methotrexate Ask the class to give examples of what they might consider to be a “drug.” Is a drug something that can be abused? Can caffeine be considered a drug? Does a drug have to treat a disease in order to be classified as such? Name drugs with which the class is most familiar. Which are generic names and which are brand names?

Pharmacology Professionals Pharmacist (PharmD) Pharmacologist (MD or PhD) Subspecialties include: Medicinal chemistry (synthesize new drugs) Molecular pharmacology (interaction of drugs and subcellular structures) Chemotherapy (drugs that destroy microorganisms, parasites, malignant cells) Toxicology (harmful effects of drugs and antidotes) Only M.D.s can prescribe drugs in this country. Is this the same in other countries? Are there prescribed drugs in this country that are available as over-the-counter drugs in other countries?

Biological Effects of Drugs Pharmacodynamics: drug effects in the body Pharmacokinetics: calculation of drug concentration in tissues and blood over a period. How does the body alter drugs when they are ingested? What does “first pass” effect mean? Have students look up the definition of this term. What sorts of things might professionals who develop medicines have to consider about pharmacokinetics when they develop a drug?

QUICK QUIZ: Which term means below the skin? intravenous subcutaneous intracavity transdermal Correct answer is B: subcutaneous

QUICK QUIZ: Which term means below the skin? intravenous subcutaneous intracavity transdermal Correct answer is B: subcutaneous

Drug Names, Standards, and References Chemical Name: chemical formula Generic Name: legal and scientific name Brand Name: trademark of drug manufacturer Look up examples in the PDR or a drug manufacturer’s manual and show students the many ways that drugs are listed and referenced. Also look up pictures of pills, tablets, etc. in the PDR. Is there an advantage to this system? Chemical name Generic name Brand name 6-aminopenicillanic acid ampicillin Omnipen Polycillin

Drug Standards and References Food and Drug Administration (FDA) United States Pharmacopeia (USP) Hospital Formulary Physicians’ Desk Reference® (PDR®)

Administration of Drugs Oral Sublingual Rectal Parenteral: Intracavitary injection Intradermal injection Intramuscular injection (IM) Intrathecal injection Intravenous injection Subcutaneous injection (SC) Inhalation Topical Application Ask students for one example of the benefits of each of these routes of drug administration. Give examples of specific drugs that are more effective via a certain route. Discuss how changing the route can make a therapeutic drug toxic, or easily abused. (Ritalin is an example. When taken orally, it has therapeutic effects on attention. When taken intranasally or inhaled, a person gets high and might start to abuse it like cocaine.)

Terminology of Drug Action Receptor: target of drug Action and interaction of drugs in the body: Combination of Two Drugs Additive action Antagonistic Synergistic Other Actions of Drugs Tolerance Addiction What is the difference between tolerance and addiction? Ask students why a person can become sensitized to a drug (reverse tolerance) and be addicted even though it takes less of the drug to have the same effect. How does this phenomenon cause drug overdoses?

QUICK QUIZ: The combination of two drugs is greater than the total effects of each drug by itself: _______ synergism (potentiation) tolerance additive action idiosyncrasy Correct answer is A: synergism

QUICK QUIZ: The combination of two drugs is greater than the total effects of each drug by itself: _______ synergism (potentiation) tolerance additive action idiosyncrasy Correct answer is A: synergism

Drug Toxicity Poisonous and potentially dangerous effects of drugs Idiosyncrasy (e.g., anaphylaxis) Iatrogenic (produced by treatment) Side effects (routine, often tolerable) Contraindications (dangerous and ill-advised use) Give examples of each of these toxic effects of drugs and make certain the student knows which effects are common and which are dangerous. What are some of the things that must be considered when prescribing drugs? Give examples of drugs that use the kidneys for elimination and what must be considered by the physician in this scenario. Give examples of specific drugs and ask students to look up and report contraindications for each drug. Pregnancy is an example of a contraindication for most drugs.