CHAPTER 22 Pharmacology Pharmacology Overview Pharmacology Field of

CHAPTER 22 Pharmacology

Pharmacology Overview • Pharmacology – Field of medicine that specializes in the study of drugs, their sources, appearance, chemistry, actions, and uses • Drug – Any substance that when taken into the body, may modify one or more of its functions 2

Pharmacology Overview • Pharmacodynamics – Study of how drugs interact in the human body • Pharmacist – One who is licensed to prepare and dispense drugs 3

Pharmacology Overview • Pharmacy – Drug store • Toxicology – Study of poisons, their detection, their effects – Establishing antidotes and methods of treatment for conditions they produce 4

Drug Laws • Food, Drug, and Cosmetic Act (FDCA) – 1938 – Regulates quality, purity, potency, effectiveness, safety, labeling, and packaging of food, drug, and cosmetic products – Enforced by the Food and Drug Administration (FDA) 5

Drug Laws • Controlled substance act – Regulates manufacture, distribution, and dispensing and administration of controlled substances • Drugs that have the potential of being abused and of causing physical or psychological dependence – Enforced by the Drug Enforcement Administration (DEA) 6

Controlled Substances or Schedule Drugs • Schedule I Drugs – Not considered to be legitimate for medical use in the United States – Used for research only and cannot be prescribed – High risk for abuse • Examples: LSD, heroin, marijuana 7

Controlled Substances or Schedule Drugs • Schedule II Drugs – Accepted medical use but have a high potential for abuse or addiction – Must be ordered by written prescription – Cannot be refilled without a new, written prescription • Examples: morphine, cocaine, codeine, demerol, dilaudid 8

Controlled Substances or Schedule Drugs • Schedule III Drugs – Moderate potential for abuse or addiction, low potential for physical dependence – May be ordered by written prescription or by telephone order – Prescription expires in six months – may not be refilled more than five times in six-month period • Examples: Tylenol with codeine, butisol, hycodan 9

Controlled Substances or Schedule Drugs • Schedule IV Drugs – Less potential for abuse or addiction than those of Schedule III, with limited physical dependence – May be ordered by written prescription or by telephone order – May be refilled up to five times in a sixmonth period – prescription expires in six months • Examples: Librium, valium, darvon, equanil 10

Controlled Substances or Schedule Drugs • Schedule V Drugs – Have a small potential for abuse or addiction – May be ordered by written prescription or by telephone order – No limit on prescription refills – Some of these drugs may not need prescription • Examples: Robitussin-AC, donnagel-PG, lomotil 11

Drug Standards • Rules established to control strength, quality, and purity of medications prepared by various manufacturers – Require all preparations called by the same drug name to be of a uniform strength, quality, and purity 12

Drug Standards • United States Pharmacopeia/National Formulary (USP/NF) – Contains formulas and information that provide standards for preparation and dispensation of drugs • Recognized by U. S. government as the official listing of standardized drugs in the United States • FDCA specifies a drug is official when it is listed in USP/NF 13

Drug References • Available for health professionals responsible for safe administration of medications – Provide the following information: • Composition, action, indications for use, contraindications for use, precautions, side effects, adverse reactions, route of administration, dosage range, and what forms are available 14

Drug References • Hospital formulary – Lists all drugs commonly stocked in the hospital pharmacy – Provides information about the characteristics of drugs and their clinical use 15

Drug References • Physicians’ Desk Reference – Published yearly by Medical Economics Company – Manufacturers pay to list information about their products in the PDR – Same information that appears on Package Inserts (as required by the FDA) • Generic name, indications, contraindications, adverse effects, dosage, and route of administration 16

Drug References • Medical economics company references – Physicians’ Desk Reference for Nonprescription Drugs – Physicians’ Reference for Ophthalmology – Drug Interactions and Side Effects Index – Indications Index 17

Drug References • Drug facts and comparisons – Loose-leaf binder reference that provides information on drugs according to their therapeutic classification • Same basic facts as other drug references – Particularly helpful in comparing the various drugs within each category to other products • In reference to effectiveness, content, and cost 18

Drug Sources 19

Drug Names • Chemical name – Describes chemical structure of the drug – Formula that indicates composition of the drug 20

Drug Names • Generic name – Name that was established when drug was first manufactured • Written in lowercase letters – Official name of a drug – Each drug has only one generic name – Original manufacturer is only company that can use generic name for the first 17 years 21

Drug Names • Brand name – Name under which the drug is sold by a specific manufacturer • Spelling always begins with a capital letter – Also known as the Trade Name – Name is owned by the drug company and no other company may use that name • Each brand name carries a registered trademark symbol ® 22

Drug Actions – Drug Interactions • Drug actions – How drugs produce changes within the body • Drug effect – Changes that take place in the body as a result of drug action • Slowing down or speeding up processes • Destroying certain cells or parts of cells • Replacing substances that the body lacks or fails to produce 23

Drug Actions – Drug Interactions • Desired effect – Effect of drug in the body that was intended • Side effect – Additional effect on the body by the drug that was not part of the goal for that medication • Not usually severe enough to warrant discontinuing the medication 24

Drug Actions – Drug Interactions • Adverse reaction – One in which the body reacts to a drug in an unexpected way that may endanger a patient’s health and safety • Contraindication – Any special symptom or circumstance that indicates that the use of a particular drug or procedure is dangerous, not advised, or has not been proven safe for administration 25

Drug Actions – Drug Interactions • Local effect – Response to a medication that is confined to a specific part of the body • Systemic effect – Generalized or widespread response to a drug by the body because it is absorbed into the bloodstream 26

Drug Actions – Drug Interactions • Cumulation – Occurs when a drug is not completely excreted from the body before another dose is given – Drug starts to accumulate in the body tissues when repeated doses are given • Toxic effects may occur 27

Drug Actions – Drug Interactions • Idiosyncracy – An unusual, inappropriate response to a drug or to the usual effective dose of a drug – Anaphylactic Shock = severe idiosyncratic reaction • Acute respiratory distress, hypotension, edema, tachycardia, cool pale skin, cyanosis, and possible convulsions shortly after administration of the medication 28

Drug Actions – Drug Interactions • Potentiation – Occurs when two drugs administered together produce a more powerful response than the sum of their individual effects • Tolerance – Resistance to effect of a drug • A characteristic of drug addiction 29

Routes of Administration • Oral – Given by mouth and swallowed – Advantage • Easiest and safest method • Most economical method – Disadvantage • Slow method of absorption • Possibility of being destroyed by gastric juices 30

Routes of Administration • Sublingual – Placed under the tongue – dissolves in saliva – Advantage • More rapid absorption rate than oral • Higher concentration of medication reaches bloodstream – Disadvantage • Not convenient route of administration for badtasting medications or irritating medications 31

Routes of Administration • Buccal – Placed in mouth next to cheek (tablet form) – Advantage • More rapid absorption rate than oral • Higher concentration of medication reaches bloodstream – Disadvantage • Possibility of swallowing the pill 32

Routes of Administration • Inhalation – Medication is sprayed or inhaled into nose, throat, and lungs – Advantage • Good absorption due to large surface contact area • Provides rapid treatment – Disadvantage • Sometimes difficult to regulate dose • Not suitable method for medications that irritate mucous membrane lining 33

Routes of Administration • Rectal – Medication inserted into rectum and is slowly absorbed into mucous membrane lining of rectum (suppository) – Advantage • One method of choice when patient is nauseated or cannot take medications orally – Disadvantage • Absorption is slow and irregular 34

Routes of Administration • Vaginal – Medication is inserted into the vagina in the form of a suppository, cream, foam, or tablet – Advantage • Easiest method for treating the specific area – Disadvantage • Medications sometimes stain underwear • No other disadvantages 35

Routes of Administration • Topical – Medication is applied directly to the skin or mucous membrane for a local effect to area – Advantage • Easy method, convenient – Disadvantage • Slow absorption through skin 36

Routes of Administration • Transdermal – Method of applying a pre-measured amount of medicine to unbroken skin through an adhesive-backed disk – Advantage • Good method for administering medications slowly into bloodstream over a period of time – Disadvantage • Units can be dangerous if they come in contact with skin of children or pets 37

Routes of Administration • Parenteral – Administered by injecting medication into body using a needle and syringe – Must be in liquid form – Administered by one of following methods • • Intradermal Intramuscular Intravenous Subcutaneous 38

Routes of Administration • Intradermal – Small amount of medication is injected just beneath epidermis – Used for allergy testing, tuberculin skin testing, and some vaccinations • Needle Angle: 10 to 15 -degree 39

Routes of Administration • Intramuscular – Medication is injected directly into muscle – Used for administering antibiotics, medications that might be irritating to layers of the skin, and medications that require dosages larger than amount allowed for subcutaneous injections • Needle Angle: 90 -degree 40

Routes of Administration • Intravenous – Medication is injected directly into the vein, entering the bloodstream immediately – Used when medication is needed quickly – Used for infusing medication over a period of time, by adding the medication to a bag of intravenous fluids • Needle Angle: 25 -degree 41

Routes of Administration • Subcutaneous – Medication is injected into subcutaneous layer, or fatty tissue of skin – Used for administering insulin, hormones, and local anesthetics • Needle Angle: 45 -degree 42

Parenteral Routes of Administration 43

DRUG CLASSIFICATIONS Pharmacology

Analgesic • Pronounced – (an-al-JEE-sik) • General definition – Relieves pain • Example: acetylsalicylic acid, aspirin, Bayer Children’s Aspirin 45

Anesthetic • Pronounced – (an-ess-THET-ik) • General definition – Partially or completely numbs or eliminates sensitivity with or without loss of consciousness • Example: lidocaine (Xylocaine) 46

Antiarrhythmic • Pronounced – (an-tee-ah-RITH-mik) • General definition – Corrects cardiac arrhythmias (irregular beats) • Example: digoxin (Lanoxin) 47

Antibiotic (Anti-infective) • Pronounced – (an-tih-BYE-ot-ik) • General definition – Stops or controls growth of infection-causing microorganisms • Example: phenoxymethyl-penicillin sodium (Pen. Vee-K, Penicillin VK, Veetids, V-Cillin K) 48

Anticoagulant • Pronounced – (an-ti-koh-AG-yoo-lant) • General definition – Prevents clot continuation and formation • Example: warfarin sodium (Coumadin) 49

Anticonvulsant • Pronounced – (an-tih-kon-VULL-sant) • General definition – Prevents or relieves convulsions (seizures) • Example: clonazepam (Klonopin) 50

Antidepressant • Pronounced – (an-tih-dee-PRESS-ant) • General definition – Prevents, cures, or alleviates mental depression • Example: amitriptyline hydrochloride (Elavil, Amitril) 51

Antidiabetic • Pronounced – (an-tih-dye-ah-BET-ik) • General definition – Helps control the blood sugar level • Example: metformin (Glucophage) 52

Antidiarrheal • Pronounced – (an-tih-dye-ah-REE-ul) • General definition – Prevents or treats diarrhea • Example: loperamide hydrochloride (Imodium) 53

Antidiuretic • Pronounced – (an-tih-dye-yoo-REH-tic) • General definition – Suppresses the formation of urine • Example: vasopressin (Pitressin) 54

Antiemetic • Pronounced – (an-tih-ee-MET-ik) • General definition – Prevents or relieves nausea and vomiting • Example: meclizine hydrochloride (Bonine, Dramamine II, Antivert) 55

Antifungal • Pronounced – (an-tih-FUNG-gal) • General definition – Destroys or inhibits the growth of fungi • Example: fluconazole (Diflucan) 56

Antihistamine • Pronounced – (an-tih-HISS-tah-meen) • General definition – Opposes action of histamine, released in allergic reactions • Example: cetirizine (Zyrtec) 57

Antihypertensive • Pronounced – (an-tih-high-per-TEN-siv) • General definition – Prevents or controls high blood pressure • Example: nadolol (Corgard) 58

Anti-infective (Antibiotic) • Pronounced – (an-tih-in-FEK-tiv) • General definition – Stops or controls the growth of infectioncausing microorganisms • Example: amoxycillin (Amoxil, Polymox) 59

Anti-Inflammatory • Pronounced – (an-tih-in-FLAM-ah-toh-ree) • General definition – Counteracts inflammation in body • Example: naproxen sodium (Anaprox, Aleve) 60

Antineoplastic • Pronounced – (an-tih-nee-oh-PLASS-tik) • General definition – Prevents development, growth, or reproduction of cancerous cells • Example: fluorouracil (Adrucil) 61

Antitussive • Pronounced – (an-tih-TUSS-iv) • General definition – Relieves cough due to various causes • Example: dextromethorphan hydrobromide (Benylin DM, Robitussin Pediatric, Vick’s Formula 44) 62

Antiulcer Agent • Pronounced – (an-tih-ULL-ser agent) • General definition – Treats and prevents peptic ulcer and gastric hypersecretion • Example: ranitidine hydrochloride (Zantac) 63

Antiviral Agent • Pronounced – (an-tih-VYE-ral agent) • General definition – Treats various viral conditions such as serious herpes virus infections, chickenpox, and influenza A • Example: acyclovir (Zovirax) 64

Beta Blocker • Pronounced – (BAY-tah BLOCK-er) • General definition – Treats hypertension, angina, and various abnormal heart rhythms • Example: metoprolol tartrate (Lopressor) 65

Bronchodilator • Pronounced – (brong-koh-DYE-lay-tor) • General definition – Expands bronchial tubes by relaxing bronchial muscles • Example: theophylline (Bronkodyl) 66

Calcium Channel Blocker • Pronounced – (KAL-see-um CHAN-ell BLOCK-er) • General definition – Treats hypertension, angina, and various abnormal heart rhythms • Example: amlodipine (Norvasc) 67

Diuretic • Pronounced – (dye-yoor-RET-ik) • General definition – Increases urine secretion • Example: furosemide (Lasix) 68

Hormone • Pronounced – (HOR-mohn) • General definition – Treats deficiency states where specific hormone level is abnormally low • Example: estrogen, conjugated (Premarin) 69

Hypnotic • Pronounced – (hip-NOT-ik) • General definition – Induces sleep or dulls the senses • Example: pentobarbital (Nembutal) 70

Immunosuppressant • Pronounced – (im-yoo-noh-suh-PRESS-ant) • General definition – Suppresses the body’s natural immune response to an antigen, as in treatment for transplant patients • Example: cyclosporine (Sandimmune) 71

Laxative • Pronounced – (LACK-sah-tiv) • General definition – Prevents constipation or promotes the emptying of the bowel contents with ease • Example: docusate calcium (Surfak) 72

Lipid-Lowering Agent • Pronounced – (LIP-id lowering agent) • General definition – Reduces blood lipid (fat) levels • Example: atorvastatin (Lipitor) 73

Sedative • Pronounced – (SED-ah-tiv) • General definition – Exerts a soothing or tranquilizing effect on the body • Example: phenobarbital (Nembutal) 74

Skeletal Muscle Relaxant • Pronounced – (SKELL-eh-tal muscle rih-LAK-sant) • General definition – Relieves muscle tension • Example: carisoprodol (Soma) 75

Vitamin • Pronounced – (VIGH-tah-min) • General definition – Prevents and treats vitamin deficiencies and used as dietary supplement • Example: ascorbic acid (vitamin C) 76

Common Charting Abbreviations • Guidelines – Medical abbreviations are a form of shorthand • Serve as a universal language for medical professionals • Provide specific information and/or orders in an abbreviated format – Health professional should use standard abbreviations accepted by their place of employment • When abbreviations have more than one meaning 77