Pharmacology Clear and Simple A Guide to Drug Classifications and Dosage Calculations by Cynthia J. GRADED A+. COMPREHENSIVE DOC

INTRODUCTION TO PHARMACOLOGY 1 CHAPTER 1 History of Pharmacology 3 History of Pharmacology 4 Sources of Drugs 6 Categorizing Medications 8 The Roles of the Licensed Practical Nurse, Licensed Vocational Nurse, and M ...

INTRODUCTION TO PHARMACOLOGY 1 CHAPTER 1 History of Pharmacology 3 History of Pharmacology 4 Sources of Drugs 6 Categorizing Medications 8 The Roles of the Licensed Practical Nurse, Licensed Vocational Nurse, and Medical Assistant in the Administration of Medications 10 CHAPTER 2 Basics of Pharmacology 15 What is Pharmacology? 16 The Drug Cycle 16 Issues Affecting the Drug Cycle 19 The Importance of Side Effects 20 Drug Resources for Information 22 CHAPTER 3 Patient Safety in Medication Administration 31 Patient Rights for Safety 32 The Right Route and Technique 34 Medication Names and Abbreviations 35 Factors Affecting Medication Administration 37 Protecting the Patient: Ethical and Safety Considerations 40 Protecting the Health-Care Worker 42 CHAPTER 4 Regulations 51 History of Drug Regulations 52 The FDA and Drug Development 53 Drug Control 60 Substance Abuse 64 CHAPTER 5 Prescriptions and Labels 73 Medication Orders 74 Parts of a Prescription 76 Drug Labels 79 UNIT 2 CALCULATIONS 87 CHAPTER 6 Review of Mathematics 89 Working with Fractions 90 Decimals 98 Ratios and Proportions 104 Solving for an Unknown 108 Contents xii Contents CHAPTER 7 Measurement Systems 117 Measurement Systems 117 CHAPTER 8 Dosage Calculations 131 Methods for Calculating Drug Dosages 132 Special Circumstances 140 Reconstituting Powders 143 Parenteral Calculations 143 Calculating Fluid Balance 148 UNIT 3 ADMINISTRATION OF MEDICATIONS 155 CHAPTER 9 Enteral Medications and Administration 157 Enteral Medications 158 CHAPTER 10 Parenteral Medications and Administration 171 Parenteral Medications 172 Topical Medications and Administration 172 Ophthalmic Medications and Administration 175 Otic Medications and Administration 176 Vaginal Medications and Administration 176 Nasal Route of Medication Administration 178 Inhaled Medications and Administration 180 Injectable Medications 183 UNIT 4 CLASSIFICATIONS OF DRUGS 213 CHAPTER 11 Integumentary System Medications 215 Integumentary System: Vulnerable Barrier 216 Skin Infections and Medications 216 Inflammatory Conditions and Medications 219 Skin Cancer and Medications 221 CHAPTER 12 Musculoskeletal System Medications 229 The Musculoskeletal System 230 Medications Used to Treat Muscular Disorders 231 Medications Used to Treat Abnormal Calcium Levels 232 Medications for Bone and Joint Inflammation 233 Medications to Treat Phantom Limb Pain 235 CHAPTER 13 Nervous System Medications 243 The Nervous System 244 The Autonomic Nervous System and Medications 245 Medications to Control Pain and Fever 246 Medications to Treat Anxiety, Insomnia, Sedation, and Seizures 248 Medications to Treat Behavioral, Emotional, and Mood Disorders 250 Medications to Treat Degenerative Disorders 252 Contents xiii Local and General Anesthetic Medications 254 Alcohol 255 CHAPTER 14 Eye and Ear Medications 267 The Eye 268 Eye Medications 268 The Ear 271 Ear Medications 272 Medications and Ototoxicity 273 CHAPTER 15 Endocrine System Medications 281 The Endocrine System 282 Endocrine System Medications 286 Medications That Treat Adrenal Disorders 291 CHAPTER 16 Cardiovascular System Medications 299 The Cardiovascular System 300 Myocardial Infarction, Stroke, and Clotting 302 Cardiovascular Medications 302 Medications for Lipid Disorders 311 CHAPTER 17 Immunological System Medications 323 The Immune Response 324 Medications That Affect the Immune System 325 CHAPTER 18 Pulmonary System Medications 353 The Pulmonary System 353 Pulmonary Medications 355 CHAPTER 19 Gastrointestinal System Medications 367 Gastrointestinal System 368 Gastrointestinal Medications 369 CHAPTER 20 Reproductive and Urinary System Medications 389 Hormones of the Reproductive System 390 Medications for Disorders Related to Female Hormones 390 Labor Medications 394 Infertility Medications 395 Medications for Other Female Reproductive Disorders 395 Medications for Male Reproductive Disorders 396 The Urinary System 396 CHAPTER 21 Vitamins, Minerals, Herbs, and Complementary and Alternative Medicine 409 Vitamins 410 Minerals, Lipids, and Amino Acids 413 Herbal Medicines 416 Complementary and Alternative Medicine 417 xiv Contents GLOSSARY 425 APPENDIX A Drug Classifications 443 APPENDIX B Drug Classification Index by Generic Name 447 APPENDIX C Controlled Substances Schedules 463 APPENDIX D Routine Pediatric and Adult Immunizations 465 APPENDIX E Administering Medications to Children 475 APPENDIX F Pediatric Dosage Calculations 477 APPENDIX G Examples of Herbs, Vitamins, Minerals, Amino Acids, and Lipids Used as Remedies 479 APPENDIX H Basic Math Concepts 489 APPENDIX I Answers to Check Ups 491 INDEX 503 1 Introduction to Pharmacology 1 CHAPTER 1 History of Pharmacology 3 CHAPTER 2 Basics of Pharmacology 15 CHAPTER 3 Patient Safety in Medication Administration 31 CHAPTER 4 Regulations 51 CHAPTER 5 Prescriptions and Labels 73 3 1 CHAPTER History of Pharmacology Medications, their origins, and their uses are older than any written records that we have. Many ancient cultures have contributed to the knowledge base and evolution of pharmacology, including Greek, Chinese, Egyptian, Persian, and Arabic. The healers were called by many names, but all shared an extensive knowledge of plants, minerals, and animal products. Pharmacology has evolved significantly from the days when these resources were used to cure the ill without understanding why they worked or did not work. Some ancient remedies are still valuable medicines today, whereas others have been discarded as worthless or dangerous. With the advent of scientific inquiry and technology, researchers around the world have created new and better medications. The ability to isolate pure substances and formulate drugs in a laboratory enables pharmaceutical companies to mass-produce needed medicines in a timely manner. In this chapter, you will learn about the history of pharmacology and sources used for developing drugs; the acceptance of alternative medicine, and its place in medicine; and the six main categories of drugs and their uses. LEARNING OUTCOMES At the end of this chapter, you should be able to: 1.1 Define all key terms. 1.2 List three societies critical to the development and evolution of pharmacology. 1.3 List four sources of drugs. 1.4 List 10 drugs, and record their sources. 4 UNIT 1 Introduction to Pharmacology KEY TERMS Al-Hawi Alternative medicine Antineoplastic Bovine Curative Destructive Diagnostic Drug/droog Ebers Papyrus Palliative Pharmacodynamics Pharmacology Pharmakon Porcine Prophylactic Replacement drugs Synthetic drugs ■ HISTORY OF PHARMACOLOGY The history of pharmacology helps us to understand that even though there have been huge advances in medications, scientists are coming to understand that by disregarding ancient practices, they have been missing a treasure trove of useful medications. Many practitioners are utilizing alternative medicine to maximize their patients’ health, and scientists are looking to older remedies to see if and why they work and how to reproduce them in the modern world. We as practitioners also need to understand that many patients are using many different forms of self-medication, from home remedies to substances they learned about on an infomercial that promise to cure all types of problems; if these substances are not understood, they may interfere or counteract a prescribed pharmaceutical medication. In other words, we need a complete picture of every substance patients are taking in order to assist in their care. The term pharmacology is of Greek origin from two words: pharmakon, meaning “medicine,” and ology, meaning “the study of.” Pharmakon also meant poison and remedy, poison because some of the early medicines were toxic enough to kill, and remedy because, at times, early medicines cured the illness. The word drug has a Dutch origin in which droog meant “dry” as in the use of dry herbs. Most ancient societies had little knowledge about the human body and how it worked, so treating illness was often based on trial and error. Early records document that treatments consisted of plants, minerals, and animal products because no other sources were available. “Healers” were known as wise men, shamans, witch doctors, medicine men and women, and so on (Fig. 1-1), depending on the culture, and were chosen based on their knowledge of which plants or other substance to use, how to prepare it, and how much to give the patient. Pharmacology in Ancient Times and Cultures Early documentation of medicine and various remedies is evident in several cultures. For example, “The Yellow Emperors’ Inner Classic,” a Chinese document, was a very early discussion of yin-yang and acupuncture. The first Chinese manual on pharmacology was written in the first century A.D. and included 365 medicines, 252 of which were herbs. In Egypt, a medical document called the Ebers Papyrus was written circa 1550 B.C. and lists about 700 “recipes” for a host of illnesses, from crocodile bites to psychiatric illnesses. Another document, the Al-Hawi, is a large, 20-volume medical book written by the physician Al-Razi in ancient Persia (Iran). It was translated into Latin in the 13th century and greatly influenced medicine in medieval Europe. The contributions from these cultures led to the advancement of pharmacology. When treatments for many conditions were discovered, the findings were recorded on papyrus or paper to pass on to future generations. Documenting this early information was extremely important, as belief systems changed over time. Without these earlier writings, traditional oral knowledge might have been lost or suppressed and much progress could not have been made. During the 17th and 18th centuries, there was a real lack of knowledge in the use of medications and their dangers. A prime example of this is mercury, which was used for a variety of ailments from skin conditions to syphilis. Specifically, in the late 1700s a prominent physician, Dr. Benjamin Rush used a mercury compound in high doses to treat yellow fever patients. Of course, it has since been discovered that mercury is so harmful to humans that we no longer use mercury blood pressure cuffs or thermometers for fear of exposure. CHAPTER 1 History of Pharmacology 5 Pharmacological Advances Through the 19th and 20th Centuries Over time, an increasingly scientific approach to the discovery and understanding of drugs was taken. During the 1800s, chemists were able to identify and then isolate the active ingredients (those pure chemicals in the plants that had the actual therapeutic properties). They were also able to determine how the drug acted on the body. This marked the beginning of modern pharmacology. Up until the early 1900s, preparing medicine was very labor-intensive; the pharmacist had to distill and prepare each medicine when it was ordered (Fig. 1-2). Not until World War II (1939 to 1945) did the mass-production of medicine begin (Fig. 1-3). More U.S. soldiers died in World War I from infection and accidents than from actual combat injuries; however, the mass-production of penicillin minimized the number of deaths from infection during World War II (Table 1-1). For instance, the death rate from pneumonia FIGURE 1-2: Pharmacist preparing a prescription, 1939. (From the Library of Congress Prints and Photographs Division, Washington, D.C.) FIGURE 1-1: Eskimo medicine man. (From the Library of Congress Prints and Photographs Division, Washington, D.C.) 6 UNIT 1 Introduction to Pharmacology in the U.S. Army was 18% during World War I, decreasing to 1% during World War II. Death from combat injuries complicated by infections also decreased. With the discoveries of new drugs like penicillin that could save millions of lives, the belief grew that new drugs must be better than old standard herbs and treatments, especially if created or refined in a scientific manner. Pharmacology therefore advanced rapidly in the second half of the 20th century as many new drugs were either discovered or developed. In an effort to discover possible new drugs, researchers studied plants, marine animals, and micro-organisms in soil, water, and air. Partially or totally synthesized medications were produced by combining two or more compounds or elements. Partially synthesized medications were made by adding a pure chemical to a natural substance. Totally synthesized medications were created by combing two or more pure chemicals to produce a new substance that could be used as a medication. One major breakthrough was the discovery of ways to create large amounts of viable drugs from a small amount of natural resources using genetic engineering. For example, human insulin can be mass-produced by adding the human insulin gene to a nonpathogenic strain of Escherichia coli. Pharmacology in the 21st Century In the 21st century science is booming. One of the most promising advances in the field of medications is that of pharmacogenetics, which is the “study of individual candidate genes as powerful tools to explain interindividual variability in drug response.” In other words, the patient’s genetic material is analyzed, and then in the case of cancer, the tumor’s genetics are analyzed to figure out the best drug and what dosage will work best to combat the disease. Currently there are certain medications and doses used to treat conditions for every adult patient with that condition. Through these advances in pharmacogenetics, the ability to individualize drugs and their dosage is happening in the treatment of HIV and rheumatoid arthritis. In addition, the hope is that in the future we can specifically tailor drugs and dosages for opioids and antihypertensives among other medications. ■ SOURCES OF DRUGS Although most drugs are now manufactured in laboratories, many agents are still derived from natural substances such as plants, animals, minerals, and toxins. Some are utilized by extracting active ingredients from animals or plants and using these ingredients to manufacture a medication. Other times FIGURE 1-3: Mass-production of medication, 1944. (From the Library of Congress Prints and Photographs Division, Washington, D.C.) TABLE 1.1 U.S. Casualties in Major Wars War Number Serving Battle Deaths Disease and Accidents Civil War 2,213,363 140,414 224,097 Spanish-American War 306,760 385 2,061 World War I 4,743,826 53,513 63,195 World War II 16,353,659 292,131 115,185 Source: U.S. Department of Justice CHAPTER 1 History of Pharmacology 7 the original or natural source serves as a template for creating a synthetic equivalent, which is especially useful if the natural source is a rare plant. Scientists are constantly researching natural sources (plants, animals, marine animals, and microbes) in the hope of finding new sources of medications. Some drugs are made by combining chemicals with natural products, such as hydrocodone, which combines natural opium in the form of codeine combined with acetaminophen (a man-made medication), whereas other drugs are synthesized in a laboratory. Barbiturates are an example of synthetic drugs because they are chemically derived from barbituric acid (itself an artificial compound of urea and malonic acid). Plants Today plants are rarely used as medications; instead the active component of the plant is extracted and utilized in the manufacturing of the drug. Digoxin (Lanoxin), a drug used to treat heart failure, is made from the foxglove plant and has been used for healing since the 1500s. Most estrogen hormone replacements come from yams. Procaine (Novocain), used as an anesthetic, is derived from the coca plant. Rose hips are a rich source of vitamin C and are sold as an ingredient in vitamin C supplements. Aspirin (acetylsalicylic acid) is a compound based on salicin, which is found in the bark of a white willow tree, and is used to relieve pain and to treat inflammation. Unfortunately, as less land becomes available for growing plants, fewer plants will exist for making medications. For example, as the rain forest diminishes, the rare plants that are located only in this environment may become extinct. In this instance, these rare plants are used as a template to manufacture a medication instead of using the plants and depleting them. CRITICAL THINKING If people rely on plants for medication, what effect does the increasing human population have on the potential supply of medications? ❋? Animals Domesticated animals are also a source of drugs. To ensure the purity of the drugs, donor animals are generally well cared for. Some examples include sheep, which provide lanolin, a topical skin medication that comes from the wool. Cows (bovine) and pigs (porcine) are good sources of hormone replacements. If a patient’s body cannot manufacture a hormone, animal hormones can serve as a substitute. Horses provide humans with the replacement hormone conjugated estrogen (Premarin), which comes from a pregnant mare’s urine. In addition, insulin is collected from the pancreases of cows or pigs. We obtain IGG (Immunoglobulin G) by injecting an antigen into animals (most commonly cows) and collecting the antibody that is formed. The drug heparin is extracted from porcine intestinal mucosa and bovine lungs. CRITICAL THINKING Cows and pigs are good sources of hormones. Do you think animals may be a better hormone source than humans? Why or why not? ❋? Minerals When foods grown from rich soil are unavailable, calcium, iron, zinc, magnesium, copper, and selenium are some of the minerals that are offered as necessary supplements. For patients taking certain medications, mineral replacement is critical. Diuretic drugs such as furosemide (Lasix) cause the body to lose excess water through the kidneys, and potassium, a vital mineral, is also excreted with the water. Potassium is needed for the heart to function normally, so supplemental potassium chloride is frequently prescribed in addition to the medication. Potassium is also contained in sweet potatoes, bananas, and oranges. Minerals are also used to treat certain conditions. For example, gold is used in the treatment of arthritis, iodine is used to treat goiter, and magnesium sulfate is used for constipation and eclampsia. 8 UNIT 1 Introduction to Pharmacology Toxins Toxins, by definition, are poisons. Despite this fact, chemical and biological toxins are commonly used in medicine. The key is in the dosage. For instance, certain radioactive chemicals are used to diagnose and treat illnesses. Radioactive iodine, for example, in small doses can help pinpoint problems in a patient’s thyroid, a small gland in the neck. In higher doses, radioactive iodine is used to shrink thyroid tumors. Biological toxins can also be used in medicine. Botulinum toxin (Botox), which comes from a bacterium called Clostridium botulinum, is used in patients with torticollis (a condition in which neck muscles contract causing the head to turn to one side), strabismus (eye misalignment), and migraines. It is used in tiny doses. CRITICAL THINKING What are some of the dangers of using toxins as medicine? ❋? CRITICAL THINKING What are some of the ethical issues of genetically engineered drugs? ❋? Synthetic Medications Synthetic drugs can be created by chemical processes, genetic engineering, or by altering animal cells. Often, drugs that are obtained from another source can be synthesized in the laboratory, thus preserving natural resources. For example, paclitaxel (Taxol), a drug for patients with cancer, was first made from the bark of the Pacific yew tree. Then a template or blueprint was developed to create a synthetic form of this drug, thus preserving the yew tree. Insulin can be obtained from pigs or cows, but a synthetic source is most commonly used. Human insulin is produced by using recombinant technology to add the insulin gene into a nonpathogenic strain of E. coli. This change occurred because of concern over the possible transmission of disease from animals to humans. In addition, there is a risk for immune reactions because of impurities found in the animal products. One additional advantage is that synthetic medications are usually more inexpensive because they are mass-produced. Because scientists have been able to map the human genome, it is becoming possible to choose medications that are appropriate for individual patients, not patients as a whole. One area of uniqueness is the variation in the amount of drug-metabolizing enzymes each patient has and the effectiveness of these enzymes. The scientist can manipulate the DNA material of the medication source by changing it or combining it with DNA from another organism to target the patient’s levels of the drug-metabolizing enzyme. Therefore, prescribers are able to choose drugs that work better for one population than for another. Research is also being conducted on the use of existing drugs in targeted populations. For example, BiDil is a combination of two generic drugs—hydralazine hydrochloride and isosorbide dinitrate—and is used to treat African American patients with heart failure. ■ CATEGORIZING MEDICATIONS The term pharmacodynamics refers to the effect of a drug on the body, or more scientifically, the negative and positive biochemical or physiological changes that a drug creates. Drugs fall into six categories of desired effects (Table 1-2). ■ Curative. Some drugs restore normal physiological function, as in diuretics, which help the body rid itself of excess fluid. ■ Prophylactic. These drugs prevent diseases or disorders, as in antibiotics given before surgery to prevent infection. CHAPTER 1 History of Pharmacology 9 ■ Diagnostic. Some drugs help diagnose a disease, such as barium that patients swallow to help highlight digestive problems on a radiograph. ■ Palliative. Other drugs, such as pain relievers, do not cure disease, but they make patients more comfortable. ■ Replacement. These drugs “replace” missing substances. Levothyroxine sodium (Synthroid), for example, is a drug that replaces a missing thyroid hormone. ■ Destructive. Some medications destroy tumors and microbes. Antineoplastic (anticancer) drugs are an example of destructive, toxic drugs. Medications are used for various reasons during a patient’s life span. As a health-care provider, you must know how the different categories of drugs may affect a patient. Understanding this information will help you provide effective counseling, patient care, and safe administration of drugs depending on your role and scope of practice. TABLE 1.2 Drug Categories Category Curative Prophylactic Diagnostic Palliative Replacement Destructive Main Action Cures or treats a problem Prevents a problem Helps diagnos