NR 293 QUESTIONS AND ANSWERS Week 1-Pharm

NR 293 QUESTIONS AND ANSWERS Week 1-Pharm Chapter 1 The nursing process • A research-supported organizational framework for professional nursing practice • Ensures the delivery of thorough, individualized, and quality nursing care to patients • Requires critical thinking • Ongoing and constantly evolving process Contemporary Trends: The Quality and Safety Education for Nurses (QSEN) Project • Preparing future nurses with the knowledge, skills, and attitudes (KSAs) needed to continuously improve the quality and safety of patient care within the health care system • KSAs flow out of the QSEN initiatives and are being integrated into nursing education curricula and clinical outcomes. Six Major Initiatives of QSEN • Patient-centered care • Teamwork and collaboration • Evidence-based practice (EBP) • Quality improvement (QI) • Safety • Informatics Contemporary Trends: Interprofessional Education Collaboration (IPEC) • Objective: Develop core competencies for interprofessional collaborative practice Interprofessional education occurs when students from two or more professionals learn from and with each other. • Goal: Improve health outcomes Five Steps of the Nursing Process • Assessment • Nursing diagnosis • Planning Goals Outcome criteria (measurement) • Implementation, including patient education • Evaluation Assessment • Data collection, review, and analysis • Medication profile Any and all drug use Prescriptions Over-the-counter medications Vitamins, herbs, and supplements Compliance and adherence • ONLY RN CAN DO IT!!!! Planning • Identification of goals and outcome criteria • Goals Objective, measurable, and realistic with an established time period for achievement of the outcomes that are specifically stated in the outcome criteria • Outcome criteria Concrete descriptions of patient goals Expectations for behavior For drug therapy: outcome is safe and effective administration of medications Implementation • Initiation and completion of specific nursing actions as defined by the nursing diagnoses, goals, and outcome criteria • Independent, collaborative, and dependent The “Rights” of Medication Administration • Right drug • Right dose • Right time • Right route • Right patient • Right documentation Current practice standards suggest these additional “Rights”: • Right reason or indication • Right to refuse Roles of Nursing Students in Medication Administration • Must do: o Safe medication practices and contribute to a culture of safety o Know the limits of own knowledge and judgement, and seek help o Assess the appropriateness of the medication practice by considering the patient, the medication, and the environment o Adhere to the facility Policy expectations for direct supervision when administering • Nursing student need to assess o Drug allergies o Drugs expected actions, dose range, side effects of the medication, and any precautions to be taken o The developmental stage of the infant/child/adolescent patient as well as adults and elderly patients o Any alterations in the patient’s condition or functional status which interferes with their physical capacity to take medication (for instance not being able to swallow oral medications) Chapter 2 Overview • Drug Any chemical that affects the physiologic processes of a living organism • Pharmacology Study or science of drugs Encompasses a variety of principles Drug Names Chemical name • Describes the drug’s chemical composition and molecular structure Generic name (nonproprietary name) • Name given by the United States Adopted Names Council Trade name (proprietary name) • The drug has a registered trademark; use of the name is restricted by the drug’s patent owner (usually the manufacturer). • Drug Classifications Drugs are grouped together based on similar properties • Drug classifications Structure (ex. beta blocker) • Subclass (ex. selective, nonselective) Therapeutic use (ex. antibiotic) • Subclass (ex. penicillins) Prototypical drugs: first drug in a class of drugs Pharmacologic Principles • Pharmaceutics • Pharmacokinetics • Pharmacodynamics • Pharmacogenomics (pharmacogenetics) • Pharmacotherapeutics • Pharmacognosy • Pharmacoeconomics • Toxicology Definition of Pharmaceutics • The study of how various drug forms influence the way in which the drug affects the body. • Dissolution—dissolving of solid dosage forms and their absorption Definition of Pharmacokinetics (BODY) • The study of what the body does to the drug o Absorption o Distribution o Metabolism o Excretion Definition of Pharmacodynamics • The study of what the drug does to the body Definition of Pharmacotherapeutics • The clinical use of drugs to prevent and treat diseases • Defines principles of drug actions—the cellular processes that change in response to the presence of drug molecules • Drugs are organized into pharmacologic classes. Definition of Toxicology • Science of the adverse effects of chemicals on living organisms • Clinical toxicology deals specifically with the care of poisoned patients. Definition of Pharmacognosy • The study of natural (versus synthetic) drug sources (i.e., plant, animals, minerals) Definition of Pharmacoeconomics • Study of the economic factors influencing the cost of drug therapy • Cost–benefit analysis Pharmaceutics • Different drug dosage forms have different pharmaceutical properties. • Dosage form determines drug dissolution rate. Enteral Route • The drug is absorbed into the systemic circulation through the oral or gastric mucosa or the small intestine. o Oral o Sublingual o Buccal o Rectal (can also be topical) Parenteral Route • Intravenous (fastest delivery into the blood circulation) • Intramuscular • Subcutaneous • Intradermal • Intraarterial • Intrathecal • Intraarticular Topical Route • Skin (including transdermal patches) • Eyes • Ears • Nose • Lungs (inhalation) • Rectum • Vagina Pharmacokinetics • Absorption Bioavailability • The extent of drug absorption First pass effect • Large proportion of a drug is chemically changed into inactive metabolites by the liver. • Much smaller amount will be bioavailable. • Distribution Transport of a drug by the bloodstream to its site of action Albumin is the most common blood protein and carries the majority of protein-bound drug molecules. Metabolism • Also referred to as biotransformation • Biochemical alteration of a drug into an inactive metabolite, a more soluble compound, a more potent active metabolite (as in the conversion of an inactive prodrug to its active form), or a less active metabolite. Metabolism (cont.) • Cytochrome P-450 enzymes (or simply P-450 enzymes), also known as microsomal enzymes • Lipophilic: “fat loving” • Hydrophilic: “water loving” • Enzymes Excretion • Elimination of drugs from the body • Renal excretion (primary organ responsible for excretion) • Biliary excretion • Bowel excretion Half-life: time required for half (50%) of a given drug to be removed from the body Measures the rate at which the drug is eliminated from the body After approximately five half-lives, most drugs are considered to be effectively removed from the body. Steady state • Physiologic state in which the amount of drug removed via elimination is equal to amount of drug absorbed with each dose. Pharmacokinetics Drug Effects cont • The length of time until the onset and peak of action and the duration of action play an important part in determining the peak level (highest blood level) and trough level (lowest blood level) of a drug. If the peak blood level is too high, then drug toxicity may occur. • Peak level: highest blood level of a drug • Trough level: lowest blood level of a drug • Toxicity: occurs if the peak blood level of the drug is too high • Therapeutic drug monitoring Pharmacodynamics • The study of what the drug does to the body The mechanism of drug actions in living tissues Therapeutic effect Mechanism of action Drug–receptor relationships Enzymes Nonselective Interactions Pharmacotherapeutics • The clinical use of drugs to prevent and treat diseases • Defines principles of drug actions—the cellular processes that change in response to the presence of drug molecules • Drugs are organized into pharmacologic classes. • Contraindications • Acute therapy • Maintenance therapy • Supplemental (or replacement) therapy • Palliative therapy • Supportive therapy • Prophylactic therapy • Empiric therapy • Monitoring • Therapeutic response • Adverse effects • Toxic effects • Therapeutic index • Drug concentration • Patient condition • Tolerance: decreasing response to repeated drug doses • Dependence: physiologic or psychological need for a drug • Physical dependence: physiologic need for a drug to avoid physical withdrawal symptoms • Psychological dependence: also known as addiction and is the obsessive desire for the euphoric effects of a drug • Drug interactions Additive effects Synergistic effects Antagonistic effects • Adverse drug event (ADE): ex: allergic reaction • Adverse drug withdrawal event: if you quickly withdrawal from the medication if for example the patient forgets the medication and then gets a symptom • Six Rights of drug administration to prevent errors: Right drug Right dose Right time Right route Right patient Right documentation • Medication use process in which errors can occur: Prescribing Dispensing Administering Monitoring • Adverse drug reactions: Pharmacologic reaction Hypersensitivity (allergic) reaction Idiosyncratic reaction Drug interaction • Other drug effects Teratogenic Mutagenic Carcinogenic effects • Pharmacognosy Four main sources for drugs: • Plants • Animals • Minerals • Laboratory synthesis Pharmacoeconomics • Cost-benefit analysis • Examine treatment outcomes in relation to the comparative total costs of treatment with drug(s) Toxicology • Science of adverse effects of chemicals on living organisms • Clinical toxicology: Care specifically to the poisoned patient • Poison Control Centers • Treatment based on system of priorities ABCs Prevent absorption of the toxic substance and/or speed its elimination from the body Summary • Thorough understanding of pharmacologic principles is essential for safe, quality nursing practice. • Application of principles enables the nurse to provide safe and effective drug therapy. • While administering the medication go through the six-9-10 rights also discuss it with the patient. Any time a patient questions the drug-you double checks your orders. Exam: P450 enzyme: • Beta blocker, 450 enzyme, cytochrome, and how does it relate to certain group • What is teratogenic, mutagonenic, and carcinogenic • Cultural component to P 450 enzyme • Drug classifications Thursday Chapter 3: lifespan considerations Lifespan Considerations • The human body changes from the beginning of life to the end of life. • These lifespan changes have dramatic effects of the four phases of pharmacokinetics. • Special considerations: • Pregnancy • Newborn • Pediatric • Older adult Drug Therapy During Pregnancy • Drugs cross the placenta by diffusion • Factors affecting safety: • Drug properties • Fetal gestational age • Maternal factors: smoking, alcohol, mothers health • FDA has implemented pregnancy safety categories. • FDA now requires pregnancy labeling to be included in package inserts (phase-in process). New Rule • Three subsections in the prescribing information: • Pregnancy • Lactation • Female and males of reproductive potential • Because this is a phase-in process, nurses may see the A to X classifications and the new rule classifications. ► Audience Response System Question #1 When teaching a pregnant woman about the use of drugs during pregnancy, which statement will the nurse include? A. Exposure of the fetus to drugs is most detrimental during the second trimester of pregnancy. B. Pregnant women must never take drugs to control high blood pressure. C. Drug transfer to a fetus is most likely to occur during the last trimester of pregnancy. D. A fetus is at greatest risk for drug-induced developmental defects during the second trimester of pregnancy. Note: No input is required to proceed. ► Answer to System Question #1 ANS: C Drug transfer to the fetus is most likely to occur during the last trimester of pregnancy. Exposure of a fetus to drugs is most detrimental during the first trimester of pregnancy, and fetuses are at greatest risk for drug-induced developmental defects during the first trimester of pregnancy. Pregnant women need to take medications to control situations such as high blood pressure. Drug Therapy During Breastfeeding • Breastfed infants are at risk for exposure to drugs consumed by the mother. • Drug levels in breast milk are usually lower than those in the maternal circulation. • Consider risk-to-benefit ratio. Neonatal and Pediatric Considerations: Pharmacokinetics • Absorption o Gastric pH less acidic until 1 to 2 years of age ( because one starts introducing food to the child). o Gastric emptying slowed o Intramuscular absorption faster and irregular • Neonatal and Pediatric Considerations: Pharmacokinetics (Cont.) o Distribution • Greater total body water means lower fat content. • Decreased level of protein binding • Immature blood–brain barrier—more drugs enter the brain Neonatal and Pediatric Considerations: Pharmacokinetics (Cont.) • Metabolism o Liver immature; does not produce enough microsomal enzymes o Older children may have increased metabolism, requiring higher doses than infants. o Other factors Neonatal and Pediatric Considerations: Pharmacokinetics (Cont.) • Excretion o Kidney immaturity affects glomerular filtration rate and tubular secretion. o Decreased perfusion rate of the kidneys may reduce excretion of drugs. Factors Affecting Pediatric Drug Dosages • Skin is thin and permeable. • Stomach lacks acid to kill bacteria. • Lungs have weaker mucus barriers. • Body temperatures less well regulated, and dehydration occurs easily. • Liver and kidneys are immature, impairing drug metabolism and excretion. Methods of Dosage Calculation for Pediatric Patients • Body surface area method o Uses the West nomogram • Always use weight in kilograms, not pounds • Always use centimeters, not inches • Body weight dosage calculations o Uses mg/kg General Considerations • Prepare all equipment and supplies first. • Have caregivers stay as appropriate. • Assess for comfort methods before, during, and after drug administration. • Infants • Toddlers • Preschoolers • School-age children • Adolescents • Audience Response System Question #2 When administering medications to pediatric patients, the nurse understands that the dosage calculations for pediatric patients are different than for adults because pediatric patients A. are more likely to develop edema. B. have more stomach acid. C. have skin that is less permeable. D. have immature liver and kidney function, resulting in impaired drug metabolism and excretion. Note: No input is required to proceed. ► Answer to System Question #2 ANS: D In pediatric patients, body temperature is less well regulated, and dehydration occurs easily; pediatric patients lack stomach acid to kill bacteria and have skin that is thinner and more permeable. It is true that pediatric patients have immature liver and kidney function, resulting in impaired drug metabolism and excretion. Considerations for Older Adult Patients • Decline in organ function occurs with advancing age. • Drug therapy in older adults is most likely to result in adverse effects and toxicity. Considerations for Older Adult Patients (Cont.) • Older adults: older than age 65 years • High use of medications • Polypharmacy • Noncompliance, nonadherence • Increased incidence of chronic illnesses • Sensory and motor deficits Older Adults: Pharmacokinetics • Absorption o Gastric pH less acidic o Gastric emptying slowed o Movement through GI tract slowed because of decreased muscle tone and activity o Blood flow to GI tract reduced o Absorptive surface of GI tract reduced • Older Adults: Pharmacokinetics (Cont.) • Distribution o Lower total body water percentages o Increased fat content o Decreased production of proteins by the liver, resulting in decreased protein binding of drugs (and increased circulation of free drugs) • Older Adults: Pharmacokinetics (Cont.) • Metabolism o Aging liver produces fewer microsomal enzymes, affecting drug metabolism. o Reduced blood flow to the liver • Older Adults: Pharmacokinetics (Cont.) • Excretion o Decreased glomerular filtration rate o Decreased number of nephrons o Drugs are cleared less effectively because of decreased excretion. Older Adults: Problematic Medications (MEMORIZE THIS) Medication Administration, Lifespan Considerations, and the Nursing Process Assessment • Age • Allergies to drugs and food • Dietary habits • Sensory, visual, hearing, cognitive, and motor-skill deficits • Financial status and any limitations • List of all health-related care providers Medication Administration Considerations: Assessment • Listing of medications • Existence of polypharmacy • Self-medication practices • Laboratory test results • History of smoking and use of alcohol • Risk situations related to drug therapy Medication Administration Considerations: Planning • Nursing diagnoses o Imbalanced nutrition o Deficient knowledge o Risk for injury • Outcomes • May involve patient, caregiver, or legal guardian • Individualized: Medication Administration Considerations: Implementation • Basic Nine Rights of medication administration • Pediatric considerations for safe administration o Mixing medications to disguise taste o Age-appropriate terminology o Safety considerations • Older adult considerations for safe administration o Take as directed; do not double-up doses or discontinue without guidance from prescriber o Safety considerations o Be alert for polypharmacy Medication Administration Considerations: Evaluation • Observe and monitor for therapeutic effects • Observe and monitor for adverse effects • Evaluate understanding of drug purpose, dose, dose frequency, adverse effects, special considerations Chapter 4 Cultural, Legal, and Ethical Considerations Audience Response System Question #1 Which racial group is predicted to be nearly one in three U.S. residents in 2050? A. African American B. Asian C. Hispanic D. White Note: No input is required to proceed. ► Answer to System Question #1 ANS: C It is predicted that by 2050, nearly one third of the U.S. population will be Hispanic. The non-Hispanic, single-race white population is projected to be only slightly larger in 2050. The African-American population is projected to increase from 41 million (about 14%) to about 66 million (or 15%) by 2050. The Asian population is projected to increase from 15 million to about 40 million, rising from a current 5.1% to 9.2% of the total population. Ethnopharmacology • Body of knowledge for understanding the specific impact of cultural factors on patient drug response • Lack of clarity in terms: race, ethnicity, and culture Cultural Considerations • Pharmacogenomics: study of how certain genetic traits affect drug response • Drug polymorphism • Adherence with therapy • Environmental and economic considerations • Pharmacokinetics • Pharmacodynamics • Varying drug responses in different racial or ethnic groups Cultural Considerations (Cont.) • Health beliefs and practices • Barriers to adequate health care for the culturally diverse U.S. patient population o Language, poverty, access, pride, and beliefs regarding medical practices o Medications may have a different meaning to different cultures. Cultural Assessment • Languages spoken: need for interpreter • Health beliefs and practices • Past uses of medicine • Herbal treatments, folk remedies, and home remedies • Over-the-counter drugs and treatment Cultural Assessment (Cont.) • Usual response to illness • Responsiveness to medical treatment • Religious practices and beliefs • Support from the patient’s cultural community • Dietary habits • Audience Response System Question #2 Which of the following statements regarding African Americans’ responses to antihypertensive medication therapy is true? A. African Americans respond better to diuretics than to beta blockers. B. African Americans do not respond to diltiazem. C. Single-drug therapy is effective for African Americans. D. Hypertension is uncommon in the African-American population. Note: No input is required to proceed. ► Answer to System Question #2 ANS: A African Americans respond less effectively to beta blockers. African Americans respond best to calcium channel blockers, especially diltiazem. African Americans respond less effectively to single-drug therapy. African Americans tend to get prescribes a diuretic with antihypertensive. Legal Considerations • Food and Drug Administration (FDA) • Drug Enforcement Agency (DEA) • Individual state laws HIPAA • Health Insurance Portability and Accountability Act (HIPAA) o 1996 o Maintain privacy regarding protected health information New Drug Development • Food and Drug Administration (FDA): primary purpose of the FDA is to protect patients and ensure drug effectiveness. • Dietary Supplement Health and Education Act of 1994 • National Center for Complementary and Alternative Medicine of 1998 New Drug Development (Cont.) • Expedited drug approval process • U.S. FDA drug approval process o Preclinical testing o Clinical studies o Investigational drug studies o Expedited drug approval U.S. FDA Drug Approval Process for new medication • Informed consent • Investigational new drug study • Preclinical investigational drug studies • Clinical phases of investigational drug studies o Phase I: coming out with research o Phase II: have approval and develop informed consent and it is reviewed by institutional board to reassure that the protocols are not harmful. Approval takes a long time from 6 months to 6 years. o Phase III: Trials in small number of people o Phase IV: Larger study U.S. FDA Drug Approval Process (Cont.) • Black box warning: levels of how a medication can be taken. When it is a black box is a warning about certain medications) o Class I: The most serious type of recall : use of the drug product carries a reasonable probability of serious adverse health effects or death o Class II: Less severe- use of the drug products may result in temporary or medically reversible health effects, but the probability of lasting major adverse health effects is low o Class III: Least severe-use of the drug product is not likely to result in any significant health problems. Legal Considerations Related to Drug Therapy and Nursing Practice • State and federal legislation • Nurse practice acts ► Scope of nursing practice ► Expanded nursing roles ► Educational requirements ► Standards of care ► Minimally safe nursing practice ► Differences between nursing and medical practice ► Legal Considerations Related to Drug Therapy and Nursing Practice (Cont.) Guidelines from professional nursing groups • American Nurses Association (ANA) • Institutional policies and procedures; state and federal hospital licensing • Specific Nurse Practice Acts • Standards of Practice • HIPPA Ethical Terms Related to Nursing Practice • Autonomy • Beneficence • Autonomy • Confidentiality • Justice • Nonmaleficence • Veracity Legal and Ethical Principles: Elements of Liability for Nursing Malpractice • Duty • Breach of duty • Causation • Damage Ethical Considerations • ANA Code of Ethics for Nurses • International Council of Nurses Code of Ethics for Nurses • Placebos Chapter 5 Medication Errors: Preventing and Responding “ Too Err Is Human” • 1999 report by Institute of Medicine (IOM) • Brought medical errors to the public’s attention • Preventable errors were responsible for 7000 deaths per year. • 3% to 6.9% of hospitalized patients experience a medication error. • Two follow up reports from the IOM found no significant change in rates of preventable errors. Medication Errors: Prevention • Most medication errors occur as a breakdown in the medication use system, as opposed to being the fault of the individual. • Key to preventing errors: o Reporting of errors o Reporting of potential errors o Nonpunitive approach to error reporting or “Just Culture” o QSEN initiatives Medication Errors and Adverse Drug Events • Adverse drug events o Medication errors o Adverse drug responses (ADRs) ► Allergic reaction (often predictable) ► Idiosyncratic reaction (usually unpredictable) Medication Errors • Preventable • Common cause of adverse health care outcomes • Drugs commonly involved in severe medication errors: central nervous system drugs, anticoagulants, and chemotherapeutic drugs • More potential for harm with “high-alert” medications • Medication Errors (Cont.) • SALAD (sound-alike, look-alike drugs) • LASA (look-alike, sound-alike) Example: buspirone and bupropion prednisone and prednisolone Issues Contributing to Errors • Errors can occur during any step of medication process ► Procuring ► Prescribing ► Transcribing ► Dispensing ► Administering ► Monitoring Issues Contributing to Errors (Cont.) • Organizational issues • Educational system issues • Sociologic factors • Use of abbreviations “Near Miss” Versus “Close Call” • Near Miss: ► Event or situation that did not produce patient injury, but only because of chance • Close Call: ► An event or situation or error that took place but was identified and captured prior to reaching the patient • Strategies to Minimize Errors • Awareness (“speak-up”) • Computerized prescriber order entry (CPOE) • Bar codes and scanning devices • Automated dispensing machines • Effective communication Types of Medication Errors • No error, although circumstances or events occurred that could have led to an error • Medication error that causes no harm • Medication error that causes harm • Medication error that results in death Preventing Medication Errors • Multiple systems of checks and balances should be implemented to prevent medication errors. • Prescribers must write legible orders that contain correct information, or orders should be entered electronically. • Authoritative resources, such as pharmacists or current (within the past 3 to 5 years) drug references or literature, must be consulted. Preventing Medication Errors (Cont.) • Nurses need to always check the medication order three times before giving the drug. • The Six Rights of medication administration should be used consistently. Preventing Medication Errors (Cont.) • Assessment • Two patient identifiers • Do not administer if you did not draw up or prepare yourself. • Minimize verbal or telephone orders. ► Repeat order to prescriber. ► Spell drug name aloud. ► Speak slowly and clearly. • List indication next to each order. Preventing Medication Errors (Cont.) • Never assume anything about items not specified in a drug order (e.g., route). • Do not hesitate to question a medication order for any reason when in doubt. • Do not try to decipher illegibly written orders; contact the prescriber for clarification. • Do not use unapproved abbreviations, acronyms. Preventing Medication Errors (Cont.) • Never use a “trailing zero” with medication orders. ► Do not use 1.0 mg; use 1 mg. ► 1.0 mg could be misread as 10 mg, resulting in a 10-fold dose increase. • Preventing Medication Errors (Cont.) • ***Always use a “leading zero” for decimal dosages. ► Do not use .25 mg; use 0.25 mg. ► .25 mg may be misread as 25 mg. Preventing Medication Errors (Cont.) • Take time to learn special administration techniques of certain dosage forms. • Always verify new medication administration records. • Read labels. • Use generic names to avoid sound-alike trade names. Preventing Medication Errors (Cont.) • Always listen to and honor any concerns expressed by patients regarding medications. • Check patient allergies and identification. • Know where to find information on medications, preparation, side-effects; Use only current sources. • Mandatory second nurse verifications for high-risk medications and/or patient population • Minimize interruptions when preparing/delivering medications. Reporting Medication Errors • Report to prescriber and nursing management. • Document error per policy and procedure. • Factual documentation only o Medication administered o Actual dose o Observed changes in patient condition o Prescriber notified and follow-up orders o Reporting Medication Errors (Cont.) • External reporting of errors o United States Pharmacopeia Medication Errors Reporting Program o MedWatch, sponsored by the Food and Drug Administration o Institute for Safe Medication Practices o The Joint Commission Preventing Pediatric Medication Errors • Obtain and document accurate weight (kg) • Report all medication errors. • Know the drug thoroughly. • Follow the Six Rights of medication administration. • Avoid verbal orders in general. • Avoid distractions. • Communicate with everyone. Ethical Issues • Notification of patients • Possible consequences for nurses Medication Reconciliation • Continuous assessment and updating of patient medication information o Verification o Clarification o Reconciliation Medication Reconciliation (Cont.) • Process in which medications are “reconciled” at all points of entry and exit to or from a health care entity • Patients provide a list of all the medications they are currently taking (including herbals and over-the-counter drugs). • Prescriber then assesses the medications and decides if they are to be continued upon hospitalization. Medication Reconciliation (Cont.) • Designed to ensure that there are no discrepancies between what the patient was taking at home and in the hospital. • Medication Reconciliation (Cont.) • Should be done at each stage of health care delivery: o Admission o Status change (e.g., from critical to stable) o Patient transfer within or between facilities or provider teams o Discharge (the latest medication list should be provided to the patient to take to his or her next health care provider). Medical terminology -Quiz 1 1. Anaphylaxis: A serious potentially life-threatening allergic reaction to a medication 2. Antagonist: A medication that inhibits the activity of one or more receptors in the body. 3. Drug interaction: Change in the pharmacologic or pharmacokinetic activity when two medications are administers in combination and can potentially undesirably effect 4. Toxicity An adverse physiological effect of a medication or medication interaction 5. Trough level : Lowest concentration of medication attained within the body after it is reduced from the peak level. EXAM Preparation: • ATI manual Week 2 Vancomycin- red man syndrome • Used for C-diff and MRSA • Infuse slowl Chapter 38-Antibiotics Part 1 Microbial Infection • Microorganisms are everywhere. • Can be harmful or beneficial • Defenses • Physical barriers (e.g., intact skin or ciliated respiratory mucosa) • Physiologic defenses (e.g., stomach gastric acid, antibodies) • Phagocytic cells Bacteria • There is gram positive and gram negative Infections • Community-associated infections • An infection that is acquired by a person who has not been hospitalized or had a medical procedure within the past year: • e.g., dialysis, surgery, catheterization Infections: Sites of Origin • Health care–associated infections • Contracted in a hospital or institutional setting • Occurs more than 48 hours after admission • More difficult to treat - causative microorganisms are often drug resistant and the most virulent • Methicillin-resistant Staphylococcus aureus (MRSA) is most common. • Previously known as nosocomial Health Care–Associated Infections: Prevention • Handwashing • Antiseptics: inhibits the growth of microorganism but does not kill them. • Disinfectant: kills organisms, used on nonliving objects Antibiotics • Medications used to treat bacterial infections • Ideally before beginning antibiotic therapy, the suspected area of infection should be cultures to identify the causative organism, and potential antibiotic susceptibilities Antibiotic Therapy Empiric therapy: treatment of an infection before specific culture information has been reported or obtained Antibiotic Therapy (Cont.) Antibiotic Therapy (Cont.) Antibiotic Therapy (Cont.) Definitive therapy: antibiotic therapy tailored to treat organism identified with cultures Prophylactic therapy: treatment with antibiotics to prevent an infection, as in intraabdominal surgery or after trauma A L L E R G IC R E A C T IO N S : P E N IC IL L IN S & S U L F O N A M ID E S 2 B R O A D C L A S S E S O F A N T IB IO T IC S M A N Y P E O P L E H A V E A L L E R G IC A N A P H Y L A C T IC R E A C T IO N S Antibiotic Therapy (Cont.) M O S T C O M M O N S E V E R E R E A C T IO N S : D IF F IC U LT Y B R E AT H IN G ; S IG N IF IC A N T R A S H , H IV E S , O R O T H E R S K IN R E A C T IO N ; A N D S E V E R E G A S T R O IN T E S T IN A L ( G I ) IN T O L E R A N C E P R E G N A N C Y - R E L A T E D H O S T FA C T O R S Genetic host factors: glucose-6- phosphate dehydrogenase deficiency and slow acetylation Anatomic site of the infection Antibiotics: Classes Antibiotic Therapy: Mechanism of Action Interferes with cell wall synthesis Interferes with protein synthesis Interferes with DNA replication Acts as a metabolite to disrupt critical metabolic reactions inside the bacterial cell Basic Sites of Antibiotic Activity • Cell wall synthesis • DNA replication • RNA replication • Antimetabolites • Protein synthesis (30S ribosomes) • Protein synthesis (50S ribosomes Actions of Antibiotics • Bactericidal: kill bacteria • Bacteriostatic: inhibit the growth of susceptible bacteria rather than kill them immediately, eventually leads to death. Antibiotics: Sulfonamides • One of the first groups of antibiotics • Often combined with another antibiotic • Sulfamethoxazole combined with trimethoprim (a nonsulfonamide antibiotic), known as Bactrim, • Septra, or co-trimoxazole and often abbreviated as SMX-TMP, is used commonly in clinical practice. Sulfonamides: Mechanism of Action Bacteriostatic action Prevent synthesis of folic acid (required for synthesis of purines and nucleic acid) Do not affect human cells or certain bacteria; they can use preformed folic acid Only affect organisms that synthesize their own folic acid Sulfonamides: Indications • Effective against both gram-positive and gram-negative bacteria • Treatment of urinary tract infections (UTIs) caused by susceptible strains of: • Enterobacter spp., Escherichia coli, Klebsiella spp., Proteus mirabilis, Proteus vulgaris, Staphylococcus aureus Sulfonamides: Indications (Cont.) Sulfonamides: Adverse Effects Body system Adverse effects Blood Hemolytic and aplastic anemia, agranulocytosis, Integumentary Photosensitivity, exfoliative dermatitis, Stevens-John necrolysis Sulfonamides: Adverse Effects (Cont.) Body system Adverse effects GI Nausea, vomiting, diarrhea, pancreatitis Other Hepatotoxicity, convulsions, crystalluria, toxic nephr neuritis, urticaria, cough Beta-Lactam Antibiotics • Penicillins • Cephalosporins • Carbapenems • Monobactams Penicillins Penicillins (Cont.) Penicillin G Penicillin V Nafcillin Cloxacillin Oxacillin Dicloxacillin Amoxicillin Ampicillin Carbenicillin Piperacillin Ticarcillin Piperacillin/tazobactam Beta-Lactamase Inhibitors • Bind with beta-lactamase enzyme to prevent break down of penicillin molecule • Clavulanic acid (clavulanate) • Tazobactam • Sulbactam • Avibactam Examples of Combination Agents Penicillins: Mechanism of Action Penicillins: Indications • Prevention and treatment of infections caused by susceptible bacteria, such as: • Gram-positive bacteria, including Streptococcus spp., Enterococcus spp., Staphylococcus spp. Penicillins: Contraindications • Usually safe and well-tolerated medications • Contraindicated: known drug allergy • Type of reaction that occurs in patients who state they are allergic to penicillins • Not all end in “cillin” (e.g., Zosyn, Augmentin) • Many medication errors have occurred when a penicillin drug called by its trade name is given to a patient with a penicillin allergy. Penicillins: Adverse Effects • Allergic reactions to the penicillins occur in 0.7% to 4% of treatment courses. • Urticaria, pruritus, angioedema • Patients allergic to penicillins have an increased risk of allergy to other beta-lactam antibiotics. • Only patients with a history of throat swelling or hives from penicillin should not receive cephalosporins. Penicillins: Adverse Effects (Cont.) Penicillins: Interactions • MANY interactions! • Nonsteroidal antiinflammatory drugs • Oral contraceptives • Warfarin • Others Cephalosporins Cephalosporins (Cont.) • First generation • Second generation • Third generation • Fourth generation • Fifth generation Cephalosporins: First Generation Cephalosporins: First Generation (Cont.) • Used for surgical prophylaxis and for susceptible staphylococcal infections • Cefazolin (Ancef and Kefzol): intravenous (IV) or intramuscular (IM) • Cephalexin (Keflex): PO Cephalosporins: Second Generation Cephalosporins: Second Generation (Cont.) Cephalosporins: Third Generation Cephalosporins: Third Generation (Cont.) • Ceftriaxone (Rocephin) • IV and IM, long half-life, once-a-day dosing • Elimination is primarily hepatic. • Easily passes meninges and diffused into cerebrospinal fluid to treat central nervous system infections. Cephalosporins: Third Generation (Cont.) • Ceftazidime (Ceptaz, Fortaz, Tazidime) • IV and IM forms • Excellent gram-negative coverage • Used for difficult-to-treat organisms such as Pseudomonas spp. • Excellent spectrum of coverage • Resistance is limiting usefulness. Cephalosporins: Fourth Generation • Broader spectrum of antibacterial activity than third generation, especially against gram-positive bacteria • Uncomplicated and complicated UTI • Cefepime (Maxipime) Cephalosporins: Fifth Generation • Ceftolozane (Zerbaxa) o Contains beta-lactamase inhibitor o Enhances gram negative activity • Ceftaroline (Teflaro) o Broader spectrum of antibacterial activity o Effective against a wide variety of organisms ▪ MRSA Cephalosporins: Adverse Effects Similar to penicillins Mild diarrhea, abdominal cramps, rash, pruritus, redness, edema Potential cross-sensitivity with penicillins if allergies exist Carbapenems Carbapenems (Cont.) Monobactams Aztreonam (Azactam) Synthetic beta-lactam antibiotic Primarily active against aerobic gram-negative bacteria (E. coli, Klebsiella spp., Pseudomonas spp.) Bactericidal Parenteral use only Used for moderately severe systemic infections and UTIs Macrolides Erythromycin (E-mycin, E.E.S, others) Azithromycin (Zithromax) Clarithromycin (Biaxin) Fidaxomicin (Dificid, Dificlir) Macrolides: Mechanism of Action Prevent protein synthesis within bacterial cells Considered bacteriostatic Bacteria will eventually die In high enough concentrations, may also be bactericidal Macrolides: Indications Macrolides: Indications (Cont.) Fidaxomicin (Dificid): newest macrolide The most common adverse effects are nausea, vomiting, and GI bleed. Indicated only for the treatment of C. difficile–associated diarrhea Pregnancy category B Minimal absorption Macrolides: Adverse Effects GI effects, primarily with erythromycin Nausea, vomiting, diarrhea, hepatotoxicity, flatulence, jaundice, anorexia Azithromycin and clarithromycin: fewer GI adverse effects, longer duration of action, better efficacy, better tissue penetration Tetracyclines Tetracyclines (Cont.) Demeclocycline (Declomycin) Oxytetracycline (Terramycin) Tetracycline Doxycycline (Doryx, Vibramycin) Minocycline (Minocin) Tigecycline (Tygacil) Tetracyclines (Cont.) Tetracyclines: Indications Tetracyclines: Adverse Effects Tetracyclines: Adverse Effects (Cont.) May also cause: Vaginal candidiasis Gastric upset Enterocolitis Maculopapular rash Other effects Audience Response System Question #2 Which of the following does the nurse identify as being a concern for patients receiving tetracycline? A. Tetracycline should not be administered to anyone older than age 65 years. B. Tetracycline has no impact on the effectiveness of oral contraceptives. C. Tetracycline used with warfarin decreases its effectiveness and enhances clot formation. D. Tetracyclines should not be administered with dairy products. Note: No input is required to proceed. Answer to System Question #2 ANS: D Assess for significant drug interactions, including simultaneous use of antacids, antidiarrheal drugs, dairy products, calcium, enteral feedings, and iron preparations. There is concern regarding the use of these drugs in patients younger than 8 years of age because of the problem of permanent mottling and discoloration of the teeth. Tetracyclines may also decrease the effectiveness of oral contraceptives. Assess the patient taking oral anticoagulants more closely because of possible potentiation of bleeding. Nursing Implications Before beginning therapy, assess drug allergies; renal, liver, and cardiac function; and other lab studies. Be sure to obtain thorough patient health history, including immune status. Assess for conditions that may be contraindications to antibiotic use or that may indicate cautious use. Assess for potential drug interactions. Nursing Implications (Cont.) Nursing Implications (Cont.) For safety reasons, check the name of the medication carefully because there are many drugs that sound alike or have similar spellings. Audience Response System Question #3 When completing an admission assessment, the patient states that she is allergic to sulfa drugs. What will the nurse do next? A. Mark the allergy on her medical record. B. Place an “allergy” armband on the patient. C. Ask the patient for more information about the allergic reaction she had. D. Notify the physician about the patient’s allergy. Note: No input is required to proceed. Answer to System Question #3 ANS: C Some patients say they are “allergic” to drugs when in fact what they experienced was a common and mild adverse effect. The nurse should clarify the patient’s statements with open-ended questions. Nursing Implications Audience Response System Question #4 A patient has a prescription for a sulfa drug as treatment for a UTI. She is also taking an oral contraceptive, an oral sulfonylurea antidiabetic drug, and phenytoin for a history of seizures. Which drug may pose a potential serious interaction with the sulfa drug? A. The oral contraceptive B. The oral antidiabetic drug C. The phenytoin D. All of these Note: No input is required to proceed. Answer to System Question #4 ANS: D The combination of the sulfa drug with the oral contraceptive may reduce the effectiveness of the contraceptive. The combination with the oral antidiabetic drug may potentiate the hypoglycemic effect of the sulfonylurea drug, and the combination with the phenytoin may potentiate the toxic effects of the phenytoin. Nursing Implications Nursing Implications (Cont.) Cephalosporins Assess for penicillin allergy; may have cross-allergy. Give orally administered forms with food to decrease GI upset even though this will delay absorption. Some of these drugs may cause a disulfiram (Antabuse)-like reaction when taken with alcohol. Nursing Implications (Cont.) Macrolides These drugs are highly protein bound and will cause severe interactions with other protein-bound drugs. The absorption of oral erythromycin is enhanced when taken on an empty stomach, but because of the high incidence of GI upset, many drugs are taken after a meal or snack. Nursing Implications (Cont.) Tetracyclines Avoid milk products, iron preparations, antacids, and other dairy products because of the chelation and drug-binding that occur. Take all medications with 6 to 8 oz of fluid, preferably water. Because of photosensitivity, avoid sunlight and tanning beds. Nursing Implications (Cont.) Audience Response System Question #5 The nurse identifies Zosyn as being a member of which group? A. Cephalosporins B. Macrolides C. Penicillins D. Sulfonamides Note: No input is required to proceed. Answer to System Question #5 ANS: C Zosyn is a penicillin. The nurse should be aware of the fact that many times, these drugs are referred to by their trade names and do not always end in “cillin,” such as with Zosyn and Augmentin. Chapter 39 Antibiotics Part 2 Multidrug-Resistant Organisms Multidrug-Resistant Organisms (Cont.) Multidrug-Resistant Organisms (Cont.) Multidrug-Resistant Organisms (Cont.) ESBL Organisms that produce ESBL are resistant to all beta-lactam antibiotics and aztreonam. Can be treated only with carbapenems or sometimes quinolones Use of carbapenems: resistance occurred; production of carbapenemase, which renders all carbapenems ineffective Tigecycline and colistimethate Aminoglycosides Aminoglycosides (Cont.) Gentamicin Neomycin (Neo-Fradin) Tobramycin (TOBI) Amikacin Aminoglycosides: Indications Aminoglycosides: Indications (Cont.) Aminoglycosides: Adverse Effects Aminoglycosides: Adverse Effects (Cont.) Therapeutic drug monitoring Ototoxicity and nephrotoxicity are the most significant Headache Paresthesia Fever Superinfections Vertigo Skin rash Dizziness Aminoglycosides: Therapeutic Drug Monitoring Serum levels measured to prevent toxicity Serum level needs to be at least eight times higher than the MIC. Time-dependent killing Concentration-dependent killing Peak: highest drug levels for once-daily regimens Trough: lowest to ensure adequate renal clearance of the drug and avoid toxicity Aminoglycosides: Therapeutic Drug Monitoring (Cont.) Quinolones Also called fluoroquinolones Excellent oral absorption Absorption reduced by antacids Effective against gram-negative organisms and some gram-positive organisms Quinolones (Cont.) Ciprofloxacin (Cipro) Norfloxacin (Noroxin) Levofloxacin (Levaquin) Moxifloxacin (Avelox) Gemifloxacin (Factive) Delafloxacin (Baxdela) Quinolones: Mechanism of Action Bactericidal Alter DNA of bacteria, causing death Do not affect human DNA Used to treat S. aureus, Serratia marcescens, and Mycobacterium fortuitum Bacterial resistance to quinolone antibiotics: Pseudomonas aeruginosa, S. aureus, Pneumococcus spp., Enterococcus spp., and the broad Enterobacteriaceae family that includes E. coli. Quinolones: Indications Gram-negative bacteria such as Pseudomonas spp. Complicated urinary tract, respiratory, bone and joint, GI, skin, and sexually transmitted infections Anthrax (ciprofloxacin) Quinolones: Interactions Oral quinolones: antacids, calcium, magnesium, iron, zinc preparations, or sucralfate Patients need to take the interacting drugs at least 1 hour before or after taking quinolones. Dairy products Enteral tube feedings Probenecid Nitrofurantoin Oral anticoagulants Audience Response System Question #1 During intravenous (IV) quinolone therapy in an 88-year-old patient, which potential problem is of most concern when assessing for adverse effects? A. Hepatotoxicity B. Rhabdomyolysis C. Tendon rupture D. Nephrotoxicity Note: No input is required to proceed. Answer to System Question #1 ANS: C A black box warning is required by the U.S. Food and Drug Administration for all quinolones because of the increased risk of tendonitis and tendon rupture with use of these drugs. This effect is more common in older patients, patients with renal failure, and patients receiving concurrent glucocorticoid therapy (e.g., prednisone). Quinolones: Adverse Effects Quinolones: Adverse Effects (Cont.) Miscellaneous Antibiotics Clindamycin (Cleocin) Linezolid (Zyvox) Metronidazole (Flagyl) Nitrofurantoin (Macrodantin, Furadantin) Quinupristin–dalfopristin (Synercid) Daptomycin (Cubicin) Vancomycin (Vancocin, Vancoled) Colistimethate (Coly-Mycin) Telavancin (Vibativ) Miscellaneous Antibiotics (Cont.) Clindamycin (Cleocin) Used for chronic bone infections, genitourinary infections, intraabdominal infections, other serious infections May cause pseudomembranous colitis (also known as antibiotic-associated colitis, Clostridium difficile diarrhea, or C. difficile infection) Potential interaction with vecuronium Miscellaneous Antibiotics (Cont.) Daptomycin (Cubicin) Only drug of the new class known as lipopeptides Mechanism of action is not completely known. Binds to gram-positive cells in a calcium-dependent process and disrupts the cell membrane potential Used to treat complicated skin and soft tissue infections caused by susceptible gram-positive bacteria, including MRSA and VRE Miscellaneous Antibiotics (Cont.) Colistimethate (Coly-Mycin) Polypeptide antibiotic that penetrates and disrupts the bacterial membrane of susceptible strains of gram-negative bacterial Commonly referred to as colistin Serious adverse effects Can cause acute respiratory failure when administered by inhalation Miscellaneous Antibiotics (Cont.) Dalbavancin (Dalvance) Lipoglycopeptide Similar to telavancin in that it is indicated for the treatment of skin and skin structure infections caused by susceptible gram-positive organisms Effective against MRSA Extremely long half-life and dosed once weekly Most common side effects include nausea, diarrhea, and headache. Miscellaneous Antibiotics (Cont.) Linezolid (Zyvox) New class: oxazolidinones Used to treat vancomycin-resistant Enterococcus faecium (VREF, VRE), hospital-acquired, and skin structure infections, including those with MRSA May cause hypotension, serotonin syndrome if taken with selective serotonin reuptake inhibitors (SSRIs), and reactions if taken with tyramine-containing foods Audience Response System Question #2 A patient is prescribed linezolid (Zyvox) to treat hospital-acquired pneumonia. It is most important for the nurse to determine if the patient is also taking which medication? A. A diuretic B. An SSRI C. A cardiac glycoside D. A thyroid replacement drug Note: No input is required to proceed. Answer to System Question #2 ANS: B Linezolid has the potential to strengthen the vasopressor (prohypertensive) effects of various vasopressive drugs such as dopamine by an unclear mechanism. Also, there have been postmarketing case reports of this drug causing serotonin syndrome when used concurrently with serotonergic drugs such as the SSRI antidepressants. It is recommended that SSRIs be stopped while patients are receiving linezolid therapy, if possible. Miscellaneous Antibiotics Metronidazole (Flagyl) Used for anaerobic organisms Intraabdominal and gynecologic infections Protozoal infections Several drug interactions Miscellaneous Antibiotics (Cont.) Nitrofurantoin (Macrodantin) Primarily used for UTIs (E. coli, S. aureus, Klebsiella spp., Enterobacter spp.) Use carefully if renal function is impaired Drug concentrates in the urine May cause fatal hepatotoxicity Miscellaneous Antibiotics (Cont.) Quinupristin–dalfopristin (Synercid) 30:70 combination; works synergistically Used for bacteremia and infections caused by VRE and for treatment of complicated skin and skin structure infections caused by S. pyogenes and S. aureus, including MRSA May cause arthralgias or myalgias Telavancin (Vibativ) Miscellaneous Antibiotics Vancomycin (Vancocin) Treatment of choice for MRSA and other gram-positive infections Oral vancomycin is indicated for the treatment of antibiotic-induced colitis (C. difficile) and for the treatment of staphylococcal enterocolitis. Must monitor blood levels to ensure therapeutic levels and prevent toxicity May cause ototoxicity and nephrotoxicity Audience Response System Question #3 A 58-year-old man is receiving vancomycin as part of the treatment for a severe bone infection. After the infusion, he begins to experience some itching and flushing of the neck, face, and upper body. He reports no chills or difficulty breathing. What should the nurse suspect? A. An allergic reaction has occurred. B. An anaphylactic reaction is about to occur. C. The medication will not be effective for the bone infection. D. The IV dose may have infused too quickly. Note: No input is required to proceed. Answer to System Question #3 ANS: D These symptoms are know as red man syndrome and may occur during or after an infusion of vancomycin. This syndrome is characterized by flushing or itching of the head, face, neck, and upper trunk area. Symptoms can usually be alleviated by slowing the rate of infusion to at least 1 hour. Red man syndrome is bothersome but usually not harmful. Rapid infusions may also cause hypotension. Miscellaneous Antibiotics Vancomycin (Vancocin) Red man syndrome may occur Flushing or itching of head, neck, face, upper trunk Antihistamine may be ordered to reduce these effects. Additive neuromuscular blocking effects in patients receiving neuromuscular blockers Should be infused over 60 minutes Rapid infusions may cause hypotension. Nursing Implications Before beginning therapy, assess drug allergies; hepatic, renal, and cardiac function; and other laboratory study results. Be sure to obtain a thorough patient health history, including immune status. Assess for conditions that may be contraindications to antibiotic use or that may indicate cautious use. Assess for potential drug interactions. Nursing Implications (Cont.) It is essential to obtain cultures from appropriate sites before beginning antibiotic therapy. Instruct patients to take antibiotics exactly as prescribed and for the length of time prescribed; they should not stop taking the medication early even if they feel better. Nursing Implications (Cont.) Assess for signs and symptoms of superinfection: fever, perineal itching, cough, lethargy, or any unusual discharge For safety reasons, check the name of the medication carefully because there are many drugs that sound alike or have similar spellings. Each class of antibiotics has specific adverse effects and drug interactions that must be carefully assessed and monitored. Audience Response System Question #4 A group of office workers is concerned because a package was opened that contained a white powder substance. There is a concern that the white powder is anthrax. Which drug does the nurse anticipate being prescribed for the office workers? A. Daptomycin (Cubicin) B. Colistimethate (Coly-Mycin) C. Ciprofloxacin (Cipro) D. Quinupristin–dalfopristin (Synercid) Note: No input is required to proceed. Answer to System Question #4 ANS: C Ciprofloxacin (Cipro) is the drug of choice for the treatment of anthrax (infection with Bacillus anthracis). Nursing Implications Monitor for therapeutic effects: Improvement of signs and symptoms of infection Return to normal vital signs Negative culture and sensitivity tests Disappearance of fever, lethargy, drainage, and redness Monitor for adverse reactions. Chapter 40 Antiviral Drugs General Principles of Virology Viral replication A virus cannot replicate on its own. It must attach to and enter a host cell. It then uses the host cell’s energy to synthesize protein, DNA, and RNA. General Principles of Virology (Cont.) Viruses enter the body through at least four routes: Inhalation Ingestion Transplacentally Inocculation Viruses are difficult to kill because they live inside the cells. Any drug that kills a virus may also kill cells. Viral Illnesses Smallpox (poxviruses) Sore throat Conjunctivitis (adenoviruses) Warts (papovaviruses) Influenza (orthomyxoviruses) Respiratory infections (coronaviruses, rhinoviruses) Gastroenteritis (rotaviruses, Norwalk-like viruses) Human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) (retroviruses) Herpes (herpesviruses) Hepatitis (hepadnaviruses) Viral Illnesses (Cont.) Most viral illnesses are bothersome but survivable. Effective vaccines have prevented some illnesses. Effective drug therapy is available for a small number of viral infections. Antiviral Drugs Antiviral drugs kill or suppress the virus by destroying virions or inhibiting the ability of viruses to replicate; controlled by current antiviral therapy. Immunoglobulins are concentrated antibodies that can attack and destroy viruses. Antiviral Drugs (Cont.) Viruses controlled by current antiviral therapy Cytomegalovirus (CMV) Hepatitis viruses Herpesviruses HIV Influenza viruses (the “flu”) Respiratory syncytial virus (RSV) Antiviral Drugs (Cont.) Key characteristics of antiviral drugs Able to enter the cells infected with virus Interfere with viral nucleic acid synthesis, regulation, or both Some drugs interfere with ability of virus to bind to cells. Some drugs stimulate the body’s immune system. Antiviral Drugs (Cont.) Best responses to antiviral drugs are in patients with competent immune systems. A healthy immune system works synergistically with the drug to eliminate or suppress viral activity. Audience Response System Question #1 An 82-year-old woman is unable to take the influenza vaccine because of allergies, but she has been exposed to the virus through a family reunion. She does not yet have symptoms of the flu. Which option would be best for her? A. She should receive the flu vaccine as soon as possible. B. She should receive zanamivir (Relenza) in the inhalation form. C. She should begin oral oseltamivir (Tamiflu) therapy when symptoms begin. D. She should begin oral oseltamivir (Tamiflu) therapy as soon as possible. Note: No input is required to proceed. Answer to System Question #1 ANS: D Oseltamivir (Tamiflu) is the only one indicated for prophylaxis of influenza infection. Both oseltamivir and zanamivir can be used to treat active influenza illness. Treatment with oseltamivir and zanamivir ideally should begin within 2 days of symptom onset. Antiviral Drugs Opportunistic infections Occur in immunocompromised patients Would not normally harm an immunocompetent person Require long-term prophylaxis and antiinfective drug therapy Can be other viruses, fungi, bacteria, or protozoa Antiviral Drugs (Cont.) Antiviral drugs Used to treat infections caused by viruses other than HIV Antiretroviral drugs Used to treat infections caused by HIV, the virus that causes AIDS Herpes Simplex and Varicella-Zoster Virus Infections Herpesviridae HSV-1 (oral herpes) HSV-2 (genital herpes) Chickenpox and shingles (HHV-3 or VZV) Epstein-Barr (HHV-4) CMV (HHV-5) Human herpesviruses 6 and 7 are not especially clinically significant; immunocompromised patients Kaposi’s sarcoma (HHV-8) Herpes Simplex and Varicella-Zoster Virus Infections (Cont.) Herpesviridae (cont.) HSV-2 (genital herpes) • Highly transmissible • “Neonatal” herpes Chickenpox (HHV-3 or VZV): varicella virus vaccine Herpes Simplex and Varicella-Zoster Virus Infections (Cont.) Herpesviridae (cont.) Shingles (HHV-3 or VZV) • Painful: opioids for pain control • Postherpetic neuralgias • Acyclovir may speed recovery; best results are generally seen when the antiviral drug is started within 72 hours of symptom onset. • Zostavax Hepatitis B Mild, without symptoms or chronic hepatitis or liver failure and death Transmission of hepatitis B virus occurs through blood and body fluid exposure. Transmission to infants Hepatitis B vaccine Antiviral drug therapy for hepatitis B: lamivudine, tenofovir, and telbivudine, and alfa-interferon Hepatitis C Leading cause of liver failure leading to liver transplantation Symptoms Transmission: infected blood and sexual contact Alcoholic disease can lead to development of hepatitis C. Treatment: interferon, ribavirin, simeprevir, and sofosbuvir Antiviral Drugs (Non-HIV) Mechanism of action Most of the current antiviral drugs work by blocking the activity of a polymerase enzyme that normally stimulates the synthesis of new viral genomes. Used to treat non-HIV viral infections Influenza viruses HSV, VZV CMV Hepatitis Antiviral Drugs (Non-HIV) (Cont.) Adverse effects Vary with each drug Healthy cells are often killed also, resulting in serious toxicities. ● Interactions Antiviral Drugs (Non-HIV) (Cont.) Amantadine (Symmetrel) Narrow antiviral spectrum; active only against influenza A Most recent guidelines do not recommend use for treatment or prevention of flu. Central nervous system (CNS) effects: insomnia, nervousness, light-headedness Gastrointestinal (GI) effects: anorexia, nausea, others Antiviral Drugs (Non-HIV) (Cont.) Rimantadine (Flumadine) Same spectrum of activity, mechanism of action, and indications as amantadine Fewer CNS adverse effects Causes GI upset Antiviral Drugs (Non-HIV) (Cont.) Acyclovir (Zovirax) Synthetic nucleoside analogue Used to suppress replication of HSV-1, HSV-2, VZV Drug of choice for treatment of initial and recurrent episodes of these infections Oral, topical, parenteral forms Antiviral Drugs (Non-HIV) (Cont.) Ganciclovir (Cytovene) Synthetic nucleoside analogue Used to treat infection with CMV Oral, parenteral forms CMV retinitis Ophthalmic form surgically implanted (Vitrasert) Antiviral Drugs (Non-HIV): Dose-Limiting Toxicities Ganciclovir Bone marrow toxicity Foscarnet and cidofovir Renal toxicity Antiviral Drugs (Non-HIV): Neuraminidase Inhibitors Oseltamivir (Tamiflu) and zanamivir (Relenza) Active against influenza types A and B Reduce duration of illness Oseltamivir: causes nausea and vomiting Zanamivir: causes diarrhea, nausea, sinusitis Treatment should begin within 2 days of influenza symptom onset. Antiviral Drugs (Non-HIV): Ribavirin (Virazole) Synthetic nucleoside analogue Given orally, or by oral or nasal inhalation Inhalation form (Virazole) used for hospitalized infants with RSV infections Has significant teratogenic and/or embryocidal effects Caution with pregnant and child-bearing aged health care workers Antiviral Drugs (Non-HIV): Daclatasvir (Daklinza) Direct acting antiviaral Treatment of chronic hepatitis C, genotype 3 Adverse effects: bradycardia, fatigue, headache, nausea, increased liver function tests Antiviral Drugs (Non-HIV): Simeprevir (Olysio) Protease inhibitor (PI) Chronic hepatitis C Approved in 2013 Used in conjunction with standard hepatitis C treatments Not to be used as monotherapy Antiviral Drugs (Non-HIV): Sofosbuvir (Solvaldi) First-in-class RNA polymerase inhibitor for the treatment of chronic hepatitis C Sofosbuvir is considered “break-through” therapy. First drug treatment for hepatitis C that can be given without interferon Not to be used as monotherapy Viekira Pak (ombitasvir/paritaprevir/ritonavir) Epclusa (sofosbuvir/velpatasvir) Zepatier (elbasvir/grazoprevir) Telbivudine (Tyzeka) Nucleoside analogue reverse transcriptase inhibitor Chronic hepatitis B Caution with patients with renal dysfunction Adverse effects: fatigue, headache, diarrhea, nausea, arthralgia, myalgia, steatosis HIV and AIDS Four Stages of HIV Infection* Stage 1: asymptomatic infection Stage 2: early, general symptoms of disease Stage 3: moderate symptoms Stage 4: severe symptoms, often leading to death *World Health Organization model Audience Response System Question #2 A patient with HIV infection is seen in the clinic. The nurse notes the patient is experiencing weight loss, chronic diarrhea, fever, and dropping CD4 counts. The nurse anticipates the patient