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Introduction
- U.S. FDA Drug Approval Process i) Clinical phases of investigational drug studies (1) Phase I- primary focus is safety of the drug in humans (pharmacokinetics). Includes all healthy participants (2) Phase II- small amount of people who have the disease: checking effectiveness and short term common side affects (3) Phase III- Determine drug clinical effectiveness, safety, and dosage. Looking for large sample for infrequent or rare side affects (4) Phase IV- market the drug, samples, medical sales
- Schedule for Controlled Substances a) Schedule I: High abuse potential, not legally approved, street drugs b) Schedule II: As above with accepted use c) Schedule III: Lower abuse potential d) Schedule IV: Still lower abuse e) Schedule V: Contain only small amount of narcotic, minimal risk for abuse
- Over the Counter Drugs a) Important to obtain information in medication history when interviewing client b) Example: garlic is a blood thinner c) Admitting nurse will ask about medication regimen, OTC drugs, and herbal remedies
- Legal Aspects a) All medication orders must contain the “six rights” b) The MAR must state the reason(s) for PRN medications c) All medications administered must be documented on the MAR (after being administered) d) All adverse effects following medication administration must be documented i) Failure to assess and evaluate ii) Failure to ensure safety iii) Medication errors iv) Failure to monitor v) Failure to identify allergies vi) Failure to implement proper nursing action vii) Failure to clarify unclear medication orders viii)Lack of proper assessment ix) Failure to acknowledge and react to adverse reactions e) If adverse effect occurs: 1 st thing the nurse is going to do is stop the medication f) Then assess the patient, document, call HCP a) All medication orders must be signed or co-signed b) Verbal orders must be stated as such on the order sheet, read back, and followed up with signature
Chapter 1: The Nursing Process and Drug Therapy
- Assessment a) Drug history b) Complete prior to the administration of medications c) “Brown bag” assessment---include OTC/herbal products d) Contraindications e) Allergies f) Drug Order i) Client’s full name ii) Date written iii) Drug name and dosage iv) Route of administration v) Frequency of administration vi) Authorized signature
- Nursing Diagnosis a) Result of critical thinking, creativity, and accurate collection of data b) Three step processes: i) Part 1: human response of the patient to illness, injury, or significant change ii) Part 2: identifies factors related to the response iii) Part 3: listing of clues, cues, evidence, and other data that support the nurse’s claim that this diagnosis is accurate c) Potential Client Problems related to Medication i) Knowledge deficit ii) Non-compliance iii) Anxiety iv) Impaired physical mobility v) Alterations in sensory perception vi) Impaired swallowing vii) Risk for injury viii)Various disturbances, deficits, excesses, impairments in bodily functions, and/or other problems or concerns
- Planning a) Ultimate aim of outcome is the safe/effective administration of medications b) Major purposes are to prioritize the nursing diagnoses and specify goals and outcome criteria, including the time frame for their achievement c) Provides time to obtain equipment for interventions, review the possible procedures or techniques, and gather information d) Plan outcome criteria – what are the mutual goals between you and your client e) Plan that the client will gain therapeutic benefits of the medications without complications
- Goals and Outcome criteria
b) Monitors fulfillment of goals and outcome criteria c) Ongoing part of nursing process d) Monitoring client response to drug therapy i) Expected & unexpected responses ii) Did the client understand what you taught him/her? iii) Return demonstration iv) Verbally states understanding v) Is the medication doing its “job?” vi) Is the client presenting with side/adverse/toxic effects? Chapter 2: Pharmacologic Principles a) Pharmaceutics- study of how various dosage forms influence the way in which the drug affects the body b) Pharmacokinetics- study of what the body does to the drug i) 4 major processes (1) Absorption (2) Distribution (3) Metabolism (4) Excretion c) Pharmacodynamics- study of what the drug does to the body i) Involves drug receptor relationships d) Pharmacotherapeutics- clinical use of drugs to prevent and treat diseases i) It defines the principals of drug actions- the cellular processes that change in response to the presence of drug molecules e) Toxicology- study of the adverse effects of drug and other chemicals on living systems f) Pharmacognosy- the study of natural drug sources g) Pharmocoeconomics- the study of economic factors impacting the cost of drug therapy
- Pharmaceutics a) Dosage form determines the rate at which drug dissolution occurs i) Dissolution- process by which solid forms of drugs disintegrate in the GI tract and become soluble before being absorbed into circulation b) Drug absorption of various oral preparations i) Fastest to Slowest (1) Oral disintegration, buccal tablets, and oral soluble wafers (a) Oral à rely on gastric and intestinal enzymes and pH environments to break down the medication down into particles that are small enough to be absorbed into circulation (2) Liquids, elixirs, and syrups (3) Suspension solutions (4) Powders (5) Capsules (6) Tablets
(7) Coated tablets (8) Enteric-coated tablets (a) Have a coating that prevents them from being broken down in stomach. Not absorbed until they reach the higher (more alkaline) pH of intestines (b) Slower dissolution, slower absorption c) Dosage Forms i) Enteral ii) Parenteral (1) pH of injections must be very similar to that of the blood for these drugs to be administered safely (2) 100% of absorption is assumed to occur immediately iii) Topical (1) Aerosols, ointments, creams, pastes, powders, solutions, foams, gels, Transdermal patches, inhalers, rectal and vaginal suppositories (2) Applied directly on surface of skin d) Pharmacokinetics i) Absorption (1) = The rate at which a drug leaves its site of administration and becomes bioavailable (a) Bioavailability- extend of drug absorption (i) Example: a drug is absorbed from the intestine and passes through the liver before reaching systemic circulation. If a large proportion of the drug is chemically changed into inactive metabolites in the liver, then a much smaller amount of the drug will pass into circulation à Much smaller amount will be bioavailable (ii) Many drugs delivered by mouth have a bioavailability <100% (iii) Drugs given IV have a bioavailability of 100% (b) First-pass effect- the initial metabolism in the liver of a drug absorbed from the GI tract before the drug reaches systemic circulation through the bloodstream (i) Reduces bioavailability of the drug to less than 100% (2) Factors affecting rate and amount of absorption (a) Drug solubility (b) Dosage form (route) (c) GI variations (d) Blood flow (e) Pain and stress (f) Drug &/or food interactions (3) 3 basic routes of administration (a) Enteral Route (i) Factors altering drug absorption
- Acid changes within the stomach a. Time of day b. Age of patient
(2) Drugs are distributed first to areas with extensive blood supply à heart, liver, kidneys, brain (3) Slower distribution à muscles, skin, fat (4) Protein binding (a) Only drugs that are not bound to plasma proteins can freely distribute to intravascular tissue to reach their site of action (b) If bound usually too large to pass through walls of capillaries into tissues (c) Albumin is the most common blood protein and carries the majority of protein bound drug molecules (i) What is unbound is considered free (d) Conditions causing low albumin such as extensive burns and malnourished states results in a larger fraction of free drug (i) Increase risk of drug toxicity due to larger fraction of unbound drug (e) When taking two meds that are highly protein bound they may compete for binding sites in albumin (i) Competition causes more free, unbound drug (ii) This can lead to unpredicted drug-drug interaction (iii) Drug-drug interaction- presence of one drug decreases or increases the actions of another drug that is administered concurrently (5) Water vs. fat soluble (a) Drug that is highly water soluble (hydrophilic) will have smaller volume of distribution and high concentrations (b) Fat soluble drugs (lipophilic) have larger volume of distribution and low blood concentrations (6) Blood-brain barrier- make it difficult to distribute drugs iii) Metabolism (biotransformation)- process by which the boy changes a drug from its original form to a form that is pharmacologically inactive and can be readily eliminated or excreted (1) Liver (main organ) (a) Other metabolic tissue: (i) Kidneys (ii) Lungs (iii) Plasma (iv) Intestinal mucosa (2) Cytochrome P-450 enzymes (microsomal enzymes) (a) Hepatic metabolism involves enzymes known as cytochrome P- 450 (b) Control a variety of actions that aid in metabolism of medications (c) One of the most important systems that influence drug-drug interactions (d) Largely targeted at lipid soluble drugs which are difficult to eliminate (3) Many drugs can inhibit drug-metabolizing enzymes and are called enzyme inhibitors
(a) Can result in accumulation of drug and prolong the affect which can lead to toxicity (4) Some drugs stimulate drug metabolism called enzyme inducers (a) Can decrease pharmacological affects (b) Often occurs with the repeated administration of certain drugs that stimulate the formation of new enzymes (5) Factors that affect metabolism (a) Genetics (b) Diseases (c) Concurrent use of other medications (d) Decreased metabolism: (i) Cardiovascular dysfunction (ii) Renal insufficiency (iii) Starvation (iv) Obstructive jaundice (v) Slow acetylator (e) Increase metabolism (i) Fast acetylator- caffeine, nicotine (ii) Barbiturates (iii) Rifampin therapy iv) Excretion- process where drugs and/or metabolites are eliminated from the body (1) Organs for excretion (a) Primary organ is the kidneys (b) Liver and bowel also play a role (2) Excretions and secretions (a) Glomerular filtration (b) Active tubular Reabsorption (c) Active tubular secretion (d) Biliary excretion- excretion of drugs by the intestines (i) Taken up by the liver, released into the bile, and eliminated in the feces (e) Enterohepatic recirculation- once certain drugs are in the bile then may be reabsorbed into the bloodstream, returned to the lover, and again secreted into the bile. In the body for much longer periods (3) Dialysis v) Half-life (1) = time required for one half (50%) of a given drug to be removed from the body (2) Measure of the rate at which the drug is eliminated from the body (3) After about 5 half-lives, most drugs are considered to be affectively removed from the body (4) Concept of half-live is clinically useful for determining when steady state will be reached
b) Acute Therapy i) Often involves more intensive drug treatment and is implemented in the acutely ill or the critically ill ii) Needed to sustain life or treat disease iii) Ex. Vasopressors to maintain BP and CO after open heart surgery iv) Ex. chemo in newly diagnosed cancer c) Maintenance Therapy i) Does not eradicate problem but will prevent progression of a disease or condition ii) Treatment of chronic illnesses such as hypertension iii) Ex. oral contraceptives for birth control d) Supplemental Therapy i) Supplies body with a substance needed to maintain normal function ii) Needed bc it cannot be made by the body or is being produces insufficient iii) Ex. insulin for diabetics or iron for iron deficient anemia e) Palliative Therapy i) Make the patient as comfortable as possible ii) Relief of symptoms, pain, and stress of serious illnesses iii) Improve quality of life iv) Ex. high dose opioid analgesics to relieved pain in final stages of cancer f) Supportive Care i) Maintains integrity of body functions while patient is recovering from illness or trauma ii) Ex. provisions of fluids and electrolytes to prevent dehydration in a patient that is vomiting and has diarrhea, blood pressure products to a patient that has lost blood during surgery g) Prophylactic Therapy and Empiric Therapy i) Prophylactic therapy- drug therapy provided to prevent illness or other undesirable outcome during planned events (1) Ex. pre-op antibiotics for surgical procedures (2) Ex. vaccines given to people going to travel abroad ii) Empiric therapy- drug administration when a certain pathologic condition has an uncertain but high likelihood of occurrence based in the patient’s initial presenting symptoms h) Therapeutic index i) = Ratio of a drug’s toxic level to the level that provides therapeutic benefits ii) Determines safety iii) Low therapeutic index means that difference between a therapeutically active dose and a toxic dose is small (1) Greater risk at causing adverse reaction (2) Ex. warfarin and Digoxin iv) High therapeutic index- amoxicillin (1) Rarely associated with overdose events i) Interactions
i) More drugs a patient receives the more likely they are to interacts ii) Especially in older adults iii) Examples: (1) Leafy green vegetables with warfarin à decreased anticoagulant effect (2) Dairy products with antibiotics à decreased effect and treatment failures (3) Grapefruit juice à decreased metabolism of drugs and increased effects (4) Aged cheese, wine à hypertensive crisis iv) Drug interactions occur when there is a competition between two drugs for metabolizing enzymes, such as P-450 enzymes v) Additive effects (1+1=2) – drug interactions in which the effect of a combination of two or more drugs with similar actions is equivalent to the sum of the individual effects of the same drug given alone vi) Synergist Effects (1+1= greater than 2)- combined effects are greater than the sum of the effects for each drug given alone vii) Antagonistic effects (1+1= less than 2)- combination of two drugs results in drug effects that are less than the sum of the effects for each drug given separately viii)Incompatibility- two parenteral drugs or solutions are mixed together and the result is a chemical deterioration of one or both of the drugs or the formation of a physical precipitate j) Adverse Drug Events i) The most common cause of adverse drug events external to the patient are errors by caregivers and malfunctioning equipment ii) Internal adverse events can be when a pt consumes alcohol when advised not to iii) 2 most common categories (1) Medication error (2) Adverse drug reaction- any reaction to a drug that is unexpected and undesirable and occurs at therapeutic drug doses (a) Pharmacological reaction- extension of the drug’s normal effects in the body (i) Ex. when BP meds lower BP to the point of patient unconsciousness (b) Allergic reaction- immunologic hypersensitivity reaction resulting from the unusual sensitivity of a patients to a particular medication (c) Idiosyncratic reaction- abnormal and unexpected response to a medication, other than an allergic reaction, that is peculiar to an individual patient (i) Usually caused by a deficiency or excess of drug-metabolizing enzymes (ii) Ex. glucose- 6 - phospahte Dehydrogenase (G6PD) deficiency (d) Anaphylactic reaction – unexpected severe reaction that usually involves the respiratory system (3) Other drug Effects (a) Teratogenic effects- structural deficits in the fetus
a) epoetin alfa i) Biosynthetic form of the natural hormone erythropoietin (1) Usually secreted by kidneys in response to low RBCs ii) Promotes synthesis of erythrocytes by stimulating RBC progenitor cells in the bone marrow iii) Used for treatment of anemia associated with end-stage renal disease, chemotherapy-induced anemia, and for anemia associated with zidovudine therapy iv) Causes progenitor cells in the bone marrow to manufacture large number of immature RBCs and greatly speed up their maturation v) Ineffective without adequate body iron stores and bone marrow function vi) Patients need to receive an oral iron preparation vii) Adverse effects: Hypertension, fever, headache, pruritus, rash, nausea, vomiting, arthralgia, and injection site reaction viii)Contraindications: (1) Drug allergy (2) Uncontrolled hypertension (a) Hb levels above 10 for cancer patients (b) above 12 g/dl for renal patients (3) Head and neck cancers (a) Risk of thrombosis (4) When Hb levels are above 12 g/dL patients experience heart attack, stroke, and death
- Iron a) Dietary sources: meats, certain vegetables and grains b) Dietary iron must be converted by gastric juices before it can be absorbed c) Some foods enhance iron absorption i) Orange juice, veal, fish, ascorbic acid d) Some foods impair iron absorption i) Eggs, corn, beans, cereal products containing phytates e) Parenteral form: Iron dextran f) Indications i) Prevention and treatment of iron-deficiency syndromes ii) Administration of iron alleviates the symptoms of iron-deficiency anemia, but the underlying cause of the anemia should be corrected g) Contraindications i) Known drug allergy ii) Hemochromatosis (iron overload) iii) Hemolytic anemia iv) Any other anemia not associated with iron deficiency h) Adverse Effects i) Causes nausea, vomiting, diarrhea, constipation, and stomach cramps and pain ii) Causes black, tarry stools iii) Injectable forms cause pain upon injection i) Iron Toxicity
i) Symptomatic and supportive measures (1) Suction and maintenance of the airway, correction of acidosis, control of shock and dehydration with intravenous fluids or blood, oxygen, and vasopressors ii) In patients with severe symptoms of iron intoxication, such as coma, shock, or seizures, chelation therapy with deferoxamine is initiated (1) Deferiprone is used in iron overload j) Interactions i) Absorption enhanced when given with ascorbic acid ii) Decreased when given with antacids and calcium
- Parenteral Iron a) Iron dextran (INFeD, Dexferrum) i) May cause anaphylactic reactions, including major orthostatic hypotension and fatal anaphylaxis ii) Test dose of 25 mg of iron dextran is administered before injection of the full dose, and then remainder of dose is given after 1 hour iii) Used less frequently; replaced by newer products ferric gluconate and iron sucrose iv) Available only for injection
- Nursing Process a) Assessment i) Important to assess for a document any S&S anemia: (1) Fatigue (2) Changes in nails and skin (3) Fissuring/cracking at angles of lips ii) Erythropoiesis – stimulating agents (1) Used to treat anemia associated with end stage renal disease and/or chemotherapy induced anemia (2) Assessment of adequate body iron stores and bone marrow function prior to administration (3) Documents baseline vitals (a) BP may elevate as Hct rises (4) Assess for uncontrolled hypertension or Hgb levels higher than 10 g/dL in cancer pt. and 12 in renal iii) Iron products (1) Significant contraindications include (a) Hemochromatosis (b) Hemolytic anemia (c) Any other anemia that is not iron-deficiency related b) Diagnosis i) Activity intolerance related to fatigue and lethargy associated with anemias ii) Imbalanced nutrition, less than body requirements, related to the disease process iii) Constipation related to adverse effects of iron products
(b) Indications (i) Used against solid and hematologic tumors (c) Adverse Effects (i) Pulmonary fibrosis (ii) nephrotoxicity (iii) neurotoxicity (iv) bone marrow suppression (v) peripheral neuropathy (vi) ototoxicity (2) Cytotoxic antibiotics (a) Natural substance produced by the mold Streptomyces (b) Have bone marrow suppression as a common toxicity (c) Other toxic reactions include heart failure and rarely left ventricular failure (d) Mechanisms of Action (i) Interact with DNA through process called intercalation, in which the drug molecule is inserted between two DNA strands blocking synthesis (e) Indications (i) Treat a variety of solid tumors and some hematologic malignancies (f) Adverse effects (i) Hair loss, nausea, vomiting, and myelosuppression (ii) Pulmonary fibrosis (iii) Pneumonitis (iv) Tissue damage in the event of Extravasation (v) Hear failure (vi) Liver, kidney, and cardiovascular toxicities (g) Interactions (i) Dose reduction or elimination of Digoxin use may be required (ii) Toxicity when combined with other drugs
- Nursing Process a) Assessment i) Alkylating drugs (1) Assess deep tendon reflexes a baseline hearing (2) Assess results of baseline pulmonary functioning testing and perform respiratory assessment (3) Documents urinary patterns and abnormal symptoms (4) Note hydration status ii) Cytotoxic antibiotics (1) CT and ultrasounds may be conducted to check cardiac ejection fraction
- Cell cycle- specific drugs a) More effective against growing tumors b) Cytotoxic during a specific phase of the cellular growth cycle c) Drug classes include:
i) Antimetabolites ii) Mitotic inhibitors iii) Alkaloid Topoisomerase II inhibitors iv) Topoisomerase I inhibitors v) Antineoplastic enzymes
- Chemotherapy a) Drugs have a narrow therapeutic index b) Combination of agents is usually more effective than single-agent therapy c) Nearly all agents cause side effects and adverse effects d) Dose-limiting side effects e) Harmful to all rapidly growing cells i) Harmful cancer cells ii) Healthy, normal human cells (1) Hair follicles (2) GI cells (3) Bone marrow cells
- Extravasation a) Leaking of an antineoplastic drug into surrounding tissues during IV administration b) Can result in permanent damage to nerves, tendons, muscles, loss of limbs c) Skin grafting or amputations may be necessary d) Continuous monitoring of the IV site is essential e) If suspected, stop the IV infusion immediately but do not remove the IV tube f) If possible, aspirate remaining drug or blood from the tube g) Do Not remove IV line - may need to give antidote through the existing IV tube, then remove the catheter h) Cover area with sterile, occlusive dressing i) Apply warm or cold compresses and elevate the limb
- Nursing Implications a) Assess baseline blood counts before giving any antineoplastic agents b) Monitor for complications i) GI mucous membranes: stomatitis, altered bowel function with high risk for poor appetite, nausea, vomiting, diarrhea, and inflammation and possible ulcerations of GI mucosa c) Monitor for complications i) Myelosuppression (1) Leukopenia (↓ WBCs) (a) s/s of infection – fever, chills, tachycardia (b) Abnormal breath sounds; productive cough with change in color of sputum; change color of urine (2) Anemia (↓ RBC count) (a) s/s: hypoxia; fatigue; and loss of energy; pallor of skin, oral mucosa and conjunctiva
c) Also stimulates the production of antigens against a specific antibody d) Vaccinations with live bacteria or virus provide lifelong immunity e) Vaccinations with killed bacteria or virus provide partial immunity, and booster shots are needed periodically
- Active Immunization a) The body is exposed to a relatively harmless form of an antigen b) Immune system is stimulated and “remembers” antigen if exposures occur c) The immunizations do not cause a full-blown infection
- Passive Immunization a) Serum immune globulins from humans or animals that are injected into a person b) Substances needed to fight off infection given directly to a person c) The host immune system is bypassed d) Short-lived compared with active immunization, but works faster e) Naturally acquired passive immunity i) From mother to fetus through the placenta ii) From mother to infant through breast milk f) Artificially acquired passive immunity i) Acquired from an external source (injection of antibodies or immunoglobulins) g) Passive is good for people who are immuno-deficient and cannot amount immune response to toxoids or vaccines h) Also used in people who already have the disease (1) Such as rabies, tetanus, and hepatitis (2) Body does not have time to make adequate immune defense against them before death occurs i) 3 Categories: antitoxins, immunoglobulins, antivenins
- Indications a) Active immunization i) Prevents infection caused by bacterial toxins or viruses ii) Provides long-lasting or permanent immunity b) Passive immunization i) Antitoxins, antivenins, immune globulins ii) Minimizes effects of poisoning by the venoms of spiders and certain snakes iii) Provides quick immunity before a person’s own immune system has a chance to make antibodies (such as exposure to hepatitis B or rabies viruses)
- Side Effects a) Range from mild and transient to very serious or life threatening b) Minor effects: fever, minor rash, soreness at injection site, itching c) Severe effects: fever >103° F, encephalitis, convulsions, anaphylactic reaction, dyspnea, and others d) Minor reactions: treated with acetaminophen and rest e) Serious or unusual reactions i) Serum sickness
ii) Report serious or unusual reactions to the Vaccine Adverse Event Reporting System (VAERS)
- Nursing Implications a) Assess client’s health history, medication history, allergies, pregnancy status b) Assess previous reactions and responses to immunizations c) Assess for contraindications, including immunosuppression d) If discomfort occurs at the injection site, apply warm compress + acetaminophen e) Do not give aspirin to children (Reye’s Syndrome) Immunosuppressant Agents
- Immune System a) Autoimmune or immune-mediated diseases - when body attacks itself b) Defends the body against invading pathogens, foreign antigens, and its own cells that become cancerous c) Involved in hypersensitivity/anaphylactic reactions that can be life threatening d) The rejection of kidney, liver, and heart transplants is directed by immune system i) Rejection occurs from an immune response targeted against the transplanted organ ii) Immunosuppressants are used to inhibit the immune system and prevent organ rejection iii) Transplant patients are on immunosuppressant therapy for their lifetime
- Immunosuppressants a) Agents that decrease/prevent immune response (suppresses immune system) b) Used to prevent or treat rejection of transplanted organs c) Suppress certain T-lymphocyte cell lines, preventing their involvement in the immune response d) Result: a pharmacologically immunocompromised state similar to that of a patient with cancer or in a patient with AIDS e) Primarily indicated for the prevention of organ rejection, but some are used for immunologic diseases such as rheumatoid arthritis and multiple sclerosis f) Indications i) Organ rejection ii) Reduce frequency of relapses in relapsing-remitting multiple sclerosis g) Contraindications i) Known drug allergy ii) Renal or hepatic failure iii) Hypertension iv) Concurrent radiation therapy v) Should only be given in urgent situations for pregnant patients h) Adverse Effects i) Increases risk for opportunistic infections ii) Increases risk for certain types of cancers, especially skin iii) Avoid live vaccines
