ATI RN Pharmacology for Nursing (8th Edition) PDF

07/24/15 April 19, 2019 9:51 AM rm_rn_2019_pharm_chp6 CHAPTER 6 UNIT 1 PHARMACOLOGICAL PRINCIPLES Psychological factors: Emotional state and expectations Individual...

07/24/15 April 19, 2019 9:51 AM rm_rn_2019_pharm_chp6 CHAPTER 6 UNIT 1 PHARMACOLOGICAL PRINCIPLES Psychological factors: Emotional state and expectations Individual can influence the effects of a medication. The placebo CHAPTER 6 effect describes positive medication effects that Considerations psychological factors, not biochemical properties of the medication, influence. of Medication Diet: Inadequate nutrition (starvation) can affect the Administration protein-binding response of medications and subsequently increase the medication’s response. Medical problems Various factors affect how clients respond to Inadequate gastric acid inhibits the absorption of medications that require an acid medium to dissolve. medications. It is important for nurses to identify Diarrhea causes oral medications to pass too quickly these factors to help them individualize nursing through the gastrointestinal tract for adequate absorption. Vascular insufficiency prevents distribution of a care when administering medications. medication to affected tissue. Liver disease or failure impairs medication metabolism, which can cause toxicity. FACTORS AFFECTING MEDICATION Kidney disease or failure prevents or delays medication DOSAGES AND RESPONSES excretion, which can cause toxicity. Body weight: Because body tissues absorb medications, Prolonged gastric emptying time delays the absorption individuals who have a greater body mass require larger of medications in the intestines. doses. Because the percentage of body fat an individual has can alter the distribution of a medication, basing dosages on body surface area can be a more precise method of PHARMACOLOGY AND CHILDREN regulating an individual’s response to a medication. Although most medications adults take are useful for children, the dosages are different. Providers base Age: Young children who have immature liver and kidney pediatric dosages on body weight or body surface area function, and older adults, often with reduced liver and (BSA). Newborns and infants have immature liver and kidney function, require proportionately smaller kidney function, alkaline gastric juices, and an immature medication doses to compensate for their heightened blood-brain barrier, making them especially sensitive sensitivities to medications. to medications that affect the CNS. Providers base some Sex: Females respond differently to medications than medication dosages on age due to a greater risk for males due to a higher proportion of body fat and the decreased skeletal bone growth, acute cardiopulmonary effects of female hormones. failure, and hepatic toxicity. Genetics: Genetic factors (missing enzymes) can alter ADDITIONAL PHARMACOKINETIC FACTORS SPECIFIC the metabolism of certain medications, thus enhancing TO CHILDREN or reducing a medication’s action. The usual effect is Decreased gastric acid production and slower gastric either fewer benefits from the medication or greater emptying time medication toxicity. Decreased first-pass medication metabolism Increased absorption of topical medications (greater Biorhythmic cycles: Responses to some medications blood flow to the skin and thinner skin) vary with the biologic rhythms of the body. For example, Lower blood pressure (more blood flow to the liver and hypnotic medications work better when given at the usual brain and less blood flow to the kidneys) sleep time than at other times. Higher body water content (dilutes Tolerance water-soluble medications) Reduced responsiveness to a medication clients take over Decreased blood protein-binding sites (until 1 year of time (morphine) is pharmacodynamic tolerance. Other age). This can result in an increase in the blood level of medications (barbiturates) cause metabolic tolerance as protein-binding medications. metabolism of the medication increases over time and Increased effects on the CNS system because the the effectiveness of the medication declines. blood-brain barrier is not fully developed at birth Some clients develop cross-tolerance to another Varying minimum effective concentration levels with IV medication after they have become tolerant to a and subcutaneous administration chemically similar medication. Accumulation: Medication concentration in the body increases due to the inability to metabolize or excrete a medication rapidly enough, resulting in a toxic medication effect. For older adults, decreased kidney and liver function are the major causes of medication accumulation leading to toxicity. RN PHARMACOLOGY FOR NURSING CHAPTER 6 INDIVIDUAL CONSIDERATIONS OF MEDICATION ADMINISTRATION 45 07/24/15 April 19, 2019 9:51 AM rm_rn_2019_pharm_chp6 07/24 NURSING ACTIONS WHEN ADMINISTERING MEDICATIONS PROMOTING ADHERENCE TO CHILDREN Give clear and concise instructions, verbally and in writing. Check that dosages are accurate for weight or BSA. Ensure that the dosage form is appropriate. Administer Be aware that most medications do not undergo testing liquid forms to clients who have difficulty swallowing pills. on children. Provide clearly-marked containers that are easy to open. Initial pediatric dosages are an approximation. Assist the client with setting up a daily calendar and Some adult medication forms and concentrations require using pill containers. dilution, calculation, preparation, and administration of Discuss the availability of and access to local resources very small doses for administration to children. for obtaining and paying for medications. Limited sites exist for IV medication administration. Suggest that the client obtain assistance from a friend, Give written and verbal instructions to guardians to neighbor, or relative. promote adherence to medication regimens. Advise clients to dispose of medications they no longer take and those that have expired via drug take-back programs or by mixing medication in a sealable bag PHARMACOLOGY AND with an undesirable substance like cat litter and OLDER ADULTS (65+ YEARS) disposing in household trash. PHYSIOLOGIC CHANGES WITH AGING THAT AFFECT PHARMACOKINETICS Increased gastric pH (alkaline) PHARMACOLOGY AND PREGNANCY, LACTATION, AND Decreased gastrointestinal motility and gastric emptying time, resulting in a slower rate of absorption REPRODUCTIVE POTENTIAL Decreased blood flow through cardiovascular system, Pregnancy: Any medication clients who are pregnant liver, and kidneys ingest will affect the fetus. Decreased hepatic enzyme function Most medications are potentially harmful to the fetus. Decreased kidney function and glomerular filtration rate Therefore, prescribers must weigh the benefits of Decreased protein-binding sites, resulting in lower medication administration against possible fetal risk. blood albumin levels The U.S. Food and Drug Administration classified Decreased body water, increased body fat, and decreased medication into five categories based on possible risk to lean body mass the fetus. New guidelines include omitting the OTHER FACTORS AFFECTING MEDICATION THERAPY categories and including information for clients who are Multiple or severe illnesses pregnant, lactating, or of reproductive potential. Impaired memory or altered mental state Medications clients take during pregnancy include Changes in vision and hearing nutritional supplements (iron, vitamins, minerals) and Decreased mobility and dexterity medications that treat nausea, vomiting, gastric acidity, Poor adherence and mild discomforts. Inadequate supervision of long-term therapy Due to the physiologic changes during pregnancy in Limited financial resources the kidney, liver, and gastrointestinal tract, clients Polypharmacy: The practice of taking several might require a compensatory increase or decrease in medications simultaneously (prescription, over-the- medication dosage, depending on the specific medication. counter [OTC], herbal, recreational) with diminished Providers manage chronic medical disorders (diabetes bodily functions and some medical problems can mellitus and hypertension) in conjunction with contribute to the potential for medication toxicity. careful maternal-fetal monitoring. Pregnancy is a contraindication for live-virus vaccines (measles, NURSING INTERVENTIONS mumps, rubella, varicella, yellow fever) due to possible Decreasing the risk of adverse medication effects teratogenic effects, including gross malformations and Obtain a complete medication history, and include all neurobehavioral, congenital, and metabolic anomalies. OTC medications, illicit drugs, and herbal supplements. The Advisory Committee on Immunization Practices Make sure medication therapy starts at the lowest recommends that clients who are pregnant during possible dose. influenza season receive the inactivated influenza vaccine. Assess and monitor for therapeutic and adverse effects. Monitor plasma medication levels to provide a rational Lactation: Most medications that clients who are lactating basis for dosage adjustment. take enter breast milk. These clients should avoid Assess and monitor for medication-medication and medications that have an extended half-life, are medication-food interactions. sustained-released, or are harmful to infants. For Document findings. medications that are safe, give the medication Notify the provider of adverse effects. immediately after breastfeeding to minimize the medication’s concentration in the next feeding. Give the lowest effective dosage for the shortest possible time. 46 CHAPTER 6 INDIVIDUAL CONSIDERATIONS OF MEDICATION ADMINISTRATION CONTENT MASTERY SERIES 07/24/15 April 19, 2019 9:51 AM rm_rn_2019_pharm_chp6 Reproductive potential Some medications include special considerations for males Active Learning Scenario and females of reproductive potential to reduce the risk of fetal harm and to preserve reproductive ability, if desired. A nurse is preparing an educational session about Other medications can affect hormone levels that client-specific factors to consider when administering impact reproduction and lead to infertility. This can be medications. Use the ATI Active Learning Template: a desired or undesired effect for the client. Basic Concept to complete this item. Special interventions can include pregnancy testing before and during medication therapy, and beginning or RELATED CONTENT: Identify four general factors altering contraceptive use. that affect medication dosages and responses. Ensure the client understands the impact of prescribed UNDERLYING PRINCIPLES: Identify three medical medications on reproductive potential, and understands problems that affect medication dosages and responses. any special actions to take during medication use. Application Exercises 1. A nurse is preparing to administer medications 2. A nurse in a provider’s office is reviewing the medical to a 4-month-old infant. Which of the following record of a client who is pregnant and at the first pharmacokinetic principles should the nurse prenatal visit. Which of the following immunizations consider when administering medications can the nurse administer safely to this client? to this client? (Select all that apply.) A. Varicella vaccine A. Infants have a more rapid gastric emptying time. B. Rubella vaccine B. Infants have immature liver function. C. Inactivated influenza vaccine C. Infants’ blood-brain barrier is poorly developed. D. Measles vaccine D. Infants have an increased ability to absorb topical medications. E. Infants have an increased number 3. A nurse on a medical-surgical unit administers a hypnotic medication to an older adult client at of protein-binding sites. 2100. The next morning, the client is drowsy and wants to sleep instead of eating breakfast. Which of the following factors should the nurse identify as a possible reason for the client’s drowsiness? A. Reduced cardiac function B. First-pass effect C. Reduced hepatic function D. Increased gastric motility RN PHARMACOLOGY FOR NURSING CHAPTER 6 INDIVIDUAL CONSIDERATIONS OF MEDICATION ADMINISTRATION 47 07/24/15 April 19, 2019 9:51 AM rm_rn_2019_pharm_chp6 Application Exercises Key Active Learning Scenario Key 1. A. Gastric emptying is longer and inconsistent in infants. Using the ATI Active Learning Template: Basic Concept Medications administered orally remain in the stomach for RELATED CONTENT: General factors a longer period of time, and absorption is more complete. Body weight Because gastric emptying is inconsistent, the time for therapeutic effects to occur is difficult to predict. Age B. CORRECT: Infants have immature liver function Sex until 1 year of age. Administer medications the Genetics liver metabolizes in smaller dosages. Biorhythmic cycles C. CORRECT: Infants have a poorly developed blood-brain Tolerance barrier, which places them at risk for adverse effects from Accumulation medications that pass through the blood-brain barrier. Psychological factors Administer these medications in smaller dosages. Diet D. CORRECT: Because infants have more blood flowing to the skin and their skin is thin, their UNDERLYING PRINCIPLES: Medical problems medication absorption is increased, making them Inadequate gastric acid inhibits the absorption of prone to toxicity from topical medications. medications that require an acid medium to dissolve. E. Infants have limited protein-binding sites compared Diarrhea causes oral medications to pass too quickly through with adults, which makes them more vulnerable to the gastrointestinal tract for adequate absorption. increased effects of medications. Medication doses Vascular insufficiency prevents distribution must be smaller during the first 12 months of life. of a medication to affected tissue. NCLEX® Connection: Pharmacological and Parenteral Therapies, Liver disease or failure impairs medication Expected Actions/Outcomes metabolism, which can cause toxicity. Kidney disease or failure prevents or delays medication excretion, which can cause toxicity. 2. A. Pregnancy is a contraindication for vaccines that contain Prolonged gastric emptying time delays the a live virus, including the varicella vaccine. absorption of medications in the intestines. B. Pregnancy is a contraindication for vaccines that contain a live virus, including the rubella vaccine. NCLEX® Connection: Pharmacological and Parenteral Therapies, C. CORRECT: During influenza season, providers recommend the Expected Actions/Outcomes inactivated influenza vaccine for clients who are pregnant. D. Pregnancy is a contraindication for vaccines that contain a live virus, including the measles vaccine. NCLEX® Connection: Pharmacological and Parenteral Therapies, Medication Administration 3. A. Reduced cardiac function would not cause the client’s medication to have a prolonged effect. B. The first-pass effect would cause faster metabolizing of the hypnotic medication, thus having a decreased effect. C. CORRECT: Older adults have reduced hepatic function, which can prolong the effects of medications the liver metabolizes. The client probably needs a lower dosage of the hypnotic medication. D. Increased gastric motility would cause a lesser effect of the medication, not an increased or prolonged effect. NCLEX® Connection: Pharmacological and Parenteral Therapies, Expected Actions/Outcomes 48 CHAPTER 6 INDIVIDUAL CONSIDERATIONS OF MEDICATION ADMINISTRATION CONTENT MASTERY SERIES 07/24/15 April 19, 2019 9:51 AM rm_rn_2019_pharm_unit2 NCLEX® Connections When reviewing the following chapters, keep in mind the relevant topics and tasks of the NCLEX outline, in particular: Psychosocial Integrity SUBSTANCE USE AND OTHER DISORDERS AND DEPENDENCIES Plan and provide care to clients experiencing substance-related withdrawal or toxicity. Provide symptom management for clients experiencing withdrawal or toxicity. Pharmacological and Parenteral Therapies ADVERSE EFFECTS/CONTRAINDICATIONS/ SIDE EFFECTS/INTERACTIONS Provide information to the client on common side effects/ adverse effects/potential interaction of medications and inform the client when to notify the primary health provider. Monitor for anticipated interactions among the client's prescribed medications and fluids. Identify a contraindication to the administration of a medication to the client. EXPECTED ACTIONS/OUTCOMES: Use clinical decision making/critical thinking when addressing expected effects/outcomes of medications. MEDICATION ADMINISTRATION: Educate client about medications. Reduction of Risk Potential LABORATORY VALUES: Notify primary health care provider about laboratory test results Physiological Adaptation MEDICAL EMERGENCIES: Notify primary health care provider about unexpected client response/emergency situation. RN PHARMACOLOGY FOR NURSING NCLEX® CONNECTIONS 49 07/24/15 April 19, 2019 9:51 AM rm_rn_2019_pharm_unit2 50 NCLEX® CONNECTIONS CONTENT MASTERY SERIES