July 11, 2022

After studying Module 3: Lecture Materials & Resources, discuss the following: Therapeutic drug monitoring is a frequent practice in health care. How does age affect drug absor

After studying Module 3: Lecture Materials & Resources, discuss the following:

Therapeutic drug monitoring is a frequent practice in health care. How does age affect drug absorption, metabolization and excretion?
The use of salt substitutes can cause hyperkalemia in older adults when use in conjunction with what types of drugs?
Describe how you would prevent and evaluate risk factors for medication nonadherence in older adults?

Submission Instructions:

Your initial post should be at least 500 words, formatted and cited in current APA style with support from at least 2 academic sources

Chapter 15

Laboratory and Diagnostic Tests

Aging does not affect the life span of an erythrocyte, but replenishment after bleeding may be delayed due to a decrease in hematopoietic tissue in the marrow of the long bones.

Anemia may be unnoticed if it is mild.

Anemia symptoms include fatigue, shortness of breath, and paresthesia.

Chronic pulmonary disease or heart failure may led to overproduction of RBCs—polycythemia.

Red Blood Cells

Hematocrit and hemoglobin values decline slightly after the age of 90.

Hemoglobin and Hematocrit

Decrease in leukocytes may be related to drugs or severe infection.

Increase in leukocytes is generally seen with infections.

White cell count may be only moderately elevated in older adults with infection like pneumonia.

Other typical symptoms of infection such as fever, pain, and lymphadenopathy may be minimal or absent in older adults with infections, therefore look for sudden onset of confusion or lethargy.

Drugs can also cause an increase in leukocytes.

White Blood Cells

Reduced effect on the bone marrow to release and store neutrophils

Impaired function of lymphocytes in vitro is suspected to cause a reduction in antibody response in later life.

Possibility of decline in monocyte function leading to increased susceptibility to infections and increased incidence of malignancies

Educating older adults about importance of participating in cancer screenings and maintaining immunizations throughout life are essential.

Effect of Aging on White Blood Cells

Decrease in folic acid can indicate macrocytic anemia, megaloblastic anemia, and liver and renal disease.

Alcohol and various other drugs are known to interfere with absorption of folate.

Anticonvulsants, antimalarials, and methotrexate decrease folic acid levels.

Important to assess patients regarding their nutritional intake, including alcohol consumption habits

Elevated levels of folic acid may be seen in people with pernicious anemia.

Folic Acid

Deficiency is caused by malabsorption secondary to gastric bypass, pancreatic disease, ileal resection or inflammation, prolonged use of certain medications, and strict vegan diets.

Malabsorption may be result from the effect of antibodies on gastric parietal cells and a decrease in intrinsic factor leading to pernicious anemia.

Prevalence of pernicious anemia increases significantly with aging.

Low B12 levels may cause fatigue, weakness, and memory loss.

Vitamin B12

Serum iron levels show progressive decreases with advancing age.

Iron deficiency anemia is the most common form of anemia seen in older adults.

Anemia is not a normal consequence of aging.

Nurse should assess older adults for poor dietary intake of iron-containing foods and occult or chronic blood loss.

Iron

Excreted by the kidneys

Estrogen thought to promote excretion of uric acid; elevated levels rarely seen in women before onset of menopause

Altered levels may result from faulty excretion, overproduction of uric acid, or presence of other substances that compete for excretion sites.

Elevated levels seen with gout

Thiazide diuretics, caffeine, low-dose aspirin, and antiparkinsonian drugs can also increase uric acid.

Uric Acid

Increased PT seen in liver disease, vitamin K deficiency, bile duct obstruction, and salicylate intoxication

Medications that cause increase in PT: allopurinol, cephalothin, cholestyramine, clofibrate, and sulfonamides

Digitalis and diphenhydramine can cause decreased PT level.

Prothrombin Time (PT)

Older adults are often prescribed the drug warfarin (Coumadin) after open-heart surgery and for chronic atrial fibrillation.

Adequacy of warfarin therapy can be assessed by following patient’s PT level.

The PT value is traditionally reported in seconds and includes a value called the international normalized ratio (INR).

INR should be between 2 and 3 for most thrombosis and between 3 and 4 for patients with history of recurrent thromboembolism or mechanical heart valves.

PT and Warfarin Therapy

Heparin can inactivate prothrombin, so PTT is a good indicator of whether an older adult is receiving adequate anticoagulation therapy.

Nursing considerations include monitoring for bleeding and correct administration of the heparin dosage.

Partial Thromboplastin Time (PTT)

Ordered when a person has symptoms of thrombus, embolus, or disseminated intravascular coagulation

Age, vascular disease, and kidney or hepatic disease may affect test results.

D-Dimer Test

Indicates the presence of inflammation, so it is useful for monitoring the course of inflammatory activity in autoimmune diseases, infection, and cancers

Mild elevations may be associated with advancing age.

Due to the nonspecific nature of ESR values, interpret results in older adults in conjunction with subjective and objective findings on examination

Erythrocyte Sedimentation Rate

Marker present in acute phase of an inflammatory response

CRP is useful in assessing patients with tissue injury (MI), autoimmune disease, or infection.

C-Reactive Protein

Which of the following statements about laboratory results are true for the older adult patient?

Leukocytes may be only slightly elevated when infection is present.

Patients with rheumatoid arthritis who are taking methotrexate need folic acid supplements.

The most common type of anemia is pernicious anemia.

The patient with gout who is taking thiazide diuretics may have more attacks.

The therapeutic level of warfarin is assessed with the PTT.

Quick Quiz!

ANS: A, B, D

Answer to Quick Quiz

Decreases in platelet counts (to fewer than 100,000/mm3) require investigation.

Half of patient’s over age 60 diagnosed with low platelets have Myelodysplastic syndrome (MDS) which can progress to leukemia.

Spontaneous bleeding can occur when platelets are below 20,000/mm3.

When 40,000/mm3 or below, prolonged bleeding after procedures can occur.

Platelets

Older adults may have serious problems with electrolyte imbalance.

Dehydration is the most common form of electrolyte disorder occurring in older adults.

Usually attributed to excess loss of water or altered fluid intake

Electrolytes

Index of body water deficit or excess

Regulation maintains blood pressure, transmission of nerve impulses, and regulates body fluid levels in and out of cells.

Movement of sodium affects blood volume, which is tied to thirst mechanism and total body fluids.

Sodium

Increases with age, related to the kidneys’ inability to excrete free water because of decreased basal levels of renin and aldosterone

Vague symptoms like malaise, confusion, headache, and nausea may progress to coma and seizures.

Determine whether an older adult has low sodium level but normal osmolarity; this is known as hypertonic hyponatremia

Excessive glucose, triglycerides, or plasma proteins in the blood cause normal or high osmolarity.

Hyponatremia

Hypernatremia can occur from infusion of high-sodium solute fluids, excess water loss, and excessive diarrhea and decreased oral intake.

Symptoms are like those of hyponatremia, and the most common neurologic signs are lethargy, weakness, progressing to altered consciousness, and coma.

Hypernatremia

Imbalances in older adults are caused by the same changes in the renal system as those affecting sodium.

Salt substitutes are high in potassium and should be used with caution especially with potassium sparing drugs which can lead to hyperkalemia.

Hypokalemia may be caused by gastrointestinal loss and the use of diuretics.

Potassium imbalance may predispose older adults to tachyarrhythmias and potentiate digitalis toxicity.

Potassium

Hyperkalemia may cause muscle twitching, arrhythmias, and gastrointestinal symptoms.

Hypokalemia muscle weakness, confusion, and absence of bowel sounds

Signs and Symptoms of Hyperkalemia and Hypokalemia

Closely tied to sodium

Losses and excesses in sodium affect chloride levels.

Chloride levels have not been shown to change with aging.

Chloride

Changes in calcium regulation occur with aging but there is no alteration in serum calcium levels due to homeostasis.

Loss of calcium from bone maintains the normal level of calcium in the blood, but the resulting bone loss secondary to calcium leaching can lead to osteoporosis.

Calcium is protein bound with albumin so any change in albumin level also affects calcium.

Calcium has an inverse relationship with phosphorous.

Calcium

Mineral found mostly in bone, in combination with calcium.

Phosphorus plays an important role in the maintenance of homeostasis.

Phosphorus levels are slightly decreased in comparison with younger adults.

Phosphorus

Mineral important to enzyme action for production of energy

Most important sites of function are muscles (especially the heart) and nerves.

With aging, gastrointestinal absorption of magnesium decreases and excretion of magnesium by the kidneys increases, coupled with lower dietary intake can lead to hypomagnesemia.

Magnesium

Four methods of diagnosing diabetes are: Fasting plasma glucose, oral glucose tolerance test, glycohemoglobin (hemoglobin A1c HbA1c), random blood sugar

Glucose metabolism alters with aging; reduced insulin effectiveness and islet cell dysfunction.

Higher incidence of diabetes in older adults

Hypoglycemia is harder to recognize, dizziness and visual disturbances are more common than palpitations and sweating.

Glucose

Measures amount of albumin and globulin within the body

Identifies nutritional problems, kidney, and liver disease

Total Protein

Monitors nutritional status, liver and kidney disease

Albumin levels decrease with age

Levels <3.5 g/dL have been associated with increased mortality in hospitalized patients.

Low albumin levels are also associated chronic disease including diabetes, hyperthyroidism, and HF.

High albumin levels are associated with blood loss and dehydration.

Albumin

Prealbumin is used to assess nutritional status.

Measures protein status over the short term and is a more accurate measurement of malnutrition because of its short half-life of 1.9 days

Plasma prealbumin level is useful in monitoring therapy with total parenteral nutrition.

Prealbumin

Urea is major waste product of protein catabolism and a result of ammonia conversion in the liver, excreted by kidneys.

Levels indicate both liver and kidney function.

Values for older men are slightly higher than the adult normal levels of 7–22 mg/dL.

In older women, BUN levels are also increased but at lower levels than for older men.

Blood Urea Nitrogen (BUN)

End product of protein metabolism

Rise in a patient’s BUN and creatinine levels indicates kidney disease.

Physiologic decline in GFR does not cause a rise in creatinine level secondary to a decrease in muscle mass with aging.

A creatinine level should not be considered an independent indicator of renal function, better to calculate creatinine clearance for a more realistic indication of renal function.

Creatinine

Measure of GFR, estimated from serum creatinine and urine creatinine levels

24-hour urine test is required along with a serum level within the same 24-hour period.

Creatinine clearance is a reflection of an older adult’s overall health status.

It decreases an average of 6.5 mL/min each decade of life after age 20.

Used to monitor medication response

Creatinine Clearance

An optimal triglyceride level is 100 mg/dL or lower.

Total cholesterol levels are a combination of LDL and HDL levels in the bloodstream.

Total cholesterol levels be kept at less than 200 mg/dL.

HDL, “good cholesterol” level >60 mg/dL is considered healthy, protects against heart disease.

LDL, “bad cholesterol” levels <70 mg/dL for risk of heart disease; <100 mg/dL for those at high risk but without established disease; <130 mg/dL for those at moderate risk for heart disease; <160 mg/dL for those at low risk for heart disease.

Triglycerides and Cholesterol

Neurohormone secreted from cardiac ventricles in response to ventricular stretching and pressure overloading

Help in diagnosis and treatment of patients with congestive heart failure (CHF)

Values cannot be used to differentiate between systolic and diastolic heart failure.

Brain Natriuretic Peptide

Testing for alkaline phosphatase (ALP) identifies liver and bone disorders, in older adults it’s used in the biochemical assessment of Paget disease and other bone diseases.

Aspartate transaminase (AST) primarily used to diagnose liver disease

Liver Enzymes

Troponin T and troponin I are the preferred tests for suspected heart attack.

Appear 2–8 hours after cardiac injury and can remain elevated up to 2 weeks after a myocardial infarction

Troponin

Includes assessment of two hormones secreted by the thyroid gland: thyroxine (T4) and triiodothyronine (T3)

They are a screening tool for hypothyroidism or hyperthyroidism.

T4 and T3 are generally elevated in hyperthyroidism and decreased in hypothyroidism.

TSH is elevated in hypothyroidism and decreased in hyperthyroidism.

Thyroid Function Tests

High levels of PSA may indicate the presence of prostate cancer, but an enlarged or inflamed prostate can also increase PSA levels.

Patients need to understand the risks of testing for prostate cancer.

Prostate-Specific Antigen (PSA)

Which of the following statements about laboratory results are true for the older adult patient?

Hyperkalemia can cause digitalis toxicity.

Hypernatremia may be related to laxative abuse.

Albumin levels decrease with aging.

The BUN level stays the same, but the creatinine level rises in renal failure.

ALP is used to assess Paget’s disease.

T3 and T4 are decreased in hypothyroidism.

Quick Quiz!

ANS: B, C, E

Answer to Quick Quiz

Protein in the urine (proteinuria) is an abnormal finding, means damage to the kidneys’ glomeruli.

Glucose spills into the urine when blood glucose exceeds 180 mg/dL and with kidney damage or disease.

Bacteriuria >100,000 colony-forming units (CFU) per milliliter of urine indicates infection.

Confusion, new onset of incontinence, lethargy, nocturia, and anorexia may be the first indication of underlying UTI.

Leukocytes in urine (pyuria) are more indicative of UTI.

Urinalysis (1 of 2)

Positive leukocyte esterase indicates the need for microscopic examination and urine culture and sensitivity testing.

Nitrite test is used with leukocyte esterase to diagnose UTI.

Presence of ketones in urine occurs with diabetic ketoacidosis, a low-carbohydrate diet, starvation or fasting, and severe vomiting.

Urine pH reflects the body’s homeostatic state.

Hematuria is always an abnormal finding.

Urinalysis (2 of 2)

Components of ABG testing are pH, oxygen, and carbon dioxide content, oxygen saturation, and bicarbonate level.

Be aware of supplemental oxygenation at the time of blood draw

Pulse oximetry is a reliable alternative to ABG testing and less invasive.

Decrease in chest wall recoil and in alveolar surface area, and less effective oxygen-to-carbon dioxide (CO2) exchange contribute to potential changes in oxygenation with aging.

Arterial Blood Gas (ABG) Testing

Therapeutic drug monitoring is performed in older adults receiving drugs such as digoxin, theophylline, valproic acid, and phenytoin.

Therapeutic Drug Monitoring

Chapter 16

Drugs and Aging

Drugs are important in the management of conditions and the maintenance of well-being in older adults.

All drugs carry some level of risk.

Important to understand how aging and conditions associated with aging can affect drug processes and actions.

Demographics of Drug Use

Aging alters dynamic processes that drugs undergo to produce therapeutic effects.

Pharmacokinetic changes: what the body does to the drugs.

Pharmacodynamic changes: what the drug does to the body.

Changes in Drug Response With Aging

Movement of a drug from site of administration to systemic circulation

Aging is accompanied by decreased secretion of gastric acid, slowed gastric emptying, and decreased gastrointestinal motility which may slow absorption of oral drugs.

The first dose of a new drug may take longer to take effect.

Reduction in subcutaneous fat alters topical drug absorption.

Pharmacokinetic Changes: Absorption

Movement of drug from systemic circulation to site of action

Total body water decreases with aging; results in higher concentrations of water-soluble drugs.

Decreased lean body mass and increased percentage of fat storage offer increased storage capability for fat-soluble drugs.

Decreased protein available for binding may cause toxicity and difficulty maintaining stable drug levels of drugs that are highly protein bound.

Pharmacokinetic Changes: Distribution

Biotransformation of drugs into metabolites that are more easily excreted

A decrease in hepatic blood flow occur that may result in a decrease in the amount of a drug inactivated before entering the systemic circulation causing a greater amount of active drug, increasing the risk that standard drug doses may have toxic effects.

Pharmacokinetic Changes: Metabolism

Elimination of drugs from body primarily via kidneys

With decreased renal function, half-life increases and drugs may accumulate to toxic levels.

Renal function typically decreases with aging and the best indicator of renal function is glomerular filtration rate (GFR).

Pharmacokinetic Changes: Excretion

Careful patient monitoring to assess adequacy of drug to achieve desired effect and to identify any adverse effects that can create problems for the patient

Become familiar with signs and symptoms of toxicity for each drug that the patient takes so that any problem is detected in the early stages

Important to understand therapeutic drug monitoring

Nursing Management

Age-related changes affect all substances involved in pharmacodynamics.

Drug sensitivity may be either increased or decreased unrelated to drug levels.

Autonomic control and reflex activity become less responsive, may be less able to tolerate certain drugs.

Pharmacodynamic Changes

Assess responses to drugs so therapy can be adjusted, if needed, to improve patient outcomes.

Nursing Management

As result of the age-related changes in pharmacokinetics and pharmacodynamics some drugs and drug classes are less likely to be tolerated.

Beers Criteria for Potentially Inappropriate Medication Use in Older Adults is screening tool and list detailing inappropriate drugs for older adults.

Recognize that drugs considered appropriate and frequently prescribed may also carry serious drug-related risks.

Usage must be weighed in terms of benefit versus risk.

Inappropriate Drugs for Older Patients

Important to view drugs in terms of desired versus undesired outcomes

Drugs may have detrimental effects on cognition, emotion, ambulation, continence, and other essential functions.

Negative effects on quality of life must be carefully considered as part of pharmacologic therapy.

Some patients may prefer to endure a condition rather than suffer an adverse effect so inquire why a patient refuses a drug and if substitution is available.

Drugs and Quality of Life

Most common interaction is the result of altered metabolism via the CYP450 hepatic enzyme system.

Drugs can induce or inhibit the activity of various CYP isozymes, which causes increased or decreased biotransformation of drugs.

Drugs may interact indirectly through opposing or antagonistic actions.

Drugs may also interact chemically.

Drug–Drug Interactions

These occur less commonly

Drug metabolism or effect of certain drugs can be altered when combined with certain foods

These dangerous interactions can cause drug levels to accumulate or reach toxic levels

Drug–Food Interactions

These interactions may exacerbate patient conditions and hinder healing.

Drugs generally contraindicated in patients with coexisting underlying disease

Drug–Disease Interactions

“Giving medications without a clear indication, giving two similar medications for the same indication, giving medications that are contraindicated, and/or giving medications where the dosage is either too high or too low”

Having one or more chronic conditions requiring several medications for management; may see more than one provider for the same health problem; may have prescriptions filled at more than one pharmacy

Additional contributors: use of over-the-counter and alternative medicines or supplements

Polypharmacy

Assess whether a new symptom or problem could be caused by a drug the patient is taking.

Employ nonpharmacologic interventions, whenever possible.

Nursing Management of Polypharmacy

The injuries resulting from patient harm are commonly referred to as adverse drug events (ADEs).

Study showed a marked increase in fatal drug errors among those who take their drugs at home.

Development of new drugs has resulted in an increase in the number of prescriptions for drugs.

Many patients may keep drugs long after they have expired rather than disposing of them.

Errors may occur when rights of administration are not followed.

Drug Errors

Which of the following are true statements about pharmacology and the older adult?

Polypharmacy in older adults occurs when they get their prescription filled at many different pharmacies.

Because of age-related changes, older adults may be more sensitive to side effects of a drug, like dry mouth.

Older adults would rather have their condition treated and will put up with side effects.

The best indicator of renal function when monitoring a drug elimination is the creatinine level.

It is importance to ask about the over-the-counter and herbal medications the older adult is using.

Quick Quiz!

ANS: A, B, E

Answer to Quick Quiz

Often prescribed for older adults despite evidence demonstrating their “limited efficacy and significant adverse effects”

Have been prescribed for hitting, yelling, and screaming; refusing care and wandering; and, inconsolable crying, agitation, and aggression

These drugs do not help persons with dementia become more involved in their care, interact better with others, or stop inappropriate behavior.

These drugs increase risk for falls, fractures and breaks, incontinence, strokes, and death.

Antipsychotics

Drugs used to treat insomnia and anxiety have the potential for bothersome and sometimes potentially dangerous adverse effects.

Often occur secondary to medication side effects or to medical conditions such as dementia, thyroid abnormalities, or depression

Barbiturates are not recommended.

Benzodiazepines with long half-lives should be avoided.

Antihistamines are potentially inappropriate drugs for use in older adults.

Anxiolytics and Hypnotics

For anxiety, non–central nervous system (CNS) depressants such as buspirone are effective agents.

For sleep short-term treatment with benzodiazepine receptor agonists (BZRAs)—zolpidem; pyrazolopyrimidines—zaleplon; and melatonin receptor agonists—ramelteon are appropriate, short-term, alternatives

Better Options for Insomnia and Anxiety

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After studying Module 3: Lecture Materials & Resources, discuss the following: Therapeutic drug monitoring is a frequent practice in health care. How does age affect drug absor

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