Ppt chapter 08-1

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins

Chapter 8

Life Span: Older Adults


Question

• There is a decline in the organ function of the elderly patient.

– A. True

– B. False


Answer

• A. True

• Rationale: There is a general decline in the organ function of the elderly patient, which impacts drug therapy.


Overview

• In general, aging organs and body systems are less responsive to a drug’s effect. Age-related changes affect the patient’s response to drug therapy because both the therapeutic and the adverse effects are altered.

• The nurse also needs to be aware that many older adults take multiple prescribed and over-the-counter (OTC) drugs.

• The older adult is defined as a person who is 65 years of age or older.

• Many older adults are independent and in generally good health.

• They may receive drug therapy for chronic conditions.


Pharmacotherapeutics

• The pharmacotherapeutics of drug therapy for older adults are similar to those for younger adults.

• Some drug therapies are more frequently used than others in older adults because of their therapeutic effects.

• Older adults are prone to certain disease processes.


Pharmacokinetics

• The processes of drug absorption, distribution, metabolism, and excretion may be affected or impaired by the normal physiologic changes of aging.

• Changes ultimately affect the extent and duration of the systemic availability of a drug.


Physiologic Changes in the Older Patient


Absorption

• Although absorption seems to be the least affected pharmacokinetic process during aging, in the older adult, increased gastric pH levels, decreased rate of blood flow, decreased GI motility, and reduced body surface area may influence the rate of absorption.

• Disease processes are more likely than age-related changes to alter an older adult’s absorption patterns.

• The overall effects of aging on the GI tract result in a slowed drug absorption rate.


Distribution • Several physiologic factors affect the distribution of a

drug in older adults, including decreased body mass, reduced plasma albumin levels, and a less effective blood–brain barrier.

• Other age-related factors that may affect drug distribution include declining cardiac output, extreme changes in body weight, poor nutrition, dehydration, inactivity, and extended bed rest.

• Plasma levels of the protein albumin, which is produced by the liver, are also reduced in the elderly.

• Age-related changes in the central nervous system (CNS) can alter drug distribution.


Question

• In the older adult, fat-soluble drugs have a decreased volume of distribution.

– A. True

– B. False


Answer

• B. False

• Rationale: The body mass of a person decreases with age. In the older adult, the proportion of body fat increases as the percentage of lean muscle mass decreases. Consequently, body water decreases in proportion to the total body weight. A highly fat-soluble drug exhibits an increased volume of distribution.


Metabolism • The liver’s efficiency at metabolizing gradually declines

with age.

• In the older adult, three major physiologic changes occur:

– First, the size of the liver changes.

– Second, blood flow to the liver declines.

– Third, the ability to metabolize drugs is reduced.

• Aging affects the efficiency of both phases of metabolic activity.

• Nurses may mistakenly interpret an older patient’s altered cognition as normal rather than the effect of a drug.


Excretion

• Aging can substantially decrease renal efficiency.

• The serum creatinine concentration is maintained in the normal range because creatinine production declines in the older adult.

• A normal creatinine level does not indicate normal renal function in elderly patients.


Question

• Which two main processes of kidney function are altered in the older adult, thereby affecting drug excretion?

– A. Blood flow and blood pressure

– B. Body surface area and glomerular filtration

– C. Glomerular filtration and renal tubular secretion

– D. Decreased gastric pH and blood flow


Answer

• C. Glomerular filtration and renal tubular secretion

• Rationale: All of the other factors listed are normal effects of aging but do not affect excretion of the drug. Glomerular filtration and renal tubular secretion play a significant role in drug excretion.


Pharmacodynamics

• Decreased organ efficiency in the older adult alters pharmacodynamic responses.

• Because absorption is prolonged in the older adult, response to single doses of drugs is commonly delayed.

• The drug receptors in the older adult do not function as efficiently.

• Decreases in the number of receptors are also associated with decreases in the respective neurotransmitters themselves.


Contraindications and Precautions

• Although drug contraindications are generally similar for older adults and younger adults, due to the older adult’s decreased renal function and possibly metabolic function, many drugs should be used with caution.

• The Beers criteria are a standard tool for the identification of potentially inappropriate medications in older adults.

• Use of inappropriate drugs may be a substantial problem in the current health care system.

• The nurse must realize that there will be occasions when an “inappropriate” drug will be used because it is the best therapy.


Beers Criteria




Adverse Effects

• Physiologic changes in older adults place them at greater risk for certain adverse effects.

• Adverse drug effects are a cause of hospital admissions in older adults.

• Because of the less effective blood–brain barrier, older adults may be more vulnerable to CNS adverse effects.

• Older adults may experience a paradoxical effect from the drug therapy.

• Age-related health problems often mimic the adverse effects of drug therapy.


Drug Interactions

• Drug interactions are the same for older adults as for other populations.

• It is not uncommon for older adults to be taking between 8 and 12 prescribed and OTC drugs to treat a variety of diseases.

• Often, the combination of so many different drugs causes serious drug interactions.


Health Status

• Aging is associated with a decline in normal bodily maintenance and function.

• The major organ systems (cardiovascular, respiratory, GI, genitourinary, endocrine, and others) all become much less efficient with advancing age.

• Decline in organ function results in health problems that often require drug therapy.

• When assessing the older patient’s health status, assess for polypharmacy.


Health Status (cont.)

• When assessing the older patient’s renal function status, remember that normal laboratory value ranges may be deceptive.

• Assessment should always include a thorough inventory of all the drugs the patient is currently taking, dosage, and dosing schedule.

• Gaps in the knowledge of older adult patients indicate that teaching about drug therapy is needed.

• In addition, assess whether the older adult patient is taking the medication as prescribed.


Lifestyle, Diet, and Habits

• Assessment of several basic areas of daily living is essential in drug therapy.

• If older adults have difficulty swallowing solid food, they may need to have the drug crushed for administration.

• The use of alternative medications, such as herbs and botanicals, has increased with older adults as it has with the general population.

• Another important assessment is how drug therapy and the related adverse effects have altered the older adult’s lifestyle or impaired the quality of life.


Lifestyle, Diet, and Habits (cont.)

• The mental status of older patients is extremely important to their quality of life.

• Habits regarding drug therapy should be considered when planning drug administration in the hospital.

• Because older adults typically have fixed incomes, question patients to determine whether their health insurance includes payment or partial payment for drug therapy.


Environment

• Determine whether the patient lives alone or with other family members.

• Assess the patient’s access to a pharmacy.


Culture and Inherited Traits

• Be sensitive to beliefs and cultural values that may have an effect on drug therapy.

• Some ethnic or cultural groups still practice folk medicine.

• The number of some of the cytochrome P-450 isoenzymes, needed for drug metabolism, may vary based on genetic inherited traits.


Nursing Diagnoses and Outcomes

• Risk for Injury related to adverse effects of drug therapy stemming from polypharmacy and drug interactions secondary to increased therapeutic effect, delayed elimination, and prolonged drug half-life

– Desired outcome: The older adult patient will not sustain an injury while on drug therapy.

• Ineffective Therapeutic Regimen Management because of impaired memory

– Desired outcome: The patient will effectively manage the therapeutic regimen with the help of memory aids.


Question

• Which of the following factors affect drug administration in the older adult?

– A. Chronic disease

– B. Decreased organ function

– C. Polypharmacy

– D. All of the above


Answer

• D. All of the above

• Rationale: Age-related changes that affect drug administration include health problems, decreased organ functioning, and polypharmacy.


Maximizing Therapeutic Effects

• For any drug therapy to be therapeutic, the appropriate dose must be taken at the appropriate times.

• The more complicated the overall therapeutic regimen, the greater the likelihood of poor adherence to the drug therapy.

• Nonadherence does not always mean that the patient directly refuses to follow the recommended drug therapy schedule.

• Nurses and prescribers can improve adherence by making drug regimens as easy to follow and as uncomplicated as possible.


Maximizing Therapeutic Effects (cont.)

• When a new drug therapy begins, plan a new drug schedule to coincide with other prescribed schedules whenever possible.

• Older adults must be monitored diligently for initial and continuing therapeutic drug effects.

• Patients cannot benefit from drug therapy if they do not receive the proper prescribed drug therapy.

• Although electronic records are generally considered to be more reliable than paper records, research has found that electronic records are not 100% accurate, either.


Minimizing Adverse Effects • Whenever possible, alternatives to drug therapy should be

considered as the initial treatment for problems.

• Drugs should be used with great caution in older adults because these patients exhibit a narrow risk-to-benefit ratio.

• Older adults are at increased risk for drug overdose or toxicity.

• Additionally, distinguish carefully between the normal signs and symptoms of aging and the onset of adverse effects from drug therapy.

• Obtain a current drug profile and an accurate history of the patient’s usual abilities and changes in abilities or health status.

• Help devise a drug schedule that minimizes the risks of adverse effects.


Providing Patient and Family Education

• Educate patients about drug therapy in various ways.

• One possibility is to develop and emphasize written instructions regarding drug use and times of administration to help prevent confusion.

• Also, teach patients and families about expected or possible adverse effects and how to differentiate between them and normal signs of aging.


Assessment and Evaluation

• Assess the older patient continually for therapeutic and adverse effects of drug therapy.

• Assess the home environment and family support to determine the older patient’s ability to adhere to drug therapy.

• Consistent and regular monitoring of the older patient is extremely important.

Ppt chapter 08-1

Documents

older adultscopyright

older patientcopyright

drug distribution

drug excretion

processes of drug absorption

drug therapies

decreased body mass

aslowed drug absorption