Transcript Chapter 27

Chapter 27
Drugs and Older Adults
Copyright © 2015 Cengage Learning®
Introduction
• Today, people are living longer and are
taking more medications
– Forty percent of people of age 60 years and
older in the U.S. take at least five prescribed
medications, and many add OTC medications
and supplements
• Increased serious complications resulting from
adverse drug reactions
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Introduction (cont’d.)
• About 50% of hospitalizations are the
result of adverse drug effects in the elderly
– In 2012, an estimated 100,000 deaths
annually were caused by medication-related
problems (MRPs)
• MRPs can be mistaken for what is often
considered a normal consequence of aging or for
progression of disease
• Cognitive impairment and behavioral changes are
frequently the result of drug therapy
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Introduction (cont’d.)
• The aging process is an individualized
matter
– Because of genetic or environmental factors
or good health practices, some older adults
may not feel or appear particularly different
• However, there are gradual changes in body
composition and organ function as we grow older
• These changes can affect the reaction to drugs
and make the individual more sensitive to a wide
variety of medications
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Physiological Changes with Age
• Complex changes of aging involve both
anatomic and physiological factors
– Affect how drugs are processed in the body
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Absorption
Distribution
Metabolism (biotransformation)
Excretion
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Physiological Changes with Age
(cont’d.)
• Cumulative effects of drugs in older adults
can be due to:
– Inadequate absorption
– Impaired distribution
– Slower metabolism
– Impaired excretion
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Physiological Changes with Age
(cont’d.)
• Absorption
– Gastric motility decreases
– Gastric acid production diminishes, increasing the
gastric pH, causing a more alkaline environment
– Many older adults also take medication that
reduces gastric acid
• Examples: ranitidine (Zantac) or omeprazole (Prilosec)
• Antacids are also used frequently
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Physiological Changes with Age
(cont’d.)
• Distribution
– Once drugs are absorbed and enter the
circulation, many of them bind to proteins
• Albumin: principal protein used to bind drugs
– As we age, the liver produces less albumin
• Allows more of the drug to be unbound (free) to
reach receptor sites and therefore have a greater
than expected response
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Physiological Changes with Age
(cont’d.)
– Phenytoin (Dilantin) responds quite noticeably
to drops in plasma albumin levels
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Physiological Changes with Age
(cont’d.)
• Metabolism
– The liver serves as a major site for drug
metabolism
• As we age, the mass of functional liver tissue and
blood flow to the liver decreases
• Ability of the liver to break down drugs declines,
and drugs remain in the body longer
• Repeated dosing can result in the accumulation of
the drug and increases the risk for toxicity
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Physiological Changes with Age
(cont’d.)
• Excretion
– In the older adult, kidney size, blood flow, and
glomerular filtration all decrease, resulting in a
decline in creatinine clearance
• Illnesses such as hypertension, heart failure, and
diabetes add to the age-related loss and further
reduce creatinine clearance
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Physiological Changes with Age
(cont’d.)
– Drug by-products normally eliminated through
the kidneys can accumulate
• Can lead to toxic effects
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Physiological Changes with Age
(cont’d.)
• Seniors and drug development
– Pharmaceutical research is frequently
focused on younger individuals
– Older adults are often excluded from or
underrepresented in clinical trials
• Results may be inappropriately extrapolated to
other populations with negative outcomes
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Physiological Changes with Age
(cont’d.)
– Some medicines safe for a 30-year-old may
produce unexpected results in a person over
age 50 or 60
• Example: digoxin (Lanoxin)
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Potentially Inappropriate Medication
Use in Older Adults
• The Beers List
– Results of a survey conducted to determine
the most inappropriate drugs for ambulatory
nursing home residents and adults 65 or older
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Potentially Inappropriate Medication
Use in Older Adults (cont’d.)
– Goal to improve care of older adults by
reducing their exposure to potentially
inappropriate medications (PIMs)
• Health care professionals treating older adults
should have ready access to the Beer’s List and
recognize common classes of medications that can
produce problems
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Drugs to Avoid with Certain
Medical Conditions
• Drugs that produce significant
anticholinergic effects
– Antipsychotic agents
– Antidepressants
– Antiparkinson agents
– Antispasmodics
– Antihistamines
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Drugs to Avoid with Certain
Medical Conditions (cont’d.)
• Drugs that can cause mental impairment
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Anticholinergics
Antidepressants and antipsychotics
Benzodiazepines
Corticosteroids
H2 receptor antagonists
Meperidine
Phenothiazines
Sedative hypnotics
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Drugs to Avoid with Certain
Medical Conditions (cont’d.)
• Drugs that can cause or contribute to
syncope/falls
– Anticonvulsants
– Antidepressants
– Antipsychotics
– Alpha blockers
– Benzodiazepines
– Nonbenzodiazepine hypnotics
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Drugs to Avoid with Certain
Medical Conditions (cont’d.)
• Gastrointestinal conditions
– Anyone taking NSAIDs should be cautioned
about the real danger of serious complications
• In older adults, there may be no warning signs of
pain, and the first symptoms of trouble may be a
“silent” bleed that could lead to fatal GI
hemorrhage
• Key to avoiding problems with NSAIDs is to use
the lowest effective dose for the shortest period of
time
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Drugs to Avoid with Certain
Medical Conditions (cont’d.)
– Avoid prolonged use (no longer than two
weeks) of OTC antacids without medical
supervision
– Constipation can be worsened by
anticholinergics and oral antimuscarinics
(e.g., oxybutynin, tolterodine) for urinary
incontinence
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Drugs to Avoid with Certain
Medical Conditions (cont’d.)
• Cardiovascular disease
– Studies have indicated increased risk of
cardiovascular problems (thrombotic events, MI,
and stroke) with the use of NSAIDs and COX-2
inhibitors
– Older adult patients with heart failure should
avoid the calcium-channel blockers diltiazem
and verapamil, the antidiabetic glitazones
(Actos, Avandia), cilostazol (Pletal), and
dornedarone (Multaq)
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Polypharmacy
• Individuals, especially older adults, may be
the victims of polypharmacy
– Excessive use of multiple drugs
• OTC, herbals, or prescriptions given at one time
for the treatment of a patient’s medical conditions
– Polypharmacy becomes problematic when
negative outcomes occur
• May result in unnecessary prescriptions, increased
risk of dangerous interactions with potentially
serious adverse side effects, and possible
medication nonadherence
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Polypharmacy
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Polypharmacy (cont’d.)
• Helpful guidelines
– Educate yourself, your patients, and their
families
– With newly prescribed drugs, note diagnoses,
allergies, and other medications
– Monitor long-term drug use
– Question any inappropriate medicine or
dosage
– Document all adverse side effects, calls to the
physician, and action taken
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