Drug Therapy in Geriatric Patients Flashcards
Older patients are _____ to drugs and they show ___ individual variation
more sensitive
wider
Older adults experience more ADRs and
drug-drug interaction
Principal factors underlying ADRs and drug-drug interaction in older adults:
- altered pharmacokinetics secondary to organ system degeneration
- multiple and severe illness
- multi drug therapy
- poor adherence
For incurable chronic illness, the objective is to
reduce symptoms and quality of life
Decline in absorption, distribution, metabolism, and excretion of drugs ______ drug sensitivity
increases
The _____ of absorption may be slowed (delayed gastric emptying and reduced splanchnic blood flow) and drug responses may be _____
rate
delayed
Gastric acidity is ____ in older adults and my alter the absorption of certain drugs
reduced
Some drugs require high acidity to dissolve, and their absorption may be ____
reduced
Factors that alter drug distribution in older adults:
- increased percentage of body fat
- decreased percentage of lean body mass
- decreased total body water
- reduced concentration of serum albumin
Increase in body fat provides storage depot for ______
lipid soluble drugs like propranolol which reduces plasma levels and response
Due to decline in lean body mass and total body water, ______ become distributed in smaller volume than younger adults. The concentration is increased and causing more intense effects.
water soluble drugs (ethanol)
_____ levels can be significantly reduced in older adults who are malnourished
albumin
Reduced albumin levels ___ sites for protein binding of drugs causing levels of free drug to rise
decrease
Rates of hepatic drug metabolism tend to ____ with age
decline
Reasons for decline of hepatic drug metabolism:
reduced hepatic blood flow, reduced liver mass, and decreased activity of some hepatic enzymes
Drug half-lives may be ____ thereby prolonging responses
increased
Beginning in early adulthood renal function and renal drug excretion undergo______
progressive decline
Most important cause of ADRs in older adults
drug accumulation secondary to reduced renal excretion
Decline in renal function is a result of:
reductions in renal blood glow, GFR, active tubular secretion and number of nephrons
When patients are taking drugs that eliminated by the kidneys, what should be assessed?
renal function
Proper index of renal function
creatinine clearance
Why test creatinine clearance and not serum creatinine levels?
creatinine levels do not adequately reflect kidney function in older adults because the source of serum creatinine-lean muscle mass- declines in parallel with the decline in kidney function
creatinine levels may be ___ even though renal function is greatly____
normal
reduced
Alterations in receptor properties may underlie altered sensitivity to some drugs
but info is limited
Beta adrenergic blocking agents are less effective in older adults because of:
- a reduction in number of beta receptors
- a reduction in the affinity of beta receptors for beta rector blocking agents
Warfarin and certain CNS depressants produced effects more intense in older adults because of:
increase in receptor number
receptor affinity
ADRs are ____ times more common in older adults
seven
Older adults are uncomfortable revealing____ and ____
alcohol and recreational drug use
Most ADR deaths are
dose related
Factors that predispose older adults to ADRs:
- drug accumulation secondary to reduced renal function
- polypharmacy
- greater severity of illness
- presence of comorbidities
- use of drugs that have a low therapeutic index (digoxin)
- increased individual variation secondary to altered pharmacokinetics
- inadequate supervision of long-term therapy
- poor patient adherence
This list identifies drugs with a high likelihood of causing adverse effects in older adults
Beers list
Like the Beers list, this list has an advantage of also considering the cost of drug therapy
STOPP
The set of lists that can be used to promote the selection of appropriate treatment in addition to the avoidance of inappropriate treatment
START/STOPP
Nonadherence can result in
therapeutic failure from under dosing or erratic dose or toxicity from overdosing
Most common nonadherence
under dosing with therapeutic failure
Examples of unintentional nonadherence:
forgetfulness
failure to comprehend instructions
inability to pay
use of complex regimens
Reasons for intentional nonadherence
patients conviction that the drug was not needed in the dosage prescribed, unpleasant side effects, price
Promoting adherence for unintentional nonadherence:
- simplify regimen with smallest number of drugs and doses per day
- explain treatment plan with clear, concise, verbal and written instructions
- choose appropriate dosage form (liquid for difficulty swallowing)
- larger print on drug containers and easy to open containers for patients with arthritis
- suggest use of calendar, diary, pill counter
- ask if patient has access to pharmacy and can afford meds
- enlist help
- monitor for therapeutic responses, ADRs, and plasma drug levels
Promoting adherence for intentional nonadherence:
intensive education
End of life goals
shift from disease prevention and management to provision of comfort measures
Meds that were once considered important in care like for cholesterol management may:
no longer be relevant and can be discontinued
End of life drug of choice for constipation
first line choices are osmotic laxatives (lactulose, polyethylene glycol)
stool softener are second line if abdominal cramping is a concern
bisacodyl suppositories or enemas for patients that cannot swallow
End of life drug of choice for delirium
haloperidol or olanzapine
Benzos like midazolam for acute episodes
End of life drug of choice for dyspnea
oxygen if hypoxemia present
opioids, first line drug of choice
glucocorticoids
bronchodilators if associated with bronchospasm
End of life drug of choice for fatigue
dexamphetamine
methylphenidate
End of life drug of choice for N/V
ondansetron, aprepitant, dexamethasone
metoclopramide for gastroparesis and liver failure
haloperidol for unknown causes, bowel obstruction or renal failure
glucocorticoids secondary to brain tumors and bowl obstructions
End of life drug of choice for pain
fentanyl for patient with renal/hepatic dysfunction
methadone for patients with renal dysfunction without hepatic dysfunction
End of life drug of choice for respiratory secretions
anticholinergics- glycopyrrolate
