Chapter 22: Geriatric patient Flashcards
Incidence of polypharmacy
51% of ages 65-74 use 2+ prescription drugs
12% use 5+
ADRs rate where in causes of death in America
4-6th
Results of advances in medicine for the elderly
prolonged and improved life
increased risk for adverse drug reactions
what are the most common classes of drugs used by the elderly population living in the community
analgesics
diuretics
cardiovascular drugs
sedative hypnotics
what are the most common classes of drugs used by the elderly in nursing homes
antipsychotics and sedative-hypnotics
followed by
diuretics, antihypertensives, analgesics, cardiovascular drugs, and antibiotics
changes in pharmacokinetics related to aging
slowed renal clearance
slowed metabolism
increased risk of CNS side effects
slowed orthostatic response
changes influencing absorptionin the older adult
reduced GI blood flow
reduced gastric acidity
reduced absorptive surface from microvilli atrophy
most drugs are absorbed by passive diffusion
changes influencing distribution in older adults
decrease in total body water and extracellular fluid volume
decrease in cardiac output
decrease in brain and cardiac blood flow
increased total body fat percentage
decrease of total body water in the elderly has what effect on distribution
water-solubla drugs have a reduced volume of distribution which causes increased plasma concentrations of hydrophillic drugs like lithium
what effect does the increase of total body fat in the elderly have on drug distribution
lipohilic drugs have an increased half-life from increased storage in fatty tissue
this can prolong the action of the drug, exacerbate its effect, and increase toxicity
changes influencing metabolism in older adults
reduced CYP450 enzymes impacts the oxidation reaction in phase 1 metabolism
what contributes to a smaller liver reserve than expected for age
the influence of comorbidities, alcohol, medications, and environmental toxins/pollutants
what metabolic changes result in increasing half-life of medications prolonging their availability
ages related reduced hepatic clearance
reduced hepatic blood flow causes reduced first-pass effect
changes influencing excretion in the older adult
reduction in renal mass as well as the number and size of nephrons
reduction in blood flow glomerular filtration rate
reduction in tubular secretion
out of the changes r/t aging that affect pharmacokinetics, which is the most important
changes that influence excretion
cockcroft-gault equation for estimating creatinine clearance
CrCl = (140-age) x (total body weight in kg)
(72) x (serum creatinine in mg/dL)
*result is multiplied by 0.85 in women because of lower muscle mass
changes in pharmacodynamic in the older adult
different effects of a drug on the patient despite identical serum concentrations
what causes the changes in pharmacodynamic in the older adult
altered sensitivyt at receptor site
post-receptor effect
impairment of physiologic and homeostatic mechanism
example of altered receptor sensitivity
increased CNS sedation with benzodiazepines, opioids, neuroleptics
examples of impaired physiologic reserve
more urinary retention and constipation
more blurry vision
increased risk of anticholinergic drugs to glaucoma patients
increased fall risk with sedative hypnotics
examples of some medications that can cause urinary retention d/t anticholinergic effects
antihistamines like:
diphenhydramine (Benadryl)
promethazine (Phenergan)
ipratropium (Atrovent)
prevalence of HTN in older adults
70%
HTN places the elderly at a higher risk for
MI, CHF, CVA, PAD
risk factor for dementia
Is SBP or DBP the primary target for HTN treatment in older adults? why?
SBP because it continues to rise
DBP rises until about age 70, then it begins to fall
drug classes used to treat HTN in the older adult
diuretics
beta-blockers
CCBs
ACE inhibitors
ARBs
alpha blockers
definition of orthostatic hypotension
SBP drop of 20mmHg or more or a drop in DBP of 10mmHg or more
which medication is superior for preventing MI and should be used as first line HTN treatment in older adults
thiazide diuretics
what should be monitored for when an older patient is on a diuretic
hyponatremia, hypokalemia, metabolic alkalosis
beta-blockers in older adults
not first line therapy if uncomplicated HTN
good choice for adjunct therapy with history of HF, MI, or symptomatic coronary disease
Calcium Channel blockers in older adults
2nd or 3rd line treatment for HTN
most common side effect of CCBs in the elderly
peripheral edema that does not respond to diuretics
will resolve with discontinuation of medication
ACE inhibitors
2nd or 3rd line therapy
Avoid with drugs that raise potassium levels
watch for hyperkalemia or worsening renal function
ARBs in older adults
non-peptide selective blocker that is generally well-tolerated
monitor for hyperkalemia
caution with renal insufficiency
alpha blockers in older adults
should NOT be used as 1st or 2nd line therapy
do not use for BPH as there are safer drugs
when should clonodine be avoided for HTN treatment
when there is underlying heart block d/t its bradycardic effect
what does diagnosis of dementia require
losses in multiple cognitive domains as well as functional losses
Alzheimers disese is most common
pathological findings in AD
plaques and neurofibrillary tangles
deficiency of acetylcholine
drug classes used to treat dementia
cholinesterase inhibitors (ChEs)
NMDA Inhibitors: Memantine (Namenda)
examples of cholinesterase inhibitors
donepezil (Aricept) - mild-severe stages
rivastigmine (Exelon) - mild-mod
galantamine (Razadyne) - mild-mod
cholinesterase inhibitors are only indicated for
treatment of alzheimers
cholinesterases mechanism of action
inhibits the enzyme acetylcholineserase to increase acetylcholine concentrations at the synaptic cleft
minor delay in progression of the disease
contraindications for cholinesterases
seizure disorder and COPD
major side effects of cholinesterase inhibitors
n/v, diarrhea, abdominal pain, anorexia
cholinesterase inhibitors interactions
avoid drugs with anticholinergic effects like antihistamines and antimucarinic drugs used for irinary incontinence as the two will cancel each other out because their mechanism of action is so similar
Memantine (Namenda)
only drug in its class (NMDA inhibitors)
used for mod-severe dementia
when should namenda be avoided
HTN
severe liver or renal impairment
when should Namenda be discontinued
end-stage dementia
why is there increased presence of urinary incontinence in dementia
loss of frontal lobe inhibition so reliance of sympathetic and parasympathetic urine control in purely on brainstem
medication class used to treat urinary incontinence
muscarinics
non-pharmacologic treatment options for urinary incontinence
correct underlying problem
void at regular intervals
kegels
avoid caffeine, alcohol, artificial sweetners
drug treatment may not be very effective
examples of muscarinics
oxybutynin (Detrol, Oxytro patch)
tolterodine (Detrol)
trospium (Sanctura)
darifenacin (Enablex)
solifenacin (VESIcare)
fesoterodine (Toviaz)
muscarinics mechanism of action
reversible acetycholine receptor blockers that block PNS endings on detrusor muscle of bladder to reduce spasms of smooth muscle, reducing the urge to urinate
muscarinic clinical use
urge incontinence in cognitively intact patients
muscarininc interactions
cholinesterase inhibitors
other anticholinergic can cause increased drowsiness
all except trospium interact with drugs that use CYP3A4 or 2D6 systems
trospium interacts with digoxin, triamterene, and trimethoprim
muscarininc contraindications
bowel/bladder obstruction
myasthenia gravis
untreated angle-closure glaucoma
drugs classes that require special consideration in older adults
antiarrhythmics
anticoagulants
antihistamines
antiparkinson agents
antipsychotics
anxiolytics
corticosteroids
digoxin
NSAIDs
opioid analgesics
tricyclic antidepressant
antiarrhuthmic use
only for rhytm disorders that are both symptomatic and life threatening
should always be initiated and monitored by a cardiologist
adverse effects of amiodarone in older adults
cough, progressive dyspnea, hypo-and hyperthyroidism, liver toxicity, GI effects, corneal microdeposits, confusion, slurred speech, photosensitivity
examples of anticoagulants used in the elderly
ASA
clopidogrel (Plavix)
dipyridamole (Aggrenox
warfarin (Coumadin)
ASA use
all patients with established vascular disease should take ASA 81mg daily unless contraindicated
clopidogrel (Plavix)
maintains patency od stented coronary arteries
dipyridamole (Aggrenox)
combo of ASA 25mg and ER dipyridamole
prevents stroke in patients with history of TIA
warfarin (Coumadin)
reduces stroke risk
significant risk of bleeding
usually co-managed by coumadin clinic
most common indication for coumadin usage
nonvalvular A-fib
antihistamines
generally avoid
if neede short-ter use of chlorpheniramine may help with URI
Zyrtec is acceptable for chronic allergies
diphenhydramine is particularly harmful
standard antiparkinson agents used for treatment
pramipexole (Mirapex)
ropinorole (Requip)
carbidopa-levodopa (Sinimet)
symptoms of too much dopamine
uncontrolled movements, worsened confusion, visual hallucinations
medications that can cause parkinson-like symptoms
antihistamine/antinauseants (phenergan, compazine, reglan)
older antipsychotics (haldol, chlorpromazine)
newer atypical antipsychotics (risperidone, olanzapine, quetiapine)
two directly aticholinergic drugs that should be avoided in the elderly
cogentin
artane
most common use of antipsychotic in the elderly
behavior treatment in dementia
cons of antipsychotic use in the elderly
high risk of toxicity
increases risk of MI, CVA, vascular mortality
can cause EPS
can cause tardive dyskinesia
neuroleptic malignant syndrome
signs of antipsychotic toxicity
sedation, orthostatic hypotension, weight gain, hyperlipidemia, development of diabetes
anxiolytics to avoid with the elderly
long-acting benzodiazepines:
diazepam (Valium)
chlordiazepoxide (Librium)
Chlorazepate (Tranxene)
Flurazepam (Dalmane)
anxiolytics are stongly associated with
confusion, weakness, slurred speech, ataxia, falls
shorter-acting benzodiazepines in the elderly
safer but still have risk of toxicity
lorazepam (Ativan)
temazepam (Restoril)
oxazepam (Serax)
pharmaceutical drugs with less toxicity than benzodiazepines in the elderly
Buspirone and SSRIs
corticosteroids in the elderly
can be life saving
chronic use of corticosteroids in the elderly
can cause serious side effects of sodium retention, agitation, psychosis, diabetes, skin ecchymosis, and osteoporosis
all older adults on chronic corticosteroid therapy should have what monitored
bone density
ensure adequate intake of calcium and vitamin D
Digoxin clinical use in the elderly
for systolic heart failure
rate control of A-fib
only after using a vasodilator, diuretic, and beta-blocker
major side effects of digoxin
anorexia, confusion
serum digoxin level
should stay below 1ng/mL
NSAIDs
used for pain relief when pain is interfering with function
consider acetominophen first flowwled by glucosamine/chondroitin
consider tramadol
can cause serious toxicity in older adults
frequent adverse effects with NSAIDs
- GI: gastric bleeding, perforation, and obstruction
- RENAL: acute renal failure, interstitial nephritis, nephritic syndrome
- CARDIAC: frequently raised BP, may worsen volume overload in disease like HF
NSAID interactions
avoid cox-2 inhibitors (Celebrex)
opioid analgesics in the elderly
can be safer options than the alternatives
long-term never cause GI bleeding or renal dysfunction
major toxicities: CNS and respirtatory side effects and constipation
opioid analgesics to NOT use in older adults due to their serious side effects
meperidine (Demerol)
pentazocaine (Talwin)
propoxyphene (Darvocet)
tricyclic antidepressants in the elderly
(Elavil)
rarely indicated
side effects: dry mouth, blurry vision, constipation, urinary retention, orthostatic hypotension, quinidine-like effects (serious ventricular arrhythmias)
questions to ask before prescribing a new drug for an elderly patient
- do I have a comprehensive list of medications?
- is the patient compliant?
- are drugs appropriate?
- are side effects an issue (could new symptom or lab simply be a side effect)
- polypharmacy?
- undermedicated?
- reassess frequently
