Pharm in Elderly Flashcards
what physiological change leads to the greatest effect on pharmacokinetics and pharmacodynamics?
decreased hepatic and renal function
why is absorption of certain drugs changed in elderly patients? (2)
longer gastric emptying time
decreased gastric acid production = alkaline environment
what 4 drugs will have less bioavailability and exposure in elderly patients due to their decreased gastric acid production?
ketoconazole
itraconazole
atazanavir
kinase inhibitors (COVID)
how does a decreased body water in elderly effect distribution? what’s a drug example?
increase concentration (Cp) of hydrophilic drugs (lithium)
how does a decreased lean body mass in elderly effect distribution? what’s a drug example?
decreased volume of destribution (Vd) for drugs that bind to muscle (digoxin)
how does increased fat in elderly effect distribution? what’s a drug example?
increase half life of lipophilic drugs (diazepam)
how does a decreased albumin in elderly effect distribution? what’s a drug example?
increase concentration of unbound drugs (warfarin)
how does a decreased alpha-acid glycoprotein in elderly effect distribution? what’s a drug example?
increased concentration of unbound drugs (propranolol)
what must be done in elderly when there is an increased effect on distribution?
decrease dose
obesity in elderly leads to higher bioavailability of ____________ drugs
lipid-soluble
ascites in elderly leads to higher bioavailability of ____________ drugs
water-soluble
what does a decrease in perfusion and cardiac output lead to in elderly? (5)
increased drug circulation time
prolonged distribution
delayed absorption
delayed Tmax
delayed onset of effect
how is distribution effected in elderly? (2)
decreased efficacy of BBB = increased pharmacological response
how is metabolism in the elderly effected? (3)
decreased liver size
lower liver blood flow
reduced phase 1 activity (P450 enzyme)
which 3 drugs that go through phase 1 activity (P450 enzyme) will have lower metabolism in elderly?
diazepam to desmethyldiazepam
temazepam
oxazepam
which type of drugs do we want to use in elderly to maintain normal metabolism?
phase 2 inactivity
what 3 drugs that go through phase 2 inactivity will help maintain a normal metabolism in elderly?
lorazepam
temazepam
oxazepam
how will bioavailability be affected in elderly after oral administration?
increased
how is excretion of drugs effected in elderly? what 2 drugs?
decreased
penicillin
aminoglycosides
what causes a change in excretion of drugs in elderly? (4)
decreased renal blood flow
decreased GFR
decreased functioning neurons
decreased tubular secretion
during which 2 times are compensatory mechanisms important to maintain glomerular perfusion pressure and renal function?
periods of decreased intravascular volume
periods of decreased perfusion pressure d/t renal artery stenosis
which 2 endogenous substances compensate to maintain glomerular perfusion pressure and renal function? what are their jobs?
angiotensin II - potent vasoconstrictor (efferent)
PGs - potent vasodilator (afferent)
which 3 drugs are problematic to GFR in elderly patients?
ACEI
ARBs
NSAIDS
how do NSAIDS affect GFR?
block PGs
cause vasoconstriction
less fluids into glomerulus
lower pressure
lower GFR
how do ACEIs and ARBS affect GFR?
increase vasodilation
drops pressure
drops kidney function
risks renal failure