Prescribing in the Elderly Flashcards
name the 4 components of pharmacokinetics
ADME absorption distribution metabolism excretion
what does DOAC mean?
direct acting oral anticoagulant
acidic drugs require a/an ___ pH for absorption
acidic
morphine is an acidic drug T or F
F, basic
older people have a more acidic/basic environment
basic
how does an increased gastric pH affect small bowel surface area?
decreases it
what is the best preparation for older people who are taking drugs orally?
liquids/syrup
what kind of binding do drugs need to undergo before they begin to act?
protein binding
what kind of protein binds to acidic drugs
albumin
is albumin acidic or basic
basic
what kind of protein binds to basic drugs?
alpha 1 glycoprotein
is alpha 1 glycoprotein acidic or basic?
acidic
increased fat in old people increases the __ of fat soluble (lipophylic) drugs
volume of distribution (Vd)
what is Vd?
the volume if all the drug you gave to the patient was distributed in the plasma
a high Vd means alot of the drug has distributed itself into ___ instead of ___
fatty tissue instead of plasma
a low Vd means alot of the drug has distributed itself into the ___ instead of ___
plasma instead of fatty tissue
a high Vd means the drug is lipophylic T or F
T
a low Vd means the drug is hydrophilic T or F
T
define half life
the time it takes for a drug to go down to half its level of activity
how to work out half life of a drug
Vd/Cl
a lipophylic drug is going to have a __ half life
long (Vd is higher)
why is clearance lower in old people?
liver and kidneys dont work as well
older patients have __ half lifes, why is this?
longer
drug hangs about in their system for longer as liver and kidneys dont work as well
albumin is __ in old people
low
older patients have more first pass metabolism T or F, why is this
F, it is slower because liver function is reduced
why is GFR lower in old people
tubular secretion rate reduced
renal blood flow reduced
larger size
why is creatinine not helpful as a marker in old people?
is muscle dependent and old people dont have much
why do B blockers have less effect in older people?
less B2 receptors
define the therapeutic index
maximum toxic conc/ minimum effective conc
what value would give a drug a narrow therapeutic index?
<2
name an antibiotic with a narrow therapeutic index
gentamicin
vancomycin
cyclosporin
the therapeutic window __ with age
decreases
most common side effect of opioids
constipation
what should be given to prevent constipation with opioids?
senna or lactulose
what drug type is known to cause iatrogenic diabetes?
steroids
long term NSAID treatment doesn’t work in patients with ____
hypertension (NSAIDs cancel out the effect of hypertensive agents and diuretics)
what combination of pain drugs is particularly bad for falls
opioids and benzodiazepines
what drugs are good at treating both hypertension and angina?
CCB
BB
statins should only be given for up to _ months post MI
6
