Polypharmacy Flashcards
what are the medication related problems / ARD’s in the elderly?
falls cognitive loss / delirium dehydration incontinence depression end result = loss of functional capacity, poor QOL, nursing home
what are the signs/symptoms of ARD’s in the elderly?
present as symptoms of ‘growing old’
- dizziness
- nervousness
- falls
- confusion
- fatigue
- insomnia
- drowsiness
- depression
- incontinence
how does the elderly have increased sensitivity to drugs?
change in receptor bidding
decreasing in receptor binding sites
altered translation of receptor initiated cellular response into biochem reaction
name 2 drugs in which the elderly have an increased sensitisation to and the effect this has.
diazepam = increased sedation warfarin = increased anti coagulation
name drugs which most commonly cause ARD’s in the elderly.
NSAIDS warfarin ACE inhibitors antidepressants diuretics
what are the main principles for prescribing in the elderly?
make sure diagnosis is correct and it isn’t an ARD
ensure drug can be tolerated by the elderly
consider if drug therapy is needed
use smaller dose / reduced frequency of administration (and titrate up)
review medications regularly
what criteria can be used to determine if a drug is safe to prescribe in the elderly?
Beers’ criteria
STOPP/START criteria
what is the difference in the absorption of drugs in the elderly?
reduction in the rate of absorption but no change in the extent of absorption
decrease in saliva production therefore decrease in rate of absorption of GTN spray
the exception is levodopa: the enzyme that metabolises levodopa is reduced in the elderly therefore is metabolised slower and therefore rate of effectiveness is quicker than it would be in the young
what is the difference in the distrubution of drugs in the elderly?
increase in adipose tissue therefore fat soluble drugs have a greater distribution, half life and duration i.e. diazepam
decrease in water content therefore water soluble drugs have a decreased distribution but increased serum levels i.e. digoxin
decreased albumin therefore decreased protein binding, increasing serum levels of acidic drugs i.e. furosemide
increased permeability of blood brain barrier
what is the difference in the metabolism of drugs in the elderly?
decrease in liver mass and hepatic blood flow resulting in decreased first pass metabolism
= increased toxicity of drugs due to decreased metabolism and excretion
decreased first pass metabolism caused increase in bioavailability of some drugs i.e. propranolol
but decrease bioavailability of drugs i.e. enalapril
what is the difference in excretion of drugs in the elderly?
renal function decreases with age
decreased renal clearance and increased half-life od drugs = toxicity
what healthcare factors contribute to poly pharmacy?
not review medications regularly
presuming the patient expects medications
no effort to simplify medication regime
prescribe without sufficiently investigating the situation
lack of knowledge of geriatric pharmacology
ordering automatic refills
medication promoted and publication bias
