Drugs and Polypharmacy in the Elderly Flashcards
what is polypharmacy?
5 or more drugs
list the common ADRs in elderly
falls cognitive loss/delirium dehydration incontinence depression unsteadiness confusion fatigue insomnia drowsiness
what may the end results of ADRs in the elderly be?
loss of functional capacity
poor QoL
Nursing home
a typical 85 yr in hospital takes 8-9 prescribed drugs + 2 OTC drugs. Why?
more acute and chronic illness
more doctor’s visits
drugs given to counteract side effects of another
what healthcare provider factors contribute to polypharmacy?
no regular med review
presumes patient expects medications
prescribes without sufficiently investigating situation
provides unclear, complex or incomplete instructions about how to take meds
no efforts to simplify regimen
automatic refills
medications promoted and publication bias
lack of knowledge of geriatric clinical pharmacology
how does drug absorption change in the elderly?
physiological changes occur that effect the rate but generally not the extent of absorption from the GIT
delay in onset
reduction in saliva production - GTN
how does drug distribution change as we age?
Reduced muscle mass increased adipose tissue reduced body water protein binding chances increased permeability across BBB
what happens to fat soluble drugs as a result of increased adipose tissue?
increased Vd
increased t1/2
increased duration of action
diazepam
What happens to drug distribution as a result of reduced body water?
water soluble drugs: increased Vd increased serum levels digoxin more likely to go into toxic range
What happens as a result of decreased albumin?
decreased binding
increased serum levels of acidic drugs
furosemide
how does drug metabolism change as we age?
hepatic metabolism is affected by decreased liver mass and blood flow. this results in toxicity due to reduced metabolism and excretions. increase in bioavailability of some drugs e.g. propranolol. decrease in bioavailability of pro drugs e.g. enlapril
what happens to drug excretion as we age?
renal function decreases which reduces clearance and increases half life
why is there increased sensitivity to some medicines as we age?
change in receptor binding
decrease in receptor number
altered translation of a receptor initiatied cellular response into a biochemical reaction
give examples of drugs which there is increased sensitivity
diazepam - increased sedation
warfarin - increased anti-coagulation
