Prescribing for the Elderly Flashcards
what are the effects of age on absorption
- reduced gastric acid production
- longer gastric emptying
- decreased esophagel motility
- loss of subcutaneous fat / increased rate absorption for topical medications
- increased fragility of veins / iv infusions more difficult
general clinical effect of ageing absorption
decreased active transport
decreased first pass effect
what are the effects of ageing on distribution
decreased total body water
decreased lean body mass
decreased cardiac output
what are the effects of an ageing metabolism
primarily on hepatic functions and blood flow
capacity of the liver to metabolise drugs
unpredictable and dependent on us elf alcohol and medication also
ageing causes decreased liver mass and therefore reduced metabolism of drugs.
effects of age on renewal function
decreased skinny size and renal blood flow
decreased number of nephrons and tubular secretion
resulting in decreased glomerular filtration rate and decreased rug clearance
what are the effects off ageing on elimination
decreased GFR / renal blood flow and renal mass
decreased renal clearance increased 1/2 life of renal cleared drugs
reduction in number of or functioning nephrons means increased potential for toxicity ad side effects
age related changes to pharmacoDYNAMICS
– ↑ sensitivity to sedation and psychomotor impairment with benzodiazepines
– ↑level and duration of pain relief with narcotic agents
– ↓HR response to beta-blockers
– ↑sensitivity to anti-cholinergic agents
– ↑cardiac sensitivity to digoxin
what are the reasons for more adverse reactions seen in the elderly
more drugs normal taken to begin with so more adverse reaction likelihood
prescribing errors
- polypharmacy
- drug interactions with other prescriptions
- unawareness of age related physiological changes
low body weight
age > 85
Drug usage errors
how to combat compliance in the elderly
recognise
- forgetfulness
- prior experience
- physical disabilities
recommend
- taking careful drug history
- prescribing with specific rational
- define goal of drug therapy
- simplify drug regime
compensate for
- visual loss
- cognitive and muscle dysfunction
sociocultural factors may effect compliance
- loss of loved one
limited or fixed income
what is polypharmacy
concurrent use of multiple medications
often the primary reason for ADR, as adverse effects from each drug and they’re interactions
how to help polypharmacy
prescribing combination drugs or longer acting forms
- fewer pills to remember
revaluation of medication periodically
encourage to use one pharmacy
