Lecture 7 - elderly Flashcards
describe physiology and ageing of elderly people
considerable variability. individualist assessment and targets
loss of total body water and muscle mass - increase in body fat
presentation/ signs/ symptoms may change
describe physiological changes affecting absorption
physiological changes - increase gastric pH or decrease GI mobility and blood
which drugs are affected by an increase in gastric pH
calcium requires acidic environment for more optimal absorption.
enteric coated medication (absorption can vary)
concurrent use of antacids or PPI may affect absorption
what are physiological changes affecting volume of distribution.
reduced body water = reduced volume of distribution for hydrophilic drugs fro example, lithium
reduced lean body mass = reduced volume of distribution for drugs that binds to muscles eg digoxin
increased body fat = increased volume of distribution for lipophilic drugs eg diazepam and trazodone
reduced album = increased concentration of free drug eg warfarin and phenytoin
true or false - a reduce volume of distribution of lithium causes a lower concentration which may lower efficacy
False - causes a higher concentration which may lead to toxicity
What can the increased VoD of highly lipophilic drugs cause?
a longer elimination half life
what are physiological changes affecting metabolism
first pass metabolism is decreased by 1% per annum in people aged over 40 years which causes an increase expected effect
metabolic clearance of drugs by the liver may be reduced by a reduction in blood flow, and decreases CYP450 system and decrease liver size and mass
what are physiological changes affecting elimination ?
decreased size of the kidneys
reduced renal blood flow
reduced numbers of functional nephrons
decreased tubular secretion
all which lead to reduced glomerular filtration rate
what is delirium and what are potential causes ?
delirium is th acute deterioration in metal functioning triggered mainly by acute medical illness, surgery, trauma or drugs
UTIs,
drug
urinary retention
other infection
severe constipation
pain
dehydration
Why may creatinine clearance be inaccurate in the elderly?
They have decreased muscle mass (muscle wasting) and malnutrition (decreased protein intake)
what are some complications that may occur with falls?
fractures
hospital admissions
injuries
loss of confidence
haematoma
disability
death
what are common medicines associated with falls ?
Commonly implicated drugs/drug groups…
- Sedatives: benzodiazepines, z-drugs
- Alpha-blockers/ACE-inhibitors: hypotension
- Drugs inducing electrolyte disturbances or dehydration
what are key groups poorly tolerated in elderly?
antipsychotics
NSAIDs
Digoxin >250mcg
anticholinergic
antihypertensives
benzos
combination analgesia
diuretics
anti diabetics (sulfonylureas)
anticoagulants
what are anticholinergic medicines adverse effects ?
ADR: dry mouth, constipation, urinary retention, hypotension, drowsiness, impaired cognition, balance …falls
