Elderly Flashcards
What does ageing lead to changes in?
Physiology
Physical ability
Mental health and capacity
How does ageing affect absorption of drugs?
Slowed down gut motility so absorption rate of oral drug slows down takes longer for drug to get into system
How does ageing affect distribution of a drug?
PROTEIN BINDING
Reduction in serum albumin –> less protein for drug to bind to –> higher concentration in blood and more free drug to have an effect e.g. phenytoin or diazepam
How does ageing affect distribution of a drug?
Solubility
Less water in older people –> same amount of water soluble drug so at higher concentration –> risk of ADRs –> lowered dose e.g. digoxin 125mcg instead of 250mcg
More fat in older people –> fat soluble drugs stay in body longer –> prolonged effect of drugs such as nitrazepam or amitriptyline.
Avoid drugs with long half-life where possible
How does ageing affect metabolism of a drug?
LIVER IMPAIRMENT
reduced liver function —> drug needs to be metabolised but takes longer –> toxicity
Prodrugs —> need to metabolised before they are active —> can take longer to reach therapeutic levels or be at lower concentrationsa
How does ageing affect distribution of a drug?
KIDNEY IMPAIRMENT
toxic metabolites not cleared
drug stays in body longer
–> can cause further damage if drug/metabolites are nephrotoxic
e.g. digoxin dose is 62.5mcg in renal impairment
What is frailty?
Clinically recognised state of increase vulnerability due to decline in body’s physiological and psychological reserves.
What can frailty lead to?
reduced functional reservoir
less resilient to external stressors frequent hospitalisation due to geriatric syndromes
increase suscesceptibility to ADRs?
What are some geriatric syndromes?
Falls
Immobility
Delirium
Incontinence
Describe the difference in response to minor illness in a fit older person vs a frail older person.
Fit: small temporary reduction in functional ability but can bounce back
Frail: already has lowered functional ability and steep drop with minor illness. may never get back to same level of functional ability
How is frailty measured?
Rookwood clinical frailty scale
Very fit, fit, managing well, vulnerable, mildly frail, moderately, frail, severely frail, very severely frail, terminally ill
Patient factors that contribute to medication risk in older people?
Changes in physiology
changes in physical and mental health
increased interactions and adverse events
Medication and clinical factors that contribute to medication risk in older people?
co-morbidities
polypharmacy
increased interactions and adverse reactions
formulation
Socioeconomic factors that contribute to medication risk in older people?
Poverty - nutrition, heating
social support
Transport
Literacy
religion or cultural beliefs
