Iatrogenic disease Flashcards
Why is inappropriate prescribing more common in older people?
Older people have a higher prevelance of chronic disease
increased likelyhood of polypharmacy
Age-related physiological changes
What are the physiological changes that occur in older people?
reduced hepatic
and renal function
What is pharmacodynamics? (give an example)
how the drug interacts with the body to produce a response (e.g. drug receptor interactions)
How does pharmacodynamics change as we get older?
You get increased AND decreased sensitivity to certain drugs
Which drugs increase in sensitivity in older people due to altered pharmacodynamics?
benzodiazepines
neuroleptics
opiods
Which drugs decrease in sensitivity in older people due to altered pharmacodynamics?
Furosemide
β-agonist
β-blockers
What is pharmacokinetics?
what the body does to the drug (ADME)
Which of the pharmacokinetic properties doesn’t change in older age and why?
Absorption
as the age-related changes in the GI tract are not clinically significant
Which drugs are at particular risk of being affected by age-related pharmacokinetic changes?
Drugs with a narrow therapeutic range
What factors can lead to an altered volume of distribution in older people?
Body fat increases (increases Vd for fat-soluble drugs)
Total body water decreases (decreases Vd of water-soluble drugs)
Serum albumin decreases (increasing effects of albumin bound drugs)
How is hepatic metabolism altered in old age and why?
Hepatic metabolism decreases.
As liver volume and
enzyme activity decreases
What proportion of drugs are metabolised by the liver?
The majority
How is renal elimination affected in older pts?
reduced GFR
Give an example of a renally excreted drug which has a narrow therapeutic range which must be altered in older age?
Digoxin
What is the name of the screening tool which tells at risk medications in the elderly?
STOPP
