Polypharmacy and Drugs Flashcards
Absorption changes in elderly
Rate effected -> delay in onset of action
Distribution changes in the elderly
Reduced muscle mass
Increased adipose tissues (fat soluble drugs)
- increase vD
- increased half life
- increased duration of action
Decreased body water (water soluble drugs)
- decreased vD
- increased serum levels acidic e.g. furesimide
Increased permeability across BBB
Metabolism changes in the elderly
Hepatic metabolism - decreased liver mass - decreased liver blood flow Leading to - toxcitiy - decreased first pass metabolism ( increased and decreased bioavailability)
Excretion changes in the elderly
Renal function decreases with age
Decreased clearance and increased half life of drugs = toxicity
What is pharmacokinetics?
What the organism does to the drugs
Features of pharmacokinetics
Absorption
Distribution
Metabolism
Excretion
Pharmacodynamics in the elderly
increased sensitivity to particular medicines due to - change in receptor binding - decreased receptor no - altered response e.g. diazepam = increased sedation Warfarin = increased anticoagulation
Drug-disease interactions in the elderly
Older people = more chronic diseases
Diseases can affect drug pharmacokinetics
Drugs can worsen diseases
Drug-drug interactions in the elderly
Older people have more chronic diseases
Likelier to be on more drugs
Drugs can interact leading to changes
What does polypharmacy mean?
Many drugs
What is ‘creeping cardex’ syndrome?
Drugs for preventative reasons but not reviewed
drugs for short term symptomatic relief but never stopped
Drugs to relieve side effects of other drugs
Drugs most associated with admission due to ADRs
NSAIDs Diuretics Warfarin ACEIs Anti-depressants
What is hypotraemia associated with?
Risks of falls and fractures
Prescribing tools and guides
Beers criteria
START-STOPP criteria
NHS Scotland polypharmacy guidance
Reasons for de prescribing
ARDs disease drug interactions drug drug interactions better alternative not effective not indicated not evidence based minimise polypharmacy
What is de-prescribing?
To reduce, substitute or discontinue a drug
Psychiatric treatment in the elderly
Care with treating "agitation" Increased effects of sedative (falls, confusion) Antipsychotic S/Es - postural hypotension - stroke - confusion - movement disorders Antidepressants less effective
Analgesia in the elderly
lower dose of opoids needed (more sensitive)
Increased adverse effects of NSAIDs
- renal impairment
- GI bleeding
CVS drugs in the elderly
Digoxin = increased toxicity so less doses needed
Diuretics
- decreased clearance (abnormal U and Es)
- Continence and mobility issues
- often innapropriate indication (swelling)
Anti HTNs
- exaggerated BP and HR effects
- postural hypotension
- ACEIs may not be in active form
- renal adverse effects
Anticoagulants
- more sensitive to warfarin and increased risk from it
Antibiotics in the elderly
Increased adverse effects
- diarrhoea
- C diff infection
- blood dyscarias (trimethoprim)
- delirium (quinolones)
- Seizures
- Renal impairment
