Prescribing for older patients Flashcards
older persons in clinical trials
often excluded from clinical trials
leads to lack of evidence and good quality guidlines
changes that occur in raging that effect pharmacokinetics and pharmacodynamics
volume of distribution: which influences loading doses
clearance: which influences maintenance doses
changes are more pronounced with frailty
implications of frailty
increased body fat
decreased lean body mass
age related reduction in albumin
consequence of reduction in albumin
total drug levels of albumin bound drugs can be unreliable e.g. valproate, phenytoin
can be toxic at apparently therapeutic levels
sarcopenia
age related loss of skeletal muscle mass and strength
ADME stands for
absorption
distribution
metabolism
excretion
changes in absorption
slowed gastric motility and reduced hepatic metabolism
delayed absorption and reduced bioavailability of drugs administered orally
changes in distribution
sarcopenia and relative adiposity
reduced plasma albumin
reduced volume of distribution of water soluble drugs and increased volume of distribution of fat soluble drugs
changes in metabolism
reduced hepatic volume and blood flow
reduced phase 2 clearance
changes in excretion
glomerular filtration rate reduced
reduced renal drug clearaance
changes in pharmacodynamcs
reduced resilience to external stressors
may be some reduced receptor function in presence of chronic inflammation
exaggerated or reduced drug effects
4 main classes of medications causing ADR in older patients
warrfarin
insulin
oral antiplatelet agents
oral hypoglycaemic agents
‘prescribing cascade’
occurs when a new medication is prescribed to treat symptoms that have arisen from an unrecognised adverse drug effect that is the result of an existing therapy
prescribing omissions
also known as under prescribing
failure to prescribe a medication for which there is a clinical indication and which, for the patient, is appropriate to prescribe
potentially inappropriate medications
PIMS
medications where risk of adverse events from the drug outweighs the clinical benefit
prescribing tools
STOPP
START
Drug Burden Index
Beers Criteria
Inappropriate Medication Use and Prescribing Indicators Tool
deprescribing
the process of withdrawal of an inappropriate medication, supervised bu a healthcare professional with the goal of improving outcomes
deprescribing
the process of withdrawal of an inappropriate medication, supervised bu a healthcare professional with the goal of improving outcomes
principles of deprescribing
monitoring outcomes (withdrawal and rebound symptoms, original symptom recurrence, symptom improvements)
stop one drug at a time and wean over weeks
benefits of deprescribing
resolve related adverse drug effects
improve patient satisfaction and QOL
improve physical and cognitive function
reduce financial cost to patient and community
