Drugs and polypharmacy Flashcards
4th leading cause of death
ADRI’S
Common iatrogenic drug problems (4)
Confusion, dry mouth, constipation, blurred vision, urinary retention
What can anticholinergics cause?
orthostatic hypotension
confusion and an unsteady gate can be caused by?
tricyclics and narcotics
you can have digoxin toxicity with?
normal serum concentrations
CNS toxicity can be caused by?
benzodiazepines
Costly medication-related problems/ADRs in older patients?
- Falls
- Cognitive Loss /delirium
- Dehydration
- Incontinence
- Depression
End result of ARDI’s (3)
Loss of functional capacity
Poor quality of life
Nursing home placement
why do elders tend to have more prescriptions (some examples)
- More acute & chronic disease
- More doctors visits
- Drugs often given to counteract a side effect of another drug
- Several other factors arising from prescribers, patients and the system
Adverse drug reactions look like “growing old” - wha side effects to ADRs can often be dismissed ?
Unsteadiness Dizziness Confusion Nervousness Fatigue Insomnia Drowsiness Falls Depression Incontinence
Prescribing Cascade
Drug 1
- ADE interpreted as new medical condition
Drug 2
- ADE interpreted as new medical condition
Drug 3
how may an elder present with Hyperthyroidism
- Depression
- Cognitive impairment
- Muscle weakness
- Atrial fibrillation
- Heart failure
- Angina
how may a younger patient present with Hyperthyroidism? (4)
Tremor
Anxiety
Weight loss
Diarrhoea
Healthcare provider factors thatcontribute to polypharmacy? think of some examples
- Presumes that patient expects meds
- Prescribes without sufficiently investigating clinical situation
- No med review with patient on regular basis
-
absorption is not affected by?
it is affected by? why is this
age
- rate of absorption is increased with age
- GI transit time slows
a reduction in saliva production may result in?
a reduction in the rate of absorption of buccally administered drugs e.g. glyceryl trinitrate (GTN)
distribution - what changes in the body as you get older (4)
- Reduced muscle mass
- Increased adipose tissue
- protein binding changes
- Increased permeability across the blood-brain barrier
distribution - fat soluble drugs
↑ Vd, ↑ T1/2, ↑ duration of action e.g. diazepam
distribution - water soluble drug?
↓Vd, ↑ serum levels e.g. digoxin, furosemide
distribution -protein binding changes
Decreased albumin
↓ binding, ↑ serum levels acidic drugs e.g. furosemide
what is hepatic metabolism affected by?
- Decreased liver mass
- Decreased liver blood flow
consequences of hepatic metabolism
- Toxicity due to reduced metabolism/excretion
- Reduced first pass metabolism
↑ in bioavailability with some drugs e.g. propranolol
Can cause ↓ bioavailability of pro-drugs e.g. enalapril
what function decreases with age affecting excretion
Renal function
excretion affect with age? - what does it ultimately lead to?
Reduces clearance and increases half-life of many drugs leading to toxicity