Polypharmacy

Question 1

What are some definitions of polypharmacy?

Answer 1

1. 6+ meds inc, plus one potentially inappropriate med (Beers List)
2. Med does not match documented diagnosis
3. More medication used or prescribed than clinically indicated

Question 2

Why is polypharmacy an issue in the elderly?

Answer 2

• Physiological changes > altered ADME
• Increased comorbidities = more prescriptions
• Multiple consultants, no ring master
• Non recognition of AEx therefore prescription to “treat” AEx

Question 3

What are the RFx for polypharmacy?

Answer 3

• Age
• Lower socioeconomic status
• Lower educational level
• Poorer health and specific diseases have been shown to increase risk

Question 4

What are the diseases shown to increase risk of polypharmacy?

Answer 4

• Cognitive impairment
• HTN
• Anaemia
• asthma
• Angina
• Osteoarthritis
• Gout
• DM

Question 5

What are examples of negative outcomes associated with polypharmacy?

Answer 5

• Increased falls risk
• Oversedation and diminished cognitive function
• Over / under anticoagulation
• Failure to prescribe indicated meds
• Urinary incontinence
• Decline in ADLs
• Cost to patient and public
• Increased risk of mortality

Question 6

What are the essentials of prescribing medications in avoiding polypharmacy?

Answer 6

• Clear indication for Rx
• Start low, go slow
• Single change (not multiple)
• Add second drug before pushing mono therapy to max dosage
• Periodic review
• Simplification or regime
• Inform pt of potential AEx
• Document response and include all potential side effects
• Low index of suspicion for untoward effects of prescribed meds

Question 7

Alteration of absorption / first pass metabolism with ageing?

Answer 7

• Unchanged absorption

- Reduced first pass metabolism (reduced liver mass, reduced blood delivery to liver)

Question 8

What is the significance of alteration of absorption / first metabolism occurring with ageing?

Answer 8

• Same amount of medication absorbed BUT

- increased bioavailability of some drugs (e.g. metoprolol, nortriptyline)

Question 9

What is the significance of volume of distribution changes in the elderly?

Answer 9

• Increased body fat

- Decreased body water

Question 10

Significance of volume of distribution changes in the elderly?

Answer 10

• Prolonged half life of fat soluble drugs (e.g. diazepam)

- Increased serum concentrations of water soluble drugs e.g. digoxin, paracetamol

Question 11

Protein binding changes with ageing?

Answer 11

Lower serum albumin in frail or unwell elderly

Question 12

Significance of protein binding changes with ageing?

Answer 12

Increased free concentration of protein bound drugs e.g. warfarin, phenytoin

Question 13

Metabolism changes in ageing?

Answer 13

• Reduced oxidative metabolism (liver)

- Unchanged conjugative metabolism (liver)

Question 14

Significance of metabolism changes with ageing?

Answer 14

Prolonged half life, higher steady state concentrations of some drugs (e.g. diazepam, metoprolol, phenytoin)

Question 15

Excretion changes with ageing?

Answer 15

Reduced with decreased GFR and tubular excretion

Question 16

Significance of excretion changes with ageing?

Answer 16

Prolonged half life, higher steady state concentrations of some drugs or metabolites (e.g. digoxin, cephalexin, morphine)

Question 17

What are the broad considerations regarding pharmacology and the elderly?

Answer 17

ELderly are:

• more sensitive to amounts of drugs (weight, renal fxn etc)
• more susceptible to AEx
• more likely to have AEx w/ serious sequelae

Question 18

What is pharmacokinetics

Answer 18

what body does to drug

Question 19

Prescription review questions?

Answer 19

Is drug:
?still indicated
?nicest for the job
?causing Sx
?be replaced by a single agent
?route appropriate (i.e. syrup, patch)
?appropriately timed
?cheapest

Question 20

Considerations to optimise drug prescription?

Answer 20

?administration aids e.g. spacer
?regular v PRN
?does pt understand Rx and precautions