Elderly- Polypharmacy

Question 1

What does polypharmacy mean?

Answer 1

Many drugs

Question 2

As the number of drugs a patient takes increases, what also increases?

Answer 2

The chance of adverse drug reactions

Question 3

What are common Medication related problems/ ADRs in older people?

Answer 3

• Falls
• Cognitive Loss /delirium
• Dehydration
• Incontinence
• Depression
• Unsteady- dizziness and confusion

Question 4

Why older people take so many drugs?

Answer 4

• More acute and chronic illnesses

* Prescribing cascade- drugs given to counteract the side effect of another drug

Question 5

What are symptoms of ADR that can be confused with old age?

Answer 5

Unsteady, dizzy, confusion, falls, depression, incontinence

Question 6

What is the prescribing cascade?

Answer 6

• Given a drug that causes an ADR
• ADR interpreted as a new condition
• Given another drug to treat the ADR

Question 7

What changes as people get older?

Answer 7

Pharmacokinetics

Question 8

How does absorption of a drug change as a person gets older?

Answer 8

Physiological changes occur that effect the rate but generally not the extent of absorption from the GI tract– May lead to a delay in onset of action

Question 9

How does the distribution of a drug change as a person gets older?

Answer 9

Body composition changes
• Reduced muscle mass
• Increased adipose tissue
• Reduced body water

Question 10

How do changes in distribution affect fat soluble drugs?

Answer 10

Increased volume of distribution
Increased half-life
Increased duration of action

Question 11

How do changes in distribution affect water soluble drugs?

Answer 11

Decreased volume of distribution
Decreased half-life
Decreased duration of action

Question 12

How does protein binding change as a person gets older?

Answer 12

There is a decrease in albumin
Decreased binding leads to increased serum levels acidic drugs e.g. furosemide

Increased permeability across blood brain barrier

Question 13

How does metabolism change as a person gets older?

Answer 13

Hepatic metabolism is affected by
• Decreased liver mass
• Decreased liver blood flow

Question 14

What are the consequences of decreased hepatic metabolism?

Answer 14

• Toxicity due to reduced metabolism/excretion
• Reduced first pass metabolism
• Increase in bioavailability with some drugs e.g. propranolol
• Decreased bioavailability of pro-drugs e.g. enalapril (pro-drugs are drugs that have to pass through the liver to be metabolised to work)

Question 15

How does excretion change with increasing age?

Answer 15

• Renal function decreases with age

* Reduces clearance and increases half-life of many drugs leading to toxicity

Question 16

Why is there increased sensitivity to particular medications?

Answer 16

• Changes in receptor binding,
• Decrease in receptor number,
• Altered translation of a receptor initiated cellular response into a biochemical reaction.

Question 17

What are the 3 main principles of prescribing in older people?

Answer 17

• Review prescriptions regularly
• Try to keep regimes simple
• Consider compliance issues in older people

Question 18

What is deprescribing?

Answer 18

To reduce, substitute or discontinue a drug

Question 19

What are most adverse drug events from?

Answer 19

Anticholinergics and Sedatives

Question 20

What effect can benzodiazepines have on elderly people?

Answer 20

Falls and confusion

Question 21

What effect can anti-psychotics have on elderly people?

Answer 21

Postural hypotension, stroke, confusion, movement disorders

Question 22

What is the problem with anti-depressants in elderly people?

Answer 22

They are less effective and more dangerous

Question 23

What is the problem with opioids in the elderly?

Answer 23

Older people are more sensitive to effects, so lower doses needed

Question 24

What effects can NSAID’s have in the elderly?

Answer 24

Can cause renal impairment and GI bleeding

Question 25

What is the problem with digoxin in the elderly?

Answer 25

Increased toxicity so lower doses needed

Question 26

What is the problem with anti-hypertensives in the elderly?

Answer 26

• May have exaggerated effects on BP and HR
• More likely to be issues with postural hypotension
• Renal adverse effects

Question 27

What is the problem with anticoagulants in the elderly?

Answer 27

More sensitive to warfarin so greater risk from warfarin i.e. GI bleeding, falls

Question 28

What adverse effects can antibiotics have on the elderly?

Answer 28

• Diarrhoea and c. diff infection
• Blood dyscrasias (trimethoprim, co-trimoxazole)
• Delirium (quinolones)
• Seizures
• Renal impairment (aminoglycosides)