Prescribing in Older People

Question 1

What is pharmacokinetics

Answer 1

What the body does to the drug

Question 2

What are the 4 components of pharmacokinetics

Answer 2

Absorption
Distribution
Metabolism
Excretion

Question 3

How does absorption change in the elderly

Answer 3

Generally rate affected but not extent

May lead to delay onset of action

Question 4

Why might a bucally administered drug have lower rate of absorption in the elderly

Answer 4

Due to reduced saliva production

Question 5

Which drug is the exception for absorption in the elderly

Answer 5

Levodopa

Question 6

Why is levodopa absorbed much faster in the elderly

Answer 6

Substantial mucosal metabolism of this drug occurs by the enzyme

dopa-decarboxylse
amount of enzyme in elderly decreases

leading to substantial in the absorption rate of levodopa in elderly

Question 7

How does distribution of a fat soluble drug change in the elderly

Answer 7

Increase adipose tissue in elderly
For fat soluble drugs the distribution increases
Leading to increased duration of action

Question 8

How does distribution of a water soluble drug change in the elderly

Answer 8

Decrease in body water
Therefore distribution of drug decreases
Leading to increased serum levels

Question 9

How does protein binding change

Answer 9

Decreased albumin
This decreased binding capacity
Increases serum levels of protein binding drug

Question 10

How does permeability across BBB change

Answer 10

Increased permeability across BBB

Drugs more readily distributed in CNS

Question 11

How is hepatic metabolism affected

Answer 11

Decreased liver mass
Decreased blood flow to liver
Therefore toxicity due to reduced metabolism and excretion

Question 12

How does excretion change with age

Answer 12

Renal function declines
Therefore reduced clearance of a drug and increased half life of many drugs
Thus leading to toxicity

Question 13

What is pharmacodynamics

Answer 13

What the drug does to the organism

Question 14

Why are the elderly particularly sensitive to some drugs

Answer 14

Change in receptor binding
Decrease in receptor number
Altered translation of a receptor initiated cellular response into a biochemical reaction

Question 15

Do elderly have more or less co-morbidities

Answer 15

More

Question 16

Why is polypharmacy applicable to the elderly

Answer 16

Because they often have many co-morbidities

Meaning they need to be on multiple drugs

Question 17

Principles of starting a drug in the elderly

Answer 17

Start slow 
Go slow 
Titrate up slowly 
Be clear about review 
Find drug information BNF

Question 18

Who are drug clinical trials often performed on

Answer 18

Younger people

Which may mean the benefit do not translate to an older age grou p

Question 19

Name some drugs most associated with admission due to ADR

Answer 19

o	NSAIDs
o	Diuretics 
o	Warfarin 
o	ACEI
o	Antidepressants 
o	BB 
o	Opiates 
o	Digoxin 
o	Prednisolone 
o	Clopidogrel

Question 20

What is meant by polypharmacy

Answer 20

Many drugs

Question 21

What does more drugs equal

Answer 21

More adverse drug reactions

Question 22

What are common ADR in older people

Answer 22

Falls 
Cognitive loss/delirium 
Dehydration 
Incontinence 
Depression

Question 23

How many drugs does the typical 85yr old take

Answer 23

8-9

Question 24

Why do older people need to take more drugs

Answer 24

More acute and chronic illness
More doctors visits
Drugs often given to counteract a SE of another drug

Question 25

What is the Creeping Cardex Syndrome

Answer 25

When drug started for preventative reasons but not reviews

Drugs started with an intention for short term symptomatic relief, but never stopped

Drug then starts to cause side effects

Drugs started to relieve side effects of other drugs

Question 26

Which prescribing tools are available

Answer 26

BNF
Beer’s Criteria
START-STOPP criteria
NHS Scotland Polypharmacy Guidance

Question 27

What is derescribing

Answer 27

To reduce, substitute or discontinue a drug

Question 28

For which reasons might you deprescribe a drug

Answer 28

Adverse drug rection 
Drug to drug interaction 
Better alternative 
Not effective 
Not indicated 
Not evidence based 
minimise polypharmacy

Question 29

Describe opioids in elderly

Answer 29

More sensitive to effects
Lower doses needed
Pethidine and tramadol may be less useful

Question 30

Describe NSAIDs in elderly

Answer 30

Increased adverse affects
Renal impairment
GI bleeding
Be careful

Question 31

Describe sedatives in elderly

Answer 31

Increased effects of benzodiazepines
Falls
Confusion

Question 32

Describe anti-psychotis in elderly

Answer 32

Increased adverse effect
Postural hypotension 
Stroke 
Confusion 
Movement disorders

Question 33

Describe digoxin in elderly

Answer 33

Increased toxicity

Lower doses needed

Question 34

Describe diuretics in elderly

Answer 34

Decreased peak effect, but reduced clearance
Abnormal urea and electrolytes
Other issues around continence and mobility
Often inappropriate indication (swollen legs)

Question 35

Describe anti-hypertensives in elderly

Answer 35

May have exaggerated effects on BP and HR

More likely to be issues with postural hypotension

Question 36

Describe ACE-i in elderly

Answer 36

Often pr-drugs which may not be metabolised to the active form
Renal adverse effects

Question 37

Describe anti-coagulants in elderly

Answer 37

more sensitive to warfarin

Greater risk from warfarin i.e GI bleeding, falls

Question 38

Describe anti-biotics in elderly

Answer 38

Incrrased adverse effects:
Diarrhoea and C-diff infection 
BLood dyscrasiasis
Delirium 
seizures
Renal impairment