Drugs and Polypharmacy

Question 1

Define polypharmacy

Answer 1

Use of 5+ medications but unnecessary medication

Which can place an older person at risk of avoidable toxic reaction

Question 2

How many different drugs do you need to take before there is a guaranteed ADR?

Answer 2

9

Question 3

What % of ADRs are preventable?

Answer 3

1/3rd in ambulatory settings

1/2 in nursing homes

Question 4

What are some costly medication related problems/ARDs in older patients?

Answer 4

Falls
Cognitive loss/dementia
Dehydration 
Incontinence
Depression 

Leading to loss of functional capability, reduced QoL, nursing home placement

Question 5

What is the typical drug consumption of a 85yo?

Answer 5

8-9 prescribed drugs

2 OTC

Question 6

Why are elderly patients taking more drugs?

Answer 6

More acute and chronic disease
More doctor visits (may see diff doctors each time –> more and more drugs)
Drugs given to counteract SEs of other drugs

Question 7

What are some ARD symptoms that may just get labelled as ‘getting old’?

Answer 7

Unsteadiness
Dizziness
Confusion 
Nervousness
Fatigue
Insomnia
Drowsiness
Falls
Depression 
Incontinence

Question 8

Describe the ‘prescribing cascade’ that often happens in the pharmacological management of an elderly patient

Answer 8

Drug 1 give, ADE interpreted as new medical condition, so drug 2 given and so on

Question 9

What is stated in the SIGN guideline 116 for management of diabetes?

Answer 9

Aim for HbA1c <7% or individualised
BP <130/80
ACEi>ARB>CCB>thiazide
Avoid alpha and beta blockers
Statins if <40
Aspirin for secondary prevention only
Lifestyle advice

Question 10

What is the problem with the sign 116 guidelines in elderly patients?

Answer 10

Very strict targets
If multimorbid will be very difficult to reach targets
Not much evidence that really tight glycaemic control is beneficial in elderly (only beneficial if started mid-life and long term)

Question 11

Apart from diabetes, what other condition shows loss of benefit for tight control in geriatric populations?

Answer 11

HTN (tight BP control may be dangerous in these groups)

Beneficial only for those able to walk, for those unable if was detrimental to give anti-hypertensives

Question 12

What are the problems with guidelines for those who are multi-morbid?

Answer 12

There are many guidelines for each individual condition but none to fit all of their conditions

Cross-referenced NICE guidelines for T2DM, depression, heart failure and 11 other specific diseases

Question 13

How are elderly patients medicines meant to be checked?

Answer 13

All >75y meant to have annual medication review

Question 14

What are some healthcare provider factors that contribute to polypharmacy?

Answer 14

No med review
Presumes patient expects meds
Prescribes without sufficient Ix
Evidence that a particular drug is best for a problem
Complications of many problems and multiple providers
Unclear, complex or incomplete instructions on how to take meds
No effort to simplify med regimen
Ordering automatic refills
Medications promoted and publication bias
Lack of knowledge of geriatric clinical pharmacology

Question 15

How does absorption differ in older people?

Answer 15

Rate of absorption affected but not extent of absorption from GIT

Question 16

Give an example of how absorption may differ in an older person

Answer 16

GTN
Delayed absorption due to changed physiology & reduced saliva production, so patient may take more drug than they need –> BP falls –> vasovagal syncope

Question 17

What is the exception to the rule for how absorption differs in the elderly?

Answer 17

Levodopa
There is substantial mucosal metabolism of this by dopa-decarboxylase enzyme
Reduced dopa-decarboxylase as this is secreted in saliva and there is reduced saliva production
So increased absorption and higher peak level quicker than younger patients

Question 18

What body compositional changes in elderly patients mean they have different distribution of drugs?

Answer 18

Reduced muscle mass and water content
Increased fat content

Particularly significant if drug highly lipid soluble, widely distributed into muscle/contained in water

Question 19

How will the distribution of fat soluble drugs difer in an elderly patient?

Answer 19

Vd increased due to increased body fat

(e.g. fat soluble drugs - haloperidol, diazepam)

Adipose tissue acts as a reverse for these drugs, so enhanced t1/2

Question 20

How will the distribution of fat soluble drugs differ in an elderly patient?

Answer 20

Tend to reduce Vd –> higher serum levels

E.g. of water soluble drugs - digoxin, theophylline, atenolol, propranolol, hydrochlorothiazide

Question 21

How does protein binding differ in elderly patients?

Answer 21

Total serum albumin decreases by 12%
So more unbound, free drug
Common diseases in elderly depress albumin (HF, renal dx, RA, hepatic cirrhosis, some malignancies)

Question 22

Give examples of protein bound drugs

Answer 22

Furosemide, diazepam, cimetidine, propanolol

Question 23

How is the blood brain barrier affected by age?

Answer 23

More permeable so drug more easily distributed to CNS

Question 24

Why must you be careful in dosing digoxin in the elderly?

Answer 24

Reduction of muscle mass means there is a significant reduction in digoxins Vd so loading dose must be substantially reduced

Question 25

How is hepatic metabolism in the elderly differ?

Answer 25

Decreased liver mass and decreased liver blood flow

Question 26

What are the consequences of reduced metabolism in the elderly?

Answer 26

Toxicity due to reduced metabolism/excretion
Reduced first pass metabolism (increased bioavailability of some drugs, e.g. propranolol and reduced bioavailability of pro-drugs, e.g. enalapril)

Question 27

How is excretion affected by increased age?

Answer 27

Renal function decreases with age
Reduced clearance –> increased t1/2 –> increased toxicity

Consider elderly patients to have some renal function as young person with CKD

Question 28

Elderly patients have decreased/increased sensitivity to particular medicines. Why is this?

Answer 28

Increased

Due to changes in receptor binding, decrease in receptor number, altered translation of receptor iniaited cellular response into a biochemical reaction

Question 29

What medications are elderly people more sensitive to?

Answer 29

Diazepam

Warfarin

Question 30

What are the worst drugs to give elderly patients?

Answer 30

Anticholingerics

Sedatives

Question 31

Give examples of anticholingerics

Answer 31

Oxybutinin 
TCAs
Antiemetics
Antipsychotics
Ranitidine, phenytoin, digoxin, fluoxetine, lithium

Question 32

What can you use to assess the risk of giving an elderly patient an anticholingeric?

Answer 32

Anticholingeric burden scale

Question 33

Finish the sentence:

The more anticholingeric burden you have, the more likely you are to…

Answer 33

Develop symptoms, have poorer outcomes, develop dementia etc.

Question 34

What are the principles for prescribing for older people?

Answer 34

Ensure clear diagnosis
Consider if drug therapy the best option
Lower doses/reduced frequency generally needed
Think about particular problems with that drug in the elderly
Review new drug and check if achieving its aim
Address compliance issues (e.g. dispending aids)

Question 35

Where can you find drug information for elderly patients?

Answer 35

BNF

Schedule of product characteristics

Question 36

What are usual prescribing tools to help you in geriatrics?

Answer 36

Beer’s criteria (list of inappropriate drugs for older people)
STOPP-START criteria (advice on medical optimisation)
NHS polypharmacy guidance

Question 37

What does the NHS polypharmacy guidance look at?

Answer 37

Aims of drug Rx
Need
Effectiveness
Safety 
Cost effectiveness
Adherence/patient centeredness

Question 38

What is deprescribing?

Answer 38

To reduce, substitute or discontinue a drug

Question 39

Why might you deprescribe?

Answer 39

ADRs
DDIs
Better alternative
Not effective
Not indicated
Not evidence based
Minimise polypharmacy (proactive deprescribing)

Question 40

What are the benefits for proactive deprescribing?

Answer 40

Drops mortality and admission to care homes

Question 41

How is deprescribing done locally?

Answer 41

When GPs do their annual >75 reviews, they meet with geriatricians and pharmacists to reduce polypharmacy
Target high risk groups, e.g. care homes