Drugs and Polypharmacy

Question 1

What is polypharmacy?

Answer 1

The use of many drugs - one unnecessary medication can be enough to place an older person at risk of a toxic reaction

Question 2

How many serious adverse drugs reactions are there annually in the US?

Answer 2

Over 2 million

Question 3

How many deaths are there annually due to adverse drug reactions (US)?

Answer 3

100,000

Question 4

Adverse drug reactions are the 4th leading cause of death, true or false?

Answer 4

True

Question 5

What is the rate of ADRs in nursing home patients?

Answer 5

350,000 annually

Question 6

What number of ADRs in ambulatory settings are preventable?

Answer 6

Nearly 1/3rd

Question 7

What number of ADRs in nursing facilities are preventable?

Answer 7

Half

Question 8

What are some common iatrogenic drug problems?

Answer 8

Confusion, dry mouth, constipation, blurred vision, urinary retention and orthostatic hypotension with anticholinergics

Confusion and unsteady gait with tricyclics

Digoxin toxicity with normal serum concentrations

CNS toxicity with long-acting benzodiazepines

Confusion with narcotics

Question 9

What are the most costly medication-related problems/adverse drug reactions in the elderly?

Answer 9

Falls
Cognitive loss/delirium
Dehydration
Incontinence
Depression

Question 10

What are possible end results of ADRs in older patients?

Answer 10

Loss of functional capacity
Poor quality of life
Nursing home placement

Question 11

How many prescriptions do older adults get compared to those < 50?

Answer 11

Older adults (> 50) get 2-3 times as many prescription

Question 12

What percentage of the population receiving prescription drugs, and percentage of prescription drugs in total do older adults account for?

Answer 12

12% of the population

> 32% of prescription drugs

Question 13

How many drugs does a typical 85 year old take?

Answer 13

8-9 prescriptions and 2 OTC drugs at any one time

Question 14

What common adverse drug reactions may be mistaken for ‘normal’ ageing?

Answer 14

Unsteadiness
Dizziness
Confusion
Nervousness
Fatigue
Insomnia 
Drowsiness
Falls
Depression
Incontinence

Question 15

How many associated drug-drug interactions are there with type 2 diabetes mellitus, heart failure, and depression?

Answer 15

T2DM - 133
Heart failure - 111
Depression - 89

Question 16

What are the healthcare provider factors that contribute to polypharmacy?

Answer 16

No medical review with patient on a regular basis
Presumes that patient expects medications
Prescribes without sufficiently investigating clinical situation
Evidence that a particular drug is the best drug for a problem, complicated by existence of many problems and multiple providers
Provides unclear, complex or incomplete instructions on how to take medications
No effort to simplify drug regimen
Ordering automatic refills
Lack of knowledge of geriatric clinical pharmacology

Question 17

What are the drugs with the most adverse side effects?

Answer 17

Anticholinergics

Sedatives

Question 18

What are some common peripheral side effects of antimuscarinic drugs?

Answer 18

Dry mouth 
Dry eyes
Constipation 
Reduced peristalsis 
Inability to accommodate vision 
Pupillary dilatation
Urinary retention 
Tachycardia 
Decreased sweating

Question 19

What are some common central side effects of antimuscarinic drugs?

Answer 19

Memory impairment 
Confusion
Disorientation
Agitation
Hallucinations
Delirium
Falls

Question 20

How is absorption affected in old age? Give an example of this

Answer 20

Physiological changes occur that affect the rate but generally not the extent of absorption from the GI tract, this may lead to a delay in onset of action
e.g. reduction in saliva production may result in reduction in rate of absorption of bucally administered drugs like GTN

Question 21

What is the exception to the effect of old age on absorption?

Answer 21

Levodopa - substantial mucosal metabolism of this drug occurs by enzyme dopa-decarboxylase, which is reduced in the elderly so there is a substantial increase in the absorption of levodopa in this age group

Question 22

Why are there changes in drug distribution in the elderly?

Answer 22

Body composition changes
Reduced muscle mass
Increased adipose tissue, so fat-soluble drugs have increased Vd, half-life and duration of action
Reduced body water so water soluble drugs have reduced Vd and increased serum levels
Protein binding changes
Decreased albumin - reduced binding and increased serum levels of acidic drugs e.g. furosemide
Increased permeability across blood-brain barrier

Question 23

How is drug metabolism affected in the elderly?

Answer 23

Hepatic metabolism affected by decreased liver mass and decreased liver blood flow
Results in toxicity due to reduced metabolism and excretion and reduced first-pass metabolism

Question 24

How is drug excretion affected in the elderly?

Answer 24

Renal function declines with age

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

Question 25

How are pharmacodynamics affected in the elderly?

Answer 25

Increased sensitivity to particular medicines Change in receptor binding Decrease in receptor number Altered translation of a receptor initiated cellular response into a biochemical reaction e.g. diazepam - increased sedation warfarin - increased anticoagulation

Question 26

What are the principles of prescribing for older people?

Answer 26

Where possible, be clear about diagnosis to avoid prescribing a drug to manage an adverse effect Consider whether drug therapy is the best therapeutic action Lower doses generally needed, or reduced frequency of administration Think about whether the drug causes particular problems in elderly patients Check whether lower dose is recommended in the elderly Start at lowest dose and titrate up slowly Review new drugs and check if they are achieving their aim Review all prescriptions regularly Stop any medicines that are not beneficial Try to keep regimens as simple as possible Consider compliance issues Elderly patients should not be denied a drug with proven benefits on the basis of age Bear in mind that clinical trials are often preformed in a younger population so benefits may not translate to older age group

Question 27

Where can drug information be found?

Answer 27

BNF

Question 28

What prescribing tools and guidelines can be used?

Answer 28

Beers' criteria START-STOPP criteria NHS Scotland polypharmacy guide

Question 29

When is de-prescribing indicated?

Answer 29

To reduce, substitute or discontinue a drug - adverse drug reaction - drug-drug interaction - drug-disease interaction - better alternative - not effective - not indicated - not evidence-based - minimise polypharmacy

Question 30

What is proactive deprescribing?

Answer 30

Systematic review of medication withdrawal trial in people > 65 Some evidence that it is safe and/or beneficial to stop antihypertensives, benzodiazepine and antipsychotics

Question 31

What needs to be considered in prescribing for psychiatric conditions in the elderly?

Answer 31

Care with treating agitation Sedatives are problematic Increased effects of benzodiazepines Anti-psychotics have increased adverse effects Anti-depressants are less effective and potentially more dangerous

Question 32

What needs to be considered in prescribing analgesia for the elderly?

Answer 32

Opioids - elderly are more sensitive to effects so lower doses needed Pethidine and tramadol may be less useful NSAIDs - increased adverse effects such as renal impairment and GI bleeding

Question 33

What needs to be considered in prescribing digoxin for the elderly?

Answer 33

Increased toxicity | Lower doses needed

Question 34

What needs to be considered in prescribing diuretics for the elderly?

Answer 34

Decreased peak effect but reduced clearance, so abnormal urea and electrolytes Other issues around continence and mobility Often inappropriate indication

Question 35

What needs to be considered in prescribing anti-hypertensives for the elderly?

Answer 35

May have exaggerated effects on BP and HR More likely to have issues with postural hypotension ACEIs often pro-drugs which may not be metabolised into their active form Renal adverse effects

Question 36

What needs to be considered in prescribing anti-hypertensives for the elderly?

Answer 36

More sensitive to warfarin | Greater risk from warfarin e.g. GI bleeds, falls

Question 37

What needs to be considered in prescribing antibiotics for the elderly?

Answer 37

``` Increased adverse effects Diarrhoea and c. diff infection Blood dyscrasias with trimethoprim and co-trimoxazole Delirium with quinolones Seizures Renal impairment ```