Drugs in the elderly

Question 1

Define Pharmacodynamics

Answer 1

How a drug alters the body

Question 2

Define Pharmacokinetics

Answer 2

How the body alters the drug

Question 3

Define polypharmacy

Answer 3

When the patient is taking 4 or more medications

Question 4

What is an adverse drug reaction?

Answer 4

An injury caused by taking a medication

Question 5

Name 2 risk factors associated with adverse drug reactions

Answer 5

Polypharmacy

Inappropriate prescribing

Question 6

Name the 3 factors related to adverse drug reactions

Answer 6

DoTS classification

Dose

Time course

Susceptibility

Question 7

What is the name for a reaction occurring below the therapeutic range?

Give an example of a drug where this may occur.

What would you do if this did occur?

Answer 7

Hyper-susceptibility

Penicillin

Completely avoid the drug permanently

Question 8

What is the name for a reaction occurring within the therapeutic range?

Give an example of a drug where this may occur.

What would you do if this did occur?

Answer 8

Collateral

Antihistamines cause drowsiness

Nothing normally, as minimal and manageable side effects would be outweighed by the benefits of taking the drug - unavoidable

May not be reduced without reducing the therapeutic effect, even by reducing the dose

Question 9

What is the name for a reaction occurring above the therapeutic range?

Give an example of a drug where this may occur.

What would you do if this did occur?

Answer 9

Toxic

Bleeding caused by Warfrin

Treat by reducing the dose being given

Prevent by using the minimal effective dose

Question 10

Name 6 factors that have a effect on a patients susceptibility to a drug

Answer 10

Age - Old and young are more susceptible

Disease state - hepatic/renal impairment

Physiological state - pregnancy

Genetic susceptibility - Ethnicity

Sex

Exogenous factors - drug interactions/diet

Question 11

Name 7 factors leading to increased drug reactions in the elderly

Answer 11

Decreased organ function

Co-morbidity

Poly-pharmacy

Altered Pharmacokinetics (moving substances through the body)

Altered Pharmacodynamics (receptor sensitivity/decrease in hormones)

Decreased homeostatic function

Decreased compliance

Question 12

Name 3 things that should be carried out to achieve safe prescribing in the elderly

Answer 12

Improved compliance

(Simplify, educate, monitor) (Blister packs)

De-prescribe

(Discontinue drugs that aren’t of benefit/have adverse effects that require additional drugs to alleviate)

Medication reviews

(>75yo = annual reviews, and 6 month reviews if >75 yo and poly-pharmacy)

Question 13

A reaction occurs immediately on taking a drug, what name is given to this?

Give an example of a drug that may cause this

Answer 13

First dose reaction

Ramapril causes hypertension (ACEi)

Question 14

A reaction occurs 2 weeks into taking a drug, what name is given to this?

Give an example of a drug that may cause this and the action that should be taken.

Answer 14

Early reaction

Nitrates cause headaches

Patients may become tolerant to these reactions

ADR should wear off, so continue with medication

Question 15

A reaction occurs 1 month into taking a drug, what name is given to this?

Give an example of a drug that may cause this and the action that should be taken.

Answer 15

Intermediate reaction

Neutropenia due to carbimazole

If no reaction occurs within a specific time frame then vigilance can be relaxed

Question 16

A reaction occurs AFTER one month of taking a drug, what name is given to this?

Answer 16

Late reaction

Bruising due to corticosteroids

Risk of ADR increases with increased exposure

Need for long term monitoring

Question 17

If a drug is stopped at 2 months, and a reaction occurs a week after this, what is this reaction called?

Answer 17

Withdrawal

SSRI anti-depression discontinuation

Slow withdrawal or reduction of dose to prevent

Question 18

If a drug is stopped at 2 months, and a reaction occurs a month after this, what is this reaction called?

Answer 18

Delayed reaction

Carcinogenisis/teratogenesis

Avoid use of drug in patients that are susceptible

Question 19

Roughly, how many older people take at least 1 medication

Answer 19

4 in 5

Question 20

What percentage of the elderly take 4 or more medications

Answer 20

36%

Question 21

Elderly people are 3 times more likely to suffer from adverse drug reactions.

What percentage of hospital admissions are due to this?

Answer 21

5-12%

Question 22

What percentage of older patients do not take their medicines and prescribed?

Answer 22

Up to 50%

Question 23

What is a drug interaction?

Answer 23

A situation in which a substance affects the activity of a drug when both are administered together

Question 24

What is the normal therapeutic range for a drug?

Answer 24

1-1.5mg

Question 25

How do you report suspected severe drug reactions?

Answer 25

The yellow card scheme

Question 26

What is ageing?

Answer 26

Gradual loss of function of cells and organs with the eventual outcome of death

Question 27

Name 5 factors that influence ageing

Answer 27

Genetics Psychology Lifestyle (diet/exercise) Socio-economic factors Environment

Question 28

What are the 4 main pharmacokinetic processes? How do these relate to the older population?

Answer 28

_ADME_ **Absorption** Swallowing/gastric emptying/intestinal motility/blood flow/surface area **Distribution** Tissue perfusion an blood flow/plasma protein binding/volume distribution **Metabolism** Hepatic mass decrease/hepatic blood flow decrease/thyroid function decrease/genetics **Excretion** Assumption most older people have some degree of renal impairment. Renal blood flow decreases, and GFR decreases

Question 29

Give 3 aging changes that occur in pharmacodynamics

Answer 29

Changes in receptor sensitivity (B-adrenoceptor sensitivity decreases with age) Changes in receptor number Changes in hormone levels (menopause)

Question 30

Give 7 common drugs that

Answer 30

ACE inhibitors Diazepam Digoxin NSAIDS Opiates Oral hypoglycaemics Warfrin

Question 31

Give 3 ageing changes in homeostasis

Answer 31

Decreased postural control Decreased thermo-regulation Decreased immune response

Question 32

Why does multi-morbidities increase the chance of adverse drug reactions?

Answer 32

More drugs needed so more chance of drug-drug interactions More chance of drug-disease interactions (Benzodiazepines may precipitate delirium in a patient with dementia)

Question 33

How much of the drug budget do older people take up?

Answer 33

40%

Question 34

What percentage of over 65's are on regular medication?

Answer 34

66.6%

Question 35

Why can polypharmacy be a problem?

Answer 35

Loss of patient compliance (50%) Prescription errors (5-20%) Increased ADR's and interactions Inappropriate prescribing