PM3C OVERLAP: Medicines in the elderly

Question 1

What has happened in elderly for them to have:

• reduced cardiac output
• slower Heart rate
• lower max HR

Answer 1

Reduced cardiac output caused by stiffened ventricles
Slower HR due to loss of pacemaker cells

Lower Max HR due to less sensitivity to noradrenergic stimulation

Question 2

What causes

• risk of arrhythmias
• hypertension
• postural hypotension

Answer 2

arrhythmias risk due to calcification of conduction systems

Hypertension due to arterial walls stiffening

Postural hypotension due to calcification of valves

Question 3

Why do elderly people have

• reduced bone mass
• cognitive impairment
• increased risk of CVD

Answer 3

Reduced oestrogen levels

Question 4

What causes muscle weakness, anaemia, mood problems in elderly?

Answer 4

Reduced testosterone

Question 5

What things cause reduced bone mass in elderly?

What does this increase the risk of?

Answer 5

Reduced oestrogen
Increased parathyroid hormone (promotes bone degradation and osteoclasts)
Impaired absorption and transport of calcium, reduced vitamin D activity, poor nutrition, cartilage changes (less lubrication)

Increased risk of osteoporosis, osteoarthritis, falls

Question 6

What happens in the CNS of the elderly?

Answer 6

Atrophy of nerve cells which reduces the speed of transmission, leading to reduced memory, thinking, movement.
Also increased sensitivity to side effects - confusion, sedation, parkinsonism,falls

Question 7

why are vaccines less effective in elderly?

Answer 7

Reduced free radical generation and changes in the immune system, changes in cytokine levels

Question 8

What causes latent infections to re-emerge in elderly e.g.TB?

Answer 8

Reduced phagocytosis

Question 9

What drug classes increase the risk of falls?

Answer 9

Sedatives
BP drugs
HR drugs - blood may not be pumped around
Drugs causing hypoglycaemia e.g. anti-diabetics

Question 10

Elderly have reduced albumin, mass, water and increased body fat - wha does this cause?

Answer 10

Reduced Vd for hydrophilic drugs- higher peak plasma concentration
Increased Vd for lipophilic drugs, and longer half life
Increased sensitivity to plasma bound drugs - risk OD

Question 11

When prescribing water soluble drugs such as digoxin and lithium in the elderly - what should be considered?

Answer 11

Reduced intracellular fluid means that there will be a reduced body weight. Standard dosing will give a greater dose, and water soluble drugs have reduced Vd so may reach increased plasma concs

Question 12

When prescribing lipid soluble drugs in the elderly e.g. diazepam, TCAs - what should be considered?

Answer 12

initially there will be a large uptake of drug into lipid compartments causing a reduction in plasma concentration, but accumulation results in a prolonged effect so drug is slowly released over time which could risk side effects - reduce the dose.

Question 13

When prescribing highly plasma protein bound drugs in the elderly e.g. phenytoin, warfarin, SV - what should be considered?

Answer 13

There may be more free drug and this can increase risk of toxicity and overdose

Question 14

If elderly have reduced hepatic blood flow, reduced liver mass and hepatic enzyme activity - what are the implications of this?

Answer 14

Increased steady state level
Increased half life
Increased active metabolites

Question 15

What are the implications of reduced GFR?

Answer 15

Renal elimination is decreased so half life of renally excreted drugs is prolonged, risking accumulation and toxicity esp with drugs of narrow TI
e.g. digoxin can cause bradycardia and increased falls
gentamicin can cause AKI & ototoxicity

Question 16

How to minimise ADRs in the elderly and increase adherence

Answer 16

Minimise polypharmacy, regular reviews
minimise complexity of the regimen
Reminder cards/devices, including plain/wing caps for RA patients not clic-locks

Question 17

How can you de-prescribe?

Answer 17

Use of STOPP/START criteria
Use of NICE guidance and clinical decision aids
calculating anticholinergic burden
Looking at the risks and benefits, and adverse effects
Simplifying drug regimens preferably to OD/Once weekly dosing
Always agree changes with the patient and avoid ageism

Question 18

What is polypharmacy?

Answer 18

The more drugs a patient is on, the more likely they are to suffer from ADRs, interactions, concordance problems. Need to review the need for each drug and only use it for as long as necessary
(5 drugs or more triggers a medication review, but even if on one they are still at risk)

Question 19

Why are patients sensitive to CNS side effects of lipid soluble drugs

Answer 19

BBB impairment

Question 20

Diuretics, SSRIs, anti-psychotics can cause fluid and electrolyte imbalances - what can this cause?

Answer 20

Confusion
Dizziness
falls

Question 21

Why is constipation common in elderly?

Answer 21

If they are on a drug that affects GI motility, it can result. in constipation - opioids, anticholinergics
Also reduced GI motility and gastric emptying

Question 22

What effects can anticholinergic medication have in the elderly?

Answer 22

Urinary retention 
Falls risk
confusion/disorientation
Dry mouth
Blurred vision 
Postural hypotension
Heart rhythm disturbance
Constipation
dry eyes 
Mood swings

Question 23

Why are elderly people a more risk of falls?

Answer 23

Drugs
centre of gravity of shifted and more rigid
dementia
poor eyesight

Question 24

What drugs can increase confusion in elderly patients?

Answer 24

anticholinergics 
anti-parkinsons medications 
TCAS
Opioids
Steroids 
Benzodiazepines 
hypoglycaemics
Diuretics 
SSRIs
Antipsychotics