Pharmacology: Psychotropics in Older Adults

Question 1

What are the changes in pharmacodynamics in the elderly?

Answer 1

• Reduced reflex control of haemostasis
• Increased sensitivity of receptors
• Increased serious side effects e.g. neutropenia (clozapine), stroke (antipsychotics), bleeding (SSRIs)

Question 2

What are the changes in pharmacokinetics in the elderly?

Answer 2

• Reduced gut motility –> slower absoprtion
• Increased fat, less water, less albumin –> altered drug distribution
• Reduced renal function –> reduced renal excretion

Question 3

What are the important prescribing principles in the elderly?

Answer 3

• Clear indication of prescribing
• Check BNF/pharmacist/senior
• Check organ function + use lower dosing
• Avoid polypharmacy where possible
• Check interactions
• Advise of side effects/complications
• Think falls, bleeds, arrhythmias, sedation, swallow, movement disorder etc
• Start low go slow

Question 4

Martin in a 67yr old farmer who is brought into A&E by his wife due to him becoming suddenly more confused, forgetful and suspicious. She described in the last 24 hours he has had several ‘blank’ episodes that last a couple of minutes like ‘he is not in the room’. He can’t remember what happens and overall has become increasingly confused. She tried to get him to come to hospital but he’s stubborn and wouldn’t. Eventually he had a big episode which made his face droopy for several minutes, before returning to normal and so she called an ambulance. Martin is finding it difficult to find certain words. His wife tells you that he has been experiencing similar but milder difficulties for 6 months now and had a ‘funny turn’ around that time in which he became confused and started ‘talking slurry’ but he made a full recovery. He is significantly more forgetful and confused today. His wife also tells you that Martin has been more suspicious of others in the last few weeks. He can be quite ‘snappy’ with others and in particular his neighbour and close friend Dave who is also a farmer. Dave noticed that Martin forgot to bale his hay and seemed to struggle to work the hay baler, and Martin got angry about this. Martin has been suspicious of Dave but hasn’t explained why.

Past psych hx- Nil

Past medical hx- Hypertension, Type 2 Diabetes

Answer 4

Bendroflumethazide - vascular dementia is not treated with other dementia medication so it is important to reduce CV risk factors instead.

Question 5

Give 3 examples of AChEi.

Answer 5

Donepezil, Rivastigmine and Galantamine

Question 6

What is the MOA of AChEi? What are the indications?

Answer 6

MOA:

• Reversible inhibitors of AChE
• Acts on Nucleus Basalis of Meynert
• Slows rate of cognitive decline and possible BPSD

Indications:

• Mild-mod AZ and LBD (esp Rivastigmine)
• Not used in FTD or vascular

Question 7

What are the contraindications for AChEi?

Answer 7

1. GI disease: recent pancreatitis
2. Cardiorespiratory disease: bradycardia, sick sinus syndrome or significant AV conduction block, asthma/COPD

Question 8

What are the side effects of AChEI?

Answer 8

GI - nausea, vomiting, diarrhoea, anorexia, fatigue, dizziness, headache

SLUDGE (with miosis and muscle spasm) - cholinergic crisis can result in respiratory arrest

Question 9

What are the “sludge” symptoms?

Answer 9

Symptoms as a result of cholinergic toxicity causing massive discharge of the parasympathetic nervous system

• Salivation
• Lacrimation
• Urination
• Defecation
• Gastrointestinal distress
• Emesis
• + muscle spasm

Question 10

What is the MOA of memantine?

Answer 10

NMDA receptor antagonist (antiglutamate)

Prevents overstimulation of NMDA receptors by glutamate (which occurs in dementia) and protects against Calcium mediated apoptosis.

Question 11

What are the indications for memantine use?

Answer 11

Recommended for mod-severe AZ or those who cannot tolerate AChEi

Question 12

What is the pharmacological management of:

1. Vascular dementia
2. Frontotemporal dementia

Answer 12

1. Vascular dementia
   
   • No dementia drugs used
   • Manage vascular risk factors such as smoking, weight and BMI, blood pressure control, glycaemic control and lipid management.
   • Look for underlying arrythymia e.g. AF may require anticoagulation etc.
2. Frontotemporal dementia -
   
   • No drug licensed

Question 13

Which of these is not part of frontal lobe assessment?

1. Similarities
2. Lexical fluency
3. Address recall
4. Motor luria
5. Go-No-Go

Answer 13

3

Question 14

What are the components of the Frontal Assessment Battery?

Answer 14

1. Similarities (in what way are a banana and an orange alike)
2. Lexical fluency (name as many words beginning with “p” - over 11 is normal)
3. Motor Luria (copy motor sequence - e.g. rock, paper and clap)
4. Go-No-Go (tap once when I tap twice, don’t tap when I tap)

Question 15

Rank the following treatment options in order of suitability for an agitated patient with delirium on background of vascular dementia.

• Behavioural management techniques
• Olanzapine
• Rosperidone
• Sensory stimulation
• Lorazepam

Answer 15

1. Behavioural management techniques
2. Sensory Stimulation
3. Risperidone
4. Olanzapine
5. Lorazepam

Question 16

What is sensory stimulation?

Answer 16

Sensory stimulation is the activation of one or more of the senses such as taste, smell, vision, hearing and touch.

It helps increase attention and awareness and is often used in dementia/delirium

Question 17

Nurses cannot convince a delirious patient to take medication. He says they are trying to poison him. Should they hide the medication in his food?

Answer 17

No - assess capacity first. But maybe in the future.

Covert medication - can only be given this way as a last resort once paper work is done

Question 18

Which group of patients should not be prescirbed antipsychotics?

• LBD/Parkinson’s
• Vascular and LBD
• LBD and vascular dementia
• Parkinsons and Vascular
• FTD and Vascular dementia

Answer 18

LBD and Parkinson’s - will exacerbate EPSEs

Question 19

Summarise the management of BPSD.

Answer 19

BPSD = all the non-cognitive symptoms of dementia

Bio-psycho-social assessment: constipation, pain, medication effects, communication, depression, environment.

Pharmacological: NICE state ‘disturbed behaviour such as aggression and agitation, not responding to nonpharmacological treatments’.

• • Avoid Benzo: pardoxical effect, worsen cognition, falls, breathing , delirium.
• • Antipsychotic: Risperidone is licensed for short term use only (12 weeks). Discuss with family etc and explain 3X increase risk of stroke.

NOT FOR PATIENTS WITH LEWY BODY DEMENTIA/PARKINSON’S

Question 20

What is the NICE management of delirium?

Answer 20

NICE guidelines/Confusion assessment method (CAM)

1. Early diagnosis
2. Treat underlying causes
3. General principles of care: single room, good lighting, address sensory impairment, familiar staff/family, review need for medication, ensure adequate nutrition, hydration, orientation (clocks/prompts), prevent constipation, retention etc
4. Medications:, low dose antipsychotics (NICE)-Haloperidol/Olanzapine, avoid benzo/anticholingeric