Prescribing in Older People Flashcards

1
Q

Common Scenario:
85 yr old frail female admitted after a fall
Meds include: Warfarin, Perindopril, Diazepam, Ibuprofen, Furosemide, Sertraline, Amlodipine, Betahistine, Prochorperazine
What problem meds can you identify?

A

Warfarin and Ibuprofen = increased risk of bleeding
Ibuprofen/Diuretic/perindopril - affect ARF
Sertraline - low sodium/GI bleeds
Diazepam - sedation
Antihypertensives in those who fall (amlodipine)
Prochlorperazine - Parkinsonism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Patients over 65 years constitute …% of the population but use about …% of the medications

A

13% of population, 30-40% of medication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Elderly patients use … drugs and have … diseases

A

Elderly patients use multiple drugs and have multiple diseases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Greatly increased risk of drug … as well as … effects with multiple drugs

A

Greatly increased risk of drug interactions as well as adverse effects with multiple drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Drug absorption in the elderly

A
Reduced saliva
Reduced gastric acid
Decreased GI motility
Reduced SA for absorption
Reduced splanchnic blood flow
overall - rate of absorption decreased and increased time to steady state
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Levodopa competes with …

A

nutrients - plan dosing regimes to avoid meal times

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Bisphosphonates - advise to take on a …

A

empty stomach, sitting up, 30 min before food

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Drug distribution in the elderly

A

Decreased lean body mass (muscle)
Decreased volume of distribution for drugs that distribute into muscles e.g. digoxin
= increased plasma concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Digoxin toxicity

A

Cardiac (heart block, bradycardia, junctional tachycardia), Psychiatric (delirium, fatigue, malaise), Visual, GI side effects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Digoxin toxicity - Cardiac (3)

A

heart block, bradycardia, junctional tachycardia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Digoxin toxicity - A patient with normal digoxin levels (1-2 ng/mL), 6 hours post dose but renal insufficiency or severe hypokalemia may have more serious cardiotoxicity than a patient with high digoxin levels and no renal or electrolyte disturbances.
Treat how? withdrawing drug/correcting electrolytes

A

withdrawing drug/correcting electrolytes

Severe- digoxin specific antibody fragments (Digibind)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Drug Distribution in the elderly

A

increased body fat, increased volume of distribution for fat soluble drugs e.g. benzodiazepines, haloperidol = increased half life
e.g. diazepam - vol of distribution increased by x2 in elderly - half life increases from 24 hours to 90 hours in the elderly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Benzodiazepines side effects

A

Drowsiness, confusion, ataxia, dependence

Treat iv flumazenil 200mcg, antagonist, shorter half life than diazepam and so patient may become re-sedated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Drug distribution in the elderly - body water - what is the affect on distribution of water soluble drugs?

A

Decreased body water, decreased vol of distribution of water soluble drugs e.g. gentamicin
= increased plasma conc, loading doses are lower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Serum albumin - drug distribution in the elderly - what happens?

A

↓Albumin 12-25% - further depressed by heart failure, renal disease, rheumatoid arthritis, hepatic cirrhosis some malignancies
Drug binding capacity ↓ 12-25%
↑ free drug

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Phenytoin toxicity

A

Nausea, vomiting, tremor, ataxia, nystagmus, coarse facies, hepatitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Warfarin - Aspirin Interaction

A

Warfarin is highly bound to plasma albumin (99%)
Warfarin has narrow therapeutic index
Warfarin has a small volume of distribution
Aspirin can displace warfarin from plasma albumin
finish card

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Adverse effects - antiplatelet agents e.g. aspirin

A
Antiplatelet agents - aspirin 
Peptic ulcer disease
bleeding tendency
fluid retention
renal failure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Anticoagulants eg warfarin or DOAC adverse effects

A

Bleeding tendency

Interaction with other drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Digoxin toxicity - Psychiatric

A

delirium, fatigue, malaise, confusion, dizziness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Digoxin toxicity - Visual

A

blurred or yellow-green vision, halos, double vision, photophobia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Digoxin toxicity - Gastrointestinal

A

nausea, vomiting, anorexia, diarrhoea, abdominal pain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Drug distribution in the elderly - decreased body water - what is the affect on loading doses of water soluble drugs?

A

decreased body water = increased plasma conc, loading doses are lower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What drugs bind to albumin and require lower doses in the elderly?

A

phenytoin, warfarin, propranolol, diazepam levothyroxine,digoxin, furosemide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Phenytoin toxicity symptoms
``` Nausea, vomiting Tremor Ataxia Nystagmus Coarse facies Hepatitis ```
26
Warfarin – Aspirin interaction
Warfarin is highly bound to plasma albumin (99%) Warfarin has narrow therapeutic index Warfarin has a small volume of distribution Aspirin can displace warfarin from plasma albumin Displacement of 1-2% of bound warfarin doubles or triples concentration of free warfarin ↑ bleeding
27
Adverse effects - Antiplatelet agents (5)
``` aspirin Peptic ulcer disease Bleeding tendency Fluid retention Renal failure ```
28
Adverse effects - Anticoagulants warfarin or DOAC (2)
Bleeding tendency | Interaction with other drugs
29
Liver metabolism in the elderly
↓ liver volume – up to 30% reduction ↓ liver blood flow 12-40% (extremely variable) ↓ first-pass metabolism due to ↓ blood flow ↓ enzyme activity CP450 (frail elderly)- ↓ clearance of drugs = ↑ t1/2 Eg. antidepressants, antipsychotics, beta blockers, opiates, benzodiazepines, calcium channel blockers, theophylline, warfarin, phenytoin, NSAIDS, paracetamol, erythromycin
30
Excretion in the elderly
Renal blood flow ↓ Renal mass (20%) ↓ Renal function (nephrons 30%) GFR declines by 1% per year from age 40
31
Excretion in the elderly
Drugs that are more than 60% excreted by kidneys are affected by a reduction in renal function t1/2 prolonged ↑ serum levels Drugs excreted primarily by kidneys include: digoxin, atenolol, sotalol, lithium, allopurinol & many antibiotics
32
Excretion in the elderly - Therapeutic implications
Reduce dose in once daily preps | Increase dosage interval in more frequently administered drugs
33
Lithium - toxicity
12 hour post dose 0.4-0.8 mmol/l Early toxicity Li 1.5 mmol/l tremor, agitiation, twitching Intermediate – lethargy Late Li >2 mmol/l coma, fits, arrhythmia, renal failure – haemodialysis may be needed
34
Morphine undergoes phase II metabolism by ...
conjugation
35
Morphine
Undergoes phase II metabolism by conjugation Morphine-6-glucuronide 40x more potent Approx 80% analgesic action derives from Morphine-6-glucuronide Renal impairment results in accumulation of metabolite Prolonged effect, ↑ toxicity NB S/C morphine = 2x potent po
36
Morphine toxicity symptoms (5)
``` Nausea, vomiting Constipation Drowsiness Respiratory depression Hypotension ``` Treatment naloxone iv 400mcg
37
Morphine toxicity treatment
naloxone iv 400mcg
38
Pharmacodynamics - aging
Effects of aging on biochemical and physiologic effects of drugs and their mechanisms of action are not clearly known Progressive decline in homeostatic mechanisms ? Due to receptor affinity or number ? Alterations in second messenger function ? Alteration in cellular & nuclear responses
39
drug effects in the elderly - alcohol?
Alcohol causes increase is drowsiness and lateral sway in older people than younger people at same serum levels
40
drug effects in the elderly - benzos?
Benzodiazepines (↑) – enhanced sedation
41
drug effects in the elderly - warfarin?
Warfarin (↑)
42
drug effects in the elderly - Hypotensives?
Hypotensives (↑) – postural hypotension
43
drug effects in the elderly - NSAIDS?
GI effects of NSAIDs (↑)
44
drug effects in the elderly - anticholinergics?
Central effects of anticholinergics (↑)
45
drug effects in the elderly - ß1 modulators in cardiac tissue?
ß1 modulators in cardiac tissue (↓)- down regulated by 1/3
46
drug effects in the elderly - bronchodilatory response to β-agonists?
Reduced & delayed bronchodilatory response to β-agonists
47
drug effects in the elderly - Calcium channel blocking effect?
Calcium channel blocking effect on PR interval (↓)
48
Elderly patients medicines should be ... ...
Elderly patients medicines should be reviewed regularly
49
Frail patients may have difficulty swallowing tablets – if left in the mouth ... may develop
Frail patients may have difficulty swallowing tablets – if left in the mouth ulceration may develop
50
Encourage patients to take medication with enough ..., in an upright position, consider ... preparation
Encourage patients to take medication with enough fluid, in an upright position, consider liquid preparation
51
Antihypertensive medication (ACE inhibitors –eg. ramipril) – side effects
Hypotension Potassium increase Renal failure Cough
52
Antihypertensive medication (Calcium channel blockers – e.g amlodipine) – side effects
Hypotension Negatively inotropic Fluid retention
53
Antihypertensive medication (Diuretics) – side effects
``` Hypotension Hypokalaemia Hyponatremia Confusion Dehydration ```
54
‘Traditional’ antipsychotics – haloperidol - side effects (elderly)
``` Confusion Sedation Parkinsonism Tardive dyskinesia Neuroleptic malignant syndrome ```
55
How to prescribe in the elderly
``` Consider risk/benefit ratio Pharmacokinetic/dynamic factors Start low, go slow Review the effect Communicate with patient,relative,other healthcare professionals Use the BNF ```
56
AF Risk of stroke - what score?
NICE CHA2DS2-VASc – treat men >1 | Assess bleeding with HASBLEED – high risk >3 (European Society Guidelines AF)
57
Assess bleeding risk with what score? (AF)
Assess bleeding with HASBLEED – high risk >3 (European Society Guidelines AF)
58
What to do about compliance - elderly
Consider cognitive problems – carer to prompt patient with medications Simplify regimes as much as possible to once or twice daily Dossit boxes Consider manual dexterity and vision of the patient Check inhaler techniques Syrups if dysphagia for large tablets
59
Adverse drug reactions - elderly
Prevalence increases with age, length of stay, number of medications 15.3% of admissions are due to ADR
60
What % of admissions are due to Adverse drug reactions - elderly
15.3% of admissions are due to ADR
61
Steroid 3 adverse affects (elderly)
Osteoporosis Gastric irritation/ulcers Hyperglycaemia
62
Tricyclic antidepressants - 5 adverse affects (elderly)
``` Cardiac arrhythmias Drowsiness Dry mouth Constipation Urinary retention ```
63
Non steroidal anti inflammatory drugs - 3 adverse effects (elderly)
Renal failure Gastric irritation Fluid retention
64
Selective alpha blockers - 4 adverse effects (elderly)
urinary retention (relax smooth muscle in BPH) drowsiness hypotension syncope
65
STOPP/START criteria for potentially ... prescribing in older people: version 2
STOPP/START criteria for potentially inappropriate prescribing in older people: version 2
66
Key Learning Points - prescribing in the elderly
Physiological changes in the elderly alter drug responses Assess the risks and benefits when prescribing Side effects are common and can be life threatening Think about polypharmacy and compliance issues Use the BNF