2.3. Geriatrics - Drugs and Polypharmacy

Question 1

Why does Ageing occur?

Answer 1

1. It is a result of the Degeneration of Function of Various Organ Systems
2. Dyshomeostasis = Complex Interplay of these Systems also breaks down

Question 2

What is Pharmacokinetics?

Answer 2

What the Organism does to the Drug:

1. Absorption
2. Distribution
3. Metabolism
4. Excretion

Question 3

With Age, how does Absorption (Pharmacokinetics) change?

Answer 3

Physiological Changes occur that effect the Rate but generally not the Extent of Absorption from the GI tract - delayed onset of Action

Question 4

With Age, how does Distribution (Pharmacokinetics) Change?

Answer 4

1. Body Composition:
2. a) Reduced Muscle
3. b) Increased Adipose Tissue - Increase Duration of Action of Fat-Soluble Drugs
4. c) Reduced Body Water - Increase Serum Levels of Water-Soluble Drugs
5. Protein Binding Changes - Decreased Albumin
6. Increased Permeability across the Blood Brain Barrier

Question 5

With Age, how does Metabolism (Pharmacokinetics) Change?

Answer 5

Hepatic Metabolism is affected by:

1. Decreased Liver Mass
2. Decreased Liver Blood Flow

This leads to:

1. Toxicity - due to reduced Metabolism / Excretion
2. Reduced First Pass Metabolism

Question 6

With Age, how does Excretion (Pharmacokinetics) Change?

Answer 6

Renal Function decreases with Age - Reduced clearance / Increases Half-Life

Question 7

What is Pharmacodynamics?

Answer 7

What the Drug does to the Organism

Question 8

How does Pharmacodynamics change with Age?

Answer 8

Increased Sensitivity to Particular Medicines, due to:

1. Changes in Receptor Binding
2. Decrease in Receptor Number
3. Altered Translation of a Receptor-Initiated Cellular Response to into a Biochemical Reaction

Question 9

What is the relationship between Older People and Drug-Drug Interactions?

Answer 9

Older People have more Chronic Diseases, and so are more likely to be on More Drugs. Drugs can interact with resultant changes on Pharmacokinetics/dynamics

Question 10

What is important when starting a New drug, in the Elderly?

Answer 10

1. Start Low
2. Go Slow
3. Be Clear about the Review

Question 11

What is Creeping Cardex Syndrome?

Answer 11

1. Drugs started for Preventative Reasons, but not Reviewed
2. Drugs started with an intention for Short Term Symptomatic Relief, but never stopped
3. Drugs started to relieve Side-Effects of other Drugs

Question 12

When is Deprescribing done?

Answer 12

To reduce, substitute or discontinue a drug:

1. Adverse Drug Reaction
2. Drug-Drug / Drug-Disease Interaction
3. Better Alternative
4. Not Effective / Indicated / Evidence-Based
5. Minimise Polypharmacy

Question 13

What is the effect of Opioids on Geriatrics?

Answer 13

More Sensitive to Effects - Lower Doses needed

Question 14

What is the effect of NSAID’s on Geriatrics?

Answer 14

Increased Adverse Effects - Renal Impairment / GI Bleeding

Question 15

What is the effect of Digoxin on Geriatrics?

Answer 15

Increased Toxicity - Lower Doses Needed

Question 16

What is the effect of Diuretics on Geriatrics?

Answer 16

Decreased Peak Effect + Reduced Clearance

Question 17

What is the effect of Anti-Hypertensives on Geriatrics?

Answer 17

1. Exaggerated Effects on the Blood Pressure / Heart Rate
2. More likely to be an issue with Postural Hypotension
3. ACEi may not be metabolised to active form
4. Renal Adverse Effects

Question 18

What is the effect of Anti-Coagulants on Geriatrics?

Answer 18

More Sensitive to Warfarin - Greater Risk from Warfarin

Question 19

What is the effect of Antibiotics on Geriatrics?

Answer 19

Increased Adverse Effects:

1. Diarrhoea / C. Diff
2. Blood Dyscrasias
3. Delirium
4. Seizures
5. Renal Impairment