Drugs and Polypharmacy

Question 1

What happens to absorption in old age

Answer 1

There are physiological changes that effect the rate of absorption of a drug, but no the extent of its absorption

Question 2

What happens to saliva production in old age

Answer 2

Reduced saliva production and there for a reduced rate of absorption of buccally administrated drugs

Question 3

Why is there an increased absorption of levodopa in the elderly

Answer 3

enzyme dopa-decarboxylase is reduced

Question 4

State the two main factors that effect drug distribution in the elderly

Answer 4

Body composition changes and protein binding changes alongside increased permeability across the blood-brain barrier

Question 5

State how body comp changes in the elderly

Answer 5

Reduced muscle mass, increased adipose tissue and reduced body water

Question 6

What happens to drugs fat soluble drugs due to increased adipose tissue

Answer 6

Increased volume of distribution, increased half life and increased duration of actio

Example is diazepam

Question 7

State the effect of reduced body water on water soluble drugs

Answer 7

Increased Vd, increased serum levels (digoxin)

Question 8

Give examples of the drugs effected by a reduced body water

Answer 8

theophylline, atenolol, propranolol and hydrochlorthiazide

Question 9

State the main cause of protein binding changes in the elderly

Answer 9

Decreased albumin

Question 10

State the effects of decreased albumin

Answer 10

Decreased binding, increased free drug and therefore increased serum levels of acidic drugs

Question 11

State the drugs effected by decreased albumin

Answer 11

cimetidine, furosemide, NSAIDs and sulphonylureas, diazepam, salicyic acid

Question 12

How is hepatic metabolism effected by increased age

Answer 12

Decreased liver mass and reduced liver blood flow

Question 13

What are the consequences of reduced liver metabolism

Answer 13

Toxicity and reduced first pass metabolism

Question 14

What changes excretion of drugs in the elderly

Answer 14

Reduced renal function

Question 15

What is the consequence of reduced renal function

Answer 15

Reduced clearance and increased the half-life of many drugs leading to toxicity

Question 16

Why are the elderly more sensitive to particular medication

Answer 16

Change in receptor binding, decrease in receptor numbers and altered translation of a receptor initiatied cellular response into a a biochemical reaction

Question 17

State the drugs effected by increased sensitivity

Answer 17

Diazepam and warfarin

Question 18

Why are elderly patients at more risk of drug-disease interactions

Answer 18

Older people have more chronic diseases and these can affect drug pharmacokinetics

Question 19

State the increased effects of benzos in the elderly

Answer 19

Falls, confusion

Question 20

State the increased effects of anti-psychotics in the elderly

Answer 20

Postural hypotension, stroke, confusion, movement disorders

Question 21

Digoxin in the elderly

Answer 21

Increased toxicity, lower doses needed

Question 22

Diuretics in the elderly

Answer 22

Decreased peak effect but reduced clearance resulting in abnormal urea and electrolytes

Question 23

Anti-hypertensives in the elderly

Answer 23

May have exaggerated effects on BP and HR

More likely to be issues with postural hypotension

ACE inhibitors often pro-drugs which may not be metabolised to the active form

Renal adverse effects

Question 24

Anti-coagulants in the elderly

Answer 24

More sensitive to warfarin and greater risk from warfarin

Question 25

Antibiotics in the elderly

Answer 25

Diarrhoea and c. diff infection

Blood dyscrasias (trimethoprim, co-trimoxazole)

Delirium (quinolones)

Seizures

Renal impairment (aminoglycosides