Clinical Pharmacology of Old Age

Question 1

What are pharmacokinetics?

Answer 1

ADME
Absorption
Distribution
Metabolism 
Excretion

Question 2

What are pharmacodynamics?

Answer 2

Drug action on the body

Question 3

Name 3 acidic drugs

Answer 3

Phenytoin
Aspirin
Penicillins

Question 4

Name 3 basic drugs

Answer 4

Diazepam
Morphine
Pethidine

Question 5

What changes to body fat and body water do older people have? how does this influence Vd of drugs?

Answer 5

Increased fat - increases Vd of lipophilic drugs e.g. diazepam, anaethethics
Decreased water - lowers Vd of hydrophillic drugs e.g. lithium

Question 6

How is the metabolism of drugs different in elderly?

Answer 6

Reduced liver function

First pass metabolism reduced

Question 7

Does albumin bind to acidic or basic drugs?

Answer 7

Acidic drugs

Question 8

Does alpha-1 acid glycoprotein bind to acidic or basic drugs?

Answer 8

Basic drugs

Question 9

Name some drugs that have a low therapeutic index (i.e. less than 2)

Answer 9

Theophylline
Warfarin
Lithium
Digoxin
Gentamicin
Vancomycin
Phenytoin
Cyclosporin
Carbamazepine
Levothryoxine

Question 10

What class of drugs does theophylline interact with?

Answer 10

Macrolide antibiotics i.e. azithromycin, clarithromycin

Question 11

What drugs do statins interact with?

Answer 11

Macrolides

Fibrates

Question 12

What drugs do TCAs interact with?

Answer 12

Type 1 anti-arrythmics

Question 13

How do ACE inhibitors affect the mechanism of action of sulfonylureas?

Answer 13

Increase their hypoglycaemic effect

Question 14

What drug class does clopidorgrel interact with?

Answer 14

PPIs

Question 15

What types of food should patients on warfarin avoid?

Answer 15

Green leafy veg - vit K

Question 16

What food/drink should patients on statins avoid?

Answer 16

Grapefruit

Question 17

If an elderly person is started on an opioid, what should also be started prophylactically?

Answer 17

Lactulose or senna for constipation