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Flashcards in Prescribing in the elderly Deck (20)
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1
Q

What are the principles of pharmacokinetics?

A

Absorption
Distribution
Metabolism
Excretion

2
Q

What is pharmacodynamics?

A

Drugs action on the body and ARDs

3
Q

Examples of acidic drugs

A

Phenytoin
Aspirin
Penicillin

4
Q

Examples of basic drugs

A

Diazepam
Morphine
Pethidine

5
Q

Describe the physiology of old age in terms of stomach acid production

A

Less acid produced in stomach, creating a more basic environment and therefore drugs such as diazepam and morphine are more readily absorbed

6
Q

Which carrier binds to acidic drugs?

A

Albumin (basic) `

7
Q

Which carrier binds to basic drugs?

A

Alpha-1 acid glycoprotein (acidic)

8
Q

Describe old age physiology in terms of drug carrier molecules

A

Elderly people tend to have a low albumin (acidic drugs) with a higher A-1 AG (basic drugs)

9
Q

What are the implications of a higher volume of distribution of a drug?

A

Longer half life

More lipophilic

10
Q

What is half life directly and indirectly proportional to?

A

Directly proportional to the volume of distribution

Indirectly proportional to the renal and hepatic clearing system

11
Q

Do elderly people have more or less body water than younger people?

A

Less - impacts on hydrophilic drugs such as lithium and digoxin

12
Q

Describe hepatic clearance in the elderly

A

Reduced liver function due to decreased liver size, blood flow and disease
First pass metabolism reduced
Bio-transforming enzymes reduced

13
Q

Describe renal clearance in the eldery

A

Lower GFR due to decreased size, tubular secretion and renal blood flow

14
Q

What is the therapeutic index?

A

Minimum toxic concentration of a drug / minimum effective concentration

15
Q

Name some drugs with a narrow therapeutic index

A
Theophylline
Warfarin
Lithium
Digoxin
Gentamicin
Vancomycin
Phenytoin 
Cyclosporin
Carbamazepine
Levothyroxine
16
Q

What should be prescribed alongside opioids in the elderly

A

Lactulose or senna

17
Q

What advice should be given when patients are on levothyroxine and calcium?

A

DONT take at the same time as calcium interferes with the absorption of levothyroxine

18
Q

Describe the STOPP system for loperamide or coedine phosphate

A

STOP:
treatment of diarrhoea of an unknown cause
May exacerbate overflow diarrhoea
Precipitate toxic megacolon in IBD

19
Q

In what patients should metoclopramide NEVER be given?

A

In those with parkinsonism

20
Q

What is a common side effect of CCBs?

A

Chronic constipation