Clinical pharmacology of old age

Question 1

What is pharmacokinetics?

Answer 1

How the body interacts with administered substances for the entire duration of exposure

Question 2

Proportionally more of basic drugs are absorbed in older patients than in younger patients. True/false?

Answer 2

True

Question 3

As people age, there is increased gastric pH (decreased acid) and small bowel surface area decreases. When would this usually be a problem?

Answer 3

Previous GI surgery

NJ tube or PEG feed composition

Transdermal patches and oedema

Question 4

Older patients have decreased fat (proportional to muscle mass). true/false?

Answer 4

False

Increased fat, this increases the vd pf lipophyllic drugs e.g. diazepam which results in longer half lives.

Question 5

What is Vd (volume of distribution)?

Answer 5

Theoretical volume into which all of drug is fully dissolved in plasma

It is an indicator of the lipophilicity of a drug (very lipophilic = high Vd)

Question 6

Meaning of half-life?

Answer 6

Time for drug concentration to fall to half of it’s maximum concentration

Question 7

Roughly what % of body water decreased with age?

Answer 7

10-15%

Question 8

Why does liver function decrease with age?

Answer 8

Occurs due to decreased liver size, blood flow and disease

Question 9

Why does GFR decrease with age?

Answer 9

This occurs due to decreased size, tubular secretion and renal blood flow

Question 10

What are the 4 main drugs associated with adverse reactions in the elderly?

Answer 10

Warfarin

Digoxin

Insulin

Benzodiazepines

Question 11

What side-effect is frequently caused by opiates in elderly and how is this prevented?

Answer 11

Opiates frequently causes constipation - begin laxatives prophylactically

Question 12

If steroids are used what needs to be given if used long term and what other condition can it lead to?

Answer 12

Osteoporosis prevention if used long term

Can lead to steroid induced diabetes

Question 13

What can interfere with the absorption of levothyroxine?

Answer 13

Calcium

Question 14

What can opioids and be benzodiazepines lead to?

Answer 14

Impaired psychomotor function which would result in falls and confusion.

Question 15

Risk factors for adverse drug reaction in older patient?

Answer 15

Recent hospital discharge

Use of multiple drugs

Multiple prescribers

A change in the patients condition

Impaired cognitive status and /or communication problems

Question 16

What are some options for reducing polypharmacy?

Answer 16

Review medications and indications regularly, discontinue unnecessary medications

If stable, consider use of combination preparations

Attempt to prescribe a drug that would treat more than 1 existing problem (e.g. calcium channel blocker/beta blocker for increased BP and angina)

Avoid treating adverse reactions/side-effects of drug with more drugs (e.g. amlodipine leading to oedema).

Question 17

Is adherence to medication a major problem in the elderly and what specific issues can arise?

Answer 17

Can they open pill container?

Do they understand when and how to take it?

Are they remembering to take medications?