Prescribing in the elderly

Question 1

The most important effect of age on the pharmacokinetics of drugs is what?

Answer 1

Reduce renal clearance.

Many aged patients thus excrete drugs slowly, and are highly susceptible to nephrotoxic drugs.

Question 2

Why is there a reduction in the hepatic metabolism of lipid soluble drugs in elderly patients?

Answer 2

There is a reduction in liver volume.

Question 3

How should the use of hypnotics in the elderly be managed?

Answer 3

Only hypnotics with short half-lives (Loprazolam, lormetazepam, temazepam, zolpidem, zopiclone [zaleplon very short]) should be used but they can cause problems.

Question 4

Should diuretics be used in old age?

Answer 4

Diuretics are overprescribed in old age and should not be used on a long-term basis to treat simple gravitational oedema which will usually respond to increased movement, raising the legs, and support stockings.

A few days of diuretic treatment may speed the clearing of the oedema but it should rarely need continued drug therapy.

Question 5

Can NSAIDs be used in the elderly?

Answer 5

Bleeding associated with aspirin and other NSAIds is more common in the elderly who are more likely to have a fatal or serious outcome.

Their use should be at the lowest effective dose for the least amount of time.

Question 6

The usual maintenance dose of digoxin in very old patients is what?

Answer 6

125microgram daily

Question 7

The usual maintenance dose of digoxin in elderly patients with renal disease is what?`

Answer 7

62.5 micrograms

Question 8

Drug-induced blood disorders are much more common in the elderly, therefore drugs with a tendency to cause bone marrow depression such as what should be avoided unless absolutely necessary?

Answer 8

Co-trimoxazole, mianserin hydrochloride.

Question 9

What long-acting antidiabetic drug should be avoided altogether in the elderly?

Answer 9

Glibenclamide.