Geriatric drug therapy

Question 1

Absorption changes in geriatric pts

Answer 1

Decreased gastric acidity and motility

Question 2

Distribution changes in geriatric pts

Answer 2

1. Decrease in TBW - higher concentration
2. Decrease in lean body mass
3. Decrease in albumin - more free drug
4. Increase in adipose tissue - will delay clearance of lipid soluble drugs

Question 3

Metabolism changes in geriatric pts

Answer 3

1. Decrease in first pass metabolism
2. changes in phase 1 metabolism/small changes in phase 2
   - -increase bioavailability of the drug. Must be extremely careful with drugs primarily cleared by the liver

Question 4

Elimination changes in geriatric pts

Answer 4

1. Decrease in renal blood flow and GFR
2. Decline in creatinine clearance
   - –Causes an increase in the half life of the drug and elimination of drug

Question 5

Changes affecting pharmacodynamics

Answer 5

1. Less sensitive to beta-receptors
2. Less sensitive to barorecptors
3. Less sensitive to insulin receptors
4. More sensitive to centrally acting drugs like narcotics, benzodiazepines, antidepressents

Question 6

Ways to avoid adverse drug reactions in elderly

Answer 6

1. start low, go slow
2. Avoid drugs that are primarily cleared by the liver if the pt has poor liver function
3. avoid drugs that have a high renal clearance.
4. Use cockgroft-gault formula for dosing (will give you correct creatinine clearance)

Question 7

Why are sedative-hypnotic drugs bad for the elderly

Answer 7

Because the half lives of many benzodiazepines increase 50-150% between ages 30-70

Question 8

Why is it hard to clear benzodiazepines

Answer 8

Because of decline in renal function and possible liver disease

Question 9

Examples of drugs that should be avoided in elderly

Answer 9

1. Benzodiazepines
2. Opiods
3. Antipsychotics - if used inappropriately. Some have an antimuscarinic effect and may worsen memory
4. Antihypertensives
5. Digoxin
6. NSAIDS - or at least at very low dose, can cause GI bleeding

Question 10

What types of drugs are used in alzheimers pts

Answer 10

Cholinesterase inhibitors

Question 11

Reasons for non-adherence

Answer 11

1. Forgetfulness
2. Deliberate
3. Cost of the drug
4. Tremors/disabilities - ie liquid medications

Question 12

Ways to prescribe to elderly

Answer 12

1. Careful drug history
2. Prescribe only for specific reasons
3. Get rid of unnecessary or duplicate drugs
4. Define the goal of the drug therapy

Question 13

What affects do opioids have on the elderly

Answer 13

Can decrease their respiratory function

Question 14

What affect do benzodiazepines have on the elderly

Answer 14

Can cause extremely high levels of toxicity of the drug (death)

Question 15

What affect do antipsychotics have on the elderly

Answer 15

Can worsen memory

Question 16

What affect does digoxin have on the elderly

Answer 16

Can cause arrhythmias and decrease drug clearance

Question 17

What affect do antimicrobials have on the elderly

Answer 17

The b-lactam group do not get excreted very well by the kidneys

Question 18

What is the Beers List

Answer 18

A list of medications that should be avoided in elderly patients.. Assists clinicians in making informed decisions

Question 19

How does the Beers criteria categorize meds

Answer 19

By their adverse drug reactions/events in older adults due to pharmacologic properties and physiologic changes in aging