Geriatric Pharmacology

Question 1

Challenges of geriatric pharmacology?

Answer 1

State health varies, problem drug-drug interaction, polypharmacy, compliance

Question 2

How is absorption changed in geriatric?

Answer 2

Little evidence major alteration - may be delayed - time to peak concentration may be longer

Question 3

How is distribution changed?

Answer 3

1. Reduced lean body mass - decrease distribution for muscle binding drugs
2. Decrease body water - decrease VoD for hydrophilic drug
3. Decrease plasma protein - increase unbound drug
4. Increase fat - increase VoD lyophilic drugs

Question 4

How is metabolism changed?

Answer 4

Most changes in phase I reaction (CP450)

- Decreased blood flow and liver mass (hepatic clearance changed)

Question 5

Are phase I or phase II drug preferred in the elderly?

Answer 5

Phase II - no accumulation of inactive metabolite/ toxic compound

Question 6

How is elimination affected?

Answer 6

Decrease kidney function - prolong half life (problem accumulation to toxic levels)

Question 7

Main reasons adverse drug reaction in elderly?

Answer 7

Polypharmacy, decreased body weight, impaired organ function and multiple disease state

Question 8

Name two drug combinations should avoid in the elderly?

Answer 8

Benzodiazepine and antidepressant = sedation and confusion

ACE inhibition’s and potassium = hyperkalaemia

Question 9

Prescribing in the elderly?

Answer 9

Start low dose - reach therapeutic dose before adding
Avoid starting two agent same time
Don’t prescribe to tx side effect other drug
Use simplest regime
Adjust dose if renal/hepatically imparted

Question 10

Why might non-adherence be problem in the elderly?

Answer 10

Struggle to open container - weak, arthritic
Cognitive impairment - struggle to recall
Depression - poor concept of time