Geriatric Pharmacokinetics

Question 1

What physiologic changes occur in absorption in elderly patients?

Answer 1

• decreased gastric acid secretion
• delayed gastric emptying
• reduced splanchnic blood flow
• decreased GI motility

Question 2

What drug characteristics decrease the bioavaliability (F) in elderly patients?

Answer 2

• medication that require acidic pH
• high ER drugs

Question 3

How is transdermal absorption affected in elderly patients?

Answer 3

increased absorption, due to reduction in the barrier function of the skin and reduced tissue perfusion

Question 4

How is subcutaneous absorption affected in elderly patients?

Answer 4

decreased absorption, due to decrease in skin blood supply and lymphatic drainage

Question 5

How is intramuscular absorption affected in elderly patients?

Answer 5

decreased absorption, due to decreased muscle mass

Question 6

How is pulmonary absorption affected in elderly patients?

Answer 6

decreased absorption, due to decreased alveolar surface area and ventilation/perfusion ratio

Question 7

How is ocular absorption affected in elderly patients?

Answer 7

decreased absorption, due to decreased corneal permeability

Question 8

How does body composition change in elderly patients?

Answer 8

• decreased lean body mass
• increase in total body fat mass
• decrease in total body water

Question 9

How is protein binding altered in elderly adults?

Answer 9

• albumin may be slightly decreased or remain normal
• alpha-1 acid glycopreotein increased

Question 10

How is hepatic metabolism altered in elderly patients?

Answer 10

• decreased hepatic blood flow and liver mass
• decreased metabolism of high ER drugs
• increased bioavaliability for high ER drugs, increased concentrations and AUC
• decreased doses recommended

Question 11

What renal excretion alterations are seen with elderly patients?

Answer 11

• renal function declines with age
• structural and functional changes (decreased renal mass, decreased renal blood flow, decreased GFR and tubular secretion)

Question 12

What are the cardiovascular effects of elderly patients?

Answer 12

• stiffening of ventricles and arterial walls
• decreased autonomic function

Question 13

What cardiovascular drugs may require a lower initial dose in elderly patients?

Answer 13

-calcium channel blockers (CCB)
-warfarin

Question 14

What cardiovascular drug may require increased dosing in the elderly population?

Answer 14

beta blockers

Question 15

How may response of CNS medication differ in the elderly population?

Answer 15

more exaggerated response, due to increased penetration into the CNS and P-glycoprotein decreased= decreased efflux out of the CNS

Question 16

What are the endocrine effects of elderly patients?

Answer 16

• decrease in sex hormone production
• inverse relationship with insulin sensitivity and age= increased insulin resistance
• excessive HPA activation and hypersecretion of glucocorticoids

Question 17

What is the recommended dosing of loop diuretics in the elderly and why?

Answer 17

increased dosing may be needed in the elderly due to decreased peak effect (decreased diuretic and natriuretic response)