Geriatrics - PK / PD

Question 1

Absorption - Stomach Emptying

Answer 1

delayed –> retention of indigestible solids –> decreased rate of absorption

Question 2

Absorption - Stomach Acid

Answer 2

decreased acidity –> acid-labile drugs won’t get broken down

Question 3

Absorption - Intestine

Answer 3

decreased motility
decreased blood flow
not clinically significant

Question 4

Absorption - Transdermal

Answer 4

decreased for hydrophilic drugs
the same for lipophilic drugs

Question 5

Volume of Distribution

Answer 5

increased for lipophilic drugs
decreased for hydrophilic drugs

Question 6

Absorption - Bioavailability

Answer 6

reduced first-pass effect

Question 7

Distribution - Albumin Concentrations

Answer 7

no significant change in healthy

decreased in illness (binds to acidic drugs)

Question 8

Distribution - Alpha-1-Acid Glycoprotein

Answer 8

may be elevated - high affinity for basic drugs

Question 9

CYP3A4 Activity

Answer 9

reduced in hepatocytes

Question 10

Excretion - Renal

Answer 10

decreased clearance
increased half-life

Question 11

P-gp - Changes

Answer 11

decreased concentration at BBB -> increased CNS drug concentrations, increased residence time in CNS