Geriatric PK/PD: Pharmacodynamics

Question 1

Distribution to biophase

Answer 1

it’s possible that this may be negatively affected because of physiological changes but there’s not a lot of good data on it

Question 2

Receptor affinity and number in the elderly

Answer 2

Decrease

Question 3

CNS effects: baseline vs. sensitivity in the elderly

Answer 3

Elderly patients have a higher baseline when it comes to drug effects compared to younger patients. They’re more sensitive to meds and have a greater chance of having ADEs

Question 4

Mechanisms in PD changes in the elderly

Answer 4

Altered neurotransmitters and/or receptors

Hormonal changes, particularly in the sex and growth hormones

Impaired glucose metabolism or decreased availability of glucose and oxygen as cerebrovascular function declines

Functional P-gp activity decreased in the BBB

Question 5

BZDs in the elderly

Answer 5

increased CNS depression, decreased plasma concentration needed for desired effects

Question 6

EPS reactions from APS in the elderly

Answer 6

Parkinsonian reaction dominate d/t already compromised nigrostriatal pathway; tardive dyskinesia

Question 7

Muscarinic deficits

Answer 7

Anticholinergic meds affect cognitive decline

Question 8

Beta-adrenergic responsiveness and cardiovagal tone

Answer 8

Diminished response to agonists and antagonists at beta-1 and beta-2, vagolytic effects of atropine diminished

Question 9

Examples of diminished response to agonists and antagonists at beta-1 and beta-2

Answer 9

Isoproterenol AND propranolol
Hydralazine-induced reflex cardiostimulation blunted
Beta-adrenergic response to hypoglycemia blunted
Orthostatic hypotension (with or without drugs)

Question 10

Anticoagulation meds in the elderly

Answer 10

decreased doses of warfarin needed for response → decreased warfarin clearance, increased intrinsic sensitivity