Geriatrics Introduction

Question 1

What is the definition of “senior” or “older adult”?

Answer 1

conventionally age 65 in Canada
-age when many Canadians begin to receive social services
-former age of mandatory retirement
some debate among researchers
-with increased longevity, 65y is relatively young

Question 2

What is a good age to start re-evaluating for meds that can cause problems?

Answer 2

65

Question 3

True or false: old = sick

Answer 3

false
aging is a very heterogenous process

Question 4

Why are protocols and guidelines less useful in geriatric care compared to younger patients?

Answer 4

because of the increasing diversity with age
-care must be individualized

Question 5

What are some factors affecting health in older age?

Answer 5

genetics
socioeconomic status
education
social engagement and support
lifestyle: exercise/diet/smoking/alcohol

Question 6

What is the definition of life expectancy?

Answer 6

To what proportion of the maximum age a person may live
-changes throughout life
-important when considering potential benefits of meds

Question 7

What is the definition of health span?

Answer 7

Number of years that are spent free from functional limitations, pain, and morbidity
-goal of most geriatric models —> prolong the health span

Question 8

What is functional capacity an indicator of?

Answer 8

Ability to carry out everyday tasks

Question 9

Differentiate ADLs and IADLs.

Answer 9

ADLs: things you need to do to get up and going for the day
-toileting, walking, dressing, eating, bathing
-changes in ADLs need higher levels of care
IADLs: supportive tasks to maintain independence
-shopping, food preparation, medication management, financial management, house keeping
-functional impairments often show up in the IADLs before ADLs

Question 10

What is functional reserve?

Answer 10

body systems generally have capabilities beyond what is needed for everyday activities

Question 11

How does the functional reserve of an older adult compare to younger adults?

Answer 11

older adults have decreased functional reserve
-demands will exceed reserves
-increased risk of decline when faced with illness or injury

Question 12

What is the definition of functional decline?

Answer 12

reduction in ability to perform ADLs and IADLs due to decreased physical and/or cognitive function

Question 13

Is age the only factor in functional decline and health resource utilization?

Answer 13

age is a factor but not the only one
-older seniors (75+) did not always report higher healthcare use than younger seniors
-higher healthcare utilization was reported among those with more chronic medical conditions regardless of age

Question 14

Which population has seen the most PK studies done?

Answer 14

healthy adults < 80 yrs
-limited data in oldest-old, frail

Question 15

What are some GI system changes seen with age?

Answer 15

decreased gastric acid secretion
slower gastric emptying
delayed intestinal transit
decreased blood flow

Question 16

Generally speaking, what is the impact of age on absorption of drugs?

Answer 16

decrease rate of absorption (first-dose, prn’s)
no change in extent of absorption

Question 17

What is the caveat to the “no change in extent of absorption” with age?

Answer 17

decreased gastric acid secretion may decrease the extent of absorption of some meds
-iron supps
-ketoconazole/itraconazole
-calcium carbonate

Question 18

What are some strategies to combat decreased acid secretion in the old for meds that require acidity?

Answer 18

iron supps on empty stomach
use citrate form of calcium

Question 19

What is the impact of aged skin on percutaneous absorption?

Answer 19

aged skin tends to be drier and lower lipid content
decreased rate of percutaneous absorption of lipophilic meds, overall extent stays the same
-fentanyl, estradiol, testosterone

Question 20

What are the typical changes in body composition with aging?

Answer 20

25-30% increase in body fat
25-30% decrease in muscle mass/body water

Question 21

What are some medications with altered distribution in older adults?

Answer 21

highly lipophilic (accumulation = longer t1/2)
-diazepam
-amiodarone
highly hydrophilic (increased effect)
-lithium
-aminoglycosides

Question 22

What is the impact of decreased albumin levels in older adults?

Answer 22

decreased albumin levels in frail/malnourished older adults results in decreased protein binding of highly protein bound drugs
-warfarin
-phenytoin
over time, increased metabolism/elimination compensate for this increased free fraction
start low, go slow

Question 23

What is the typical change seen with the liver in older adults?

Answer 23

liver size and blood flow decrease significantly with age
-20-40% decrease in liver mass
-35% decrease in hepatic blood flow
mainly concerned about 1st pass effect

Question 24

What kind of drugs will have increased bioavailability in older adults?

Answer 24

drugs with high 1st pass effect
-morphine
-metoprolol, propranolol, labetalol
-verapamil
-amitriptyline
-levodopa

Question 25

Which phase of metabolism sees changes with aging?

Answer 25

reduction in phase I metabolism (CYP 450-mediated) with aging
no change in phase II metabolism (conjugation) with aging

Question 26

What is the consequence of the reduction in phase I metabolism with aging?

Answer 26

longer half-lives - decreased dose requirements or increase dosing interval

Question 27

What are the impacts of age on elimination?

Answer 27

decreased renal size, blood flow, GFR, and tubular secretion
-10% decline in GFR per decade after age 30

Question 28

Is serum creatinine reliable on its own to estimate renal function?

Answer 28

no
-muscle mass tends to decline with age, so SCr may be falsely low
-does not account for the effect of age on kidney function

Question 29

What are the available equations to estimate kidney function?

Answer 29

CKD-epi
MDRD
Cockfroft-Gault

Question 30

What is the use of CKD-EPI?

Answer 30

what the SHA labs use to generate eGFR
some drugs have dosage adjustments recommended based on eGFR

Question 30

What is the use of MDRD?

Answer 30

used more so for the staging of kidney disease

Question 31

Describe some important points about the Cockroft-Gault equation.

Answer 31

incorporates SCr, age, gender, and weight to estimate CrCl
the equation drug-dosing recommendations are generally based on
underpredicts renal function for those weighing less than IBW
overpredicts renal function for those weighing more than IBW

Question 32

What is the result of pharmacodynamic changes with age?

Answer 32

changes in medication response
-due to changes in receptor sensitivity or altered homeostatic mechanisms

Question 33

What are the pharmacodynamic changes seen with the CV system with aging?

Answer 33

decreased BP-lowering response to BB
decreased arterial compliance and decreased baroreceptor reflex
increased stiffness of large blood vessels –> ISH
increased susceptibility to QT prolongation

Question 34

What are the pharmacodynamic changes seen with the CNS with aging?

Answer 34

increased permeability of BBB
increased susceptibility to CNS AEs (benzos, antichols, dopaminergic meds)
decreased dopaminergic neurons in substantia nigra - increased susceptibility to EPS of DA blocking meds

Question 35

What are the pharmacodynamic changes seen with fluid and electrolytes with aging?

Answer 35

decreased thirst response
decreased GFR
decreased response to ADH
decreased response to aldosterone
more susceptible to:
-hyperkalemia
-hyponatremia
-dehydration
-SIADH

Question 36

What is the pharmacodynamic change seen with hematopoietic reserve with aging?

Answer 36

decreased hematopoietic reserve
-increased risk of hematological toxicity associated with chemotherapeutic drugs

Question 37

What is the pharmacodynamic change seen with antiepileptic drugs with aging?

Answer 37

increased response at lower serum concentrations
-also increased susceptibility to AE’s

Question 38

What is the pharmacodynamic change seen with immunosenescence with aging?

Answer 38

reduced ability to fight infections
reduced immune response following vaccinations
increased susceptibility to malignancy

Question 39

What is the pharmacodynamic change seen with the gastric mucosa with aging?

Answer 39

decreased regenerative capacity of gastric mucosa
-increased risk of GI bleeds

Question 40

What occurs to the therapeutic window with aging?

Answer 40

it narrows
-drugs are less forgiving