Intro to Geriatrics Flashcards
What is the problem with using 65 years as the marker for senior?
With increased diversity with age, protocols and guidelines are less useful in geriatric care than for younger ages
- Care must be individualized
What are some factors that affect health in older age? (5)
- Genetics
- SES
- Education
- Social engagement and support
- Lifestyle: Exercise, diet, smoking, and alcohol use
Define life expectancy
To what proportion of the max age a person may live
Define health span
Number of years that are spent free from functional limitations, morbidity, and pain
The goal of most geriatric models of care is to _______ the ______ ____
prolong the health span
Functional capacity is an indicator of ability to carry out everyday tasks. What are the 2 groups of activities?
- Activities of Daily Living (ADLs)
- Dressing, toileting, eating, bathing, walking - Instrumental Activities of Daily Living (IADLs)
- Shopping, housekeeping, food preparation, medication management, financial management
A helpful mnemonic for activities of daily living (ADLs) is BATTED - should know it
Bathing
Ambulation
Toileting
Transfers
Eating
Dressing
A helpful mnemonic for instrumental activities of daily living (IADLs) is SCUM - should know it
Shopping
Cooking/cleaning
Using telephone or transportation
Managing money and medications
What is functional reserve?
Body systems generally have capabilities beyond what is needed for everyday activities
- e.g., average adult’s cardiac output ~5L/min. Trained athlete’s cardiac output ~40-50L/min
How does functional reserve compare in older adults vs. younger adults
Older adults have decreased functional reserve compared to younger adults
- Increased risk of decline when faced with illness or injury
- E.g., older adult with dementia is more likely to experience post-operative delirium
What is functional decline?
Reduction in ability to perform ADLs and IADLs due to decreased physical and/or cognitive function
Age is a factor in functional decline and health resource utilization, but not the only factor. What else plays a role?
Higher healthcare utilization was reported among those with more chronic medical conditions, regardless of age
What changes in absorption are associated with aging? (4)
- Decreased gastric acid secretion
- Slower gastric emptying
- Delayed intestinal transit
- Decreased blood flow
Generally speaking when aging there is decreased rate of drug absorption (first-dose, prns) but no change in extent of drug absorption. What are the exceptions (that is, decreased gastric acid secretion may decrease the extent of absorption of which meds)? (3)
How might we combat this? (2)
- Iron supplements
- Ketoconazole/intraconazole
- Calcium carbonate
Suggestions to combat: - Empty stomach with iron supplements
- Use citrate form of calcium
How is percutaneous absorption affected due to aging? Give 3 medication examples
Decreased rate of percutaneous absorption of lipophyllic meds
1. Fentanyl
2. Testosterone
3. Estradiol
How does body composition change with aging? (2)
- 25-30% increase in body fat
- 25-30% decrease in muscle mass/body water
What are 2 highly lipophilic meds whose distribution is altered in older adults?
- Diazepam
- Amiodarone
What are 2 highly hydrophillic meds whose distribution is altered in older adults?
- Lithium
- Aminoglycoside antibiotics
How do albumin levels change in older adults? What are 2 examples of meds which would be affected by this?
Decreased albumin levels in frail/malnourished older adults decreases protein-binding of highly-protein-bound medications
- Phenytoin
- Warfarin
How does liver size and blood flow change with age?
Liver size and blood flow decrease significantly with age
- 20-40% decrease in liver mass
- ~35% decrease in hepatic blood flow
Drugs with high first-pass extraction will have _________ bioavailability in older adults
increased
What are some drugs with high first-pass extraction to be aware of? (5)
- Morphine
- Metoprolol, propranolol, labetalol
- Verapamil
- Amitriptyline
- Levodopa
(Start low go slow)
What changes in Phase I metabolism do we see in aging? What does that mean for the pt?
Some reduction in Phase I (CYP-450-mediated) metabolism with aging
- Longer half-lives - decreased dose requirements or increased dosing intervals
What changes in Phase II metabolism do we see in aging?
Gotcha - there are none
What are some meds that are metabolized via Phase II? (4)
- Acet
- Lorazepam, oxazepam, temazepam
- Zaleplon
- VPA
How does elimination change with age?
Decreased renal size, blood flow, GFR, and tubular secretion
- ~10% decrease in GFR per decade after age 30
Serum creatinine alone is not reliable to estimate kidney function in older adults. Why? (2)
- Muscle mass tends to decrease with age, so SCr may be falsely low
- Does not account for the effect of age on kidney function
What are some of the equations that can be used to estimate kidney function? (3)
- CKD-epi
- MDRD
- Cockroft-Gault
When does the Cockroft-Gault equation underpredict and overpredict renal function?
- Underpredicts renal function for those weighing less than their ideal body weight (IBW)
- Overpredicts renal function for those weighing more than their IBW
- If overweight/obese - use IBW to calculate CrCl
Mrs. G is an 87 year old woman being started on digoxin, which is a very water-soluble medication. How would we expect the volume of distribution of digoxin to be altered in Mrs. G based on her age?
a. Vd would increase
b. Vd would decrease
c. Vd would not be expected to change
b.
Based on the anticipated pharmacokinetic alterations of digoxin in Mrs. G, we should choose an initial digoxin dose that is:
a. Higher than usual
b. Lower than usual
c. The same as usual
b.
Lorazepam is mainly metabolized by Phase II hepatic metabolism (glucuronidation). In older adults, we would expect the metabolism of lorazepam to be:
a. Decreased (slower) than in younger adults
b. Increased (faster) than in younger adults
c. Unchanged compared to younger adults
c.
Mr. A is a 79 year old man with a serum creatinine of 100mcmol/L (normal range is 45-90mcmol/L). He is starting gabapentin, a medication that requires dosage adjustment for renal impairment. Based on this information, you:
a. Start at half the usual recommended dose of gabapentin
b. Recommend a BID dosing regimen instead of the usual TID
c. Check his weight and calculate his CrCl to determine if dosage adjustment is needed
d. Calculate his eGFR using the MDRD, and use this to determine if dosage adjustment is required
c.
Changes in medication response associated with aging is due to what?
Changes in receptor sensitivity, or altered homeostatic mechanisms
How might cardiovascular medication response change in older adults? (4)
- Decreased blood pressure-lowering response to beta-blockers
- Decreased arterial compliance and decreased baroreceptor reflex
- Predispose to orthostatic hypotension - Increased stiffness of large blood vessels –> isolated systolic hypertension
- Increased susceptibility to QT prolongation
How might CNS medication response change in older adults? (3)
- Increased permeability of BBB with age
- Increased susceptibility to CNS adverse effects of medications
- Anticholinergics
- Benzodiazepines
- Dopaminergic medications - Decreased dopaminergic neurons in substantia-nigra –> increased susceptibility to EPS side effects of dopamine-blocking meds
How does fluid and electrolyte homeostasis change in older adults? (4)
- Decreased thirst response
- Decreased GFR
- Decreased response to antidiuretic hormone
- Decreased response to aldosterone
In terms of fluid and electrolyte homeostasis, older adults are more susceptible to: (4)
- Dehydration
- Hyponatremia
- SIADH
- Hyperkalemia
How does hematopoietic reserve change in older adults? What does that do?
Decreases
- Increased risk of hematological toxicities associated with chemotherapeutic drugs
In older adults, there is a(n) _________ response to antiepileptic drugs at a lower serum concentration
increased
(also increased susceptibility to adverse effects)
What is immunosenescence? (3)
- Reduced ability to fight infections
- Reduced immune response following vaccination
- Increased susceptibility to malignancy
In older adults there is _________ regenerative capacity of gastric mucosa which leads to?
decreased
- leads to increased risk for GI bleeds
How does therapeutic window change for older adults?
It narrows, which can be a problem for some medications
