Introduction to Geriatric PT Flashcards
What are the three primary goals of health care in the elderly?
- Improve physical function and prevent disability
- Maintain independence (Avoid institutionalization)
- Prevent drug-related adverse consequences
As we age, the number of receptors ____________. The sensitivity of the receptors _________.
a. decreases
b. increases
Why does the BBB have increased permeability as we age?
Decrease in p-gp efflux transporter activity
What happens to the liver as we age?
Mass decreases
Blood flow decreases
Phase I metabolism activity decreases (1st pass effect)
PHASE II METABOLISM= NO CHANGE
What happens to the kidneys as we age?
Loss of function due to:
decreased mass and blood flow
decreased filtration and secretion
decreased GFR
What is the net effect of aging that can alter the body’s clinical response to medications?
Age-related changes PK and PD changes Concurrent medication use increases Comorbidities Frailty due to limited reserve capacity
As we age __________ transport activity decreases. What is the effect on PK?
ACTIVE; results in decreased bioavailability of nutrients, vitamins and ions
As we age hepatic first pass extraction ________________, which will increase what PK parameter?
How does this affect dosing?
Decreases; bioavailability for non-prodrugs.
Use lower doses in the elderly
As we age, we have lower lean body mass and total body water. How does this affect medication therapy?
Decreased volume of distribution which will increase plasma concentrations of hydrophilic drugs
As we age, we have a _________ in body fat. How does this affect medication therapy?
INCREASE
- Increased volume of distribution and half-life for lipophilic drugs
How does aging affect albumin levels? How does this affect medication therapy?
No change or decrease in serum albumin
- Increased amount of free, active drug resulting in more activity
Due to the decrease in Phase _____ metabolism, how are clearance and half-life affected?
Phase I metabolims
- Clearance = decreased
- Half-life = increased
Explain why as we age, we have decreased hepatic first pass extraction and how this affects drug metabolism.
a. Due to decreased number of receptors
b. This decreases clearance of the drugs while INCREASING bioavailability
Lorazepam is a safer option to use in the elderly for anxiety. Why?
It undergoes Phase II reactions readily (due to existing polarity) which are unchanged as we age so accumulation and toxicity risks are decreased compared to drugs who must undergo Phase I reactions for excretion
Why is SCr not a good measure of kidney function in the elderly?
Their SCr may look normal but in fact may not be due to:
- Lower lean body mass = decreased creatinine production
- Have a decreased GFR
What do we use to estimate GFR?
CrCl
Rounding an elderly patients CrCl to 1 may __________________ their renal function.
UNDERESTIMATE
If Cl is decreased and half-life is increased due to decreased GFR as we age, what are we more likely to notice with medication therapy?
Increase in side effects and active metabolites of drugs
Why do we want to avoid benzodiazepine use in elderly? What other medication class can we use for anxiety?
Increased sensitivity to CNS effects
a. sedation and psychomotor impairment
Use SSRIs/SNRIs instead
Why do we want to avoid Opioid analgesic use in the elderly?
Have higher level and duration of pain relief which means using lower doses
Why are we concerned about B-blocker use in the elderly?
Decreased HR and BP response resulting in a HIGHER DOSE NEEDED
Why are we concerned about B-agonist use in the elderly?
Decreased bronchodilation response resulting in a HIGHER DOSE NEEDED
Why are we concerned about digoxin use in the elderly?
Increased sensitivity of the heart; USE LOWER DOSE
Why are we concerned about anticoagulant therapy in the elderly?
Increased bleeding risk to due increased response
USE A LOWER DOSE
