Flashcards in Geriatrics Deck (116)
In the absence of specific information, it is generally prudent to do what when administering drugs to aged patients?
“Start low and go slow”
Aging has been described as a progress I’ve loss of...
Physiologic processes necessary to maintain homeostasis
Death being the ultimate failure of these mechanisms
In the elderly passive gastric absorption is
Not markedly altered
Drugs that inhibit intestinal motility have greater effect than
Due to erratic absorption and a tendency to develop sterile infiltrates, IM and SQ injections are generally recommended or not in the elder patients?
Total Body water is decreased by what % in elderly?
Due to decreased thirst, elder patient may be
A decrease in TBW, in combination w/changes in the distribution of CO, results in a
Decreased central compartment volume
Initial plasma concentrations following rapid IV admin may be increased b/c of the decreased size of the central compartment, yet the steady state distribution vol is?.... and why?
May be larger d/t increased body fat
Body fat increases and muscle mass decreases in the elderly by what%?
How does this impact lipophillic drugs?
So lipophillic drugs will have a large vol of distribution
Even in healthy and exercising elderly, what is lost?
Failure to adjust for weight raises concern for this?
Are plasma protein levels a major concern in geriatric pharmacology?
No - not been identified
Hepatic blood flow declines how much?
Liver mass reduces?
20-53% while liver mass is reduced 11-36%
Tell me about hepatic function of the elderly in regards to:
Hepatic extracellular space
Endoplasmic reticulum is diminished
Hepatic extracellular space increased
Bile flow decreased
What phase of liver metabolism is effected in the elderly? Why?
Phase I - which is catalyzed mainly by microsomal CYP450 enzymes may be decreased.
Enzyme activity is relatively preserved.
Are phase II reactions affected in old age?
Appears to be unaltered
Generally, age reduces clearance of flow-limited drugs by what ___%? Similar to the decrease in hepatic BF, but there’s is no alteration for _______ drugs.
How much does GFR decrease per yr?
What’s the overall consensus generally about renal function and aging?
In the absence of disease
Although there is a small decrease in GFR, it probably decreases less than once thought.
Aging doesn’t appear to diminish renal drug excretion significantly
In the elderly what happens to CO?
With coexisting disease, what happens to circulation time?
CO is maintained.
With coexisting dx - circulation times appear to increase
Due to increased circulation times and the delay of initial drug effects, what is a prudent action to reduce overdose and adverse CV impact?
Slower bonus injections
Opioid elimination occurs mainly by
Hepatic metabolism with renal excretion of metabolites and some parent drugs
What factors influence opioid metabolism?
Name three opioids with active metabolites:
Codeine, Morphine, Meperidine
The metabolites of some opioids that are active account many side effects as well as
The primary risks of opioids with the elderly
The incidence is increased with age
Respiratory depression was more problematic with _____ vs meperidine.
What is seen in pts receiving fentanyl?
And no resp depression in pts receiving fentanyl
Fentanyl is a highly selective:
Mu receptor agonist