Chapter 15 - Continuous IV Infusion Flashcards
(17 cards)
continuous IV infusion is ____ order drug input
zero order
the plasma profile for a continuous IV infusion depends on what 4 things
-size of dose
-Vd
in the formula, these 2 things are accounted for in the Co
-K
-Dosing interval
in the formula, these 2 things are accounted for as part of the accumulation factor
normally, do we measure the aminophylline or theophylline in the plasma?
theophylline. theophylline is the drug that actually has effect
the drug reaches steady state when it is infused for a sufficient length of time so that….
the rate of infusion = the rate of elimination
(drug input = drug output)
if a loading IV bolus dose is given before the IV infusion is started, at what rate should the IV infusion be given?
a rate in which drug input would = drug output (steady state)
true or false
the infusion rate does NOT determine how fast steady state is reached
TRUE
it depends on the half life
after ____ half lives, the amount of drug that has reached steady state is 90%
4
true or false
the half life affects the time to reach steady state
TRUE
the longer the half life, the longer it takes to reach steady state
true or false
at steady state, the rate goes in = rate goes out
true
continuous IV infusion is ___ order input and ____ order outpu
zero order input and first order output
_____x____ = rate of elimination (drug output)
Css x clearance
what does Ko stand for
infusion rate
an IV bolus and a continuous IV infusion are given at the same time
after 6 hours, which will have the higher concentration in the plasma? why?
the continuous IV infusion will have a higher concentration bc for IV bolus, all of the dose is given at once and thus all of the dose is immediately available for elimination - and according to 1st order kinetics, since a lot is available for elimination, a lot will be eliminated!
after 1 half life, what % of steady state is achieved
50%
true or false
after 2 half lives, we have achieved 25% steady state
FALSE - we have achieved 75% steady state
true or false
as the value of K increases, the % steady state achieved increases as well
true
