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The following message was posted to: PharmPK
I am dealing with old data from a protocol that I did
not design the PK section. For a drug that is given
by IV bolus followed by IV infusion, there were only 3
time points collected: a presample, 4 hours into the
IV infusion and prior to the end of the IV infusion.
From a simplistic view, clearance could be calculated
as:
Cl = infusion rate/Css
However, the IV bolus helped to get this drug to
steady state concentrations. Given this fact, can
anything be done with this data minus calculating Css?
The other potential equations that I ran across would
not calculated clearance which was written into the
protocol as the study (secondary) endpoint.
Thanks!
Jen
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The following message was posted to: PharmPK
Michelle,
If you are confident that you have a reliable Css, then the loading
dose is irrelevant, and you can use the equation you cited. But, the
real issue is whether or not you have a reliable Css, given the few
data points. Good luck, Harold.
Harold Boxenbaum, Ph.D.
Pharmacokinetic Consultant
Arishel Inc.
14621 Settlers Landing Way
North Potomac, MD 20878-4305
Email: harold.-a-.arishel.com
Website: www.arishel.com
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