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[NMusers] Why should we avoid using micro rate constants?

From: Singla, Sumeet K <>
Date: Sun, 3 Feb 2019 20:44:20 +0000

Hello everyone!

I have a question. I was trying to build a 2-compartment PK model for marij=
uana use in occasional and chronic smokers. Initially, I was using providin=
g rate constants K12 and K21 in PK block and it resulted in poor fitting. T=
hen, I later changed to CL,V1, V2 , Q and it resulted in proper fitting. I =
was perplexed as to why I couldn't get a proper fit by providing rate const=
ants? I tried to look online but couldn't find any proper explanation about=
 when (or not) we should use micro constants in PK block to define our mode=
l in NONMEM? Does anyone has any useful insights into this?

Sumeet Singla
Graduate Student
Dpt. of Pharmaceutics & Translational Therapeutics
College of Pharmacy- University of Iowa

Received on Sun Feb 03 2019 - 15:44:20 EST

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