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RE: How to calculate t1/2, z?

From: Serge Guzy <GUZY>
Date: Mon, 22 Feb 2010 12:19:42 -0800

Dear Li

I do not know if it will help you but here is a set of equations that
may be useful for you.


The initial parameterization I am using for the 3 compartment model with
first order absorption are different than yours but are sometimes
necessary to insure identifiability:



            CL,V2,V3,V4,Q3,DK42 and DKA


Then the series of equations 9already coded in Fortran) allow you to
estimate alpha, beta and gamma. I guess that the half-life you are
talking about would be Ln(2)/Gamma





c to be consistent with the regular 3 compt model, we define





c to be consistent with the regular 3 compt model, we define







c to be consistent with the regular 3 compt model, we define




























c TX=DACOS( (-BX/2D0)/DSQRT(-AX*AX*AX/27D0) )










C Terminal half-life




Best Regards;

Serge Guzy;Ph.d

President, CEO; POP_PHARM





From: owner-nmusers
On Behalf Of Li Y. Chen
Sent: Monday, February 22, 2010 8:17 AM
To: nmusers
Subject: [NMusers] How to calculate t1/2, z?


I have a three-compartment model. Dose anyone know how to calculate the
terminal half life (t1/2, Z) using the finial estimates (V2, V3, V4,
CL2, CL3, and CL4)?

t1/2, z= ln2*Varea/CL, should Varea =V2+V3+V4? How about CL?

Thank you!


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Received on Mon Feb 22 2010 - 15:19:42 EST

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