From:"Kakkar, Tarundeep" 
Subject:[NMusers] Pop PK/PD integrated plus differential equations
Date:Tue, 11 Jun 2002 16:11:29 -0400


Is there a way in NONMEM where I can instruct it to fit an integrated
equation (e.g, for a 2 comptt. model) for the PK data and a differential
equation to fit the PD data simultaneously.  I'm using ADVAN6 at this moment
and the run time is long (I even fixed population PK estimates), therefore,
I have been using POSTHOC estimates for PK at this moment. 




From:"Sam Liao" 
Subject:RE: [NMusers] Pop PK/PD integrated plus differential equations
Date: Fri, 14 Jun 2002 09:34:15 -0400


I have used hybrid equations under $DES block to save run time in PK/PD
modeling.  Just make sure to define the integrated equation in the $DES
block, not in the $PK block.

I used the two-stage approach as you did in PK/PD modeling. But, I have not
done simultaneous fit of PK and PD data using the hybrid equations.  I would
be interested to hear any discussion of the advantage of this approach over
the two-stage approach.  The run time is long even with the two-stage

Best regards,

Sam Liao, Ph.D.
PharMax Research
270 Kerry Lane,
Blue Bell, PA 19422
phone: 215-6541151
efax: 1-720-2946783