NONMEM Users Network Archive

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Re: Time varying volume of distribution implementation

From: Graaf, P.H. van der <p.vandergraaf>
Date: Sat, 23 Apr 2016 07:54:42 +0000

Natal van Riel presented on this topic in the context of large systems mode=
ls at a recent QSP meeting in Basel, see for example

Piet H. van der Graaf, PharmD PhD
Professor of Systems Pharmacology
Leiden Academic Centre for Drug Research (LACDR)
2333 CC Leiden
The Netherlands
From: M Jamei
Sent: Saturday, 23 April 2016 08:30
To: Thorsten Lehr
Cc: nmusers
Subject: Re: [NMusers] Time varying volume of distribution implementation

Hi Thorsten

We have done this in both paediatrics and pregnancy and you may find the fo=
llowing paper useful.
Changes in individual drug-independent system parameters during virtual pae=
diatric pharmacokinetic trials: introducing time-varying physiology into a =
paediatric PBPK model.
Abduljalil K, et al. AAPS J. 2014.


On 22 Apr 2016, at 22:34, Thorsten Lehr <thorsten.lehr

Dear NMusers,

I'm modeling a compound where body weight has a known impact on the volume =
of distribution. This compound is investigated in pregnant women over a lon=
g period (from gestational age of 8 weeks until they give birth). Consequen=
tly, the body weight changes over time and I have a decent formula to descr=
ibe the individual body weight change. The PK model has to be coded by ODEs=
. Does anyone has experience how to integrate a time varying volume of dist=
ribution if differential equations are used?

Best regards



Thorsten Lehr, PhD
Junior Professor of Clinical Pharmacy
Saarland University
Campus C2 2
66123 Saarbrücken

Office: +49/681/302-70255
Mobile: +49/151/22739489

Received on Sat Apr 23 2016 - 03:54:42 EDT

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