From: (RETOUT Sylvie)
Subject: population pharmacokinetic designs
Date: Thu, 1 Feb 2001 17:47:53 +0100 (WET)

Dear NMusers,

As we informed you in a previous mail, we recently proposed simple programming tools to evaluate population pharmacokinetic designs. These tools are based on the development of an expression for the Fisher information matrix for non linear mixed-effects models with a first order approximation of the model. We implemented this expression as a generic function for two software applications: S-PLUS and MATLAB. These resulting functions, PFIM_S in S-PLUS and PFIM_M in MATLAB, can be used to select and compare population designs among a large set of possible designs, avoiding a lot of simulations.

The first version (PFIM 1.0) we developed was proposed principally for an additive nmodel for the between-subjects variability. An approximation was used for an exponential model (the most often used asumption in population PK/PD).

A new version is now proposed (PFIM 1.1) which is much more appropriate for this exponential model of the between-subject variability. This new version is available on the website

This new version supersedes the pervious version - which should no longer be used.

Sylvie Retout and Stephen Duffull,
CHU Pitie Salpetriere
91, Bd de l'Hopital
75634 PARIS Cedex 13
Ph : 33 1 40 77 98 57
Fax : 33 1 45 85 15 29
Stephen Duffull
School of Pharmacy
University of Queensland
Brisbane, QLD 4072
Ph +61 7 3365 8808
Fax +61 7 3365 1688