sequential PK/PD

From: Sriram.Krishnaswami@aventis.com Subject: [NMusers] sequential PK/PD Date: Wed, 1 May 2002 16:10:44 -0500 Dear all, can someone shed light on whether or not retaining the Observed Concentrations (PK) in the data file during sequential fitting of PK/PD data as given below would affect the results in anyway? For example, Step 1: Fit PK alone $PK CL=Theta(1)*exp(eta(1)) V=Theta(2)*exp(eta(2)) Step 2: Take the individual predicted PK parameters from the table output of step 1 and feed them into the data file for PD fitting $PK CL=CLI where CLI is the individual predicted CL V=VI where V is the individual predicted V.. $ERROR Conc=F*(1+err(1)) Eff=Emax*F/(EC50+F)+err(2) Y=Indicator * Conc + (1-indicator) * Eff thanks Sriram ------------------------------------------------ Sriram Krishnaswami, Ph.D. Global Biopharmaceutics Aventis Pharma, NJ