Re: sequential PK/PD

From: Liping Zhang. [mailto:lpz@itsa.ucsf.edu] Sent: Wednesday, May 01, 2002 7:17 PM To: Krishnaswami, Sriram PH/US Cc: nmusers@globomaxnm.com Subject: Re: [NMusers] sequential PK/PD Dear Sriram, 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? to me, the way to analysis PK/PD data you asked is different with the one you described below. To make matter clear, lets call the one that retains the observed PK data (and population PK parameter estiatmes) for PD fitting Method 1, and the one that uses individual PK parameter estiamtes for PD fitting Method 2. From my experience, if you are using FO, Method 2 is better. If you are using FOCE, Method 1 is better (however it takes longer time than Method 1). Hope this helps. Best, Liping