RE: Capturing AUC between observation time intervals

From: "Sam Liao" Subject: RE: [NMusers] Capturing AUC between observation time intervals Date: Wed, 3 Apr 2002 19:05:41 -0500 Chuanpu: My mehtod will work if you fit PK and PD data sequentially. I think I understand what you are trying to do now. But you may need a supper computer to run this model even if you find the way to calculate the AUC in your PK/PD model fitting. The AUC has to be recalculated for every iteration for the whole treatment period. It may take a long time to run this model fitting. For example, some time ago, I tried to calculate AUC based on the PK fit parameters and daily dosing information for a 6-months PK/PD study in over 500 patients, then used the AUC to model the PD end points. I added 10 data points in each day to run NONMEM in simulation mode for just one patient in order to estimate how much time will it take for over 500 patients. I found that for the 60-days time course, it took 7 hours and for the 30-days, it took 10 min. NONMEM slowed down dramatically when the no. of dosing and observation increased. I used a PC with 1.5 GHz Pentium 4 with 780 KB RAM to run the job. I found this method is not feasible to use because it will probably take over 6 months to run the NONMEM simulation. The other method I used (see http://huxley.phor.com/nonmem/nm/98feb192002.html) only take few minutes to run NONMEM. Best regards, Sam Liao, Ph.D. PharMax Research 270 Kerry Lane, Blue Bell, PA 19422 phone: 215-6541151 efax: 1-720-2946783