Re: NONMEM ODE solver

Dear Dr Sale, ADAPT (including Adapt II (Rel. 4), Adapt V, and S-Adapt) uses the LSODA (Livermore Solver for Ordinary Differential equations with Automatic method switching for stiff and nonstiff problems). According to the Adapt user guide: "The ability of LSODA to detect stiffness and switch between Adam's and Gear's methods, together with its capability to control the step size and order of the selected method, makes this program [ADAPT] the most robust we know of for this application." I have not yet run a head to head comparison of the stability of the ODE solver in Adapt and NONMEM on the same project myself. However, some of my colleagues told me that they found the LSODA in Adapt very robust. I would be happy, if someone could share his/her opinion on the robustness of ODE solvers e.g. implemented in PKPD programs. Best regards Juergen ----------------------------------------------- Juergen Bulitta, PhD, Post-doctoral Fellow Pharmacometrics, University at Buffalo, NY, USA Phone: +1 716 645 2855 ext. 281, [EMAIL PROTECTED]