RE: Problem of STS in NONMEM

Dear Anyue, I don’t know what you mean by “the individual parameter estimate changed if I change the initial value of THETA” If you mean that individual ETA estimates change, that is expected when you change THETA. For CL and V to be the same, ETA need to change when THETA change. It may be that you are at local minima for EBEs. You may want to add MCETA=1000 on the $EST line in order to test more initial estimates. I would use MAXEVAL=0, not MAXEVAL=9999. Possibly I would use MAXEVAL=9999 after having fixed $OMEGA parameters to the high values you use now. Best regards, Mats Mats Karlsson, PhD Professor of Pharmacometrics Dept of Pharmaceutical Biosciences Faculty of Pharmacy Uppsala University Box 591 75124 Uppsala Phone: +46 18 4714105 Fax + 46 18 4714003 http://www.farmbio.uu.se/research/researchgroups/pharmacometrics/