Re: Help: oral and ig bioavailability by NONMEM

From: "Rik Schoemaker" <RS@chdr.nl> Subject: Re: Help: oral and ig bioavailability by NONMEM Date: Tue, 28 Aug 2001 10:09:33 +0200 Dear Weijiang, I'm a bit puzzled about your THETA(9) parameter; it seems to be=20 related to "bioavailability" for the IV dose (when both X1 and X2=20 are 0) which however should not operate on compartment 1 because=20 the IV dose is introduced in compartment 2...Why is it there? Could you try and see if the following syntax produces correct results (after checking that the IV dose indeed enters comp2): instead of: TVF1 =3D X1*THETA(7) + X2*THETA(8) F1=3DTVF1 *(1+X1*ETA(2)+X2*ETA(3)) + (1-X1-X2)*THETA(9)=20 use: F1=3D X1*THETA(7)*(1+ETA(2)) + X2*THETA(8)*(1+ETA(3)) and drop THETA(9)... Did you try using FOCE estimation with interaction? Good luck, Rik Rik C. Schoemaker, PhD Biostatistician - pharmacokineticist Centre for Human Drug Research (CHDR) Zernikedreef 10, 2333CL Leiden, Netherlands tel +31 (0) 71 5246417; fax +31 (0) 71 5246499 email rs@chdr.nl; http://www.chdr.nl