Shelley, You would use ADVAN6, ADVAN8, or ADVAN13, and code the differential equations explicitly in the $DES block. See the included CONTROL7 in the NONMEM examples.
Also note, you have an interesting error structure. Usually I have lognormal errors, that is KA = THETA(x)*EXP(ETA(x)) You have mu-referenced your variables. When I do this, the following code is produced: MU_x = LOG(THETA(x)) KA = EXP(MU_x+ETA(x)) You have instead: MU_x = THETA(x) KA = EXP(MU_x+ETA(x)) This means your KA, (which I will call KAs), is equivalent to my KA by the following transformation: KAs = LOG(KA) Is this what you mean? Matt. From: owner-nmus...@globomaxnm.com [mailto:owner-nmus...@globomaxnm.com] On Behalf Of Xiao Hu Sent: Tuesday, August 10, 2010 10:50 AM To: nmusers Subject: [NMusers] Translate ALAG1 and D1 in ADVAN2 to differential equations Dear NMusers, I'm using ADVAN2 to model the PK of a drug. To best fit the profile, the model includes ALAG1 and D1. For the next step, the ADVAN2 needs to be translated into differential equation to include a PD compartment. How should I write the differential equation for ALAG1 and D1? As you can see, there is Ka in the ADVAN2 model. I'm not very clear what's the meaning of D1 and KA when both are modeled. Any hint or previous link would be appreciated. Thanks in advance! $SUBROUTINES ADVAN2 $PK KASC=THETA(4) VSC=THETA(5) CLSC=THETA(6) LGSC=THETA(8) MU_4=KASC MU_5=VSC MU_6=CLSC MU_8=THETA(11) SD=THETA(9) SIG=SD KA=EXP(MU_4+ETA(4)) V=EXP(MU_5+ETA(5)) CL=EXP(MU_6+ETA(6)) K=CL/V S2=V/1000; DOSE IN 1000 U, CONC in U, VOLUME IN mL ALAG1=LGSC*EXP(ETA(10)) D1=EXP(MU_8+ETA(8)) Final parameter estimates: $THETA 12 ;THETA5 8.89 ;THETA6 0.0015;THETA8 0.263 ; THETA9 2.87; THETA11 Best regards, Shelley ======================================== Xiao Hu (Shelley), Ph.D. Scientist, Development Pharmacokinetics & Disposition Biogen Idec, Inc. 14 Cambridge Center Cambridge, MA 02142 ________________________________ This e-mail (including any attachments) is confidential and may be legally privileged. If you are not an intended recipient or an authorized representative of an intended recipient, you are prohibited from using, copying or distributing the information in this e-mail or its attachments. If you have received this e-mail in error, please notify the sender immediately by return e-mail and delete all copies of this message and any attachments. Thank you.
