Handling of baseline
From:Toufigh Gordi
Subject: [NMusers] Handling of baseline
Date: Thu, 17 Apr 2003 12:35:57 -0400
Dear all,
I am trying to model the cell-killing effect of a drug. Below are parts of
a proposed model, where a drug with mono-exponential kinetics affects two
different life-stages of the cells. Although I am sure the model structure
can be improved my question is how to incorporate the initial value for the
number of cell, both in the control stream and the data-file. Please feel
free to contact me directly or reply to the nmusers.
Thanks!
Toufigh Gordi
$INPUT ID AMT TIME DV EVID CMT PKPD
$DATA Monopkpd.csv IGNORE=#
$SUBROUTINE ADVAN6 TRANS1 TOL=5
$MODEL
NCOMP=3
COMP=CENT
COMP=CELL1
COMP=CELL2
$PK
V=THETA(1)
CL=THETA(2)
T12=THETA(3)*EXP(ETA(1))
K12=1/T12
T21=0.3-T12
K21=1/T21
KCEL=THETA(4)
S1=V
$DES
DADT(1)=-A(1)*CL/V
DADT(2)=-(A(2)*K12)-(A(2)*KCEL*A(1)/V)+(2*A(3)*K21)
DADT(3)=(A(2)*K12)-(A(3)*KCEL*A(1)/V)-(A(3)*K21)
$ERROR
IPRD=A(2)
IF (IPRD.LE.0) IPRD=0.0001
IPRED=LOG(IPRD)
W=SQRT(THETA(5)**2+THETA(6)**2/IPRD**2)
IRES=DV-IPRED
IWRES=IRES/W
Y=IPRED+W*EPS(1)
$THETA (33.5 FIXED) ;1 V
$THETA (50 FIXED) ;2 CL
$THETA (0, 24, 48) ;3 T12
$THETA (0, 0.1) ;4 KCEL
$THETA (0, 0.1) ;5 ERROR
$THETA (0, 0.1) ;6 ERROR
$OMEGA 0.2 ;1 IIV T12
$SIGMA 1 FIX