Problem with predicted values for peripherial compartment
Dear Users,
After a succesful estimation of PK data by using ADVAN6 I try to get some more
detailed predictions for the central and peripherial compartment as well.
Therefore some "blank" records were inserted to the initial data file, like
this:
ID AMT EVID TIME DV UVOL CMT MDV
1 4e+06 1 0.0 . 0 1 1
1 0e+00 0 0.0 0.00000 0 2 0
1 0e+00 0 0.0 0.00000 0 4 0
1 0e+00 2 0.0 . 0 2 1
1 0e+00 2 0.0 0.00000 0 3 0
1 0e+00 2 0.0 . 0 4 1
1 0e+00 0 0.5 13.93836 0 2 0
1 0e+00 0 0.5 44.12349 0 4 0
1 0e+00 0 1.0 15.06895 0 2 0
1 0e+00 0 1.0 101.76711 0 4 0
1 0e+00 2 1.0 . 0 2 1
1 0e+00 2 1.0 . 0 4 1
1 0e+00 0 2.0 13.14943 0 2 0
1 0e+00 0 2.0 108.56616 0 4 0
1 0e+00 2 2.0 . 0 2 1
1 0e+00 2 2.0 . 0 4 1
1 0e+00 2 3.0 . 0 2 1
1 0e+00 2 3.0 . 0 4 1
1 0e+00 0 4.0 10.92107 0 2 0
1 0e+00 0 4.0 117.83321 0 4 0
CMT=2 is the central CMT=4 is a peripherial comparment. The predictions for the
central compartment were OK, but the predictions for peripherial compartment
were identical with the central. On the top of this, there were no errors with
those records where the DV was a measured value.
Is there any idea?
Thanks,
István
The model:
$PROBLEM
$INPUT C ID AMT EVID TIME DV UVOL CMT
$DATA DATANONMEM.CSV IGNORE=C
$SUBROUTINE ADVAN6 TRANS1 TOL=4
$MODEL NCOMP=4
COMP=(DEPOT,DEFDOS)
COMP=(CENTRAL,DEFOBS)
COMP=(URINE)
COMP=(PERIPH)
$PK
TVKA=THETA(1)
TVCL=THETA(2)
TVCLR=THETA(3)
TVV2=THETA(4)
TVKCS=THETA(5)
TVKSC=THETA(6)
TVV4=THETA(7)
KA=TVKA*EXP(ETA(1))
CL=TVCL*EXP(ETA(2))
CLR=TVCLR*EXP(ETA(3))
V2=TVV2*EXP(ETA(4))
KCS=TVKCS*EXP(ETA(5))
KSC=TVKSC*EXP(ETA(6))
V4=TVV4*EXP(ETA(7))
S2=V2
S3=UVOL
S4=V4
$DES
DADT(1)=-KA*A(1)
DADT(2)= KSC*A(4)+KA*A(1)-A(2)*(CLR+CL+KCS)
DADT(3)= CLR*A(2)
DADT(4)= KCS*A(2)-KSC*A(4)
$THETA
(0,0.1)
(0,0.1)
(0,0.1)
(0,160)
(0,0.1)
(0,0.1)
(0,10)
$OMEGA
.1 .1 .1 .1 .1 .1 .1
$SIGMA
0.1 10
$ERROR
IPRE=F
Y=IPRE*(1+ERR(1))+ERR(2)
$ESTIMATION PRINT=5 METHOD=1 POSTHOC
$TABLE C ID TIME CMT EVID DV IPRE NOPRINT ONEHEADER FILE=benzopred.tab
István Németh PhD
Biostatistician
Developmental Drug Metabolism & Pharmacokinetics
Pharmacological and Drug Safety Research
Gedeon Richter Plc
Tel: 00 36 1 505 7082
Fax: 00 36 1 889 8526