$DES and T
From: "LSEN (Lars Erichsen)" lsen@novonordisk.com
Subject: [NMusers] $DES and T
Date: Wed, February 9, 2005 7:29 am
Dear Nonmem users,
I have a question concerning the use of $DES and the continous time
variable T:
I want to compute a concentration at any time point T and use it as
input to a PD model (see code below).
I get the warning (48): DES defined items are computed only when event
time increases...
Does this mean that CONC is only recomputed at observed time points (I
do not have any dosing events)? What happens between these time points?
When I print out to a table the first CONC value is 0 - even if TIME>0.
Results change if I add new data records to the data set with MDV=1 and
new TIME points.
Thanks in advance,
Lars.
$SUBROUTINES ADVAN6 TOL 5
$MODEL
COMP=(EFFECT)
$PK
TVKIN=THETA(1)
KIN=EXP(TVKIN)
TVKOUT=EXP(THETA(2))
KOUT=TVKOUT*EXP(ETA(1))
TVTH=THETA(3)
TH=EXP(TVTH)
K=6.41
V=0.127
KA=1.35
$ERROR
IPRE=A(1)
Y=1+IPRE+ERR(1);
$DES
CONC=DOSE*KA/(K-KA)/V*(EXP(-KA*T)-EXP(-K*T))
KIN1=0
IF(CONC.GT.TH) KIN1=1
DADT(1)=KIN*KIN1-KOUT*A(1)