TIME is not reset, it is counted from the first dose in this example. To describe the model you need
to introduce TAD (time after the most recent dose) into the data set and use it for FLAG reset:
IF(TAD.GT.LAG) FLAG=1
Same with occasion, it would be best to introduce variable OCC (occasion, 1 2
or 3) to the data set
Leonid
Jian Xu wrote:
Hi, NM users,
I have a simple question about how TIME works for multiple doses in NONMEM.
Here is my model:
1-CM with dual absorption process (based on a LAG variable)
IOV is also modeled.
Dose regimen: TID doses at 400 mg
Here is the part of dataset:
Here is the part of NONMEM control stream:
$PROB PK-TEST
$DATA PK-all.csv IGNORE = C
$INPUT C,ID,TIME,DOSE,DV,CMT,EVID,MDV,AMT,WT
$SUBROUTINE ADVAN2 TRANS2
$PK
OCC1=0
OCC2=0
OCC3=0
OCC4=0
OCC5=0
IF(TIME.LE.12) OCC1=1
IF(TIME.GT.12.AND.TIME.LE.24) OCC2=1
IF(TIME.GT.24.AND.TIME.LE.300) OCC3=1
IOV1=OCC1*ETA(4)+OCC2*ETA(5)+OCC3*ETA(6)
IOV2=OCC1*ETA(9)+OCC2*ETA(10)+OCC3*ETA(11)
TKA1= THETA(3)*DEXP(ETA(1))
TKA2= THETA(5)*DEXP(ETA(2))
LAG=0.75
FLAG=0
IF(TIME.GT.LAG) FLAG=1
TVKA=(1-FLAG)*TKA1 + FLAG*TKA2
........
I highlighted TIME in the code, and my question is that when NONMEM hits
LAG, is TIME reseted? (TIME will start from zero for each dose?)
Otherwise, after 0.75 hr, FLAG (even for second dose (0-0.75hr)) will be
always equal to 1. Secondly, during IOV calculation, is TIME relative
time to the first dose?
It is really confusing me in the code since the same name, TIME, was
used here.
Thanks in advance.
Jian
