NONMEM Users Network Archive

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Weibull distribution

From: Khaled Mohammed Abduljalil <kabdulja>
Date: Wed, 11 Apr 2007 15:15:00 +0200

Dear NONMEM users,

I have tried to study the pk profiles of a drug after
multiple oral dosage regimen of 500mg every 12hr. The
estimation process was well performed with the first dose
(only) using Weibull function. but if i apply the same
control file to the whole data (ie, single dose and
multiple doses), it does not work any more. I can not
detect my error. Could any one tell me where is it?
neither first order nor Mich.-Menten models fitted the
data like weibull model.

thank you very much in advance for your response.

sincerely yours
Abduljalil


$SUBROUTINES ADVAN6 TRANS1 TOL=3
$MODEL
COMP=(DEPOT,DEFDOSE)
COMP=(CENTRAL,DEFOBS)

$PK
CL=THETA(1)*EXP(ETA(1))
V=THETA(2)*EXP(ETA(2))
BETA=THETA(3)*EXP(ETA(3))
ALPHA=THETA(4)*EXP(ETA(4))

K=CL/V

S1=1
S2=V

$ERROR
DEL=0
IF(F.EQ.0) DEL=0.001
W=F
IPRED=F
IRES=DV-IPRED
IWRES=IRES/(W+DEL)
Y=F+EPS(1)

$DES
DADT(1)=-A(1)*(BETA/ALPHA)*((TIME/ALPHA)**(BETA-1))*EXP(-(TIME/ALPHA)**BETA)
DADT(2)=-DADT(1)-A(2)*K


$THETA
(0.01,17,80);
(10,115,900);
(0.1,2.2,30)
(0.1,2.6,30)
(0.001,2)
(0.001,1)

$OMEGA
0.1 0.2 0.08 0.2

$SIGMA
0.2

$EST METHOD=1 INTER PRINT=5 NOABORT MAXEVAL=9999
Received on Wed Apr 11 2007 - 09:15:00 EDT

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