Hi Hanna,

I did not check the whole model code, but could it be a typo in the rate for 
re-distribution that produces the difference?

DADT(3) = K23*A(2) - K23*A(3)
Kind regards

Jakob


Jakob Ribbing, Ph.D.

Senior Consultant, Pharmetheus AB



Cell/Mobile:    +46 (0)70 514 33 77

jakob.ribb...@pharmetheus.com

www.pharmetheus.com



Phone, Office:  +46 (0)18 513 328

Uppsala Science Park, Dag Hammarskjölds väg 52B

SE-752 37 Uppsala, Sweden



This communication is confidential and is only intended for the use of the 
individual or entity to which it is directed. It may contain information that 
is privileged and exempt from disclosure under applicable law. If you are not 
the intended recipient please notify us immediately. Please do not copy it or 
disclose its contents to any other person.





On 12 Dec 2016, at 10:13, Silber Baumann, Hanna 
<hanna.silber_baum...@roche.com> wrote:

> Dear nmusers,
> I have a data set which contains single and multiple ascending dose data. The 
> model development was initially performed on the single dose data.
> I initially developed a model using ADVAN4 TRANS 2 (2 compartment linear 
> model with oral administration) which I later reparameterized into ADVAN6. I 
> expected to see some minor differences in parameter estimates, OFV etc due to 
> the change in subroutine but was surprised to see large differences in both 
> parameter estimates and OFV (+180 points) but also a significant improvement 
> in overall fit (graphically) while the data was the same. With the ADVAN4 the 
> model fit was particularly poor to parts of the multiple dose data, with the 
> ADVAN6 the overall fit to all data was much improved. I was using NONMEM7.3 
> for the analysis.
> 
> I guess the ADVAN4 model gets stuck in a local minima, but using the final 
> estimates from the ADVAN6 model does not help. I would be grateful for an 
> explanation of the reasons why this happens.
> 
> I have included the two models below.
> Kind regards,
> Hanna Silber 
> 
> $PROBLEM PK with ADVAN4
> 
> $INPUT C ID TAD TIME AMT DV EVID CMT PTIM LDV DOSE BW BMI CLCR SEX AGE 
>        STUDY DAY BLQ
> 
> $DATA nmpk05DEC16.csv IGNORE=@
> 
> $SUBROUTINES ADVAN4 TRANS4
> 
> $PK
> CL = THETA(1) * EXP(ETA(1))
> V2  = THETA(2) * EXP(ETA(2))
> KA = THETA(3) * EXP(ETA(3))
> ALAG1 = THETA(6) * EXP(ETA(4))
> Q = THETA(7) * EXP(ETA(5))
> V3 = THETA(8) * EXP(ETA(6))
> 
> S2 = V2/1000
> 
> $ERROR
> IPRED = F
>     W = SQRT(THETA(4)**2*IPRED**2 + THETA(5)**2)
>     Y = IPRED + W*EPS(1)
>  IRES = DV-IPRED
> IWRES = IRES/W
> 
> $THETA
> (0,12.7) ;1 CL
> (0,275) ;2 V2
> (0,3.06) ;3 KA
> (0, 0.12) ;4 Prop.RE (sd)
> (0, 0.0153)  ;5 Add.RE (sd)
> (0,0.474) ;6 ALAG1
> (0,26.3) ;7 Q
> (0,133) ;8 V3
> 
> $OMEGA BLOCK(2) 0.0747 ;1 IIV CL
> 0.0723 0.0942 ;2 IIV V2
> $OMEGA
> 1.76  ;3 IIV KA
> 0.00166  ;4 IIV ALAG
> 0.036  ;5 IIV Q
> 0.0407  ;6 IIV V3
> 
> $SIGMA
> 1 FIX ; 
> 
> $EST METHOD=1 INTER MAXEVAL=9999 NOABORT SIG=3 PRINT=1 POSTHOC
> $COV
> ######################################################
> 
> $PROBLEM PK with ADVAN6
> 
> $INPUT C ID TAD TIME AMT DV EVID CMT PTIM LDV DOSE BW BMI CLCR SEX AGE 
>        STUDY DAY BLQ
> 
> $DATA nmpk05DEC16.csv IGNORE=@
> 
> $SUBROUTINES ADVAN6 TOL=5
> 
> $MODEL
> COMP = (ABS) ;1
> COMP = (CENT) ;2
> COMP = (PER) ;3
> 
> $PK
> CL = THETA(1) * EXP(ETA(1))
> V2  = THETA(2) * EXP(ETA(2))
> KA = THETA(3) * EXP(ETA(3))
> ALAG1 = THETA(6) * EXP(ETA(4))
> Q = THETA(7) * EXP(ETA(5))
> V3 = THETA(8) * EXP(ETA(6))
> 
> K=CL/V2
> K23 = Q/V2
> K32 = Q/V3
> 
> A_0(1) = 0
> A_0(2) = 0
> A_0(3) = 0
> 
> $DES
> DADT(1) = -KA*A(1)
> DADT(2) = KA*A(1) - K*A(2) - K23*A(2) + K32*A(3)
> DADT(3) = K23*A(2) - K23*A(3)
> 
> $ERROR
> CONC = A(2)*1000/V2
> IPRED = CONC
> IF(CONC.EQ.0) IPRED = 1
> 
> W = SQRT(THETA(4)**2*IPRED**2 + THETA(5)**2)
> Y = IPRED + W*EPS(1)
> IRES = DV-IPRED
> IWRES = IRES/W
> 
> $THETA
> (0,12.1) ;1 CL
> (0,275) ;2 V2
> (0,3.06) ;3 KA
> (0, 0.12) ;4 Prop.RE (sd)
> (0, 0.0153)  ;5 Add.RE (sd)
> (0,0.474) ;6 ALAG1
> (0,26.3) ;7 Q
> (0,133) ;8 V3
> 
> $OMEGA BLOCK(2) 0.0747 ;1 IIV CL
> 0.0723 0.0942 ;2 IIV V2
> $OMEGA
> 1.76  ;3 IIV KA
> 0.00166  ;4 IIV ALAG
> 0.036  ;5 IIV Q
> 0.0407  ;6 IIV V3
> 
> $SIGMA
> 1 FIX ; 
> 
> $EST METHOD=1 INTER MAXEVAL=9999 NOABORT SIG=3 PRINT=1 POSTHOC
> $COV
> 
> ###############################
> Data set example:
> C     ID      TAD     TIME    AMT     DV      EVID    CMT     PTIM    LDV     
> DOSE    BW      BMI     CLCR    SEX     AGE     STUDY   DAY     BLQ
> 0     11001   0       0       5       0       1       1       0       0       
> 5       54.8    20.63   74.32657        0       44      1       1       0
> 0     11001   0.5     0.5     0       1.94    0       2       0.5     
> 0.662688        5       54.8    20.63   74.32657        0       44      1     
>   1       0
> 0     11001   1       1       0       14.6    0       2       1       
> 2.681022        5       54.8    20.63   74.32657        0       44      1     
>   1       0
> 0     11001   1.5     1.5     0       22.4    0       2       1.5     
> 3.109061        5       54.8    20.63   74.32657        0       44      1     
>   1       0
> 0     11001   2       2       0       18.1    0       2       2       
> 2.895912        5       54.8    20.63   74.32657        0       44      1     
>   1       0
> 0     11001   2.5     2.5     0       15.4    0       2       2.5     
> 2.734368        5       54.8    20.63   74.32657        0       44      1     
>   1       0
> 0     11001   3       3       0       16.3    0       2       3       
> 2.791165        5       54.8    20.63   74.32657        0       44      1     
>   1       0
> 0     11001   4       4       0       15.5    0       2       4       2.74084 
> 5       54.8    20.63   74.32657        0       44      1       1       0
> 0     11001   6       6       0       11.9    0       2       6       
> 2.476538        5       54.8    20.63   74.32657        0       44      1     
>   1       0
> 0     11001   8       8       0       11.5    0       2       8       
> 2.442347        5       54.8    20.63   74.32657        0       44      1     
>   1       0
> 0     11001   12      12      0       7.71    0       2       12      
> 2.042518        5       54.8    20.63   74.32657        0       44      1     
>   1       0
> 0     11001   16.017  16.017  0       8.71    0       2       16      
> 2.164472        5       54.8    20.63   74.32657        0       44      1     
>   2       0
> 0     11001   24      24      0       5.55    0       2       24      
> 1.713798        5       54.8    20.63   74.32657        0       44      1     
>   2       0
> 0     11001   48      48      0       3.5     0       2       48      
> 1.252763        5       54.8    20.63   74.32657        0       44      1     
>   3       0
> 0     11001   72      72      0       1.86    0       2       72      
> 0.620576        5       54.8    20.63   74.32657        0       44      1     
>   4       0
> 0     11001   120.883 120.883 0       0.597   0       2       120     
> -0.51584        5       54.8    20.63   74.32657        0       44      1     
>   6       0
> 0     11001   144.9   144.9   0       0.356   0       2       144     
> -1.03282        5       54.8    20.63   74.32657        0       44      1     
>   7       0
> 0     11001   168.883 168.883 0       0.177   0       2       168     
> -1.73161        5       54.8    20.63   74.32657        0       44      1     
>   8       0
> 
> 
> 
> -- 
> 

Reply via email to