Re: An error when running a plasma/urine model in SS. Would you please help?
If SS with void at t1 after dose is needed, it can be obtained by 2 doses:
TIME=-tau, AMT=0, SS=0, CMT=-4
TIME=-tau, AMT=dose, SS=1, CMT=1
TIME=-tau+t1, AMT=0, SS=0, CMT=4
TIME=0, AMT=dose, SS=0, CMT=1
I have not tested it, so it is better to check...
Thank you
Leonid
Quoted reply history
On 7/15/2024 3:01 PM, Abdelrahman Saqr wrote:
> Thank you all for your help.
>
> Yes, that is what I believed in. The urine compartment is the problem. I tried the empirical steady state method (ADDL = -ve integer) with the plasma data only and then with the urine. The plasma achieves SS after a few number of doses; however, the urine compartment does not even with a very large number of doses. And I think this is as Saeheum has mentioned due to the emptying process.
>
> I did use the EVID to empty out the urine compartment (EVID = -v integer).
>
> I am not sure if there is a way in NONMEM to select compartments to be tested for the SS. (i.e. the central compartment is tested for SS but the output compartment is ignored)
>
> C ID TIME TAD AMT AMT_MOLAR AMT_MPA AMT_MPA_MOL RATE DV DV_MOLAR DV_AMT_MOL LN_DV_AMT_MOL Uvol CMT EVID MDV L2 ADDL II SS DVID DATE 0 1 19:30:00 -24 500 0 369.5 1.153606 -1 0 0 0 0 0 1 1 1 0 0 0 1 0 4/4/2018 0 1 19:30:00 -12 500 1.153403 369.5 1.153606 0 0 0 0 0 0 1 1 1 0 0 0 0 0 4/4/2018
>
> 0 1 8:08:00 0 0 0 0 0 0 2007 6.266001 6.266001 6.266001 0 2 0 0 1 0 0 0 1 4/5/2018 0 1 8:08:00 0 500 1.153403 369.5 1.153606 0 0 0 0 0 0 1 1 1 0 0 0 0 0 4/5/2018
>
> 0 1 8:08:00 0 0 0 0 0 0 0 0 0 0 0 4 2 1 11 0 0 0 3 4/5/2018 0 1 8:36:00 0.5 0 0 0 0 0 17010 53.10646 53.10646 53.10646 0 2 0 0 2 0 0 0 1 4/5/2018 0 1 9:08:00 1 0 0 0 0 0 21791 68.03309 68.03309 68.03309 0 2 0 0 3 0 0 0 1 4/5/2018 0 1 10:06:00 2 0 0 0 0 0 6373 19.89697 19.89697 19.89697 0 2 0 0 7 0 0 0 1 4/5/2018 0 1 11:08:00 3 0 0 0 0 0 4461 13.92757 13.92757 13.92757 0 2 0 0 8 0 0 0 1 4/5/2018 0 1 12:07:00 4 0 0 0 0 0 3867 12.07306 12.07306 12.07306 0 2 0 0 9 0 0 0 1 4/5/2018 0 1 13:07:00 5 0 0 0 0 0 7404 23.11583 23.11583 23.11583 0 2 0 0 10 0 0 0 1 4/5/2018 0 1 14:10:00 6 0 0 0 0 0 5256 16.40962 16.40962 16.40962 0 2 0 0 11 0 0 0 1 4/5/2018 0 1 14:10:00 6 0 0 0 0 0 3396 10.60256 4665.126 8.44787 440 -4 0 0 600 0 0 0 3 4/5/2018 0 1 14:10:00 6 0 0 0 0 0 0 0 0 0 0 4 2 1 6 0 0 0 3 4/5/2018 0 1 15:10:00 7 0 0 0 0 0 3318 10.35904 10.35904 10.35904 0 2 0 0 12 0 0 0 1 4/5/2018 0 1 16:10:00 8 0 0 0 0 0 4235 13.22198 13.22198 13.22198 0 2 0 0 13 0 0 0 1 4/5/2018 0 1 17:08:00 9 0 0 0 0 0 6954 21.7109 21.7109 21.7109 0 2 0 0 14 0 0 0 1 4/5/2018 0 1 18:08:00 10 0 0 0 0 0 7505 23.43116 23.43116 23.43116 0 2 0 0 4 0 0 0 1 4/5/2018 0 1 19:08:00 11 0 0 0 0 0 2390 7.461755 7.461755 7.461755 0 2 0 0 5 0 0 0 1 4/5/2018 0 1 20:08:00 12 0 0 0 0 0 20163 62.95036 11834.67 9.378788 188 -4 0 0 1200 0 0 0 3 4/5/2018 0 1 20:10:00 12 0 0 0 0 0 1316 4.108648 4.108648 4.108648 0 2 0 0 6 0 0 0 1 4/5/2018
>
> On Thu, Jul 11, 2024 at 8:28 AM Saeheum Song < [email protected] < mailto: [email protected] >> wrote:
>
> There is no steady state in urine. Urine is always accumulating and
> empty out. You can set ss to the central compartment. After setting
> ss to the central compartment, you need to empty and reset urine
> compartment using evid.
>
> On Thu, Jul 11, 2024, 2:10 AM Leonid Gibiansky
> <[email protected] <mailto:[email protected]>> wrote:
>
> Could you show the code and the data sample?
> It is possible that urine compartment does not have SS, as it
> does not
> have elimination. It needs to be emptied time to time, and it
> could be
> difficult to code SS of this system. To check, you may look on
> the urine
> compartment concentrations with additional doses: do they
> converge to SS
> to increase with time?
> Leonid
>
> On 7/9/2024 2:41 PM, Abdelrahman Saqr wrote:
> > Dear Colleagues,
> >
> > I am encountering the following error when I run a model that
> includes
> > plasma and urine data and SS data column =1.
> > When I remove the urine data (modelling only the plasma
> data), the model
> > runs without any error.
> >
> > When I drop the SS column (run a single dose or even with
> additional
> > doses), the model runs without any error.
> >
> > When I have both the urine data and SS assigned as 1 or 3, I
> face the
> > following error :
> >
> > MONITORING OF SEARCH:
> >
> > 0THE INPUT MATRIX IS SINGULAR. SOME OF THE DIAGONAL ELEMENTS
> OF THE UPPER
> > TRIANGULAR MATRIX U OF THE LU FACTORIZATION ARE
> CLOSE TO ZERO.
> > 0THE INPUT MATRIX IS SINGULAR. SOME OF THE DIAGONAL ELEMENTS
> OF THE UPPER
> > TRIANGULAR MATRIX U OF THE LU FACTORIZATION ARE
> CLOSE TO ZERO.
> >
> > 0PRED EXIT CODE = 1
>
> > 0INDIVIDUAL NO. 1 ID= 3.00200000000000E+03 (WITHIN-INDIVIDUAL)
>
> > DATA REC NO. 1
> > THETA=
> > 8.60E+00 1.39E+01 1.78E+02 1.33E-01 1.00E+00
> > OCCURS DURING SEARCH FOR ETA AT INITIAL VALUE, ETA=0
> > NUMERICAL DIFFICULTIES WITH INITIAL ESTIMATE OF
> STEADY-STATE SOLUTION.
> > DA MATRIX IS NOT INVERTIBLE AT A ZERO STATE VECTOR.
> > TRY SETTING INITIAL ESTIMATE USING SS=3.
> >
> > I appreciate your help with interpreting and fixing this error.
> > Thanks,
> >
> > --
> > *Abdelrahman Saqr *
> > MS. Experimental and Clinical Pharmacology | University of
> Minnesota
> > PhD Candidate | Department ofExperimental and Clinical
> Pharmacology
> > College of Pharmacy | University of Minnesota
> > www.linkedin.com/in/abdelrahman-saqr
> http://www.linkedin.com/in/abdelrahman-saqr
> > http://www.linkedin.com/in/abdelrahman-saqr
http://www.linkedin.com/in/abdelrahman-saqr>
> >
>
> --
> *Abdelrahman Saqr *
> MS. Experimental and Clinical Pharmacology | University of Minnesota
> PhD Candidate | Department ofExperimental and Clinical Pharmacology
> College of Pharmacy | University of Minnesota
>
> www.linkedin.com/in/abdelrahman-saqr < http://www.linkedin.com/in/abdelrahman-saqr >