Dear Katya, Jun, Luann, and Charlie,

Thank you for your advice!  The explicit on/off switching is working, although 
the results under-estimate the hemodialysis clearance by attributing the 
concentration change to sigma.

I'm still wondering what happens when compartment 3 was turned off for my 
previous code.  My interpretation now is that it sets CMT 3 to zero until it's 
turned on again, but does not set the kinetic constants (K23 and K32) to zero.  
Therefore, K23 is always there.   Is this correct?

Best regards,
Xiao

From: Ekaterina Gibiansky [mailto:[email protected]]
Sent: Wednesday, July 20, 2011 12:54 PM
To: [email protected]
Cc: Xiao Hu
Subject: Re: [NMusers] Modeling Hemodialysis clearance

Dear Xiao,

I agree with Jun's advise. You previous setting should not work as when you 
switch the compartment 3 off nothing changes for compartment 2, k23 stays the 
same as it was.

Regards,
Katya


Ekaterina Gibiansky, Ph.D.

CEO&CSO, QuantPharm LLC

Web:     www.quantpharm.com<http://www.quantpharm.com>

Email:   [email protected]<mailto:[email protected]>

Tel:     (301)-717-7032

On 7/20/2011 11:20 AM, Jun Shen wrote:
Dear Xiao,

I don't think you need an extra compartment to model the hemodialysis 
clearance. I would recommend the following.
$DES
DADT(1)=-K12*A(1)
DADT(2)=K12*A(1)-K20*A(2)-Switch*KHD*A(2)

Where KHD is the hemodialysis elimination rate constant and Switch is an data 
item defined in the dataset. In the dataset the Switch value is zero at the 
time of start of dialysis, and 1 at the end of dialysis. Also Switch values 
should be zero for all events out of dialysis sessions and 1 for all events 
within dialysis.

Jun Shen
Senior Pharmacokineticist
Seventh Wave Labs
On Wed, Jul 20, 2011 at 9:26 AM, Xiao Hu 
<[email protected]<mailto:[email protected]>> wrote:
Dear Luann,

Thanks for your advice.  I realized I did not include relevant data (Excel 
change my DATE format automatically; I had to use notepad and selected the 
wrong rows).  The following the updated data.  PK samples were collected one 
hour before hemodialysis and one hour after hemodialysis, as well as between 
two dialysis.  This may address identifiability issue.  But if the system does 
not turn off Compartment 3, the identifiability will be an issue.

C,ID,DATE,TIME,GROUP,CONC,AMT,MDV,TYPE,CMT,EVID
,102006,2010/11/11,14:35,5,0,1.25e+08,1,1,1,1
,102006,2010/11/11,14:35,5,0,0,1,1,-3,2
,102006,2010/11/11,20:35,5,44.7,0,0,1,2,0
,102006,2010/11/12,02:35,5,71.9,0,0,1,2,0
,102006,2010/11/12,14:43,5,69.8,0,0,1,2,0
,102006,2010/11/13,02:35,5,122,0,0,1,2,0
,102006,2010/11/13,14:35,5,131,0,0,1,2,0
,102006,2010/11/14,08:55,5,132,0,0,1,2,0
,102006,2010/11/14,09:00,5,0,0,1,1,3,2
,102006,2010/11/14,13:40,5,0,0,1,1,-3,2
,102006,2010/11/14,14:35,5,89.8,0,0,1,2,0
,102006,2010/11/15,10:29,5,68.7,0,0,1,2,0
,102006,2010/11/16,17:30,5,0,0,1,1,3,2
,102006,2010/11/16,21:30,5,0,0,1,1,-3,2
,102006,2010/11/18,17:40,5,0,0,1,1,3,2
,102006,2010/11/18,23:40,5,0,0,1,1,-3,2
,102006,2010/11/19,00:43,5,30,0,0,2,2,0
,102006,2010/11/21,16:20,5,30,0,0,2,2,0
,102006,2010/11/21,17:25,5,0,0,1,1,3,2
,102006,2010/11/21,23:25,5,0,0,1,1,-3,2
,102006,2010/11/23,17:40,5,0,0,1,1,3,2
,102006,2010/11/23,23:41,5,0,0,1,1,-3,2
,102006,2010/11/25,06:00,5,0,0,1,1,3,2
,102006,2010/11/25,10:00,5,0,0,1,1,-3,2
,102006,2010/11/28,12:30,5,0,0,1,1,3,2
,102006,2010/11/28,17:02,5,0,0,1,1,-3,2
,102006,2010/11/30,19:00,5,0,0,1,1,3,2
,102006,2010/11/30,23:55,5,0,0,1,1,-3,2
,102006,2010/12/02,17:55,5,0,0,1,1,3,2
,102006,2010/12/02,23:55,5,0,0,1,1,-3,2
,102006,2010/12/05,17:25,5,0,0,1,1,3,2
,102006,2010/12/05,20:35,5,0,0,1,1,-3,2
,102006,2010/12/07,18:40,5,0,0,1,1,3,2
,102006,2010/12/07,23:57,5,0,0,1,1,-3,2
,102006,2010/12/09,17:55,5,0,0,1,1,3,2
,102006,2010/12/09,23:55,5,0,0,1,1,-3,2
,102006,2010/12/16,17:48,5,0,0,1,1,3,2
,102006,2010/12/16,23:48,5,0,0,1,1,-3,2
,102007,2010/11/13,14:17,5,0,1.25e+08,1,1,1,1
,102007,2010/11/13,14:17,5,0,0,1,1,-3,2
,102007,2010/11/13,20:17,5,394,0,0,1,2,0
,102007,2010/11/14,02:17,5,298,0,0,1,2,0
,102007,2010/11/14,14:17,5,532,0,0,1,2,0
,102007,2010/11/15,10:22,5,615,0,0,1,2,0
,102007,2010/11/15,14:25,5,686,0,0,1,2,0
,102007,2010/11/16,07:42,5,740,0,0,1,2,0
,102007,2010/11/16,07:43,5,0,0,1,1,3,2
,102007,2010/11/16,11:48,5,0,0,1,1,-3,2
,102007,2010/11/16,14:17,5,703,0,0,1,2,0
,102007,2010/11/17,14:20,5,530,0,0,1,2,0
,102007,2010/11/18,10:46,5,0,0,1,1,3,2
,102007,2010/11/18,14:51,5,0,0,1,1,-3,2
,102007,2010/11/20,10:15,5,165,0,0,1,2,0
,102007,2010/11/20,11:22,5,0,0,1,1,3,2
,102007,2010/11/20,15:24,5,0,0,1,1,-3,2
,102007,2010/11/20,16:00,5,157,0,0,1,2,0
,102007,2010/11/23,09:53,5,44.7,0,0,1,2,0
,102007,2010/11/23,10:46,5,0,0,1,1,3,2
,102007,2010/11/23,14:52,5,0,0,1,1,-3,2
,102007,2010/11/25,10:33,5,0,0,1,1,3,2
,102007,2010/11/25,14:48,5,0,0,1,1,-3,2
,102007,2010/11/27,11:09,5,0,0,1,1,3,2
,102007,2010/11/27,15:01,5,0,0,1,1,-3,2
,102007,2010/11/30,10:59,5,30,0,0,2,2,0
,102007,2010/11/30,12:27,5,0,0,1,1,3,2
,102007,2010/11/30,15:33,5,0,0,1,1,-3,2
,102007,2010/12/02,12:11,5,0,0,1,1,3,2
,102007,2010/12/02,16:17,5,0,0,1,1,-3,2
,102007,2010/12/04,11:20,5,30,0,0,2,2,0
,102007,2010/12/04,12:18,5,0,0,1,1,3,2
,102007,2010/12/04,15:59,5,0,0,1,1,-3,2
,102007,2010/12/07,10:20,5,30,0,0,2,2,0
,102007,2010/12/07,11:58,5,0,0,1,1,3,2
,102007,2010/12/07,16:06,5,0,0,1,1,-3,2
,102007,2010/12/09,11:02,5,0,0,1,1,3,2
,102007,2010/12/09,14:33,5,0,0,1,1,-3,2
,102007,2010/12/12,11:44,5,30,0,0,2,2,0
,102007,2010/12/14,10:58,5,0,0,1,1,3,2
,102007,2010/12/14,15:00,5,0,0,1,1,-3,2
,102007,2010/12/16,11:18,5,0,0,1,1,3,2
,102007,2010/12/16,14:50,5,0,0,1,1,-3,2
,102007,2010/12/18,10:56,5,0,0,1,1,3,2
,102007,2010/12/18,14:56,5,0,0,1,1,-3,2
,104006,2010/11/12,12:30,5,0,1.25e+08,1,1,1,1
,104006,2010/11/12,12:30,5,0,0,1,1,-3,2
,104006,2010/11/12,18:30,5,100,0,0,1,2,0
,104006,2010/11/13,00:30,5,177,0,0,1,2,0
,104006,2010/11/13,12:30,5,350,0,0,1,2,0
,104006,2010/11/13,18:30,5,415,0,0,1,2,0
,104006,2010/11/15,12:30,5,362,0,0,1,2,0
,104006,2010/11/15,12:45,5,0,0,1,1,3,2
,104006,2010/11/15,16:45,5,0,0,1,1,-3,2
,104006,2010/11/15,17:45,5,253,0,0,1,2,0
,104006,2010/11/16,12:30,5,164,0,0,1,2,0
,104006,2010/11/17,07:40,5,0,0,1,1,3,2
,104006,2010/11/17,11:44,5,0,0,1,1,-3,2
,104006,2010/11/17,13:40,5,88.7,0,0,1,2,0
,104006,2010/11/19,06:05,5,47.7,0,0,1,2,0
,104006,2010/11/19,07:41,5,0,0,1,1,3,2
,104006,2010/11/19,11:45,5,0,0,1,1,-3,2
,104006,2010/11/19,13:06,5,31.7,0,0,1,2,0
,104007,2010/11/13,12:40,5,0,1.25e+08,1,1,1,1
,104007,2010/11/13,12:40,5,0,0,1,1,-3,2
,104007,2010/11/13,18:40,5,173,0,0,1,2,0
,104007,2010/11/14,00:40,5,234,0,0,1,2,0
,104007,2010/11/14,12:45,5,254,0,0,1,2,0
,104007,2010/11/14,18:47,5,276,0,0,1,2,0
,104007,2010/11/15,12:40,5,276,0,0,1,2,0
,104007,2010/11/16,12:40,5,332,0,0,1,2,0
,104007,2010/11/16,12:55,5,0,0,1,1,3,2
,104007,2010/11/16,16:55,5,0,0,1,1,-3,2
,104007,2010/11/16,17:58,5,275,0,0,1,2,0
,104007,2010/11/18,06:47,5,228,0,0,1,2,0
,104007,2010/11/18,07:52,5,0,0,1,1,3,2
,104007,2010/11/18,11:58,5,0,0,1,1,-3,2
,104007,2010/11/18,13:06,5,158,0,0,1,2,0
,104007,2010/11/20,06:10,5,76.3,0,0,1,2,0
,104007,2010/11/20,07:10,5,0,0,1,1,3,2
,104007,2010/11/20,11:13,5,0,0,1,1,-3,2
,104007,2010/11/20,11:59,5,67.1,0,0,1,2,0
,104010,2011/04/29,12:42,5,0,1.25e+08,1,1,1,1
,104010,2011/04/29,12:42,5,0,0,1,1,-3,2
,104010,2011/04/29,18:50,5,119,0,0,1,2,0
,104010,2011/04/30,00:42,5,203,0,0,1,2,0
,104010,2011/04/30,12:42,5,197,0,0,1,2,0
,104010,2011/04/30,18:42,5,295,0,0,1,2,0
,104010,2011/05/01,12:42,5,224,0,0,1,2,0
,104010,2011/05/02,12:44,5,268,0,0,1,2,0
,104010,2011/05/02,17:57,5,216,0,0,1,2,0
,104010,2011/05/04,05:40,5,161,0,0,1,2,0
,104010,2011/05/04,12:40,5,110,0,0,1,2,0
,104010,2011/05/06,03:00,5,66.7,0,0,1,2,0
,104010,2011/05/06,11:36,5,44.5,0,0,1,2,0
,106009,2011/01/28,14:15,5,0,1.25e+08,1,1,1,1
,106009,2011/01/28,14:15,5,0,0,1,1,-3,2
,106009,2011/01/28,20:15,5,52.7,0,0,1,2,0
,106009,2011/01/29,02:15,5,74.6,0,0,1,2,0
,106009,2011/01/29,14:15,5,85.2,0,0,1,2,0
,106009,2011/01/30,02:15,5,94.6,0,0,1,2,0
,106009,2011/01/30,14:15,5,102,0,0,1,2,0
,106009,2011/01/31,12:48,5,138,0,0,1,2,0
,106009,2011/01/31,13:05,5,0,0,1,1,3,2
,106009,2011/01/31,17:05,5,0,0,1,1,-3,2
,106009,2011/01/31,18:12,5,105,0,0,1,2,0
,106009,2011/02/02,14:07,5,118,0,0,1,2,0
,106009,2011/02/02,16:50,5,0,0,1,1,3,2
,106009,2011/02/02,20:50,5,0,0,1,1,-3,2
,106009,2011/02/02,22:01,5,95.1,0,0,1,2,0
,106009,2011/02/04,13:34,5,72.9,0,0,1,2,0
,106009,2011/02/04,15:54,5,0,0,1,1,3,2
,106009,2011/02/04,20:06,5,0,0,1,1,-3,2
,106009,2011/02/04,21:18,5,60.3,0,0,1,2,0
,106009,2011/02/07,00:50,5,0,0,1,1,-3,2
,106009,2011/02/07,11:02,5,39.4,0,0,1,2,0
,106009,2011/02/07,17:20,5,0,0,1,1,3,2
,106009,2011/02/09,01:05,5,0,0,1,1,-3,2
,106009,2011/02/09,17:05,5,0,0,1,1,3,2
,106009,2011/02/11,01:23,5,0,0,1,1,-3,2
,106009,2011/02/11,08:49,5,30,0,0,2,2,0
,106009,2011/02/11,17:15,5,0,0,1,1,3,2
,106009,2011/02/14,01:17,5,0,0,1,1,-3,2
,106009,2011/02/14,08:44,5,30,0,0,2,2,0
,106009,2011/02/14,17:17,5,0,0,1,1,3,2
,106009,2011/02/16,01:20,5,0,0,1,1,-3,2
,106009,2011/02/16,17:20,5,0,0,1,1,3,2
,106009,2011/02/18,01:08,5,0,0,1,1,-3,2
,106009,2011/02/18,17:02,5,0,0,1,1,3,2
,106009,2011/02/21,01:04,5,0,0,1,1,-3,2
,106009,2011/02/21,17:04,5,0,0,1,1,3,2
,106009,2011/02/23,17:39,5,0,0,1,1,3,2
,106009,2011/02/23,21:45,5,0,0,1,1,-3,2
,106009,2011/02/25,16:55,5,0,0,1,1,3,2
,106009,2011/02/25,20:56,5,0,0,1,1,-3,2
,106009,2011/02/28,01:06,5,0,0,1,1,-3,2
,106009,2011/02/28,17:21,5,0,0,1,1,3,2
,106009,2011/03/02,01:01,5,0,0,1,1,-3,2
,106009,2011/03/02,17:05,5,0,0,1,1,3,2
-----Original Message-----
From: Luann Phillips 
[mailto:[email protected]<mailto:[email protected]>]
Sent: Wednesday, July 20, 2011 9:45 AM
To: Xiao Hu
Cc: [email protected]<mailto:[email protected]>
Subject: Re: [NMusers] Modeling Hemodialysis clearance

Xiao Hu,

I think it may be a problem with identifiability. It can't separate the 
definition of K23 from K20 unless there are measurements during elimination for 
hemo. patients off dialysis and on dialysis.

Thoughts:
(1) Try making K20=0 for hemodialysis patients
Assumes: no elimination except during hemodialysis via K23
(2) Estimate a different theta for K20 in hemodialysis patients since it should 
be different for them (bi-modal distribution)
Assumes: very small elimination from central & with additive elimination from 
hemodialysis via K23.

Regards,

Luann Phillips
Director, PK/PD
Cognigen Corporation

Xiao Hu wrote:
> Dear NM users,
>
>
>
> I'm working on a PK model in renal disease patients with hemodialysis.
> The drug in healthy subjects is well described with a first-order
> absorption and one-compartment disposition model.  A third
> hemodialysis compartment was added; CMT=3 or -3 were included in the
> data set to turn this compartment on and off.  However, the 3rd
> compartment did not seem to be turned off, based on the fact that the
> same results were obtained whether I excluded the EVID==2 record or
> not (corresponding to CMT==3 or -3).  Both ADVAN6 and ADVAN7 provided
> the same results as well.  The code and partial data set are shown
> below.  I'm wondering if you can point me to the right direction.  I'd really 
> appreciate your input.  Thanks!
>
>
>
> Best regards,
>
> Xiao
>
>
>
> $INPUT  C ID DAT2=DROP TIME GROUP DV AMT MDV TYPE CMT EVID
>
>
>
> $DATA .\DATA\FINAL\105RI101ESRDPK.CSV
>
> IGNORE=C IGN(GROUP.NE.5) ;IGN(EVID.EQ.2)
>
>
>
> $SUBROUTINES  ADVAN7  ;ADVAN6 TOL=8
>
>
>
> $MODEL
>
> COMP=(DEPOT,INITIALOFF,DEFDOSE)
>
> COMP=(CENTRAL,DEFOBS,NOOFF)
>
> COMP=(HEMODIA,INITIALOFF)
>
>
>
> $PK
>
> K12=THETA(1)
>
> K20=THETA(2)
>
> K23=THETA(3)
>
> K32=0
>
> V2=THETA(4)*EXP(ETA(1))
>
> S2=V2
>
> $ERROR
>
> Y=F*EXP(EPS(1))
>
> IPRE=F
>
>
>
> ;$DES
>
> ;DADT(1)=-K12*A(1)
>
> ;DADT(2)=K12*A(1)-K23*A(2)-K20*A(2)
>
> ;DADT(3)=K23*A(2)
>
>
>
> $THETA
>
> (0,0.1)                 ;THETA1 K12
>
> (0,0.05)                ;THETA2 K20
>
> (0,.102)                ;THETA3 K23
>
> (0,200000)              ;THETA6 V2
>
>
>
> $OMEGA
>
> 0.2
>
> $SIGMA
>
> 0.2
>
>
>
> $ESTIMATION  MAXEVAL=9999 METH=COND  PRINT=5 MSFO=ESRD.MSF
> FILE=ESRD.EXT
>

> ,102001,2010/05/11,08:35,2,82.2,0,0,1,2,0
>
> ,102002,2010/06/30,8:00,2,0,1.25e+08,1,1,1,1
>
> ,102002,2010/06/30,8:00,2,0,0,1,1,-3,2
>
> ,102002,2010/06/30,14:03,2,416,0,0,1,2,0
>
> ,102002,2010/06/30,21:00,2,727,0,0,1,2,0
>
> ,102002,2010/07/01,08:21,2,1040,0,0,1,2,0
>
> ,102002,2010/07/01,20:00,2,1070,0,0,1,2,0
>
> ,102002,2010/07/02,08:06,2,719,0,0,1,2,0
>
> ,102002,2010/07/03,08:00,2,580,0,0,1,2,0
>
> ,102002,2010/07/04,08:00,2,518,0,0,1,2,0
>
> ,102002,2010/07/07,08:00,2,127,0,0,1,2,0
>
> ,102002,2010/07/10,08:00,2,35.2,0,0,1,2,0
>
> ,102002,2010/07/14,08:08,2,30,0,0,2,2,0
>
> ,102002,2010/07/17,08:00,2,30,0,0,2,2,0
>
> ,102002,2010/07/21,08:00,2,30,0,0,2,2,0
>
> ,102002,2010/07/23,15:05,2,30,0,0,2,2,0
>
> ,102002,2010/07/28,08:21,2,30,0,0,2,2,0
>
> ,102003,2010/08/06,8:35,3,0,1.25e+08,1,1,1,1
>
> ,102003,2010/08/06,8:35,3,0,0,1,1,-3,2
>
> ,102003,2010/08/06,14:35,3,132,0,0,1,2,0
>
> ,102003,2010/08/06,20:35,3,189,0,0,1,2,0
>
> ,102003,2010/08/07,08:35,3,210,0,0,1,2,0
>
> ,102003,2010/08/07,20:35,3,246,0,0,1,2,0
>
> ,102003,2010/08/08,08:35,3,221,0,0,1,2,0
>
> ,102003,2010/08/09,08:35,3,236,0,0,1,2,0
>
> ,102003,2010/08/10,08:35,3,180,0,0,1,2,0
>
> ,102003,2010/08/13,08:35,3,55.9,0,0,1,2,0
>
> ,102004,2010/08/31,7:40,3,0,1.25e+08,1,1,1,1
>
> ,102004,2010/08/31,7:40,3,0,0,1,1,-3,2
>
> ,102004,2010/08/31,13:52,3,309,0,0,1,2,0
>
> ,102004,2010/08/31,19:40,3,252,0,0,1,2,0
>
> ,102004,2010/09/01,07:40,3,224,0,0,1,2,0
>
> ,102004,2010/09/01,19:43,3,265,0,0,1,2,0
>
> ,102004,2010/09/02,07:40,3,306,0,0,1,2,0
>
> ,102004,2010/09/03,07:40,3,328,0,0,1,2,0
>
> ,102004,2010/09/04,07:40,3,206,0,0,1,2,0
>
> ,102004,2010/09/07,07:40,3,37.6,0,0,1,2,0
>

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