Re: Modeling Hemodialysis clearance
Xiao,
When you turn a compartment off, amount in the compartment becomes
zero, and is not changing while it is off. Whatever was coming to
this compartment from another compartment(s) still leaves this other
compartment and the system as a whole (so mass balance is not
preserved). Nothing comes back from this compartment (even if
kinetic model has distribution back from it) since nothing is there.
The system behaves as if for the time when compartment 3 is off, you
have the equation A(3)=0 instead of DADT(3)=K23*A(2).
Regards,
Katya
Ekaterina Gibiansky, Ph.D.
CEO&CSO, QuantPharm LLC
Web: www.quantpharm.com
Email: EGibiansky at quantpharm.com
Tel: (301)-717-7032
On 7/21/2011 7:39 AM, Xiao Hu wrote:
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
Quoted reply history
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
Email: [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] >
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] ]
Sent: Wednesday, July 20, 2011 9:45 AM
To: Xiao Hu
Cc: [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
>