volume but doing the same thing. I
appreciate if anybody share some of their experience here.
I am giving my initial estimate in this format: $THETA (0,500);POPVP
Regards,
Ayyappa Chaturvedula
scenarios where one performs better than
other, if at all.
Ayyappa Chaturvedula, PhD
Visiting Assistant Research Professor,
College of Pharmacy and Health Sciences,
Mercer University,
3001 Mercer University Drive,
Atlanta, GA 30341
6785476168 (O)
Dear Group,
I am working on a data set with PK -PD assessments from a three way cross-over
study with different formulations of the drug. I have measurable
concentrations at Time zero right from period 1 and the analyte of interest can
come from food. I appreciate your ideas on handling this
Dear all,
I am trying to use BAYESIAN method in NONMEM and want to know any rule of thumb
for specifying THETA for "DEGREES OF FREEDOM TO PRIOR OMEGA MATRIX".
Regards,
Ayyappa
reason, my files related XPOSE (CATAB, PATAB etc..) are not created
but others are coming fine. The run was successful with all the estimations
but having trouble with Table files. I appreciate your help to resolve this.
I am using g95 fortran compiler, Windows 7,NONMEM7.2.
Ayyappa Chaturvedula
Dear Group,
What is the meaning of SAEMOBJ zerosI am getting this but model is still
running OK. I saw a thread before in the usernet about it but no answers were
found. I appreciate your help.
Regards,
Ayyappa
Dear expert users,
I am working on a dataset where subjects were sampled at different visits at
random. I have developed a model for the data but not sure how to do a VPC as
they do not have the same sampling scheme. I appreciate some guidance in this.
Regards,
Ayyappa
Dear Group,
I have the following intel fortran compiler (now they call it composer):
Intel(R) Visual Fortran Compiler XE 12.1 Update 2 for Windows*
Intel(R) Parallel Debugger Extension 12.1 Update 2
I am running nonmem through WFN and I see the configuration file has examples
till v 11:
Joachim,
I found the following also useful in calculating df from IW distribution.
Dansirikul C, Morris RG, Tett SE, Duffull SB.
A Bayesian approach for population pharmacokinetic modelling of sirolimus. Br J
Clin Pharmacol. 2006 Oct;62(4):420-34.
Regards,
Ayyappa
From: owner-nmus...@globoma
Dear All,
I am trying to run a model using WFN. When I give the command nmgo base.ctl,
the command prompt just goes quiet. I opened the directory that is created by
this command base.nm7 and I do not see the files that are normally seen in such
runs. I have a file base.ecs and I never saw a
Dear Group,
I am probably revisiting this issue.
I am working on a study where the blood samples are collected at steady-state.
Subjects are samples for pre-dose blood sample and 4-6 samples after clinic
observed doses (typical way). The prior-dose to the clinic visit was not
recorded. I wo
Alison,
Thank you for the response, it is helpful.
Regards,Ayyappa Chaturvedula
On Mar 29, 2012, at 1:59 PM, "Alison Boeckmann" wrote:
> I cannot understand or answer most of your questions.
>
> The Exogenous supplementation example uses SS with modeled rate to
> mod
Dear group,
Yet another question to the group. I am working on a model for drug molecule
with parent-metabolite data. I am requesting NPDE in NONMEM 7.2 and plotting
NPDE overlaid on standard normal distribution to see the goodness-of-fit. Now,
do I need to plot different plots for parent an
Dear Group,
This is a topic that has been discussed and different schools of thinking exist
to my knowledge. But, I want to restate my case and get some opinions. The
question is about how important to have successful minimization and covariance
if diagnostics make sense. I have developed a
Dear users,
I am finding weight as a covariate on peripheral volume and objective function
is dropping more than on central volume in a two compartment model. I am not
sure if this is meaningful, I appreciate your comments.
Regards,
Ayyappa
@gmail.com>> wrote:
Hi Ayyappa,
did you try testing it on both volumnws at the same time? Would make more sense
to me.
Regards
Sven
Am 12.08.2012 um 01:20 schrieb Ayyappa Chaturvedula
mailto:chaturvedul...@mercer.edu>>:
Dear users,
I am finding weight as a covariate on periphera
Dear Users,
I have a seen a difference in the Eigen values given by the nonmem output
between 32 and 64 bit versions. My 64-bit nonmem run was same in terms of all
the parameter estimates but the condition number is much smaller compared to
32-bit run. Can better precision of 64-bit computer
Dear Group,
I want to implement M3 method with log transformed data. I want to use the
additive error model in log domain and wrote the following code and the runs
are fine. I want to make sure that I am doing this right.
$ERROR
CALLFL=0
IPRED=-3
IPRED=LOG(F)
W=THETA(4) ;LOG ADDITIVE ERROR
L
Dear users,
I am modeling a PK data set with sparse data (2-3 samples/ind,~250
individuals). When I plotted TPST vs Conc, I do have a reasonable spread of
concentrations across the PK profile. I started modeling (2-comp better model)
with FOCEI and was getting numerical difficulties and wante
Dear Group,
I want to test CRCL as a covariate on clearance as follows:
TVCL = THETA(1)*(CLCR/120)**THETA(2). I am using EM methods for estimation and
the following code can be used as per the manual:
MU_1= LOG(THETA(1))+THETA(6)*LOG(CLCR/120)
CL=EXP(MU_1+ETA(1))
The issue with this code for m
Thank you very much for the suggestions, very helpful.
Regards
Ayyappa
From: Bauer, Robert [mailto:robert.ba...@iconplc.com]
Sent: Monday, April 14, 2014 11:21 AM
To: Henrik B. Nyberg; Ayyappa Chaturvedula; nmusers@globomaxnm.com
Subject: RE: Mu referencing in covariate model
This does leave
Swati,
Did you run a model without additive RUV and checked if it is required?
Best Regards,
Ayyappa
> On Jan 21, 2016, at 2:44 AM, swati j wrote:
>
> Dear members of nmusers:
> I am trying to do PopPK analysis of plasma concentration-time data obtained
> from a non-steady-state PK study of
Dear Laureen,
High condition number represents overparametrization. You must check also the
correlation matrix for potential correlations above 0.95 between parameters. If
you strongly feel on the biological basis that your drug is a 3 compartment
model, then you may fix some of the parameters o
Dear All,
I have a large dataset and trying to use parallelization using default mpi
option in NONMEM 7.3. The current mpiwini8.pnm is working fine but I want to
increase number of -nodes (PSN) to 20 to be more efficient. My understanding is
that the current pnm file has upper limit for 8 nodes
Suite 100
> Gaithersburg, MD 20878
> Office: (215) 616-6428
> Mobile: (925) 286-0769
> robert.ba...@iconplc.com
> www.iconplc.com
>
>
> -Original Message-
> From: owner-nmus...@globomaxnm.com [mailto:owner-nmus...@globomaxnm.com]
> On Behalf Of Ayyappa Chat
Hi Anuja,
I would be careful about using partial data for model building. You want to be
sure that the structural model is capturing the true behavior of the drug. I
mean that you should not miss a gamma-slope if exists. You may have some prior
information on this drug (as I understand from your
Dear All,
I am trying to run a simulation using $MSFI option instead of giving $THETA
and $OMEGA. One of the model gave the following error and a recommendation:
F_LVR AND/OR F_LTH ARE TOO SMALL TO DEAL WITH INPUT FROM MSFI FILE.
RECOMMEND INSERTING AS FIRST LINE OF CONTROL STREAM:
$SIZES LTH=
AME_ETAS.MSF. Both
> should be in the same file path specified in the control stream for
> FILENAME.MSF file.
>
> Leonid
>
>
>
>
>> On 4/20/2019 11:11 AM, Ayyappa Chaturvedula wrote:
>> Dear All,
>> I am trying to run a simulation using $MSFI option
Hi Sumeet:
Couple of points, may not be solutions for the modeling problem you are having
but in general:
1. Use INTERACTION in your $EST because you are using proportional error
2. Make sure you have enough range of covariates in the data to describe the
relationships quantitatively
3. Are ther
Hi Sumeet,
Please check if your control stream accurately mentioned the column names. I
don’t see AMT as third column in $INPUT where your dose is listed.
Regards,
Ayyappa
> On Dec 2, 2019, at 9:55 PM, Singla, Sumeet K wrote:
>
>
> Hi Everyone,
>
> I am trying to relate my compound, THC
Hi Patricia,
What is the purpose of your modeling exercise? I am not sure your scenario
could be assigned to any particular distribution. If you intend to simulate
population from the model, then your assumptions would not be reasonable. If
you have rich data, you may try individual modeling ap
Hi Patricia,
What is the purpose of your modeling exercise? I am not sure your scenario
could be assigned to any particular distribution. If you intend to simulate
population from the model, then your assumptions would not be reasonable. If
you have rich data, you may try individual modeling ap
> IF(STRAT1.EQ.3) THEN; PRNT after 48 hour infusion
> W=SQRT(THETA(17)**2)
> Y = (IPRED + W*EPS(3))
> ENDIF
> IF(STRAT1.EQ.4) THEN; METB after 48 hour infusion
> W=SQRT(THETA(18)**2)
> Y = (IPRED + W*EPS(4))
> ENDIF
> IF(STRAT1.EQ.5) THEN; METB after oral administration
>
This is a related article using Monte Carlo Power Mapping (MCPM) that I
recently used. It is time efficient and takes the spirit of simulation and LLR
test.
Vong C, Bergstrand M, Nyberg J, Karlsson MO. Rapid sample size calculations for
a defined likelihood ratio test-based power in mixed-effe
Half-life is more relevant for first-order kinetics. For nonlinear PK,
half-life changes with concentration (~dose) and thus is not useful. As
David pointed out, phenytoin is a good example for this. We use the
Michaelis-Menten (MM) equation for dose calculations in case of phenytoin.
In that,
Dear all,
I am wondering if someone can provide references for the condition number
thresholds we are seeing (<1000) etc. Also, the other way I have seen when I
was in graduate school that condition number <10^n (n- number of parameters)
is OK. Personally, I am depending on correlation matrix r
ssociated with
> these moderate to high correlations.
>
> Best,
>
> Ken
>
> Kenneth G. Kowalski
> Kowalski PMetrics Consulting, LLC
> Email: kgkowalsk...@gmail.com
> Cell:248-207-5082
>
>
>
> -Original Message-
> From: owner-nmus...@gl
can observe a CN >10^20.
>
> I have not seen CN criteria indexed by n. The classifications of
> collinearity that I've seen based on CN are:
>
> Moderate: 100 <= CN < 1000
> High: 1000 <= CN < 10,000
> Extreme: CN >= 10,000
wise correlations are extreme if CN
> is very large.
>
>
>
> *From:* Ayyappa Chaturvedula [mailto:ayyapp...@gmail.com]
> *Sent:* Tuesday, November 29, 2022 11:07 AM
> *To:* Ken Kowalski
> *Cc:* nmusers@globomaxnm.com
> *Subject:* Re: [NMusers] Condition number
>
>
s (i.e., no estimation problem with modest
> standard error), you do not need to give attention to the condition number.
>
> I think I saw 10^(n – parameters) criterion in an old version of
> Gabrielsson’s book many years ago (but not in the latest version).
>
> Best regards,
&g
simply dismiss CN as
>>> not having any diagnostic value, just don’t apply it in a rule
>>> such as CN>1000 to blindly reject a model. The CN>1000 rule
>>> should only be used to call your attention to the potential for
>>> an issue that wa
Dear nmusers,
I am not getting any messages from the group. Could you please confirm my email
in the list? Thank you.
Regards,
Ayyappa
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