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Re: [NMusers] Is “DOSE=0” accepted by NONMEM?

From: Paolo Denti <paolo.denti_at_uct.ac.za>
Date: Mon, 7 Sep 2015 08:38:08 +0000

Dear Zheng,
NONMEM wants an amount there, or it won't interpret that record as a dose. =
On the other hand, if you don't put anything into the system, or you do not=
 initialise the compartments (see below), nothing is going to happen.

If you want to use a dose to initialise the system, them you can put AMT==
1 and use the bioavailability parameter to decide how much to put it F1= =
YYY.
YYY can be then be a number in the data or a parameter.

If you want to use parameters, I suggest that you look into how to model ba=
selines

Dansirikul C, Silber HE, Karlsson MO. 2008. Approaches to handling pharmaco=
dynamic baseline responses. J. Pharmacokinet. Pharmacodyn. 35:269–283.

In the same paper there are also snippets of code on how to initialise comp=
artments with the command
A_0(1) = YYY
which is a somewhat neater option.

I would prefer the second option A_0_1, but I guess if you use some of the =
basic ADVANs, NONMEM may expect a dose and give you an error if it doesn't =
find one.

Good luck.
Paolo



On 2015/09/07 08:30, Zheng Liu wrote:

Dear NONMEM users,



I have a group of patients, whose plasma drug levels are measured and known=
 at time=0 (no further drug is given to the patients afterwards.). I try =
to know, after how long time the drug will be completely cleared out from t=
hese patients. Naturally I used NONMEM to fit the patients' V and CL, in or=
der to get plasma concentration change profile.


However seems NONMEM only accepts DOSE is a positive number. If DOSE=0, N=
ONMEM can't perform the fitting. Can anyone kindly give me some suggestions=
 to solve this problem? Thanks a lot in advance!



PTID DV AMT time EVID
2 . 0
        0 1
2 6.8 0 0 0
2 1.1 0 3 0
2 0 0 6 0
3 . 0 0 1
3 1.08 0 0 0
3 0.16 0 3 0
3 0.03 0 6 0
3 0 0 9 0



Zheng


--
------------------------------------------------
Paolo Denti, PhD
Pharmacometrics Group
Division of Clinical Pharmacology
Department of Medicine
University of Cape Town

K45 Old Main Building
Groote Schuur Hospital
Observatory, Cape Town
7925 South Africa
phone: +27 21 404 7719
fax: +27 21 448 1989
email: paolo.denti_at_uct.ac.za<mailto:paolo.denti_at_uct.ac.za>
------------------------------------------------

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Received on Mon Sep 07 2015 - 04:38:08 EDT

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