NONMEM Users Network Archive

Hosted by Cognigen

RE: Simultaneous vs sequential for modeling parent AND metabolites in pop PK

From: Hussein, Ziad <Ziad.Hussein>
Date: Tue, 9 Dec 2008 16:37:56 -0000

Hi Alan,

I just had a very recent experience few weeks ago for a sequential PopPK
for parent and metabolite that was submitted to the FDA and they came
back and asked for simultaneous modelling.

Whether this is scientific or not the FDA view should be taken into

Kind regards,

-----Original Message-----
From: owner-nmusers
On Behalf Of Xiao, Alan
Sent: 09 December 2008 16:02
To: nmusers
Subject: [NMusers] Simultaneous vs sequential for modeling parent AND
metabolites in pop PK

Dear All,

I know this is an old topic but would like to see the statistics.

When you have to develop a pop PK model for both parent and active
metabolites, which approach do you prefer or have you used most:
simultaneous or sequential? Which way do you think is more scientific? I
heard comments saying that the simultaneous approach is not scientific.


ICON plc made the following annotations.
This e-mail transmission may contain confidential or legally privileged i=
that is intended only for the individual or entity named in the e-mail ad=
dress. If you
are not the intended recipient, you are hereby notified that any disclosu=
re, copying,
distribution, or reliance upon the contents of this e-mail is strictly pr=
ohibited. If
you have received this e-mail transmission in error, please reply to the =
sender, so that
ICON plc can arrange for proper delivery, and then please delete the mess=
Thank You,
ICON plc
South County Business Park
Dublin 18
Registered number: 145835

Received on Tue Dec 09 2008 - 11:37:56 EST

The NONMEM Users Network is maintained by ICON plc. Requests to subscribe to the network should be sent to:

Once subscribed, you may contribute to the discussion by emailing: