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Re: [NMusers] Simultaneous pk model of 2 drugs

From: William Denney <>
Date: Fri, 2 Sep 2016 15:01:28 -0400

Hi Chris,

I think that the most straight-forward way to handle this is to have two set=
s of compartments and write the $DES block manually (or writing the algebrai=
c equations if it's a one- or two-compartment model).

It wouldn't be straight-forward to model if the subjects receive the drugs a=
t the same time. If the drugs are received at separate times (like differen=
t periods of a study or even different studies), then the DVID flag idea wou=
ld work, too.

There are only five EVID values as far as I know, and there's not a subtle w=
ay to use them for two doses, I don't think:

• 0= observation
• 1= dose
• 2= other (I usually use it to reset the compartment)
• 3= reset the subject
• 4= reset and dose at the same time



> On Sep 2, 2016, at 1:22 PM, Penland, Chris <>=
> Greetings NMusers,
> Does nonmem have the capacity, unbeknownst to me, for modeling two simulta=
neous drugs?
> I would like some suggestions about how to define the dataset and model fo=
r a subcutaneous drug and oral drug being administered on different schedule=
s. I would use DVID = 1 and 2 for the two plasma pk observations. I figur=
e this soft of thing had to be dealt with in the past when trying to model d=
ynamic DDIs (vs, just taking one of the drugs as a covariate on the other=
s parameters).
> One approach is to specify the compartments for each to be dosed into then=
 have those feed the central, but I’m curious to see if there is som=
ething more subtle in the nonmem syntax. Is there something about EVID, that=
 I don’t know that would help (beyond EVID=1 for dosing)
> What if you had two oral drugs? Would you treat the two dosing compartment=
s as separate and possibly link them together at the parameter/covariance le=
> Thanks,
> Chris
> Chris Penland, PhD
> ECD / Quantitative Clinical Pharmacology
> Waltham, MA USA
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Received on Fri Sep 02 2016 - 15:01:28 EDT

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