Re: [NMusers] Modeling enantiomeric and racemic concentrations simultaneously

The code suggested by Martin seems reasonable (ADVAN7 is usually faster tha=
n
ADVAN5). The only com ponent you would notbe sure about is the possibility
of competetive interaction between enantiomers at the site of
metabolism/clearance. Information (even preliminary) from drug-drug
interaction studies would definitely help. The code that addresses PK
interaction would include a component where clearance of one enantiomer is
reduced/ enhanced by the concentration of the other.

I hope this helps.

Murad Melhem, Ph.D.
Cognigen Corporation
Buffalo, NY


On 6/18/07, Rasmus Jansson <rasmus.jansson_at_pharm.gu.se> wrote:
>
> Dear all,
>
> I have conducted a pharmacokinetic study in rat and I have a question
> about how to model enantiomeric and racemic concentrations simultaneously=
.
>
>
> The study design was as follows:
>
> Sparse data (2 – 3 plasma samples, n=10 rats) was collected for the t=
wo
> enantiomers, and rich data for the racemate (10-15 plasma samples, n=4
> rats) following oral administration.
>
> I would like to build an individual model for each enantiomer and use the
> racemic data to stabilize the sparse data I have on the enantiomers. Do
> you have any suggestions how this could be done and how such a control-fi=
le
> should be written?
>
>
>
> Kind regards,
>
> Rasmus Jansson
>
> _____________________________________________
> Rasmus Jansson
> Unit for Pharmacokinetics and Drug Metabolism
> Göteborg University
> P.O.Box 431, SE-405 30 Göteborg
> Sweden
> Phone: +46(0)31 786 3240
> Fax: +46 (0)31 786 3284
>
>
>

Received on Wed Jul 04 2007 - 12:46:24 EDT