Re: Modeling enantiomeric and racemic concentrations simultaneously
The code suggested by Martin seems reasonable (ADVAN7 is usually faster than
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
Quoted reply history
On 6/18/07, Rasmus Jansson <[EMAIL PROTECTED]> 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 two
> 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-file
> 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