Re: modeling of total concentration of two drugs with different kinetics in NONMEM
Yaming,
Code should not be the problem, you just model each of them separately (say, A(1) for drug 1 and A(2) for drug 2) and then combine them as
Y=A(1)/V1 + A(2)/V2 + error.
What is more difficult to to identify parameters of each drug when you have only combined measurements. This can not be discussed in general, it is specific to each problem.
Good example is monoclonal antibodies where you have total antibody concentration measured while the blood contains free antibody + antibody bound to the target.
Leonid
--------------------------------------
Leonid Gibiansky, Ph.D.
President, QuantPharm LLC
web: www.quantpharm.com
e-mail: LGibiansky at quantpharm.com
tel: (301) 767 5566
Quoted reply history
On 4/25/2012 9:22 AM, Yaming Hang wrote:
> Dear All,
>
> I’m trying to model in NONMEM the kinetics of two drug entities
> co-existing in the blood. Since the assay cannot differentiate these two
> entities, I only have the total concentration of these two in the blood.
> Does anyone has similar experience? Can you please share the NONMEM code?
>
> Thanks,
>
> Yaming
>
> Yaming Hang, Ph.D.
>
> Pharmacometrics
>
> Biogen Idec
>
> 14 Cambridge Center
>
> Cambridge, MA 02142
>
> Office: 781-464-1741
>
> Fax: 617-679-3463
>
> Email: [email protected] <mailto:[email protected]>