RE: two compartment with nonlinear elimination
Chiaying,
Your concentration-time profiles seem to suggest that there’s an absorption
phase which was not accounted for in your model/control stream. What was the
route of administration?
Ken
Quoted reply history
From: [email protected] [mailto:[email protected]] On
Behalf Of Chiaying Lin
Sent: Tuesday, September 08, 2015 7:57 AM
To: [email protected]
Subject: [NMusers] two compartment with nonlinear elimination
Dear NMusers,
I'm a NM beginner modeling for a monoclonal antibody. Below is 12 subjects's
individual predicted plot , it seems that nonlinear elimination
(Michaelis-Menten) model can fit the data well. However, when running the
control stream (two compartment models with linear and non-linear elimination),
the resulting Q THETA SE% and OMEGA SE% are quite large even thought successful
minimization.From the Correlation Matrix , I find that THETA (1) (VMAX) and
THETA(2) (KM)are highly correlated (9.67E-01). Another problem is the .fit file
can't be produced.
I have tried various error models and initial estimations, however, none had
better improvement and often got error message (error 134 or parameter estimate
is near its boundary). Does re-parameterization helpful ? or need to change to
other models?
Any suggestions for solving the problems are highly appreciated.
(control stream will be send in another e-mail)