Re: Steady state model

Sherwin, I dont understand exactly how NONMEM computes the steady state value but with ODEs it seems to be done using a numerical root finding procedure i.e. solves for the amt in each of the compartments when all the DEs have a value of zero. The amt in each compartment is set to the steady state value. There is no initial 'parameter' for the compartment. Compartment amounts are variables. Parameters are constants. Parameters (e.g. THETA values) are used in the ODEs to define the DE values. Perhaps Alison Boechmann (who wrote the code) could give a more thorough answer? Nick Sherwin K Sy wrote: > Dear NONMEM users, > > I'm wondering what equation or ODE is used in NONMEM when the steady state is set (i.e. SS = 1). Is it the case that the initial parameter for the compartment is set to a different value? If so, how does NONMEM set this value? > > I would appreciate if anyone can provide me with a reference or point me to where I can find this information, including the type of equation used for extravascular, iv bolus and iv infusion models. > > Thanks, > > Sherwin -- Nick Holford, Professor Clinical Pharmacology Dept Pharmacology & Clinical Pharmacology University of Auckland, 85 Park Rd, Private Bag 92019, Auckland, New Zealand [email protected] tel:+64(9)923-6730 fax:+64(9)373-7090 mobile: +64 21 46 23 53 http://www.fmhs.auckland.ac.nz/sms/pharmacology/holford