Re: COMPARTMENT INITIALIZATION: A_0

On Mar 29, 2012, at 1:59 PM, "Alison Boeckmann" <[email protected] > wrote: > I cannot understand or answer most of your questions. > > The Exogenous supplementation example uses SS with modeled rate to > model > an unknown dosing history prior to the observation period (i.e., > prior to time zero). All compartments receive the appropriate amount > from the SS dose, not just the central compartment. A_0 is not used. > > On Tue, Mar 27, 2012, at 03:43 PM, Ayyappa Chaturvedula wrote: > > Dear Group, > > > I am probably revisiting this issue. > > > I am working on a study where the blood samples are collected at > steady- > state. Subjects are samples for pre-dose blood sample and 4-6 samples > after clinic observed doses (typical way). The prior-dose to the > clinic > visit was not recorded. I would like to use the A_0 option to > estimate > the initial central compartment amount as a parameter along with > BSV. I > set SS=2 at the dosing event so that the compartment amounts not to > be > reset to zero but that the compartment amounts are to be set to the > sum > of the steady-state amounts resulting from the given dose plus > whatever those amounts would have been at the event time were the > steady- > state dose not given. Can somebody explain how NONMEM actually > calculates the A_0 of a compartment when SS=2 or SS=3 given and also > comment on the information does that parameter give more than the > trough > concentration measured at the clinical visit? > > > > Regards, > > Ayyappa > -- > Alison Boeckmann > [email protected] >