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]
