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| SS DOSE EVENT RECORD |
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MEANING: Specification of steady-state dose for PREDPP
CONTEXT: $INPUT record and NONMEM data set
DISCUSSION:
PREDPP recognizes two varieties of doses, transient and steady-state.
Transient doses are described separately (See dose_event). Steady-
state doses are described here.
(With NM75 there is a new way of computing SS, the Empirical steady
state method, in which there is no SS data item, and a negative value
of ADDL requests the computation. This is described separately.)
(See empirical_SS).
(See Guide Introduction_7)
A steady-state dose is a dose that is imagined to be the last of a
series of implied doses, each exactly like the dose in question, given
at a regular interval specified by the II data item and leading to
steady-state by the time the steady-state dose is given.
For steady-state doses, the SS data item must be defined and positive
(See ss_data_item).
The ADDL data item may be used on the SS dose event record to specify
additional transient doses after the steady-state dose, given at the
interval II.
The CMT data item (See cmt) applies to steady-state doses as to tran-
sient doses.
PK parameters absorption lag (ALAGn), bioavailability (Fn), modeled
rates (Rn) and modeled durations (Dn) apply to steady-state doses as
they do to transient doses, except as noted.
When absorption lag applies, it is understood to apply to all implied
doses. Steady-state is computed as if there were no ALAG, and then |
there is an advance to the appropriate point in the steady-state cycle |
(II-ALAG). |
See Guide VI, Section V.F.4, Note 4 |
MTIME parameters do not apply to steady-state doses. |
See Guide VI, Section V.F.4, Note 3 |
When bioavailability applies, it is understood to apply to all implied
doses.
Values of AMT, RATE, II data items:
AMT RATE II
>0 0 >0 Steady-state with multiple bolus doses.
>0 >0 >0 Steady-state with multiple infusions.
The final infusion is started at the event time of
the SS dose record and continues beyond its event
time. (More than one infusion continues when the
duration of the steady-state infusion is greater
than II.)
>0 -1,-2 >0 Steady-state with multiple zero-order bolus doses.
The final infusion is started at the event time of
the SS dose record and continues beyond its event
time. (More than one infusion continues when the
duration of the steady-state infusion is greater
than II.)
0 0,>0,-1 0 Steady-state with constant infusion.
The infusion terminates at the event time of the
SS dose record. The ADDL data item cannot be used
to specify additional transient doses. Doses with
rate 0 are useful when the differential equations
coded by the user explicitly provide for endoge-
nous drug production.
(The Initial Steady State feature (I_SS) may be |
specified in the model instead of using a steady- |
state dose record with rate 0.)
REFERENCES: Guide VI Section V.F
REFERENCES: Guide V Section 6.8
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