The $AESINITIAL record is used to compute the amounts in the equilibrium compartments at the beginning of an integration interval. It is used with PREDPP's ADVAN9, ADVAN15 and ADVAN17.

May also be coded $AES0.

The complete AES routine can be divided into two parts: code which computes the amounts in the equilibrium compartments at the beginning of an integration interval (these amounts depend on the amounts in the nonequilibrium compartments) and code which computes values for the right sides of the algebraic equations. An abbreviated code for AES is actually divided into two abbreviated codes which correspond to the two parts of the complete AES routine. This record gives an abbreviated code for the first part of the AES routine. The $AES record gives an abbreviated code for the second part. The $AESINITIAL record, along with all its continuation records, is called a $AESINITIAL block.

This record is optional. If it appears, it must be with the first problem specification, and only this problem specfication. If there are no equilibrium compartments, but ADVAN9 or ADVAN15 is used, the record need not appear. It may not appear when the MODEL routine is user-supplied. Implicit basic PK parameters may be used in the $AESINITIAL block (see below) only when the $PK block precedes the $AESINITIAL block.

In order to compute the amounts in the equilibrium compartments at the beginning of an integration interval, the algebraic system must be solved. However, only an approximate solution is needed. If requested, this will be used only as an initial solution, and ADVAN9 will numerically obtain a more precise solution.

See abbreviated code for general rules. Specific rules follow.

• A(ncm1+1), A(ncm1+2), … (Required. The amounts in the equilibrium compartments at the beginning of the integration interval. ncm1 is the number of nonequilibrium compartments.)

• INIT (Initialization flag.)

  • INIT=0: The A(n) are approximate.
  • INIT=1: The A(n) are exact (the default).
• AESINITIAL-defined (i.e., PRED-defined) items.

• A(1), A(2), … (Current compartment amounts; may be random variables.)
• P(1), P(2), … (Post-translation basic PK parameters; may be random variables.)
• PK-defined items (Implicit basic PK parameters; may be random variables.)
• T (Time at the beginning of the integration interval; may be random variables.)
• AESINITIAL-defined items that appeared earlier as left-hand quantities.
• Data item labels specified on the $INPUT statement.
• THETA(n).
• Global Variables in Modules: certain variables in FORTRAN modules can be used.

Forbidden Variable Names: IR DA DP DT E(n) ETA(n) EPS(n) ERR(n)

• COMRES=-1

• Calling protocol:

  • CALLFL=-1: Call ADVAN and AES with every event record (default).
  • CALLFL=1: Call ADVAN and AES once per individual record. (CALLFL may be used only when the TIME data item is not defined.)

  The pseudo assignments statements may be enclosed in parentheses. If both are present within the same set of parentheses, separate them with a semicolon. Within parentheses, a calling protocol phrase may be used instead of CALLFL, and either upper or lower case may be used. E.g.,

  1 2	$AESINIT (ONCE PER IR) ;# same as CALLFL=1 $AESINIT (EVERY EVENT) ;# same as CALLFL=-1 (default)

  See caling protocols for details.

• Follows $SUBROUTINES $INPUT $MODEL $PK
• Precedes $AES