PK/PD model options

PK/PD models can be specified by selecting a PK/Emax, PK/Indirect, or a PK/Linear model from the Type menu or by setting a PK/PD link model as discussed above.

When a PK/Emax, PK/Indirect, or a PK/Linear model is selected, there are two observation columns displayed in the mappings panel: one for concentration observations; and one for effect observations.

The following options are specific to PK/PD models

Check the Effect Cpt? checkbox to add an effect compartment to the model.
Check the Freeze PK? checkbox to freeze the PK parameters by removing the PK observation from the model. Only the parameters for the PD model are estimated.
Check the Sequential PK/PD? checkbox to estimate the PK and PD parameters sequentially.

Checking the Sequential PK/PD? checkbox freezes the PK portion of the model and turns its random effects into covariates to be imported from the first model, so that plasma concentration will be predicted identically to what it was predicted as in the first model. It also removes the PK observation from the model, since the PK portion of the model is not being fit. See “Sequential PK/PD population model fitting” for more information.

To include a hysteresis plot, on the Run Options tab, add a Table with Times and Variables C, E, CObs, EObs, Ce for built-in models (or use the specified Variable names from graphical or textual models), and then create the desired plot from the Table output.”