# Dose Control Parameters (DCP)

The dosecontrol part of a PumasModel allows for specifying special pre-processed

parameters known as the Dose Control Parameters (DCP). Unlike standard parameters which are for use in the proceeding blocks, the DCP are used to modify the internal event handling of the Pumas. The DCP are defined as follows:

• lags: the lag of the dose. A dose with a lag will take place at time t = dosetime + lag. Default is zero.
• bioav: the bioavailability of the dose. The true dose is equal to bioav*amt where amt is the dose amount from the dosage regimen. Default is 1.
• rate: the rate of the dosing.
• duration: the duration of the dose.

rate and duration handling are intertwined and always satisfy the relation amt = rate*duration. Any two of the values are given, the third is automatically defined. If both rate and duration are specified, then an error will be given unless amt = rate*duration is satisfied.

## Input Definition

If a DCP is defined as a scalar, then it applies to all doses. For example, if a dosecontrol block contains the definition:

@dosecontrol begin
lags = θ
end

and θ is a scalar, then every dose will be lagged by the parameter θ. If there are several dynamic variables (compartments) they can have individual lags associated with dosing into them like the following:

@pre begin
lags = (Depot1=θ, Depot2=0.5)
end

where the lag of dosing into Depot1 is controlled by θ and the lag of dosing into Depot2 is fixed at 0.5. Omitting dynamic variables in this way of specifying DCPs implicitly sets the value of the missing variables to the default value as specified at the top. Likewise, if a DCP is defined as a collection, then the value of the collection corresponding to the cmt-index of the dose specifies the DCP. For example:

lags = [2,0]

implies that any dose into cmt=1 will have a lag of 2, while any dose into cmt=2 will have a lag of 0.