Doses let you increase the amount of a species in a SimBiology® model during simulation, either at specific time points or regular intervals. For example, you can use a dose object to model an instantaneous supply of a drug regimen during the simulation of a model. The increase in the amount of a species occurs only during simulation and does not alter the species value permanently (that is, the value in the model is not changed).
There are two types of dose objects.
ScheduleDose object —
Applies a dose to a single species at a predefined list of time points
RepeatDose object —
Applies a dose to a single species at regular intervals
SimBiology dose objects support the following dosing types.
|Dosing Strategy||Description||Dose Object Properties Configuration|
|Bolus||Instantaneous increase in the amount of drug in the compartment||To create a bolus dose, set the |
|Infusion||Increase of the drug at a fixed rate over a period of time, which is calculated from the dose amount||Unlike a bolus dose, you also need to specify the infusion
|Zero-order||Increase of the drug at a fixed rate calculated from the dose amount and dose duration||Unlike a bolus dose, you also need to create a zero-order duration
parameter and specify the duration parameter name (|
|First-order||Increase of the drug via first-order absorption kinetics||Unlike bolus, infusion, or zero-order, you need to create an additional reaction for the drug absorption.|
There are two common ways to create dose objects using the command-line
interface. One way is to create a dose object using the
Another is to create dose objects automatically from data containing
dosing information. This first approach is useful when you want to
explore different dosing strategies through simulation. The second
approach is useful if you already have a data set with dosing information
and plan to use this dosing information in your simulation or parameter
sbiodose creates a standalone
dose object that is not attached to any model. You can apply a standalone
dose to different models during simulation by specifying it as a dosing
or attach it to any model using
You can also use it during parameter estimation using
adddose creates a dose
object and adds it to a model. You must set its
true to apply the dose to the model during simulation.
The following examples show how to add a dose object to a one-compartment
PK model using
sbiodose and set up the dose properties
manually. Alternatively, you can use the built-in PK models with different
dosing types. For details, see Create Pharmacokinetic Models.
|Bolus||Add a Series of Bolus Doses to a One-Compartment Model|
|Infusion||Add an Infusion Dose to a One-Compartment Model|
|Zero-order||Increase Drug Concentration in a One-Compartment Model via Zero-order Dosing|
|First-order||Increase Drug Concentration in a One-Compartment Model via First-order Dosing|
If you already have dosing data for one or more subjects or
patients that you would like to use in your parameter estimation,
first create a
groupedData object from
your data set. Use
to automatically generate an array of dose objects. You can then use
the dose array during parameter estimation using
For a complete workflow, see Modeling the Population Pharmacokinetics of Phenobarbital in Neonates.
You can interactively create and add doses using the SimBiology desktop. For details, see Diagram View.
To simulate models containing doses, use a deterministic (ODE or SUNDIALS) solver. Stochastic solvers do not support doses. For details, see Choosing a Simulation Solver.