For this exercise, we’ll need the campsismod
package.
This package can be loaded as follows:
library(campsismod)
Assume a very simple 1-compartment PK model with first-order
eliminate rate K
. Say this parameter has a typical value of
log(2)/12≈0.06 (where 12 is the elimination half life) and has 15% CV.
Let’s also initiate the central compartment to 1000.
This can be translated into the following CAMPSIS model ( download Notepad++ plugin for CAMPSIS ):
Let’s now create our theta.csv
with our single parameter
K
as follows:
And finally, let’s also create our omega.csv
to include
inter-individual variability on K
:
This model can now be loaded by campsismod
…
<- read.campsis("resources/minimalist_model/") model
## Warning in read.allparameters(folder = folder): No file 'sigma.csv' could be
## found.
Let’s simulated this model in CAMPSIS:
library(campsis)
<- Dataset(25) %>% add(Observations(seq(0,24,by=0.5)))
dataset <- model %>% simulate(dataset=dataset, seed=1)
results spaghettiPlot(results, "A_CENTRAL")
The same model can be created programmatically. First, let’s create an empty CAMPSIS model.
<- CampsisModel() model
Then, let’s define the equation of our model parameter
K
.
<- model %>% add(Equation("K", "THETA_K*exp(ETA_K)")) model
We can add an ordinary differential equation as follows:
<- model %>% add(Ode("A_CENTRAL", "-K*A_CENTRAL")) model
We can init the central compartment as well on the fly:
<- model %>% add(InitialCondition(compartment=1, "1000")) model
Finally, let’s define our THETA_K
and
ETA_K
:
<- model %>% add(Theta("K", value=0.06))
model <- model %>% add(Omega("K", value=15, type="cv%")) model
This model can simulated by CAMPSIS as well. Powerful, isn’t it?
library(campsis)
<- Dataset(25) %>% add(Observations(seq(0,24,by=0.5)))
dataset <- model %>% simulate(dataset=dataset, seed=2)
results spaghettiPlot(results, "A_CENTRAL")