Using dose (AMT) in Model

[Murali-Ramanathan]

Hi

I am relatively new to nlmixr.

I have a fairly standard depot compartment-central compartment model with a wrinkle

d/dt(depot) = -ka x DOSE x Function(t)
d/dt(centr) = ka x DOSE x Function(t) - k x centr

Is there a way to bring DOSE into model from the input data? I have a single bolus dose so there is no particular complexity.

Thanks
Murali

[mattfidler]

You typically add evid=1 and amt=dose in the dataset to have a bolus dose in the first compartment.

The ode would be:

d/dt(depot) = -ka * depot
d/dt(centr) = ka * depot - k * centr

Other sorts of doses are also allowed; See:

https://nlmixr2.github.io/rxode2/articles/rxode2-event-types.html

[mattfidler]

Also I develop nlmixr2 which is here:

https://nlmixr2.org

Since there hasn't been any activity on this repo for years, I am thinking of archiving it. If nlmixr comes back as another fork, they would want a separate repo probably anyway...

[Murali-Ramanathan]

Thanks Matt. I use nlmixr2 and will use that repository! I have no problem with the data file. I want to drag a data file variable into my model file.

[mattfidler]

Just refer to it by the name in the data file. It will be detected as a covariate