Show results at Time after "selected" dose

Phoenix Certara Forums Modelling and Simulation
1

I have a PKPD model where I use a dosing to start a PD challenge (I dose the “effect” into an ODE).

As the experiment is spanning multiple doses and weeks. I would like to display the results in TAD. My problem is that the time resets after both drug dosing and effect dosing.

Can I set the TAD to be after the drug dosing only OR could I input an effect into the effect compartment with the use of a sequence statement at the times defined by a flag in my dataset. Instead of using a dosing statement.

Like: (or something like that)

fcovariate(effectDose)

sequence{E=effectDose}

BR Frederik

PS I can’t send you the file.

2

Hi Frederik,

I don’t completely understand it, but let me describe what I read:

you have essentially two doses, one for the PK and one for the PD.

TAD reported by Phoenix is not useful since it will cover both dosing events together.

If you want a specific TAD calculated just for the effect dosing you would need to define another TAD, e.g. TADE

double(dosetime)
tade=t-dosetime
dosepoint(effectDose,dobefore={dosetime=t})

Not sure if this helps.

Bernd

3

It Works!

PS

What does the double function do? is it like as.double function in R.

Thx, Frederik

4

Glad, it works. And you are correct, double stands for double-precision variable and the statement just declares dosetime as variable with double precison.

BR,

Bernd