pkprofile.pkprofile: Continue an existing concentration-time profile.

Description

This method can be used to append to an existing PK profile, for instance to simulate a PK profile with parameters that change over time. Each time the parameters change, a new call to this method is used to advance the system with the new parameter values.

Usage

# S3 method for pkprofile
pkprofile(obj, t.obs = finaltime(obj) + seq(0, 24, 0.1), ..., append = TRUE)

Value

An object of class "pkprofile".

Arguments

obj: An object returned from a previous call to pkprofile.
t.obs: A numeric vector of times at which to observe concentrations.
...: Further arguments passed along.
append: Should the new profile be appended to the current samples? Otherwise, only the new samples are returned.

Warning

The new parameters take effect at the time when the previous profile ends. If the previous profile ends before the new sampling starts, the new parameters will be used to advance the system to the start of the new sampling.

Any ongoing zero-order infusion at the end of the previous profile is dropped. The remaining infusion amount will NOT be carried forward.

Examples

Run this code

t.obs <- seq(0, 24, 0.1)
amt <- 1
ka <- 1
cl <- 0.25
vc <- 5

# One-compartment model with first-order absorption
# First dose at time 0
y <- pkprofile(t.obs, cl=cl, vc=vc, ka=ka, dose=list(t.dose=0, amt=amt))

# Second dose at 24h with a lower clearance
y <- pkprofile(y, t.obs+24, cl=0.5*cl, vc=vc, ka=ka, dose=list(t.dose=24, amt=amt))

# Third dose at 48h with a higher clearance
y <- pkprofile(y, t.obs+48, cl=2*cl, vc=vc, ka=ka, dose=list(t.dose=48, amt=amt))
plot(y)