Fit_2cmpt_iv: Fit intravenous pharmacokinetic data to a two-compartment...

In nlmixr2autoinit: Automatic Generation of Initial Estimates for Population Pharmacokinetic Modeling

Fit intravenous pharmacokinetic data to a two-compartment linear elimination model

Description

Fits intravenous (IV) pharmacokinetic data to a two-compartment model with first-order elimination using the naive pooled data approach. Supports multiple estimation methods provided by nlmixr2 and can optionally return only predicted concentrations to support efficient simulation workflows.

Usage

Fit_2cmpt_iv(
  data,
  est.method,
  input.cl,
  input.vc2cmpt,
  input.vp2cmpt,
  input.q2cmpt,
  input.add,
  return.pred.only = FALSE,
  ...
)

Arguments

data	A data frame containing IV pharmacokinetic data formatted for nlmixr2,
est.method	Estimation method to use in nlmixr2. Must be one of: "rxSolve", "nls", "nlm", "nlminb", or "focei".
input.cl	Initial estimate of clearance (CL).
input.vc2cmpt	Initial estimate of central volume of distribution (V1).
input.vp2cmpt	Initial estimate of peripheral volume of distribution (V2).
input.q2cmpt	Initial estimate of inter-compartmental clearance (Q).
input.add	Initial estimate of the additive residual error.
return.pred.only	Logical; if TRUE, returns a data frame with only predicted concentrations (cp) for all observations in the input data.
...	Additional arguments passed to nlmixr2(), such as a user-defined control = foceiControl(...) or other control settings.

Value

If return.pred.only = TRUE, returns a data.frame with a single column cp (predicted concentrations). Otherwise, returns a fitted model object produced by nlmixr2.

Author(s)

Zhonghui Huang

Examples

 
dat <- Bolus_2CPT
# Fit using 'nls'
Fit_2cmpt_iv(
  data = dat,
  est.method = "nls",
  input.cl = 4,
  input.vc2cmpt = 70,
  input.vp2cmpt = 40,
  input.q2cmpt = 4,
  input.add = 10
)
# Return only predicted concentrations
Fit_2cmpt_iv(
  data = dat,
  est.method = "rxSolve",
  input.cl = 4,
  input.vc2cmpt = 70,
  input.vp2cmpt = 40,
  input.q2cmpt = 4,
  input.add = 0,
  return.pred.only = TRUE
)

nlmixr2autoinit documentation built on Nov. 14, 2025, 1:07 a.m.