Fit_2cmpt_oral: Fit oral pharmacokinetic data to a two-compartment model

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

Fit oral pharmacokinetic data to a two-compartment model

Description

Fits oral pharmacokinetic data to a two-compartment model with first-order absorption and first-order elimination using the naive pooled data approach. Supports multiple estimation methods available in nlmixr2, and optionally returns only predicted concentrations to support simulation workflows.

Usage

Fit_2cmpt_oral(
  data,
  est.method,
  input.ka,
  input.cl,
  input.vc2cmpt,
  input.vp2cmpt,
  input.q2cmpt,
  input.add,
  return.pred.only = FALSE,
  ...
)

Arguments

data	A data frame containing oral pharmacokinetic data formatted for nlmixr2,
est.method	Estimation method to use in nlmixr2, one of: "rxSolve", "nls", "nlm", "nlminb", or "focei".
input.ka	Initial estimate of the absorption rate constant (ka).
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 <- Oral_2CPT
# Fit using 'nls'
Fit_2cmpt_oral(
  data = dat,
  est.method = "nls",
  input.ka = 1,
  input.cl = 4,
  input.vc2cmpt = 70,
  input.vp2cmpt = 40,
  input.q2cmpt = 10,
  input.add = 10
)
# Return only predicted concentrations
Fit_2cmpt_oral(
  data = dat,
  est.method = "rxSolve",
  input.ka = 1,
  input.cl = 4,
  input.vc2cmpt = 70,
  input.vp2cmpt = 40,
  input.q2cmpt = 4,
  input.add = 10,
  return.pred.only = TRUE
)

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