pk.calc.c0: Estimate the concentration at dosing time for an IV bolus...

In PKNCA: Perform Pharmacokinetic Non-Compartmental Analysis

Estimate the concentration at dosing time for an IV bolus dose.

Description

Estimate the concentration at dosing time for an IV bolus dose.

Usage

pk.calc.c0(
  conc,
  time,
  time.dose = 0,
  method = c("c0", "logslope", "c1", "cmin", "set0"),
  check = TRUE
)

pk.calc.c0.method.logslope(conc, time, time.dose = 0, check = TRUE)

pk.calc.c0.method.c0(conc, time, time.dose = 0, check = TRUE)

pk.calc.c0.method.c1(conc, time, time.dose = 0, check = TRUE)

pk.calc.c0.method.set0(conc, time, time.dose = 0, check = TRUE)

pk.calc.c0.method.cmin(conc, time, time.dose = 0, check = TRUE)

Arguments

conc	Measured concentrations
time	Time of the measurement of the concentrations
time.dose	The time when dosing occurred
method	The order of methods to test (see details)
check	Check the conc and time inputs

Details

Methods available for interpolation are below, and each has its own specific function.

c0

If the observed conc at time.dose is nonzero, return that. This method should usually be used first for single-dose IV bolus data in case nominal time zero is measured.

logslope

Compute the semilog line between the first two measured times, and use that line to extrapolate backward to time.dose

c1

Use the first point after time.dose

cmin

Set c0 to cmin during the interval. This method should usually be used for multiple-dose oral data and IV infusion data.

set0

Set c0 to zero (regardless of any other data). This method should usually be used first for single-dose oral data.

Value

The estimated concentration at time 0.

Functions

• pk.calc.c0.method.logslope(): Semilog regress the first and second points after time.dose. This method will return NA if the second conc after time.dose is 0 or greater than the first.

• pk.calc.c0.method.c0(): Use C0 = conc[time %in% time.dose] if it is nonzero.

• pk.calc.c0.method.c1(): Use C0 = C1.

• pk.calc.c0.method.set0(): Use C0 = 0 (typically used for single dose oral and IV infusion)

• pk.calc.c0.method.cmin(): Use C0 = Cmin (typically used for multiple dose oral and IV infusion but not IV bolus)

PKNCA documentation built on Aug. 21, 2025, 6 p.m.