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

Value

The estimated concentration at time 0.

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.

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)