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

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	The observed concentrations
time	The observed times
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 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)