tkstats_2comp: Toxicokinetic statistics for 1-compartment model

Description

Calculate predicted toxicokinetic statistics for a 1-compartment model.

Usage

tkstats_2comp(pars, route, medium, dose, time_unit, conc_unit, vol_unit, ...)

Value

A `data.frame` with two variables: - `param_name` = `c("CLtot", "CLtot/Fgutabs", "Css", "halflife", "tmax", "Cmax", "AUC_infinity", "A", "B", "alpha", "beta", "Vbeta", "Vbeta_Fgutabs", "Vss", "Vss_Fgutabs")` - `param_value` = The corresponding values for each statistic (which may be NA if that statistic could not be computed; e.g. all of the `"x_Fgutabs"` parameters can only be computed if `route = "oral"` ).

Arguments

pars: A named numeric vector of model parameters (e.g. from [coef.pk()]).
route: Character: The route for which to compute TK stats. Currently only "oral" and "iv" are supported.
medium: Character: the media (tissue) for which to compute TK stats.. Currently only "blood" and "plasma" are supported.
dose: Numeric: A dose for which to calculate TK stats.
time_unit: Character: the units of time used for the parameters `par`. For example, if `par["kelim"]` is in units of 1/weeks, then `time_unit = "weeks"`. If `par["kelim"]` is in units of 1/hours, then `time_unit = "hours"`. This is used to calculate the steady-state plasma/blood concentration for long-term daily dosing of 1 mg/kg/day.
conc_unit: Character: The units of concentration.
vol_unit: Character: The units of dose.
...: Additional arguments not currently in use.

Author

John Wambaugh, Caroline Ring

Details

# Statistics computed

## Total clearance

$$\textrm{CL}_{tot} = k_{elim} + V_{1}$$

## Steady-state plasma concentration for long-term daily dose of 1 mg/kg/day

To convert to steady-state *blood* concentration, multiply by the blood-to-plasma ratio.

The dosing interval $\tau = \frac{1}{\textrm{day}}$ will be converted to the same units as $k_{elim}$.

### Oral route

$$C_{ss} = \frac{F_{gutabs} V_{1}}{k_{elim} \tau}$$

### Intravenous route

$$C_{ss} = \frac{1}{\textrm{CL}_{tot} \tau}$$

## Half-life of elimination

$$\textrm{Halflife} = \frac{\log(2)}{k_{elim}}$$

## Time of peak concentration

For oral route:

$$\frac{\log \left( \frac{k_{gutabs}}{k_{elim}} \right)}{k_{gutabs} - k_{elim}}$$

For intravenous route, time of peak concentration is always 0.

## Peak concentration

Evaluate [cp_1comp()] at the time of peak concentration.

## AUC evaluated at infinite time

Evaluate [auc_1comp()] at time = `Inf`.

## AUC evaluated at the time of the last observation