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invivoPKfit (version 2.0.1)

tkstats_1comp_cl: Toxicokinetic statistics for 1-compartment model with specific clearance

Description

Calculate predicted toxicokinetic statistics for a 1-compartment model. This does use the parameters for the `model_1comp_cl` that are taken from [httk] estimates.

Usage

tkstats_1comp_cl(
  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")` - `param_value` = The corresponding values for each statistic (which may be NA if that statistic could not be computed).

Arguments

pars

A named 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

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

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

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

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

### Oral route

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

### Intravenous route

$$C_{ss} = \frac{1}{24 * \textrm{CL}_{tot}}$$

## 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_cl()] at the time of peak concentration.

## AUC evaluated at infinite time

Evaluate [auc_1comp_cl()] at time = `Inf`.

## AUC evaluated at the time of the last observation

Evaluate [auc_1comp_cl()] at time = `tlast`.