tkstats_1comp_cl {invivoPKfit}R Documentation

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,
  ...
)

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.

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'.

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).

Author(s)

John Wambaugh, Caroline Ring


[Package invivoPKfit version 2.0.1 Index]