httk (version 2.6.0)

calc_vdist: Calculate the volume of distribution for a one compartment model.

Description

This function predicts partition coefficients for all tissues using predict_partitioning_schmitt, then lumps them into a single compartment.

Usage

calc_vdist(
  chem.cas = NULL,
  chem.name = NULL,
  dtxsid = NULL,
  parameters = NULL,
  suppress.messages = FALSE,
  adjusted.Funbound.plasma = TRUE,
  species = "Human",
  default.to.human = FALSE,
  ...
)

Value

Volume of distribution

Units of L/ kg BW.

Arguments

chem.cas

Either the CAS number or the chemical name must be specified when Funbound.plasma is not given in parameter list.

chem.name

Either the chemical name or the CAS number must be specified when Funbound.plasma is not given in parameter list.

dtxsid

EPA's DSSTox Structure ID (https://comptox.epa.gov/dashboard) the chemical must be identified by either CAS, name, or DTXSIDs

parameters

Parameters from parameterize_3comp, parameterize_pbtk or predict_partitioning_schmitt.

suppress.messages

Whether or not the output message is suppressed.

adjusted.Funbound.plasma

Uses Pearce et al. (2017) lipid binding adjustment for Funbound.plasma (which impacts partition coefficients) when set to TRUE (Default).

species

Species desired (either "Rat", "Rabbit", "Dog", "Mouse", or default "Human").

default.to.human

Substitutes missing animal values with human values if true.

...

Additional parameters passed to parameterize function if parameters is NULL.

Author

John Wambaugh and Robert Pearce

Details

The effective volume of distribution is calculated by summing each tissues volume times it's partition coefficient relative to plasma. Plasma, and the paritioning into RBCs are also added to get the total volume of distribution in L/KG BW. Partition coefficients are calculated using Schmitt's (2008) method. When species is specified as rabbit, dog, or mouse, the function uses the appropriate physiological data(volumes and flows) but substitues human fraction unbound, partition coefficients, and intrinsic hepatic clearance.

References

schmitt2008generalhttk

peyret2010unifiedhttk

See Also

predict_partitioning_schmitt

tissue.data

physiology.data

Examples

calc_vdist(chem.cas="80-05-7")
calc_vdist(chem.name="Bisphenol A")
calc_vdist(chem.name="Bisphenol A",species="Rat")

# Create a list of parameters (that you can potentially change):
p <- parameterize_schmitt(chem.name="propranolol")
# Need to use those parameters to predict partition coefficients:
PCs <- predict_partitioning_schmitt(parameters = p)

# Lump the tissues into a single volume of distribution
calc_vdist(parameters=c(p,PCs))
# Should be the same as chemical by name:
calc_vdist(chem.name="propranolol")