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

Description

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

Usage

calc_vdist(
  chem.cas = NULL,
  chem.name = NULL,
  dtxsid = NULL,
  parameters = NULL,
  default.to.human = FALSE,
  species = "Human",
  suppress.messages = FALSE,
  adjusted.Funbound.plasma = TRUE,
  regression = TRUE,
  minimum.Funbound.plasma = 1e-04
)

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.
default.to.human: Substitutes missing animal values with human values if true.
species: Species desired (either "Rat", "Rabbit", "Dog", "Mouse", or default "Human").
suppress.messages: Whether or not the output message is suppressed.
adjusted.Funbound.plasma: Uses adjusted Funbound.plasma when set to TRUE along with parition coefficients calculated with this value.
regression: Whether or not to use the regressions in calculating partition coefficients.
minimum.Funbound.plasma: Monte Carlo draws less than this value are set equal to this value (default is 0.0001 -- half the lowest measured Fup in our dataset).

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

Schmitt W. "General approach for the calculation of tissue to plasma partition coefficients." Toxicology In Vitro, 22, 457-467 (2008). Peyret, T., Poulin, P., Krishnan, K., "A unified algorithm for predicting partition coefficients for PBPK modeling of drugs and environmental chemicals." Toxicology and Applied Pharmacology, 249, 197-207 (2010).

Examples

Run this code


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

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