hillEquation: Estimation of the Half Maximal Inhibitory Concentration

Description

The half maximal inhibitory concentration (IC50) is a measure of the effectiveness of a compound in inhibiting biological or biochemical function. This quantitative measure indicates how much of a particular drug or other substance (inhibitor) is needed to inhibit a given biological process (or component of a process) by half.

Usage

hillEquation(conc, occ, guess = c(1, 100), control = nls.lm.control())

Arguments

conc

a vector of drug concentrations in plasma (example units are ng/mL).

occ

a vector of PET occupancy values that correspond to the measured drug concentrations in plasma.

guess

a length-two vector of starting values for the nonlinear optimization.

control

is a list of parameters used by nls.lm.control that are set by default, but may be customized by the user.

Value

IC50Half maximal inhibitory concentration
rmaxEstimated maximal occupancy
IC50SEApproximate standard error for IC50
rmaxSEApproximate standard erorr for rmax
hessianHessian matrix from the Levenburg-Marquardt procedure
infoReturn value from the Levenburg-Marquardt procedure
devianceDeviance from the Levenburg-Marquardt procedure
messageText message from the Levenburg-Marquardt procedure

Details

See reference(s).

In this version of the function the maximal occupancy (rmax) is estimated automatically. This should be optional.

References