Calculate the mean residence time (MRT) for multiple-dose data with nonlinear kinetics.

pk.calc.mrt.md(auctau, aumctau, aucinf, tau)

Arguments

auctau	the AUC from time 0 to the end of the dosing interval (tau).
aumctau	the AUMC from time 0 to the end of the dosing interval (tau).
aucinf	the AUC from time 0 to infinity (typically using single-dose data)
tau	the dosing interval

mrt.md is aumctau/auctau + tau*(aucinf-auctau)/auctau and should only be used for multiple dosing with equal intervals between doses.

Note that if aucinf == auctau (as would be the assumption with linear kinetics), the equation becomes the same as the single-dose MRT.