RepTTT.MIX {bear}R Documentation

TTT and lme for replicated study

Description

The TTT method is based on the Bateman function. The Bateman function has two outstanding points. First, the maximum of the curve (Cmax at Tmax) and secondly, the inflection point of the curve (Cinpt at Tinpt). The inflection point of the curve describes the point where the algebraic sign of the curvature changes. Tinpt is equal to two times Tmax. Thus, The twofold of the observed Tmax value can be used as a threshold of time points to be included in the calculation of lambda(z).

With a two-treatment, more than two period, two-sequence randomized crossover design, linear mixed-effects model may be used. The lme in nlme package is used to obtain estimates for the adjusted differences between treatment means and the standard error associated with these differences. Log-transformed BA measures will also be analyzed.

References

Scheerans C, Derendorf H and C Kloft. Proposal for a Standardised Identification of the Mono-Exponential Terminal Phase for Orally Administered Drugs. Biopharm Drug Dispos 29, 145-157 (2008).


[Package bear version 2.3.0 Index]