PHARMACOKINETICS OF THE TAXANES

The pharmacokinetics of the taxanes paclitaxel and docetaxel have been studied extensively in humans. Paclitaxel has distinctly nonlinear ph armacokinetics, with saturable distribution and elimination features. Docetaxel pharmacokinetics are well described by linear processes, alt hough some investigators detected subtle nonlinear characteristics. Cl inically, nonlinear pharmacokinetics produce a disproportional relatio nship between dose and drug exposure. This affects dose adjustments an d calculation and use of dose intensity to compare chemotherapy regime ns. Although the underlying mechanism of nonlinearity in paclitaxel di sposition is not well understood, both metabolic and distributive proc esses may be involved.