Patent ID: 7488466

Claim:
A method for quantitatively determining DPD (dihydropyrimidine dehydrogenase) activity, comprising: administering to a subject a preparation comprising an amount of 2- 13 C-labeled uracil as an active ingredient, measuring the excretion behavior of an isotope-labeled metabolite of 2- 13 C-labeled uracil excreted from the body, determining a pharmacokinetic parameter from the measured excretion behavior, wherein the pharmacokinetic parameter is selected from area under the curve (AUC), initial excretion rate, and maximum excretion concentration (C max ), comparing the pharmacokinetic parameter with the corresponding parameter of a subject having a normal DPD activity characterized by a linear relationship between the pharmacokinetic parameter and the amount of the preparation administered, and quantitatively determining DPD activity from the compared pharmacokinetic parameter.