[False-positive increase in 1,5-anhydro-D-glucitol due to Kampo (Japanese herbal) medicine].

We report a case presenting with a remarkable increase in blood 1,5-anhydro-D-glucitol (AG) upon taking a Kampo (Japanese Herbal) Medicine, Ninjin-Youei-To. The HPLC-analysis of the drug taken by the present case revealed 8.8 mg/g of AG in this Kampo (Japanese Herbal) Medicine. A similar increase in blood AG(maximum increase: 1.49 micrograms/mL/day) was observed when healthy normal volunteer's took Ninjin-Youei-To alone. Drug withdrawal led to a decrease in blood AG. No great change in diabetes-related items measured at the same time was noted, and glycosuria was always negative. These results led us to consider that the change in blood AG is not diabetic, but Ninjin-Youei-To-mediated. Ninjin-Youei-To is composed of 12 kinds of crude drugs, including Ginseng radix and Polygalae radix, and we made a search of the literature concerning these crude drugs. Polygalae radix, a component of Ninjin-Youei-To, was confirmed to contain AG. Where a change in blood AG does not accord with clinical symptoms and other laboratory findings, some influence or other of Kampo (Japanese Herbal) Medicine should be taken into account as a pre-analytical phase error.