Background: Traditionally, Phragmitis rhizoma has been prescribed to relive a fever,
vomiting, dysuria, and constipation, and to promote secretion of fluids. In addition, recent studies
have reported its efficacy as a diuretic and antiemetic. Our previous study demonstrated that the
Phragmitis rhizoma aqueous extract (EPR) ameliorates docetaxel (DTX)-induced myelotoxicity.
Aim and Objective: This study was aimed to investigate the effects of EPR on the
pharmacokinetics of DTX in Sprague–Dawley rats.
Materials and Methods: The animals received an intravenous injection of DTX (5 mg/kg) with or
without oral EPR (100 mg/kg) pretreatment for 1 or 6 days. The pharmacokinetics of plasma DTX
was analyzed using an ultra-performance liquid chromatography-tandem mass spectrometry
system, and pharmacokinetic parameters were estimated via noncompartmental analysis.
Results: Relative to the control group (DTX alone), EPR pretreatment did not affect significantly
the overall profiles of plasma DTX levels. Consecutively pretreated EPR for 6 days slightly altered
AUC0-t and Cmax of DTX by 122 and 145.9%, respectively, but these data did not reach the
threshold of statistical significance (p > 0.05).
Conclusion: These results indicate that DTX exposure may not be affected by EPR treatment at
the dose level used in this study, suggesting that oral EPR can be safely co-administered with
intravenously injected DTX. However, further studies under the stringent conditions are needed
when chronic treatment of EPR and anticancer drug.