Author(s)

Masashi Ishihara, Kiyoyuki Kitaichi, Katsuhiko Matsuura, Hiroshi Nakamura, Hisashi Tsurumi, Hisataka Moriwaki, Yoshinori Itoh

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A fifty-five-year-old male patient with malignant lymphoma who took oral valproic acid (VPA) tablets and itraconazole (ITZ) capsles received 3 courses of cancer chemotherapy, including 2 courses of a combination of rituximab/methotrexate/ifosphamide/etoposide/ carboplatin/ methylpredonisolon (R-IMVP16/CBDCA regimen) and subsequent one course of a combination of rituximab/ranimustine/citara bine/etoposide/merphalan (R-MEAM regimen). Plasma concentration of VPA dramatically decreased below the therapeutic concentration after the first and second chemotherapy and seizures appeared in both cases. Plasma concentration of ITZ was also lowered after the second chemotherapy course. At the third chemotherapy, Rikkunshi-to, a Japanese herbal medicine, was prescribed for 14 days. Plasma VPA concentration decreased, though to a lesser extent, after chemotherapy, in which the level was near the border of therapeutic concentration. No convulsion was observed. Therefore, care should be taken to monitor plasma drug concentration during cancer chemotherapy. Rikkunshi-to may be useful to alleviate the chemotherapy-induced decrease in plasma concentrations of orally administered drugs.

Cancer Chemotherapy; Malignant Lymphoma; Valproic Acid; Therapeutic Drug Monitoring; Convulsion; Rikkunshi-to

M. Ishihara, K. Kitaichi, K. Matsuura, H. Nakamura, H. Tsurumi, H. Moriwaki and Y. Itoh, "Rikkunshi-to Partially Reverses Cancer Chemotherapy-Induced Decrease in Plasma Valproic Acid Concentration in a Patient with Malignant Lymphoma," Chinese Medicine, Vol. 2 No. 2, 2011, pp. 58-61. doi: 10.4236/cm.2011.22011.