Efficacy of Rikkunshito, a Traditional Japanese Medicine (Kampo), in Treating Functional Dyspepsia

Background Rikkunshito, a traditional Japanese (Kampo) medicine, is widely prescribed as an oral preparation for the treatment of functional dyspepsia (FD). In our previous study, we reported that extracorporeal ultrasonography (US) is a useful technique for the assessment of the gastric accommodation reflex (AR) and duodenogastric motility. In this study, we examined the effects of Rikkunshito on the gastroduodenal function in patients with FD. Methods Sixteen FD patients (median age, 45 y) underwent US, before and after 14 days of treatment with Rikkunshito (7.5 g b.d.). For assessment of the AR, a cross-sectional area of the proximal stomach was measured after incremental ingestion of a liquid meal up to 400-mL. The expansion rate was used as the parameter to determine the AR. Then, the gastric emptying rate (GER), motility index (MI), and reflux index (RI) were evaluated using previously reported methods. Results Although no significant changes were observed in the total score of the Gastrointestinal Symptom Rating Scale (GSRS), the scores of 3 of the 15 symptoms of GSRS decreased significantly after treatment with Rikkunshito. The expansion rate of the proximal stomach was significantly greater after treatment with Rikkunshito than before the treatment. Although the GER and MI increased significantly, no significant differences in the RI were observed after treatment with Rikkunshito. Conclusion These observations suggested that Rikkunshito may be beneficial for the treatment of FD patients with impaired AR and gastric motility. These results also suggested that Rikkunshito has a therapeutic potential for FD and GERD.