Rikkunshito improves symptoms in PPI-refractory GERD patients: a prospective, randomized, multicenter trial in Japan

Abstract

To seek a promising therapeutic regimen for proton pump inhibitor (PPI)-refractory patients with gastroesophageal reflux disease (GERD) after the standard PPI treatment, we compared the efficacies of rikkunshito (a Japanese traditional medication) combined with rabeprazole (RPZ) and a double dose of RPZ in a prospective randomized multicenter trial in Japanese PPI-refractory GERD patients. One hundred and four patients with GERD symptoms remaining after 4-week treatment with RPZ (10 mg/day) were randomly assigned to 4 weeks of either combination therapy [rikkunshito (7.5 g/day) with a standard dose of RPZ (10 mg/day)] or a double dose of RPZ (20 mg/day). The primary endpoint was the improvement rate, calculated based on the frequency scale for the symptoms of GERD (FSSG) before and after treatment. Subgroup analysis was also performed with respect to each subject's background factors such as reflux esophagitis (RE)/non-erosive GERD (NERD), age, gender, and body mass index (BMI). Four-week treatment with rikkunshito combined with RPZ significantly decreased the FSSG score from 17.6 ± 6.5 to 12.0 ± 6.9, similar to the decrease seen on treatment with a double dose of RPZ. Regarding the therapeutic improvement rate, there were also significant effects in both groups. However, in the subgroup analysis based on RE/NERD, the improvement rate of male NERD patients in the rikkunshito group was significantly greater than that of such patients in the other group (P < 0.05). In the rikkunshito group, the treatment was more effective in NERD patients with a low BMI than in those with a high BMI (P < 0.05). Rikkunshito combined with standard-dose RPZ therapy may be a useful new strategy for PPI-refractory GERD patients.