Effects of the herbal medicine Rikkunshito, for functional dyspepsia: A systematic review and meta-analysis

Background and Aim Functional dyspepsia (FD) is characterized by chronic and unexplained indigestion at upper abdomen. Because of unsatisfactory effect of conventional treatments, demand is growing for complementary and alternative medicine. Rikkunshito (RKT) is a herbal medicine, which has been widely used for FD in Asia; however, the evidence is lacking. We carried out systematic review and meta-analysis to evaluate the effect and safety of RKT in the treatment of FD. Methods Electronic databases were searched in April 2019, including PUBMED, EMBASE, and Cochrane Library. All eligible studies should be randomized controlled trials (RCTs) comparing RKT or combination therapy (RKT and western medicine) group to western medicine group. The primary outcome measure was the total clinical efficacy rate (TCE). The secondary outcomes were total dyspepsia symptom scale, gastric emptying rate, gastrin, motilin, recurrence 6 months after treatment, and Hamilton depression rating scale. Results Fifty-two RCTs with 5475 patients were involved in this systematic review and meta-analysis. Compared with western medicine, RKT showed significant better result, with higher TCE (relative risk = 1.21, 95% confidence interval 1.17 to 1.25,P < 0.001). RKT presented higher reduction of total dyspepsia symptom scale, more improved gastric emptying rate, and lower recurrence 6 months after treatment compared with western medicine. However, there was no significant difference in Hamilton depression rating scale between RKT and western medicine group. Combination therapy brought significant symptom improvement with TCE compared with western medicine alone. Conclusions Rikkunshito and combination therapy might be considered an effective alternative treatment for FD. Further rigorously designed and high-quality RCTs are needed.