Esophageal Motility and Rikkunshito Treatment for Proton Pump Inhibitor-Refractory Nonerosive Reflux Disease: A Prospective, Uncontrolled, Open-Label Pilot Study Trial

BACKGROUND Only a few reports focused on esophageal motility in patients with proton pump inhibitor (PPI)-refractory nonerosive reflux disease (NERD) and there has been no established strategy for treatment. OBJECTIVE To clarify the characteristics of esophageal motility in patients with PPI-refractory NERD, we evaluated esophageal function using combined multichannel intraluminal impedance and esophageal manometry (MII-EM). In addition, we evaluated the efficacy of rikkunshito (RKT), which is a gastrointestinal prokinetic agent. METHODS Thirty patients with NERD were enrolled and underwent MII-EM. After 8 weeks of RKT (7.5 g/d) treatment, MII-EM was repeated on patients with PPI-refractory NERD. Symptoms were assessed by the Gastrointestinal Symptom Rating Scale. RESULTS In patients with PPI-refractory NERD, measures of complete bolus transit, peristaltic contractions, and residual pressure of the lower esophageal sphincter during swallowing deviated from the standard values and esophageal clearance was found to be deteriorated. RKT significantly improved the peristaltic contractions (P < 0.05), the complete bolus transit (P < 0.01), and the residual pressure of lower esophageal sphincter (P < 0.05) in these patients. The overall score (P < 0.01) and the subscale scores of acid reflux syndrome (P < 0.05), abdominal pain (P < 0.05), and indigestion syndrome (P < 0.01) in the Gastrointestinal Symptom Rating Scale were significantly improved by the 8-week RKT treatment. CONCLUSIONS In the pilot study, patients with PPI-refractory NERD had disorders of esophageal and lower esophageal sphincter motility that were improved by RKT. Further studies examining esophageal motor activity of RKT in PPI-refractory NERD are required. University hospital Medical Information Network (UMIN) Clinical Trial Registry identifier: UMIN000003092.