Effects of Rikkunshito (TJ-43) on Esophageal Motor Function and Gastroesophageal Reflux

Proton pump inhibitor-refractory gastroesophageal reflux disease: challenges and solutions

A significant percentage of patients with gastroesophageal reflux disease (GERD) will not respond to proton pump inhibitor (PPI) therapy. The causes of PPI-refractory GERD are numerous and diverse, and include adherence, persistent acid, functional disorders, nonacid reflux, and PPI bioavailability. The evaluation should start with a symptom assessment and may progress to imaging, endoscopy, and monitoring of esophageal pH, impedance, and bilirubin. There are a variety of pharmacologic and procedural interventions that should be selected based on the underlying mechanism of PPI failure. Pharmacologic treatments can include antacids, prokinetics, alginates, bile acid binders, reflux inhibitors, and antidepressants. Procedural options include laparoscopic fundoplication and LINX as well as endoscopic procedures, such as transoral incisionless fundoplication and Stretta. Several alternative and complementary treatments of possible benefit also exist.

Recent Advances in the Pharmacological Management of Gastroesophageal Reflux Disease

The management of proton pump inhibitor-refractory GERD (rGERD) is a challenge in clinical practice. Since up to one-third of patients with typical GERD symptoms (heartburn and/or acid regurgitation) are not satisfied with proton pump inhibitor (PPI) therapy, new drug development targeting different pathophysiologies of GERD is imperative. At present, no other drugs serve as a more potent acid suppression agent than PPIs. As an add-on therapy, histamine type-2 receptor antagonists, alginates, prokinetics and transient lower esophageal sphincter relaxation inhibitors have some impact on the subgroups of rGERD, but greater effectiveness and fewer adverse effects for widespread use are required. Visceral hypersensitivity also contributes to the perception of GERD symptoms, and neuromodulators including antidepressants play a role in this category. Esophageal pH-impedance monitoring helps to distinguish functional heartburn from true GERD, and psychologic medication and cognitive behavior therapy are further therapy options instead of PPIs.

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.

Effects of Metoclopramide on Esophageal Motor Activity and Esophagogastric Junction Compliance in Healthy Volunteers

Background/Aims

Prokinetic drugs such as metoclopramide are frequently used as second-line therapy for patients with gastroesophageal reflux disease. However, their beneficial effects remain unclear. Esophageal motor activities and compliance of the esophagogastric junction (EGJ) are important for prevention of gastroesophageal reflux. Although metoclopramide has been reported to increase lower esophageal sphincter (LES) pressure, its effects on EGJ compliance have not been evaluated. In the present study, we investigated the effects of metoclopramide on esophageal motor activities and EGJ compliance.

Methods

Nine healthy male volunteers without abdominal symptoms were enrolled. Peristaltic esophageal contractions and LES pressure were examined using high-resolution esophageal manometry, while EGJ compliance was evaluated with an endoluminal functional lumen-imaging probe. After obtaining baseline values for esophageal motor activities and EGJ compliance, metoclopramide (10 mg) was intravenously administered, then all measurements were repeated at 15 minutes after administration in each subject.

Results

Following administration of metoclopramide, mean resting LES pressure was significantly increased as compared with the baseline (13.7 ± 9.2 vs 26.7 ± 8.8 mmHg, P < 0.05). In addition, metoclopramide significantly augmented peristaltic contractions, especially in the distal esophageal segment (P < 0.05). On the other hand, distensibility index did not change after administration (4.5 ± 0.5 vs 4.1 ± 0.5 mm²/mmHg), suggesting no significant effect of metoclopramide on EGJ compliance.

Conclusions

Metoclopramide augmented esophageal contractions without changing EGJ compliance in healthy adults.

Effects of acotiamide on esophageal motor function and gastroesophageal reflux in healthy volunteers

Background

The prevalence of gastroesophageal reflux disease (GERD) has been increasing worldwide, with proton pump inhibitor (PPI) administration the current mainstay therapy for affected individuals. However, PPI efficacy is insufficient especially for non-erosive reflux disease. Although it has been reported that prokinetic drugs improve GERD, their effects on esophageal function remain to be clearly investigated. In the present study, we evaluated the direct effects of acotiamide, a novel prokinetic agent for the treatment of functional dyspepsia, on esophageal motor function and gastroesophageal reflux.

Methods

Ten adult healthy volunteers (average age 24 years, range 20–36 years; 7 males, 3 females) were enrolled. Esophageal body peristaltic contractions and lower esophageal sphincter (LES) pressure with and without acotiamide administration were recorded using high resolution manometry using a cross-over protocol. Total and acidic reflux levels for 24 h and during the postprandial period were also recorded using a multichannel intraluminal impedance and pH monitoring system. Data were analyzed blind by one observer.

Results

Acotiamide at a standard dose of 300 mg/day did not significantly stimulate esophageal motor function. Although the frequency of swallows with weak contraction tended to decrease with acotiamide administration, the difference as compared to no administration was not statistically significant. In addition, the drug neither decreased total or postprandial gastroesophageal acid/non-acid reflux events nor accelerated esophageal clearance time.

Conclusions

Acotiamide, a novel gastrointestinal motility modulator, at a standard dose did not significantly affect esophageal motor functions or gastroesophageal reflux in healthy adults. Additional investigations with GERD patients are necessary to elucidate its clinical significance.

Trial registration

This study was registered on 1st August 2013 with the University Hospital Medical Information Network (UMIN) clinical trials registry, as number: UMIN000011260.

Complementary and alternative medicine for gastroparesis

Complementary and alternative medicine is of great interest to patients with gastrointestinal disorders and some will choose to ask their health care providers about those therapies for which some scientific evidence exists. This review focuses on those therapies most commonly used by patients, namely acupuncture/electroacupuncture and various herbal formulations that have been the focus of clinical and laboratory investigation. A discussion of their possible mechanisms of action and the results of clinical studies are summarized.

Rikkunshito, a ghrelin potentiator, ameliorates anorexia-cachexia syndrome

Anorexia–cachexia syndrome develops during the advanced stages of various chronic diseases in which patients exhibit a decreased food intake, weight loss, and muscle tissue wasting. For these patients, this syndrome is a critical problem leading to an increased rate of morbidity and mortality. The present pharmacological therapies for treating anorexia–cachexia have limited effectiveness. The Japanese herbal medicine rikkunshito is often prescribed for the treatment of anorexia and upper gastrointestinal (GI) disorders. Thus, rikkunshito is expected to be beneficial for the treatment of patients with anorexia–cachexia syndrome. In this review, we summarize the effects of rikkunshito and its mechanisms of action on anorexia–cachexia. Persistent loss of appetite leads to a progressive depletion of body energy stores, which is frequently associated with cachexia. Consequently, regulating appetite and energy homeostasis is critically important for treating cachexia. Ghrelin is mainly secreted from the stomach, and it plays an important role in initiating feeding, controlling GI motility, and regulating energy expenditure. Recent clinical and basic science studies have demonstrated that the critical mechanism of rikkunshito underlies endogenous ghrelin activity. Interestingly, several components of rikkunshito target multiple gastric and central sites, and regulate the secretion, receptor sensitization, and degradation of ghrelin. Rikkunshito is effective for the treatment of anorexia, body weight loss, muscle wasting, and anxiety-related behavior. Furthermore, treatment with rikkunshito was observed to prolong survival in an animal model of cachexia. The use of a potentiator of ghrelin signaling, such as rikkunshito, may represent a novel approach for the treatment of anorexia–cachexia syndrome.

Physiological analysis of the effects of rikkunshito on acid and non-acid gastroesophageal reflux using pH-multichannel intraluminal impedance monitoring

PURPOSE

To clarify the effects of rikkunshito on acid reflux, non-acid reflux, and esophageal clearance in patients with gastroesophageal reflux disease (GERD).

METHODS

We enrolled seven patients with vomiting and/or stridor (median 6 years; 1 month-17 years), with a percent total time of esophageal pH <4.0 (reflux index) over 4.0%. Rikkunshito (TJ-43; Tsumura Co, Tokyo, Japan) was given in three divided doses before meals. We retrospectively investigated its efficacy using pH-multichannel intraluminal impedance before and 7 (6-10) days after starting treatment. Statistical analyses were conducted using Wilcoxon signed-rank test.

RESULTS

In the pH analyses alone, the median number of acid reflux episodes >5 min (14 versus 10, p = 0.046) and median acid-clearance time (184 versus 134 s, p = 0.03) decreased significantly, although median decrease in reflux index did not reach significance (16.0 versus 17.9%, p = 0.06). In the combined impedance and pH analyses, the median number (36 versus 36, p = 0.03) and median duration (1.9 versus 1.1%, p = 0.046) of acid reflux decreased significantly; non-acid reflux and bolus clearance time did not change.

CONCLUSION

Rikkunshito effectively reduced acid reflux, but not esophageal clearance, in patients with GERD.

Preventive effect of rikkunshito on gastric motor function inhibited by L-dopa in rats

We previously reported that ghrelin prevented l-dopa (LD)-induced inhibition of gastric emptying (GE) of a non-nutrient solution in rats. Parkinson's disease treatment involves the combined administration of l-dopa with the enzyme l-amino acid decarboxylase inhibitor, carbidopa (CD) to reduce peripheral formation of dopamine. We investigated the effect LD/CD given orogastrically (og) on GE of a non-nutrient or nutrient meal and whether og pretreatment with rikkunshito, a kampo medicine clinically used to treat gastroparesis, influenced LD/CD effect on GE and postprandial antral and duodenal motility in conscious rats. LD/CD (20/2 mgkg(-1)) decreased significantly GE to 26.3 ± 6.0% compared to 61.2 ± 3.2% in og vehicle monitored 20-min after a non-nutrient meal and to 41.9 ± 5.8% compared to 72.9 ± 5.2% in og vehicle monitored 60 min after a nutrient meal. Rikkunshito (0.5 or 1.0 g kg(-1)) reduced the LD/CD (20/2 mg kg(-1)) inhibition of GE of non-nutrient meal (36.9 ± 7.4% and 46.6 ± 4.8% respectively vs. 12.1 ± 7.4% in og vehicle plus LD/CD) while having no effect alone (56.6 ± 8.5%). The ghrelin antagonist, [d-Lys(3)]-GHRP-6 (1 mg kg(-1)) injected intraperitoneally partially reversed rikkunshito preventive effect on LD/CD-inhibited GE. Rikkunshito (1.0 g kg(-1)) blocked LD/CD (20/2 mg kg(-1))-induced delayed GE of a nutrient meal and the reduction of postprandial antral motility. In 6-hydroxydopamine-induced Parkinson's disease rat model, rikkunshito (1.0 g kg(-1), og) also prevented LD/CD-inhibited gastric emptying of a nutrient meal and enhanced fasting plasma levels of acylated ghrelin. These data indicate that oral rikkunshito alleviates the delayed GE induced by LD/CD in naïve and PD rat model in part through ghrelin-related mechanisms.

Continuous imaging of esophagogastric junction in patients with reflux esophagitis using 320-row area detector CT: a feasibility study

BACKGROUND AND AIM

The function of the lower esophageal sphincter (LES) is evaluated using an esophageal manometric study. However, information regarding the surrounding organs is difficult to obtain with use of a sensor catheter. We investigated the utility of 320-row area detector computed tomography (CT) to evaluate morphological changes of the esophagogastric junction and surrounding organs.

METHODS

The study subjects were 18 healthy volunteers and 29 patients with reflux esophagitis (RE). Immediately after swallowing a diluted contrast agent, continuous imaging of the esophagogastric junctional area was performed for 15 s. Using CT images, the presence or absence of esophageal hiatal hernia, His angle before and after swallowing, size of the diaphragmatic hiatus, morphologically identified-LES (MI-LES) length, intraluminal horizontal area of MI-LES during relaxation phase, MI-LES thickness, abdominal esophagus length, subcutaneous fat area, visceral fat area, and esophagogastric junction fat area were evaluated.

RESULTS

Analysis of CT images showed more frequent occurrence of hiatal hernia, greater His angle, and a larger diaphragmatic hiatus in patients with severe RE, while the lengths of MI-LES and abdominal esophagus were shorter in those patients. Visceral and esophagogastric junction fat areas tended to be greater in patients with RE. In all subjects, the posterior wall of the MI-LES was thicker than the anterior wall.

CONCLUSION

Continuous imaging with 320-row area detector CT is useful to evaluate morphological changes in the esophagogastric junction area in both normal individuals and patients with reflux esophagitis.

Current pharmacological management of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD), a common disorder with troublesome symptoms caused by reflux of gastric contents into the esophagus, has adverse impact on quality of life. A variety of medications have been used in GERD treatment, and acid suppression therapy is the mainstay of treatment for GERD. Although proton pump inhibitor is the most potent acid suppressant and provides good efficacy in esophagitis healing and symptom relief, about one-third of patients with GERD still have persistent symptoms with poor response to standard dose PPI. Antacids, alginate, histamine type-2 receptor antagonists, and prokinetic agents are usually used as add-on therapy to PPI in clinical practice. Development of novel therapeutic agents has focused on the underlying mechanisms of GERD, such as transient lower esophageal sphincter relaxation, motility disorder, mucosal protection, and esophageal hypersensitivity. Newer formulations of PPI with faster and longer duration of action and potassium-competitive acid blocker, a newer acid suppressant, have also been investigated in clinical trials. In this review, we summarize the current and developing therapeutic agents for GERD treatment.