The effect of rikkunshito on gastrointestinal symptoms and gastric motor function: The first study in a Belgian functional dyspepsia population

Treatment of dyspeptic symptoms with YamatoGast. A non-interventional study of a registered traditional herbal Rikkunshito extract product from Japanese Kampo Medicine in routine practice in Germany

INTRODUCTION

Dyspeptic symptoms belong to the most frequent reasons to seek medical advice and are a burden both for the individual affected and the healthcare system. In Japan, the traditional herbal Kampo prescription rikkunshito has proven benefit for this indication.

METHODS

In a prospective, multicentre, non-interventional study (NIS), the effectiveness, safety, and tolerability of a two-week treatment with the registered rikkunshito extract product YamatoGast was assessed in German patients with an acute episode of dyspeptic symptoms of functional origin under real-world conditions. The primary endpoint was the responsiveness to treatment assessed by the overall treatment effect (OTE) score. Secondary endpoints were the change in severity of dyspeptic symptoms and the change in quality of life (QoL). Safety evaluation was based on reported adverse drug reactions, drug compliance, and ratings of tolerability by physicians and patients.

RESULTS

Sixty-six patients were enrolled (mean age 48.9 years, 74% females). The treatment was well tolerated and highly beneficial, as expressed by pronounced responder rates of 78.9% for the primary endpoint OTE. All secondary endpoints were also met. The severity of dyspeptic symptoms significantly improved by 62-77% compared to baseline, confirmed by a remarkable improvement of QoL. Significant symptom relief started from the third day of treatment onwards.

CONCLUSION

In this non-interventional study, two-week treatment with YamatoGast resulted in a significant improvement of dyspeptic symptoms and was associated with high patient response and satisfaction. YamatoGast was confirmed as a safe and clinically relevant therapeutic option for patients suffering upper gastrointestinal complaints in routine practice.

Patient-Reported Outcomes in Disorders of Gut-Brain Interaction

Disorders of gut-brain interaction are characterized by chronic gastrointestinal symptoms in the absence of abnormal endoscopic or radiologic findings or objective biomarkers that can be identified during routine clinical evaluation. The assessment of the symptom pattern and severity, therefore, is the key modality to evaluate the presence, impact, and evolution of these conditions, for both clinical and regulatory purposes. Patient-reported outcomes are structured symptom assessment questionnaires designed to evaluate symptom patterns, quantify severity of symptoms, and evaluate response to treatment at follow-up. This review provides an overview of currently available patient-reported outcomes for evaluating the main disorders of gut-brain interaction, specifically, functional dyspepsia; irritable bowel syndrome; and chronic constipation. It summarizes their content, level of validation for clinical practice and for research, and the regulatory approach to these conditions. Expected future developments and need for further research on patient-reported outcomes for these and other disorders of gut-brain interaction are highlighted.

Nocebo response intensity and influencing factors in the randomized clinical trials of functional dyspepsia: A systematic review and meta-analysis

OBJECTIVES

In this study we aimed to evaluate the nocebo response rate in patients with functional dyspepsia (FD) and to explore its influencing factors.

METHODS

A literature search of the EMBASE, PubMed, and Cochrane Library databases was conducted for all articles published up to March 2021. Randomized, parallel-designed, placebo-controlled trials on pharmacological interventions for patients with FD were included. A meta-analysis that utilized random effects to analyze the incidence of adverse events (AEs) among participants who were given placebo was conducted, and the correlation between trial characteristics and the magnitude of the nocebo response rate was analyzed.

RESULTS

Altogether, 27 studies including 1866 paitents were deemed eligible and included in the analysis. The total nocebo response rate was 26% (95% confidence interval [CI] 18%-33%). The most frequently reported AEs included nasopharyngitis (9%), constipation (6%), headache (5%), and diarrhea (3%). There were significant differences in nocebo response rates among studies conducted in different country or region, treatment duration, types of medication, sponsorship and different versions of the Rome criteria used for FD diagnosis. While number of centers engaged in the study, types of FD diagnosis and dosing frequency were not significantly associated with the nocebo response rate.

CONCLUSIONS

Patients with FD exhibit notable nocebo response strength in clinical trials. The researchers should adopt a more careful approach when analyzing the relationships between AEs and interventions in such trials.

British Society of Gastroenterology guidelines on the management of functional dyspepsia

Functional dyspepsia (FD) is a common disorder of gut-brain interaction, affecting approximately 7% of individuals in the community, with most patients managed in primary care. The last British Society of Gastroenterology (BSG) guideline for the management of dyspepsia was published in 1996. In the interim, substantial advances have been made in understanding the complex pathophysiology of FD, and there has been a considerable amount of new evidence published concerning its diagnosis and classification, with the advent of the Rome IV criteria, and management. The primary aim of this guideline, commissioned by the BSG, is to review and summarise the current evidence to inform and guide clinical practice, by providing a practical framework for evidence-based diagnosis and treatment of patients. The approach to investigating the patient presenting with dyspepsia is discussed, and efficacy of drugs in FD summarised based on evidence derived from a comprehensive search of the medical literature, which was used to inform an update of a series of pairwise and network meta-analyses. Specific recommendations have been made according to the Grading of Recommendations Assessment, Development and Evaluation system. These provide both the strength of the recommendations and the overall quality of evidence. Finally, in this guideline, we consider novel treatments that are in development, as well as highlighting areas of unmet need and priorities for future research.

A double-blind randomized, multicenter, placebo-controlled study of itopride in functional dyspepsia postprandial distress syndrome

BACKGROUND

Itopride, a mixed D2 antagonist and cholinesterase inhibitor, has prokinetic effects on gastric motility. The Leuven Postprandial Distress Scale is a validated patient-reported outcome instrument for functional dyspepsia (FD) postprandial distress syndrome (PDS). We aimed to use the LPDS to assess treatment outcome in PDS and PDS/EPS (epigastric pain syndrome).

METHODS

Patients with PDS, with or without non-predominant EPS symptoms, were enrolled in an 8-week double-blind placebo-controlled multi-center trial with itopride (100 mg t.i.d.). Patients completed LPDS diaries and questionnaires to assess treatment response. Mann-Whitney test and mixed models were used.

RESULTS

One hundred patients (79% females, 39.1 ± 1.5 yo) were included. No significant difference was observed between treatment arms (p = 0.6). Compared to baseline, itopride treatment significantly improved the LPDS score (p = 0.001) and all individual symptoms (p < 0.0001). In the placebo arm, this was only the case for belching and epigastric pain (p < 0.05). In an exploratory analysis, outcomes in "pure" PDS (n = 45) and overlapping PDS/EPS (n = 55) patients were assessed and showed that the latter subgroup has the largest benefit with itopride compared to placebo (p = 0.03).

CONCLUSION

Using the LPDS score in a pilot controlled trial in FD, itopride shows no therapeutic benefit over placebo after 8 weeks of treatment. In an exploratory post hoc analysis, itopride but not placebo was associated with improvement of symptoms compared to baseline, and this was most prominent in patients with overlapping PDS/EPS. The efficacy of itopride in this subgroup needs to be evaluated in a large study using the same outcome measure. (clinialtrials.org ref.: NCT04647955).

Yokukansan Suppresses Gastric Hypersensitivity and Eosinophil-associated Microinflammation in Rats With Functional Dyspepsia

Background/Aims

Herbal medicine is an important complementary therapy for functional dyspepsia (FD). However, its effect against gastric hypersensitivity in patients with FD has rarely been evaluated. Yokukansan (YKS), a traditional Japanese herbal medicine, is effective against neuropathic and inflammatory pain. This study aims to use a maternal separation (MS) stress-induced FD model to investigate the effects of YKS against gastric hypersensitivity, gastric motility, and duodenal micro-inflammation.

Methods

The MS stress model was established by separating newborn Sprague-Dawley rats from their mothers for 2 hours a day from postnatal days 1 to 10. At the age of 7-8 weeks, the rats were treated with YKS at a dose of 5 mL/kg (1 g/kg) for 7 consecutive days. After YKS treatment, electromyographic activity in the acromiotrapezius muscle by gastric distention and the gastric-emptying rate were assessed. Immunohistochemical analysis of eosinophils in the duodenum and phosphorylated extracellular signal-regulated kinase (p-ERK) 1/2 in the spinal cord was performed.

Results

YKS treatment suppressed MS stress-induced gastric hypersensitivity and decreased the elevated levels of p-ERK1/2 in the spinal cord. In the gastroduodenal tract, YKS inhibited eosinophil-associated micro-inflammation but did not improve gastric dysmotility.

Conclusions

YKS treatment improved gastric hypersensitivity by alleviating eosinophil-associated micro-inflammation in the gastroduodenal tract. This treatment may be considered an effective therapeutic option for epigastric pain and micro-inflammation in patients with FD.

Gastrointestinal hormones and regulation of gastric emptying

PURPOSE OF REVIEW

In this review, we evaluate recent findings related to the association between gastrointestinal hormones and regulation of gastric emptying.

RECENT FINDINGS

Motilin and ghrelin, which act during fasting, promote gastric motility, whereas most of the hormones secreted after a meal inhibit gastric motility. Serotonin has different progastric or antigastric motility effects depending on the receptor subtype. Serotonin receptor agonists have been used clinically to treat dyspepsia symptoms but other hormone receptor agonists or antagonists are still under development. Glucagon-like peptide 1 agonists, which have gastric motility and appetite-suppressing effects are used as a treatment for obesity and diabetes.

SUMMARY

Gastrointestinal hormones play an important role in the regulation of gastric motility. Various drugs have been developed to treat delayed gastric emptying by targeting gastrointestinal hormones or their receptors but few have been commercialized.

Development and Validity Assessment of a Self-evaluation Questionnaire for Functional Dyspepsia: A Multicenter Prospective Study in Korea

Background/Aims

Patient-reported outcomes (PROs) are essential for clinical decision making, conduction of clinical research, and drug application acquisition in functional gastrointestinal disorders. The aim of this study is to develop a PRO instrument and to determine the respondents’ perception of the efficacy of therapeutic agents for functional dyspepsia (FD).

Methods

A self-evaluation questionnaire for dyspepsia (SEQ-DYSPEPSIA) was developed and validated through a structured process. The 2-week reproducibility was evaluated, and the construct validity was assessed by correlating the scores of SEQ-DYSPEPSIA (including typical and major FD symptom subscales). Finally, the response to medication was assessed by comparing the changes after 4 weeks of treatment.

Results

A total of 193 Korean patients (age 48.5 ± 13.6 years, 69.4% women) completed the questionnaire. SEQ-DYSPEPSIA with 11 items had a good internal consistency (alpha = 0.770-0.905) and an acceptable test-retest reliability (intraclass correlation coefficient = 0.733-0.859). The self-evaluation questionnaire (SEQ)-major FD score highly correlated with the postprandial fullness/early satiety domain of the Patient Assessment of Gastrointestinal Symptom Severity Index (correlation coefficient r = 0.741, P < 0.001), Nepean Dyspepsia Index-Korean version (NDI-K) (r = 0.839, P < 0.001), and NDI-K quality of life (r = −0.275 to −0.344, P < 0.001). After medical treatment, decrease in the SEQ-typical FD and SEQ-major FD was significantly greater in the responder group than in non-responder group (P = 0.019 and P = 0.009, respectively).

Conclusion

This study suggests that the Korean version of SEQ-DYSPEPSIA has good reliability and validity, and can be a useful PRO measurement tool in patients with FD.

Efficacy of herbal treatments for functional dyspepsia: A systematic review and meta-analysis of randomized clinical trials

Functional dyspepsia (FD) is a very common condition globally. Relevant keywords were searched for in title and abstract of selected databases, that is, Medline/PubMed, Scopus, Embase, Web of knowledge, and Google Scholar. Placebo and active-control trials on herbal remedies amongst adults who were diagnosed with FD were included. Dichotomous outcomes were presented as relative risk (RR) with 95% confidence interval (CI) and continuous outcomes were presented as pooled standardized mean difference (SMD) with 95% CI. Forty-nine randomized controlled trials (RCTs) were entered into meta-analysis (6,987 subjects). Herbal remedies resulted in a higher improvement in FD symptoms in comparison with the placebo (SMD = -0.58 [-0.66- -0.51], p < .00001 and RR = 1.73 [1.62-1.85], p < .00001). No significant difference between herbal remedies and placebo in the incidence of adverse events was observed (12.27 vs. 8.41%, RR = 1.06 [0.91-1.23], p = .45). Also, herbal remedies resulted in a higher improvement in quality of life in comparison with placebo (SMD = -0.64 [-0.73- -0.55], p < .00001). When comparing herbal remedies with conventional medicine through sensitivity analysis, no outcomes were significantly different (p > .05). Herbal remedies might be efficacious and safe in treating FD, and demonstrate comparable effect sizes for efficacy to conventional treatments. Further high-quality studies are warranted to firmly establish the clinical efficacy of the herbal remedies.

The effect of prucalopride on gastric sensorimotor function and satiation in healthy volunteers

BACKGROUND

Gastric motor function alterations have been implicated in the pathogenesis of functional dyspepsia with postprandial distress syndrome (PDS). Prucalopride, a 5-TH4 agonist, is known to stimulate gastrointestinal motility. We aimed to evaluate the effect of prucalopride on gastric sensorimotor function in healthy subjects (HV).

METHODS

Barostat and intragastric pressure (IGP) measurements were performed in 17 HV (59% females, age 29.4 ± 2.7 y) after treatment with placebo or prucalopride (2 mg) (single-blind cross-over). Isobaric stepwise distensions and gastric sensations were assessed to determine gastric compliance and sensitivity. Gastric accommodation (GA) with the barostat was quantified before and after ingestion of 200 ml of a nutrient drink (ND). GA measured by IGP was quantified as the drop of IGP from baseline during the intragastric infusion of ND until maximal satiation (60 ml/min).

KEY RESULTS

Prucalopride did not affect barostat assessed gastric compliance or sensitivity. No differences were observed in GA after prucalopride. During the barostat study, 10 min after the meal, 7 HVs reported significantly higher ratings for nausea after prucalopride (p < 0.001), and vomiting was induced in 4 of the HVs. A positive correlation was observed between the delta mean perception of nausea with the delta mean increase of intra-balloon volume before and after meal ingestion (r = 0.37, p = 0.03). During IGP measurements, no effect on nutrient tolerance was observed and increased cramp severity scores were observed which were associated with a significant increase of distal IGP (r = 0.78, p < 0.0001).

CONCLUSIONS & INFERENCES

Prucalopride does not enhances gastric accommodation but it might increase sensitivity to gastric distention. Furthermore, the increase in sensitivity seems to be related to an increase in nausea with distension. Clinicaltrials.gov: NCT04429802.

Rikkunshito as a Therapeautic Agent for Functional Dyspepsia and its Prokinetic and Non-Prokinetic Effects

Prokinetics is one of the therapeutic agents for functional and motility disorders of the stomach. However, its efficacy is limited. Kampo medicine is a unique medical system that was developed in Japan. In Kampo medicine, herbal medicine is prescribed based on the patient’s condition. Therefore, even for functional and motility disorders of the stomach, some herbal medicines are considered as a therapeutic option. Recently, there has been an increase in evidence for the efficacy or the mechanism of herbal medicine for functional and motility disorders of the stomach. Among these, rikkunshito is a well-studied herbal medicine that could be used as an alternative to prokinetics. In this review, we discuss the possibilities of rikkunshito for functional dyspepsia with its prokinetic and non-prokinetic effects and provide an overview of their current use with a focus on their therapeutic mechanism.

Herbal medicines in functional dyspepsia-Untapped opportunities not without risks

BACKGROUND

Contemporary treatments for functional dyspepsia have limitations. Herbal medicine has been suggested as adjunctive treatment. With growing scientific recognition and public interests, an in-depth review of this is timely.

AIMS/PURPOSE

To evaluate the therapeutic potential and problems that may be associated with the adoption of herbal medicines in functional dyspepsia.

METHODS

We reviewed the treatment landscape of functional dyspepsia and assessed the scientific community's interest in herbal medicine. Preclinical pharmacological and clinical trial data were reviewed for several herbal medicines available in the market. Challenges associated with adoption of herbal medicine in mainstream medicine were critically evaluated.

RESULTS

We found that herbal medicines frequently comprise a combination of herbs with multiple reported pharmacological effects on gastrointestinal motility and secretory functions, as well as cytoprotective and psychotropic properties. We identified a number of commercially available herbal products that have undergone rigorous clinical trials, involving large numbers of well-defined subjects, reporting both efficacy and safety for functional dyspepsia. Persisting concerns include lack of rigorous assessments for majority of products, toxicity, consistency of ingredients, dose standardizations, and quality control. We provide a quality framework for its evaluation.

CONCLUSIONS

We commend herbal medicine as a viable future option in managing functional dyspepsia. An attractive appeal of herbal medicine is the prospect to simultaneously target multiple pathophysiological mechanisms. Wider adoption and acceptance of herbal medicines in treatment algorithms of functional dyspepsia will require the application of the scientific rigor expected of chemical therapies, to all stages of their development and evaluation.