Asian consensus report on functional dyspepsia

Effects of GC7101, a Novel Prokinetic Agent on Gastric Motor Function: Ex Vivo Study

Background/Aims

GC7101, an extract of Lonicera Flos, is a novel developing drug for reflux esophagitis and functional dyspepsia. However, the drug’s exact pharmacological mechanism of action remains unclear. This study assessed the effects of GC7101 on gastrointestinal (GI) motor function.

Methods

We used male guinea pigs to evaluate the effects of GC7101 on GI motility. The contraction of antral circular muscle in the presence of different doses of GC7101 was measured in a tissue bath. The prokinetic effects of GC7101 were tested using the charcoal transit assay from the pylorus to the most distal point of migration of charcoal mixture. To clarify the mechanism of action of GC7101, atropine, dopamine and the selective 5-hydroxytryptamine 4 receptor antagonist, GR113808 were used.

Results

The maximal amplitude of circular muscle contraction was induced by 5 mg mL⁻¹ GC7101. The area under the curve of contraction was significantly increased at 5 mg mL⁻¹ GC7101. Addition of 10⁻⁶ M atropine, 10⁻⁸ M dopamine or 10⁻⁷ M GR 113808 to GC7101 5 mg mL⁻¹ decreased the amplitude and area under curve compared to GC7101 5 mg mL⁻¹ alone. GC7101 accelerated GI transit in a dose dependent manner except 100 mg kg⁻¹. Delayed GI transit caused by atropine, dopamine and GR 113808 was restored by GC7101 50 mg kg⁻¹.

Conclusions

GC7101, an extract of Lonicera Flos, exerts a gastric prokinetic effect in guinea pig through cholinergic, antidopaminergic and serotonergic mechanisms. Therefore, GC7101 might be a novel drug for the treatment of functional dyspepsia.

[Current issues in functional dyspepsia]

Functional dyspepsia is one of the most common gastrointestinal disorders encountered in clinical practice. Functional dyspepsia is currently defined by Rome III criteria as the chronic dyspeptic symptoms (postprandial fullness, early satiety, epigastric pain or burning) in the absence of underling structural or metabolic disease that readily explain the symptoms. According to the Rome III consensus, functional dyspepsia can be subdivided into postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS). Although the Rome III criteria have been published more than 8 years ago, not much effort has been put into validating these criteria and direct scientific evidence supporting the validity of the subdividing functional dyspepsia into PDS and EPS are lacking. This article is intended to review the validity of the Rome III criteria on the subdivisions of functional dyspepsia, i.e. PDS and EPS. The impact of sleep disorder, Helicobacter pylori-associated dyspepsia, and the emerging drug therapies in functional dyspepsia will also be discussed in this article.

Molecular approaches and modern clinical strategies for the management of Helicobacter pylori infection in Japan

Thirty years have passed since Warren and Marshall's discovery of Helicobacter pylori (H. pylori). Since then, not only peptic ulcer diseases and chronic gastritis but also non-cardia gastric cancers have been recognized as diseases originating from H. pylori infection. Several combination therapies consisting of multiple antibiotics have been developed as first- or second-line regimens to eradicate H. pylori infection. Our extensive experience in the field of anti-H. pylori medicine suggests that clinicians should consider a possible role for unidentified, invisible pathogens to elucidate the pathogenesis and improve the treatment of refractory diseases of unknown etiology.

Randomised clinical trial: rabeprazole improves symptoms in patients with functional dyspepsia in Japan

BACKGROUND

The efficacy of proton pump inhibitors (PPIs) for treating functional dyspepsia (FD) is not well established.

AIM

This study, named the SAMURAI study, aimed to assess the efficacy and dose-response relationship of rabeprazole in Japanese patients with FD in a multicentre, double-blinded, randomised, placebo-controlled trial.

METHODS

Investigated FD was diagnosed using the Rome III criteria. Subjects who did not respond to 1 week of single-blind placebo treatment in a run-in period were randomly assigned to 8 weeks of double-blind treatment with rabeprazole 10 mg, 20 mg, 40 mg or placebo, once daily. Dyspeptic symptoms were assessed by a dyspepsia symptom questionnaire (7-point Likert scale) and symptom diary.

RESULTS

Of 392 subjects entered into the run-in period, 338 were randomly assigned. Although there was no significant difference between placebo and rabeprazole groups in complete symptom relief for four major dyspeptic symptoms, the satisfactory symptom relief of rabeprazole 20 mg was significantly higher than placebo according to the dyspepsia symptom questionnaire (45.3% vs. 28.2%, P = 0.027) and the symptom diary assessment (48.7% vs. 30.0%, P = 0.016). The efficacy was not influenced by syndrome type or Helicobacter pylori status. No statistically significant differences in the incidence of adverse events were seen among treatment groups.

CONCLUSIONS

Rabeprazole 20 mg once daily but not 10 or 40 mg significantly provides satisfactory symptom relief for functional dyspepsia (ClinicalTrials.gov, Number NCT01089543).

Modified chaihu shugan powder for functional dyspepsia: meta-analysis for randomized controlled trial

Context. Modified Chaihu Shugan powder (MCSP) is a popular traditional Chinese herbal formula for functional dyspepsia, which is revised from Chaihu Shugan San and recorded in a medical classic works of China. However, its role and effect in treating functional dyspepsia have not been well established. Objective. To assess the effect and safety of modified Chaihu Shugan powder for functional dyspepsia. Methods. We searched the published and unpublished studies up to August 2012. Only RCTs of modified Chaihu Shugan powder with or without prokinetic drugs versus prokinetic drugs in the patients diagnosed with functional dyspepsia were included. Results. Twenty-two clinical trials involving 1998 participants were included. There were evidences that modified Chaihu Shugan powder (RR = 1.20, 95%, CI 1.14 to 1.27) and modified Chaihu Shugan powder plus prokinetic drugs (RR = 1.18, 95%, CI 1.11 to 1.25) were significantly better treatment options than prokinetic drugs alone in improving symptoms. No serious adverse events were described in the included trials. Conclusions. This meta-analysis showed that modified Chaihu Shugan powder alone or in combination with prokinetic drugs might be more effective than prokinetic drugs alone. However, with poor methodological quality, all the included trials were at high risk of bias. Further large-scale high-quality trials are required for assessment.

Helicobacter pylori infection in functional dyspepsia

Functional dyspepsia is the most common reason for patients to experience chronic epigastric pain or discomfort. The causes of functional dyspepsia are multifactorial but Helicobacter pylori infection is one likely candidate. Infection with this bacterial pathogen clearly results in chronic mucosal inflammation in the stomach and duodenum, which, in turn, might lead to abnormalities in gastroduodenal motility and sensitivity. Chronic gastritis might also affect a variety of endocrine functions of the stomach including the production of the gastrointestinal hormones and neurotransmitters somatostatin, gastrin and ghrelin. Although these abnormalities might generate symptoms in some patients with functional dyspepsia, the clinical evidence needs to be critically evaluated before this hypothesis can be confirmed. A Cochrane review reported that eradication of H. pylori in these patients had a small but statistically significant long-term effect on symptom relief when compared with placebo, lasting at least 12 months after 1 week of eradication therapy. The efficacy of eradication therapy was seen in all symptom subtypes of functional dyspepsia, but was more marked in Asian than Western patients. This evidence has led to alterations in most of the major guidelines throughout the world, which now recommend H. pylori eradication in patients with functional dyspepsia if they test positive for this bacterium.

Functional dyspepsia: subtypes, risk factors, and overlap with irritable bowel syndrome in a population of african patients

Background. Functional dyspepsia is the prototype functional gastrointestinal disorder. This study was designed to determine its prevalence, subtypes, and risk factors associated with the subtypes. Method. Patients with upper gastrointestinal symptoms who presented for endoscopy were administered a questionnaire containing the functional dyspepsia and irritable bowel syndrome modules of the Rome III diagnostic criteria. Results. Of 192 patients who had functional dyspepsia, epigastric pain syndrome, postprandial distress syndrome, and combination of the two subtypes accounted for 79.2%, 62.5%, and 50%, respectively. Multivariate analysis of the risk factors showed that independent predictors of postprandial distress syndrome were alcohol and irritable bowel syndrome while irritable bowel syndrome was independent predictor of epigastric pain syndrome. Alcohol, smoking, and use of nonsteroidal anti-inflammatory drugs were independent predictors of cooccurrence of postprandial distress syndrome and epigastric pain syndrome. Conclusion. Functional dyspepsia accounts for 62.5% of dyspepsia in a population of black African patients. Regarding symptomatology, epigastric pain syndrome, postprandial distress syndrome, and combination of the two subtypes account for 79.2%, 62.5%, and 50%, respectively. Risk factors for functional dyspepsia are irritable bowel syndrome, alcohol, smoking, and use of nonsteroidal anti-inflammatory drugs.

Helicobacter pylori: clinical management

PURPOSE OF REVIEW

Progress continues in our understanding of the role of Helicobacter pylori infection in gastroduodenal as well as extragastric disorders. This review gives an overview on selected areas of the H. pylori infection and their clinical implications.

RECENT FINDINGS

Indications for therapy have been extended and now include idiopathic thrombocytopenic purpura, iron deficiency anemia, and vitamin B12 deficiency. New data are presented on the role of H. pylori in neurodegenerative disorders and in the metabolic syndrome. H. pylori is associated with a (small) increase in the risk for colorectal adenoma and colon cancer. The biggest challenge is the selection of new therapies and treatment strategies because of the increasing failure of standard triple therapies. The best option in high clarithromycin resistance areas is bismuth-based quadruple therapy. Probiotic bacteria and yeasts reduce adverse effects of standard H. pylori eradication regimens. In gastric cancer prevention, screening programs based on the serological detection of preneoplastic conditions may prove useful.

SUMMARY

New algorithms for preventing H. pylori-induced disease and eradicating the organism should be individualized.

Helicobacter pylori and nonmalignant diseases

The incidence of peptic ulcer disease has declined over the last few decades, particularly in Western populations, most likely as a result of the decrease in Helicobacter pylori infection and the widespread use of proton-pump inhibitors (PPI) in patients with dyspepsia. The hospital admission rate for uncomplicated duodenal and gastric ulcers has significantly decreased worldwide. In contrast, admissions for complicated ulcer disease, such as bleeding peptic ulcers and perforation, remained relatively stable. Prophylactic H. pylori eradication was found to be associated with a reduced risk of both gastric and duodenal ulcers and their complications, including bleeding in chronic users of nonsteroidal anti-inflammatory drugs. The recent Helicobacter Eradication Relief of Dyspeptic Symptoms trial presented important data relating to symptoms and quality of life of H. pylori-positive patients with functional dyspepsia (FD) and also demonstrated significant benefits from eradication compared with the control group. The new Asian consensus report on FD recommended that dyspepsia accompanied by H. pylori infection should be considered a separate disease entity from FD and that H. pylori infection should be eradicated before diagnosing FD. The association of H. pylori with gastroesophageal reflux disease (GERD) is still controversial. Treatment for H. pylori does not seem to increase GERD symptoms or reflux esophagitis. However, documented eradication of H. pylori appears to significantly improve GERD symptoms. Additional long-term intervention studies are needed to provide more information on which to base clinical decisions.