Management of gastroesophageal reflux disease that does not respond well to proton pump inhibitors

Esophagoprotective therapy in patients with erosive esophagitis

Aim. To evaluate the advantages of using combined therapy of proton-pump inhibitors (PPIs) and esophagoprotector in comparison with basic therapy of PPIs for 4 weeks based on the results of changes in the endoscopic picture.To compare the effectiveness of 4-week PPI therapy and 4-week combination therapy with PPI and esophagoprotector Alfasoxx (sodium hyaluronate, chondroitin sulfate, poloxomer 407) in patients with erosive esophagitis (EE) of any degree according to the Los Angeles Endoscopic Classification. Materials and methods. 81 patients with EE AC according to the Los Angeles endoscopic classification (1994) was enrolled in the study on the basis of the clinic of Peter the Great, Mechnikov North-Western State Medical University. By computer randomization, patients were divided into the control group 40 patients (pantoprazole 40 mg 1 time per day) and the intervention group 41 patients (pantoprazole 40 mg 1 time per day + Alfasoxx 1 sachet qid). The therapy was carried out for 4 weeks. In all patients before and after therapy, the frequency and severity of the main symptoms of gastroesophageal reflux disease (GERD) were assessed, esophagogastroduodenoscopy was performed. Results. The advantage of combination therapy over standard PPI monotherapy in patients with EE was revealed. According to the results of the control endoscopy, healing of erosions of the esophageal mucosa was observed in 39 out of 41 (95.1%) patients in the intervention group and 32 out of 39 (82.1%) in the control group. The proportion of patients who showed an improvement in the endoscopic picture before and after treatment for 4 weeks by at least 1 level according to the Los Angeles classification was significantly higher in the comparison group 41 patients (100%), while in the control group 33 patients (85%); p0.009. After treatment, the combination therapy group had a lower incidence (p0.01) and severity of heartburn (p0.01). The same results are demonstrated by combination therapy regarding the symptom belching of air: in the study group after treatment, this symptom occurred less frequently (p=0.014), its severity was significantly less than in the control group (p0.01). There was a statistically significant decrease in the need for on-demand antacid therapy in the study group. Conclusion. In this study involving 81 patients with erosive GERD, the benefits of combination therapy were demonstrated. The addition of Alfasoxx medical device to PPI therapy increases the clinical and endoscopic efficacy of therapy. This positive effect is associated with the esophagoprotective properties of the drug, based on unique pharmacodynamic characteristics. Combination therapy for GERD is preferred in patients with EE. Studies have shown the expediency of using Alfasoxx in case of insufficient effectiveness of classical acid-suppressive therapy for GERD.

Molecular Mechanism of the Effect of Zhizhu Pill on Gastroesophageal Reflux Disease Based on Network Pharmacology and Molecular Docking

Background

To investigate the pharmacological mechanism of Zhizhu pill (ZZP) against gastroesophageal reflux disease (GERD), network pharmacology in combination with molecular docking was applied in this study.

Methods

Active compounds of ZZP and target genes related to GERD were identified through public databases. Subsequently, the obtained data were used as a basis for further network pharmacological analysis to explore the potential key active compounds, core targets, and biological processes involved in ZZP against GERD. Finally, the results predicted by network pharmacology were validated by molecular docking.

Results

Twenty active components of ZZP were identified to act on 59 targets related to GERD. Enrichment analysis revealed that multiple biological processes including response to oxygen levels, response to oxidative stress, and response to reactive oxygen species were involved in the GERD ZZP treatment with ZZP. ZZP had an impact on the prognosis of GERD mainly through the HIF-1 signaling pathway, PI3K-Akt signaling pathway, and pathways in cancer. Further analysis identified the key components and core targets of ZZP against GERD, of which nobiletin, didymin, luteolin, and naringenin were key components, and PPARG, MMP9, JUN, TP53, PTGS2, EGFR, MAPK3, CASP3, AKT1, and VEGFA were the core targets. Molecular docking verified the stable bonds formed between the key components and the core targets.

Conclusions

The results of this study predict that the therapeutic effects of ZZP in GERD are mediated at least in part via PPARG, MMP9, JUN, TP53, PTGS2, EGFR, MAPK3, CASP3, AKT1, and VEGFA. These results may be useful in providing an experimental basis and new ideas for further research on ZZP in GERD.

ESNM/ANMS consensus paper: Diagnosis and management of refractory gastro-esophageal reflux disease

Up to 40% of patients with symptoms suspicious of gastroesophageal reflux disease (GERD) do not respond completely to proton pump inhibitor (PPI) therapy. The term "refractory GERD" has been used loosely in the literature. A distinction should be made between refractory symptoms (ie, symptoms may or may not be GERD-related), refractory GERD symptoms (ie, persisting symptoms in patients with proven GERD, regardless of relationship to ongoing reflux), and refractory GERD (ie, objective evidence of GERD despite adequate medical management). The present ESNM/ANMS consensus paper proposes use the term "refractory GERD symptoms" only in patients with persisting symptoms and previously proven GERD by either endoscopy or esophageal pH monitoring. Even in this context, symptoms may or may not be reflux related. Objective evaluation, including endoscopy and esophageal physiologic testing, is requisite to provide insights into mechanisms of symptom generation and evidence of true refractory GERD. Some patients may have true ongoing refractory acid or weakly acidic reflux despite PPIs, while others have no evidence of ongoing reflux, and yet others have functional esophageal disorders (overlapping with proven GERD confirmed off therapy). In this context, attention should also be paid to supragastric belching and rumination syndrome, which may be important contributors to refractory symptoms.

Efficacy of vonoprazan for the prevention of bleeding after gastric endoscopic submucosal dissection with continuous use of antiplatelet agents

Background  Post-procedural bleeding, after gastric endoscopic submucosal dissection (ESD) for high risk thromboembolic cases that require continuous antiplatelet therapy, is challenging. Its incidence rate is > 20 % among those using conventional antacids. We evaluated the efficacy of perioperative management with vonoprazan to prevent post-ESD bleeding. Materials and methods  This was a multicenter prospective interventional trial conducted at 10 Japanese referral centers. Patients who regularly used antiplatelet agents (aspirin or thienopyridine derivatives, etc.) and who required continuous antithrombotic medication due to high thromboembolic risk were enrolled. They underwent gastric ESD with continuous aspirin therapy. Oral administration of vonoprazan (20 mg daily) was started from the day of ESD and continued for 28 days. The primary end point was the incidence of post-ESD bleeding. The sample size was 50 patients, and vonoprazan was considered to be effective when the upper threshold of the 95 % confidence interval (CI) for post-ESD bleeding did not exceed 20 %. Results  Although 50 patients were enrolled, one patient withdrew consent. Therefore, 49 patients were included in the analysis. One patient who used aspirin and clopidogrel experienced bleeding 11 days after ESD. The overall post-ESD bleeding rate was 2.0 % (1/49; 95 %CI 0.4-10.7 %). Thromboembolic events were not observed. One case of ESD-associated adverse events (perforation) and one case of drug-associated adverse events (drug eruption, possibly due to vonoprazan) were observed. Conclusions  Vonoprazan may be efficacious for preventing post-ESD bleeding in patients using continuous antiplatelet therapy, warranting further comparative study to definitively test the effectiveness of the drug.

Novel Therapies for Gastroesophageal Reflux Disease: Beyond Proton Pump Inhibitors

PURPOSE OF REVIEW

Despite the many areas of unmet needs in gastroesophageal reflux disease (GERD), proton pump inhibitors (PPIs) remain the cornerstone of medical therapy. However, since their introduction, the therapeutic limitations of PPIs in GERD management have been increasingly recognized.

RECENT FINDINGS

In this review we discuss the new medical, endoscopic, and surgical therapeutic modalities that have been developed over the last decade. They include the potassium-competitive acid blockers (P-CABs) which provide a rapid onset, prolonged, and profound acid suppression, mucosal protectants which promote the physiological protective barrier of the esophageal mucosa, new prokinetics and neuromodulators. There are growing numbers of novel therapeutic endoscopic techniques that are under investigation or were recently introduced into the market, further expanding our therapeutic armamentarium for GERD. The development of diverse therapeutic modalities for GERD, despite the availability of PPIs, suggests that there are many areas of unmet need in GERD that will continue and drive future exploration for novel therapies.

A Randomized Placebo-Controlled N-of-1 Trial: The Effect of Proton Pump Inhibitor in the Management of Gastroesophageal Reflux Disease

BACKGROUND

Gastroesophageal reflux disease (GERD) is the most frequent chronic gastrointestinal disorder. It is defined as a condition developed when the reflux of gastric contents causes troublesome symptoms (heartburn and regurgitation). This requires adequate treatment since it can lead to long-term complications including esophagus adenocarcinoma. Proton pump inhibitors (PPI) are generally used to treat GERD due to their high-security profile and efficiency on most patients. However, recurrent reflux despite initial treatment is frequent. N-of-1 trial is a study that allows the identification of the best treatment for each patient. The objective of this study is to compare the efficacy of standard dose with double dosage of esomeprazole, to improve the GERD symptoms in a single patient.

METHODS

A single-patient trial, placebo-controlled, randomized, double-blind, was carried out from September 25th, 2012, to April 26th, 2013. It included one outpatient at the gastroenterology service in a fourth-level hospital, diagnosed with nonerosive reflux disease (NERD). Yet, his symptoms were heartburn and reflux, and his endoscopic results were normal esophageal mucosa, without hiatal hernia, though pathological pH values. A no-obese male without any tobacco or alcohol usage received esomeprazole 40 mg/day and 40 mg/bid for 24 weeks. A standardized gastroesophageal reflux disease questionnaire (GerdQ) was used weekly to evaluate symptom frequency and severity. The consumption of 90% of the capsules was considered as an adequate treatment adherence. D'agostino-Pearson and Wilcoxon test were used to determine normal or nonnormal distribution and compare both treatments, respectively, both with a significant statistical difference of p < 0.05.

RESULTS

The patient completed the study with 96% of adherence. The double dosage of esomeprazole did not improve the control of symptoms compared with the standard dosage. Mean symptomatic score was 9.5±0.5 and 10.2±0.6 for each treatment, respectively (p > 0.05).

CONCLUSION

There was no significant improvement in the patient GERD symptoms increasing the dose of oral esomeprazole during the 6 months of study. N-of-1 trials in chronic pathologies including GERD are recommended due to their potential value as systematic methods that evaluate therapies without strong scientific evidence.

Persistent Postprandial Regurgitation vs Rumination in Patients With Refractory Gastroesophageal Reflux Disease Symptoms: Identification of a Distinct Rumination Pattern Using Ambulatory Impedance-pH Monitoring

OBJECTIVES

Up to 20% of patients with refractory gastroesophageal reflux disease (GERD) might have postprandial rumination. The aim of this study was to distinguish persistent GERD-related postprandial regurgitation from rumination in patients with refractory GERD undergoing ambulatory multichannel intraluminal impedance-pH (MII-pH) monitoring.

METHODS

We first characterized 24-hour and postprandial MII-pH patterns in 28 consecutive patients with confirmed rumination syndrome (positive clinical and high-resolution manometry/impedance). We compared such MII-pH patterns with those from 30 patients with typical GERD symptoms (10 nonerosive reflux disease, 10 hyperactive esophagus, and 10 functional heartburn) and 27 healthy controls. Using ROC curves, we selected the best MII-pH parameters to prepare an MII-pH rumination score. We prospectively tested the performance of the new MII-pH rumination score in 26 consecutive patients with refractory GERD (predominant regurgitation).

RESULTS

Compared with GERD controls, patients with rumination were more often females, younger, and had significantly more postprandial early nonacid reflux episodes with high proximal extent. Postprandial reflux in ruminators had a distinct nadir pH profile over time (from nonacid to acid). Despite increased reflux events, baseline impedance in ruminators was similar to that in healthy subjects. Ruminators marked postprandial symptoms earlier and much more often than patients with GERD. An MII-pH-based rumination score (using postprandial nonacid reflux/hour and Symptom Index) diagnosed rumination in 46% of patients with refractory GERD and persistent regurgitation (sensitivity 91.7% and specificity 78.6%).

DISCUSSION

Postprandial rumination is very common in refractory GERD with persistent regurgitation. A simple MII-pH score detects rumination in these patients with high sensitivity and specificity.

Prevalence and clinical characteristics of refractoriness to optimal proton pump inhibitor therapy in non-erosive reflux disease

BACKGROUND

The real size of the gastro-oesophageal reflux disease (GERD) population not responding to proton pump inhibitor (PPI) therapy has still not been fully elucidated. Causes of PPI refractoriness include incorrect diagnosis and lack of adherence to therapy, in terms of incorrect dosage and timing.

AIMS

To evaluate the prevalence of refractoriness to optimal PPI therapy and the contribution of non-erosive reflux disease (NERD), reflux hypersensitivity, and functional heartburn, to PPI refractoriness. The association of functional GI symptoms in non-responders was evaluated.

METHODS

Frequency and severity of GERD symptoms (heartburn, regurgitation, chest pain), dysphagia, belching, epigastric pain, postprandial distress, irritable bowel syndrome (IBS), globus, and ear nose and throat (ENT) symptoms were evaluated in patients previously classified as non-responders. Patients with at least one of the oesophageal symptoms with a frequency ≥3 /week were treated with esomeprazole 40 mg once daily for 8 weeks and then re-evaluated. Non-responders (patients with oesophageal symptoms ≥3 times per week) underwent 24 hour multichannel intraluminal impedance-pH monitoring.

RESULTS

Of 573 consecutive patients, 92 with oesophageal symptoms and classified as PPI-refractory underwent the esomeprazole trial; 60 did not respond. IBS, epigastric pain, and post-prandial distress episodes were associated with a poor response on multivariate analysis. NERD, reflux hypersensitivity, and functional heartburn patients constituted 32%, 42%, and 26%, respectively of the PPI-refractory group.

CONCLUSIONS

True refractoriness in patients with GERD symptoms attending a secondary care setting is lower than previously reported. Following a careful history and optimal PPI dosing, the rate of refractoriness was 20%. True NERD constitutes only a third of the PPI-refractory group.

Current Trends in the Management of Gastroesophageal Reflux Disease

Gastroesophageal reflux disease (GERD) characterized by heartburn and/or regurgitation symptoms is one of the most common gastrointestinal disorders managed by gastroenterologists and primary care physicians. There has been an increase in GERD prevalence, particularly in North America and East Asia. Over the past three decades proton pump inhibitors (PPIs) have been the mainstay of medical therapy for GERD. However, recently there has been an increasing awareness amongst physicians and patients regarding the side effects of the PPI class of drugs. In addition, there has been a marked decline in the utilization of surgical fundoplication as well as a rise in the development of nonmedical therapeutic modalities for GERD. This review focuses on different management strategies for GERD, optimal management of refractory GERD with special focus on available endoluminal therapies and the future directions.

Effect of Postprandial Administration of Esomeprazole on Reflux Symptoms in Gastroesophageal Reflux Disease: A Randomized, Controlled Trial

BACKGROUND

Esomeprazole is commonly administered with food; however, clinical data to support this practice are lacking. We aimed to determine the effect of postprandial ingestion of esomeprazole on reflux symptoms among patients with gastroesophageal reflux disease (GERD).

METHODS

Consecutive patients with GERD adequately controlled with esomeprazole 40 mg daily, entered a 2-week lead-in period during which esomeprazole was administered 30 min before breakfast. Patients were then randomized to continue preprandial ingestion or to ingest esomeprazole following a standardized meal. Outcomes included GERD frequency and severity indices, GERD-health-related quality of life (GERD-HRQL) questionnaire and Short Form 36 (SF-36).

RESULTS

Thirty-two patients (17 [53.1%] men, aged 53.5 ± 17.2 years) were included, and 16 (50%) switched to postprandial ingestion of esomeprazole. GERD frequency and severity decreased in both groups (Δ9.0 ± 7.2 vs. Δ10.0 ± 8.1, p = 0.29; Δ6.6 ± 6.8 vs. Δ10.2 ± 7.4, p = 0.57 in postprandial group vs. controls, for frequency and severity, respectively). GERD-HRQL improved in both study groups to a similar degree (Δ10.7 ± 10.5 vs. Δ10.0 ± 13.8, p = 0.97). All SF-36 subscores increased in both groups to a similar degree. In a mixed linear model, there were no differences between the study groups in the changes observed in GERD frequency (p = 0.49), severity (p = 0.32), and GERD-HRQL (p = 0.98) during the study period.

CONCLUSION

Switching to postprandial administration of esomeprazole is not associated with deterioration in reflux symptoms among patients with GERD. Esomeprazole seems to remain efficacious when administered after meals.

Management of Gastroesophageal Reflux Disease

Management of gastroesophageal reflux disease (GERD) commonly starts with an empiric trial of proton pump inhibitor (PPI) therapy and complementary lifestyle measures, for patients without alarm symptoms. Optimization of therapy (improving compliance and timing of PPI doses), or increasing PPI dosage to twice daily in select circumstances, can reduce persistent symptoms. Patients with continued symptoms can be evaluated with endoscopy and tests of esophageal physiology, to better determine their disease phenotype and optimize treatment. Laparoscopic fundoplication, magnetic sphincter augmentation, and endoscopic therapies can benefit patients with well-characterized GERD. Patients with functional diseases that overlap with or mimic GERD can also be treated with neuromodulators (primarily antidepressants), or psychological interventions (psychotherapy, hypnotherapy, cognitive and behavioral therapy). Future approaches to treatment of GERD include potassium-competitive acid blockers, reflux-reducing agents, bile acid binders, injection of inert substances into the esophagogastric junction, and electrical stimulation of the lower esophageal sphincter.

Gastroesophageal Reflux Disease Associated With Anxiety: Efficacy and Safety of Fixed Dose Combination of Amitriptyline and Pantoprazole

Background

The aim of the study was to evaluate the efficacy and tolerability of fixed dose combination of amitriptyline and pantoprazole in gastroesophageal reflux disease (GERD) associated with anxiety.

Methods

A non-randomized, open-labeled, non-comparative, multi-center study was conducted in a total of 99 patients (77 men and 22 women, mean age 44.16 ± 11.53 years). Each patient was administered a fixed dose combination of amitriptyline 10 mg and pantoprazole 40 mg once a day, for 4 weeks. GERD questionnaire, hospital anxiety and depression score (HADS) and SF-8 questionnaire (short-form health survey) were performed at baseline and at the end of study as assessment tools.

Results

At the end of study, data were extractable only in 96 patients because three patients were dropped out due to loss of follow-up at week 4. GERD symptoms and anxiety score reduced significantly (P < 0.0001) at week 4 compared to baseline. SF-8 score also improved significantly (P < 0.0001) at week 4. There were no adverse events reported.

Conclusion

Amitriptyline and pantoprazole combination was found to be effective and safe for management in GERD patients with coexisting anxiety.

The selective metabotropic glutamate receptor 5 antagonist mavoglurant (AFQ056) reduces the incidence of reflux episodes in dogs and patients with moderate to severe gastroesophageal reflux disease

BACKGROUND

Transient lower esophageal sphincter relaxations (TLESRs) induced by gastric distension are modulated by the metabotropic glutamate receptor 5 (mGluR5) that influences the vagal reflex loop. We therefore aimed to examine the effects of the selective mGluR5 antagonist mavoglurant (AFQ056) on the number of TLESRs in dogs and reflux episodes in patients with gastroesophageal reflux disease (GERD).

METHODS

In a dog model, the number of meal-induced TLESRs was determined after intravenous (0.03, 0.1, 0.3, and 1 mg kg^-1 ) and oral (1, 3, and 10 mg kg^-1 ) doses of mavoglurant with reference to vehicle. In a multicenter, randomized, double-blind, placebo-controlled, three-period crossover study, the incidence of meal-induced reflux episodes was assessed by esophageal impedance monitoring after single, oral doses of mavoglurant (50 and 400 mg) or baclofen (40 mg) in 30 patients with moderate to severe GERD.

KEY RESULTS

In dogs, mavoglurant reduced the number of TLESRs after intravenous and oral administration. In patients with GERD, the incidence of postprandial reflux episodes was significantly lower at a dose of 400 mg mavoglurant (-37.5% ; 90% confidence interval [CI]: -57.8, -17.2), whereas there was no significant difference at 50 mg of mavoglurant compared to placebo. A significantly lower incidence of reflux episodes was also noted with the active comparator baclofen (-50.3%; 90% CI: -66.2, -34.3), thereby validating this study.

CONCLUSIONS AND INFERENCES

These data suggest a potential clinical benefit of mGluR5 antagonists such as mavoglurant in patients with GERD, particularly in those with persisting symptoms despite treatment with proton pump inhibitors.

Vonoprazan fumarate for the management of acid-related diseases

INTRODUCTION

Proton pump inhibitors (PPIs) display a number of limitations and unmet clinical needs that have prompted the development of novel drugs to improve the outcomes of acid-related diseases, including the eradication of H. pylori. In this context, a new synthesized potassium-competitive acid blocker (P-CAB), vonoprazan, showed higher suppression of gastric acid secretion. Areas covered: This review discusses the current knowledge regarding the efficacy of vonoprazan in the treatment of acid-related diseases, with a particular focus on its use in Helicobacter pylori eradication. Expert opinion: Vonoprazan showed some advantages over PPIs in terms of the pharmacokinetic and pharmacodynamic profile: fast onset of action without requiring acid activation and specific administration timing, more potent and prolonged inhibition of acid secretion, including a better nighttime acid control, and a less antisecretory variability. Recent evidence suggests that vonoprazan can be preferred to PPIs as maintenance therapy for reflux esophagitis and eradication of Helicobacter pylori owing to its stronger antisecretory effect. Moreover, vonoprazan displays favorable safety and tolerability profiles, even though long-term studies on the effects of vonoprazan are required.

Alginate therapy is effective treatment for GERD symptoms: a systematic review and meta-analysis

In patients with gastroesophageal reflux disease (GERD) and erosive esophagitis, treatment with proton pump inhibitors (PPIs) is highly effective. However, in some patients, especially those with nonerosive reflux disease or atypical GERD symptoms, acid-suppressive therapy with PPIs is not as successful. Alginates are medications that work through an alternative mechanism by displacing the postprandial gastric acid pocket. This study performed a systematic review and meta-analysis to examine the benefit of alginate-containing compounds in the treatment of patients with symptoms of GERD. PubMed/MEDLINE, Embase, and the Cochrane library electronic databases were searched through October 2015 for randomized controlled trials comparing alginate-containing compounds to placebo, antacids, histamine-2 receptor antagonists (H2RAs), or PPIs for the treatment of GERD symptoms. Additional studies were identified through a bibliography review. Non-English studies and those with pediatric patients were excluded. Meta-analyses were performed using random-effect models to calculate odds ratios (OR). Heterogeneity between studies was estimated using the I2 statistic. Analyses were stratified by type of comparator. The search strategy yielded 665 studies and 15 (2.3%) met inclusion criteria. Fourteen were included in the meta-analysis (N = 2095 subjects). Alginate-based therapies increased the odds of resolution of GERD symptoms when compared to placebo or antacids (OR: 4.42; 95% CI 2.45-7.97) with a moderate degree of heterogeneity between studies (I2 = 71%, P = .001). Compared to PPIs or H2RAs, alginates appear less effective but the pooled estimate was not statistically significant (OR: 0.58; 95% CI 0.27-1.22). Alginates are more effective than placebo or antacids for treating GERD symptoms.

Alginate therapy is effective treatment for gastroesophageal reflux disease symptoms: a systematic review and meta-analysis

In patients with gastroesophageal reflux disease (GERD) and erosive esophagitis, treatment with proton pump inhibitors (PPIs) is highly effective. However, in some patients, especially those with non-erosive reflux disease or atypical GERD symptoms, acid suppressive therapy with PPIs is not as successful. Alginates are medications that work through an alternative mechanism by displacing the post-prandial gastric acid pocket. We performed a systematic review and meta-analysis to examine the benefit of alginate-containing compounds in the treatment of patients with symptoms of GERD.PubMed/MEDLINE, Embase and the Cochrane library electronic databases were searched through October 2015 for randomized controlled trials comparing alginate-containing compounds to placebo, antacids, histamine-2 receptor antagonists (H2RAs) or PPIs for the treatment of GERD symptoms. Additional studies were identified through bibliography review. Non-English studies and those with pediatric patients were excluded. Meta-analyses were performed using random-effects models to calculate odds ratios (OR). Heterogeneity between studies was estimated using the I2 statistic. Analyses were stratified by type of comparator. The search strategy yielded 665 studies and 15 (2.3%) met inclusion criteria. Fourteen were included in the meta-analysis (N = 2095 subjects). Alginate-based therapies increased the odds of resolution of GERD symptoms when compared to placebo or antacids (OR: 4.42; 95% CI 2.45-7.97) with a moderate degree of heterogeneity between studies (I2 = 71%, P = .001). Compared to PPIs or H2RAs, alginates appear less effective but the pooled estimate was not statistically significant (OR: 0.58; 95% CI 0.27-1.22). Alginates are more effective than placebo or antacids for treating GERD symptoms.

Effect of Timing of Proton Pump Inhibitor Administration on Acid Suppression

BACKGROUND

Esomeprazole has been reported to show a strong acid suppression following preprandial as compared to postprandial administration, though no known study has compared the acid suppressing effects of other proton pump inhibitors between those administrations. The aim of this study was to compare intragastric pH levels following pre- and postprandial administrations of rabeprazole and esomeprazole.

METHODS

In 15 Helicobacter pylori-negative healthy volunteers, we measured intragastric pH after 7 days of pre- and postprandial administrations of rabeprazole (10 mg) or esomeprazole (20 mg) using a 5-way crossover design.

RESULTS

Preprandial administration of esomeprazole showed stronger acid suppression than postprandial administration. The values for percent time at pH >4.0 over a 24-hour period increased from 45.3% with postprandial administration of esomeprazole to 54.4% with preprandial administration, while the percent time at pH >4.0 during daytime was increased to a greater extent from 51.4 to 66.5% with preprandial administration (p = 0.05). On the other hand, the acid suppressing effect of rabeprazole was not influenced by the timing of administration.

CONCLUSIONS

The acid suppressing effect of esomeprazole is influenced by administration timing. In contrast, the acid suppressing effect of rabeprazole is not augmented by preprandial administration.

Helicobacter pylori and Antibiotic Resistance, A Continuing and Intractable Problem

Helicobacter pylori, a human pathogen with a high global prevalence, is the causative pathogen for multiple gastrointestinal diseases, especially chronic gastritis, peptic ulcers, gastric mucosa-associated lymphoid tissue lymphoma, and gastric malignancies. Antibiotic therapies remain the mainstay for H. pylori eradication; however, this strategy is hampered by the emergence and spread of H. pylori antibiotic resistance. Exploring the mechanistic basis of this resistance is becoming one of the major research questions in contemporary biomedical research, as such knowledge could be exploited to devise novel rational avenues for counteracting the existing resistance and devising strategies to avoid the development of a novel anti-H. pylori medication. Encouragingly, important progress in this field has been made recently. Here, we attempt to review the current state and progress with respect to the molecular mechanism of antibiotic resistance for H. pylori. A picture is emerging in which mutations of various genes in H. pylori, resulting in decreased membrane permeability, altered oxidation-reduction potential, and a more efficient efflux pump system. The increased knowledge on these mechanisms produces hope that antibiotic resistance in H. pylori can ultimately be countered.

Pharmacokinetics, absorption, and excretion of radiolabeled revexepride: a Phase I clinical trial using a microtracer and accelerator mass spectrometry-based approach

Purpose

Gastroesophageal reflux disease involves the reflux of gastric and/or duodenal content into the esophagus. Prokinetic therapies, such as the selective 5-hydroxytryptamine receptor 4 agonist revexepride, may aid gastric emptying. This Phase I study evaluated the pharmacokinetics and excretion pathways of [¹⁴C]revexepride in healthy individuals using a microtracer approach with accelerator mass spectrometry.

Participants and methods

Six healthy men received a single oral dose of 2 mg [¹⁴C]revexepride containing ~200 nCi of radioactivity; blood, urine, and fecal samples were collected over a 10-day period.

Results

Almost 100% of ¹⁴C was recovered: 38.2%±10.3% (mean ± standard deviation) was recovered in urine, and 57.3%±0.4% was recovered in feces. Blood cell uptake was low, based on the blood plasma total radioactivity ratio of 0.8. The mean revexepride renal clearance was 8.6 L/h, which was slightly higher than the typical glomerular filtration rate in healthy individuals. Time to reach maximal concentration was 1.75±1.17 hours (mean ± standard deviation). No safety signals were identified.

Conclusion

This study demonstrated that revexepride had rapid and moderate-to-good oral absorption. Excretion of radioactivity was completed with significant amounts in feces and urine. Renal clearance slightly exceeded the typical glomerular filtration rate, suggesting the involvement of active transportation in the renal tubules.

Effects of Transcutaneous Electrical Acustimulation on Refractory Gastroesophageal Reflux Disease

Objective. To investigate effects and possible mechanisms of transcutaneous electrical acustimulation (TEA) performed by a wearable watch-size stimulator for refractory gastroesophageal reflux disease (RGERD). Methods. Twenty patients diagnosed as RGERD were enrolled in the study and randomly divided into four groups: esomeprazole group (Group A), esomeprazole combined with TEA group (Group B), esomeprazole combined with sham-TEA group (Group C), and esomeprazole combined with domperidone group (Group D). HRM and 24 h pH-impedance monitoring and GerdQ score were used to measure related indexes before and after treatment. Results. (1) TEA significantly increased LESP, compared with PPI treatment only or PPI plus sham-TEA. After pairwise comparison, LESP of Group B was increased more than Group A (P = 0.008) or Group C (P = 0.021). (2) PPI plus TEA decreased not only the number of acid reflux episodes but also the number of weak acid reflux episodes (P = 0.005). (3) Heartburn and reflux symptoms were improved more with PPI + TEA than with PPI treatment only or PPI plus sham-TEA (GerdQ scores, P = 0.001). Conclusion. TEA can improve symptoms in RGERD patients by increasing LESP and decreasing events of weak acid reflux and acid reflux; addition of TEA to esomeprazole significantly enhances the effect of TEA.

Contribution of immunomodulators to gastroesophageal reflux disease and its complications: stromal cells, interleukin 4, and adiponectin

Gastroesophageal reflux disease (GERD) has become the most commonly seen gastrointestinal disorder in outpatient clinics. In the United States, around 20% of the general population experience heartburn on a weekly basis. Although clinical complaints can be mild or moderate, patients with GERD may develop further complications, such as peptic strictures, Barrett's esophagus (BE), and even esophageal adenocarcinoma. Pathologically, GERD is developed as a result of chronic and enhanced exposure of the esophageal epithelium to noxious gastric refluxate. In this review article, we provide an overview of GERD and then focus on the roles of stromal cells, interleukin 4, and adiponectin in GERD and BE. The importance of inflammation and immunomodulators in GERD pathogenesis is highlighted. Targeting the immunomodulators or inflammation in general may improve the therapeutic outcome of GERD, in particular, in those refractory to proton pump inhibitors.

Gastroesophageal reflux disease-related and functional heartburn: pathophysiology and treatment

PURPOSE OF REVIEW

Patients who continue to experience heartburn symptoms despite adequate-dose proton pump inhibitor therapy have unmet clinical needs. In this review, we focus on the most recent findings related to the mechanism of heartburn symptom generation, and on the treatment of gastroesophageal reflux disease-related and functional heartburn.

RECENT FINDINGS

The immunological mechanism in the esophageal mucosa has been addressed as a potential mechanism of the onset of esophageal mucosa damage and the generation of heartburn symptoms. Peripheral or central hypersensitivity in viscera is a potentially unifying pathophysiological concept in functional heartburn. Vonoprazan, a novel and potent first-in-class potassium-competitive acid blocker, is expected to prove useful in the treatment of reflux disease.

SUMMARY

New findings in the mechanisms of heartburn symptom generation are emerging, including the immunological mediation of esophageal mucosal damage and the development of visceral hypersensitivity in functional heartburn. In the future, we anticipate the emergence of new and specific therapeutic options based on these mechanisms, with less dependence on acid-suppressing agents.

Predictors of proton pump inhibitor failure in non-erosive reflux disease: A study with impedance-pH monitoring and high-resolution manometry

BACKGROUND

Approximately one-third of gastroesophageal reflux disease (GERD) patients have symptoms resistant to proton pump inhibitor (PPI). We used the high-resolution manometry (HRM) and multichannel intraluminal impedance-pH (MII-pH) monitoring to investigate potential predictors of PPI failure in non-erosive reflux disease (NERD) patients.

METHODS

One hundred and seventeen NERD patients were included, within which there were 44 PPI failure patients. The symptomatic questionnaire GerdQ, HRM and 24-hour MII-pH monitoring were performed before PPI therapy. PPI failure was defined as persistent reflux symptoms for more than 1 day during the last week on esomeprazole (20 mg twice daily) for continuous 4 weeks. The predictors for PPI failure were investigated by multivariable logistic regression analysis.

KEY RESULTS

Proton pump inhibitor failure patients had lower body mass index (BMI) and more concomitant functional dyspepsia (FD) symptoms. PPI failure patients had a higher percentage of type I esophagogastric junction (EGJ) morphology (p = 0.005), increased EGJ augmentation (p = 0.000), higher prevalence of esophageal motility disorders (p = 0.005) and a higher ratio of negative symptom index (SI, p = 0.000). Multivariable regression analysis showed that concomitance of FD symptoms, EGJ augmentation and negative SI were independent risk factors for PPI failure in NERD.

CONCLUSIONS & INFERENCES

Approximately half of PPI failure patients were found to have esophageal motility disorders in HRM. The independent risk factors for PPI failure in NERD were concomitant FD symptoms, increased EGJ augmentation and negative SI.

Esophageal Epithelial-Derived IL-33 Is Upregulated in Patients with Heartburn

Background

Interleukin-33 (IL-33) is a tissue-derived cytokine that is constitutively expressed in epithelial cells of tissues exposed to the environment and plays a role in sensing damage caused by inflammatory diseases. IL-33 acts as both a traditional cytokine and as a chromatin-associated nuclear factor in both innate and adaptive immunity. We recently showed that IL-33 in esophageal mucosa is upregulated in reflux esophagitis. However, IL-33 expression in patients with heartburn without mucosal injury and its relationship with intercellular space (ICS) have never been examined. We therefore examined the expression of cytokines and ICS in patients with heartburn.

Methods

The expression of IL-33 in the middle and distal esophageal mucosa of patients with heartburn without mucosal break and control samples was examined using real-time RT-PCR and immunofluorescence. The mRNA expression of IL-6, IL-8, MCP-1, and RANTES, and ICS was also analyzed.

Results

IL-33 expression and the mean ICS were significantly increased in the mucosa of patients with heartburn compared to that of the control. IL-33 and ICS were not different between the patients who were taking a PPI and those who were not. The upregulated IL-33 expression in the heartburn group was located in the nuclei of the basal cell layer. Although IL-6, IL-8, MCP-1 and RANTES levels were not different between control and patients with heartburn samples, IL-33 mRNA levels were still significantly correlated with IL-6, IL-8, or MCP-1 mRNA levels.

Conclusion

Nuclear IL-33 is upregulated in patients with heartburn. Upregulated IL-33 in heartburn patients is related to the symptoms.

Randomised clinical trial: alginate (Gaviscon Advance) vs. placebo as add-on therapy in reflux patients with inadequate response to a once daily proton pump inhibitor

BACKGROUND

Many reflux patients remain symptomatic on a standard dose of proton pump inhibitor (PPI). Alginates decrease the number of reflux events by forming a raft on top of the stomach content and thus offer a supplemental mechanism of action to acid suppression.

AIM

To assess the efficacy of an alginate (Gaviscon Advance, Reckitt Benckiser, Slough, UK) on reflux symptoms in patients with persistent symptoms despite once daily PPI.

METHODS

This was a multicentre, randomised, placebo-controlled, 7-day double-blind trial preceded by a 7-day run-in period. Reflux symptoms were assessed using the Heartburn Reflux Dyspepsia Questionnaire (HRDQ). Based on symptom score during run-in, eligible patients were randomised to Gaviscon Advance 10 mL four times a day or placebo in addition to a once daily PPI. The primary endpoint was change in HRDQ score post-treatment compared to baseline.

RESULTS

One hundred and thirty-six patients were randomised. Change in HRDQ reflux score was significantly greater for Gaviscon Advance (mean: -5.0, s.d.: 4.7) than for placebo (mean: -3.5, s.d.: 5.5) with an LS mean difference of 1.6 [95% CI -3.1 to -0.1], P = 0.03. A decrease in the mean (s.d.) number of nights with symptoms was observed from 3.6 (2.8) to 3.0 (3.0) in the placebo group and from 3.9 (2.8) to 2.2 (2.7) for the Gaviscon Advance group. This reduction was significantly greater in the Gaviscon Advance group than in the placebo group [LS mean difference = -0.9, 95% CI (-1.6 to -0.2), P < 0.01].

CONCLUSION

In patients with residual reflux symptoms despite PPI treatment, adding an alginate offers additional decrease in the burden of reflux symptoms (EudraCT/IND Number: 2011-005486-21).

A stepwise protocol for the treatment of refractory gastroesophageal reflux-induced chronic cough

BACKGROUND

Refractory gastroesophageal reflux-induced chronic cough (GERC) is difficult to manage. The purpose of the study is to evaluate the efficacy of a novel stepwise protocol for treating this condition.

METHODS

A total of 103 consecutive patients with suspected refractory reflux-induced chronic cough failing to a standard anti-reflux therapy were treated with a stepwise therapy. Treatment commences with high-dose omeprazole and, if necessary, is escalated to subsequent sequential treatment with ranitidine and finally baclofen. The primary end-point was overall cough resolution, and the secondary end-point was cough resolution after each treatment step.

RESULTS

High-dose omeprazole eliminated or improved cough in 28.1% of patients (n=29). Further stepwise of treatment with the addition of ranitide yielded a favorable response in an additional 12.6% (n=13) of patients, and subsequent escalation to baclofen provoked response in another 36.9% (n=38) of patients. Overall, this stepwise protocol was successful in 77.6% (n=80) of patients. The diurnal cough symptom score fell from 3 [1] to 1 [0] (Z=6.316, P=0.000), and the nocturnal cough symptom score decreased from 1 [1] to 0 [1] (Z=-4.511, P=0.000), with a corresponding reduction in the Gastroesophageal Reflux Diagnostic Questionnaire score from 8.6±1.7 to 6.8±0.7 (t=3.612, P=0.000). Conversely, the cough threshold C2 to capsaicin was increased from 0.49 (0.49) µmol/L to 1.95 (2.92) µmol/L (Z=-5.892, P=0.000), and the cough threshold C5 was increased from 1.95 (2.92) µmol/L to 7.8 (5.85) µmol/L (Z=-5.171, P=0.000).

CONCLUSIONS

Sequential stepwise anti-reflux therapy is a useful therapeutic strategy for refractory reflux-induced chronic cough.

Refractory chronic cough due to gastroesophageal reflux: Definition, mechanism and management

Refractory chronic cough due to gastroesophageal reflux is a troublesome condition unresponsive to the standard medical anti-reflux therapy. Its underlying mechanisms may include incomplete acid suppression, non-acid reflux, transient lower esophageal sphincter relaxations and esophageal hypersensitivity. The diagnosis of this disorder depends on both the findings of multi-channel intraluminal impedance-pH monitoring and the subsequent intensified anti-reflux therapy. The strategies of pharmacological treatment for refractory chronic cough due to reflux include the optimization of proton pump inhibitors and add-on therapies with histamine H₂ receptor antagonists, baclofen and gabapentin. However, the further study is needed to satisfy its management.

Unmet Needs in the Treatment of Gastroesophageal Reflux Disease

Gastroesophageal reflux disease (GERD) is a highly prevalent gastrointestinal disorder. Proton pump inhibitors have profoundly revolutionized the treatment of GERD. However, several areas of unmet need persist despite marked improvements in the ther-apeutic management of GERD. These include the advanced grades of erosive esophagitis, nonerosive reflux disease, main-tenance treatment of erosive esophagitis, refractory GERD, postprandial heartburn, atypical and extraesophageal manifestations of GERD, Barrett's esophagus, chronic protein pump inhibitor treatment, and post-bariatric surgery GERD. Consequently, any fu-ture development of novel therapeutic modalities for GERD (medical, endoscopic, or surgical), would likely focus on the afore-mentioned areas of unmet need.

Anxiety and depression in patients with gastroesophageal reflux disease and their effect on quality of life

AIM: To explore the role of psychological factors in gastroesophageal reflux disease (GERD) and their effect on quality of life (QoL) of GERD patients.

METHODS: A total of 279 consecutive patients with typical symptoms and 100 healthy controls were enrolled in the study. All of the participants were evaluated with the Zung Self-Rating Anxiety Scale (ZSAS), the Zung Self-Rating Depression Scale (ZSDS) and the SF-36 questionnaire. The scores for anxiety, depression and QoL of the two groups were analyzed. The correlation between psychological factors and QoL was also analyzed.

RESULTS: Compared with healthy controls (34.70 ± 8.00), the scores of ZSAS in the non-erosive reflux disease (NERD) group (48.27 ± 10.34) and the reflux esophagitis (RE) group (45.38 ± 10.27) were significantly higher (P < 0.001). The mean ZSAS score of the NERD group was significantly higher than that of the RE group (P = 0.01). Compared with healthy controls (37.61 ± 8.44), the mean ZSDS scores were significantly higher in the NERD group (49.65 ± 11.09, P < 0.001) and the RE group (46.76 ± 11.83, P < 0.001). All dimensions of the SF-36 form were negatively correlated with the SAS and SDS scores in patients with NERD and RE (P < 0.05). According to the SF-36 form, vitality, mental health and social functioning were significantly correlated with symptoms of depression in patients with NERD and RE. General health was obviously affected by symptoms of depression in patients with NERD (P < 0.05).

CONCLUSION: Anxiety and depression may play an important role in the occurrence of GERD and especially that of NERD. The QoL of patients with GERD is reduced by anxiety and depression.

Randomized clinical trial: effect of the 5-HT4 receptor agonist revexepride on reflux parameters in patients with persistent reflux symptoms despite PPI treatment

BACKGROUND

Approximately, 20-30% of patients with gastro-esophageal reflux disease (GERD) experience persistent symptoms despite treatment with proton pump inhibitors (PPIs). These patients may have underlying dysmotility; therefore, targeting gastric motor dysfunction in addition to acid inhibition may represent a new therapeutic avenue. The aim of this study was to assess the pharmacodynamic effect of the prokinetic agent revexepride (a 5-HT4 receptor agonist) in patients with GERD who have persistent symptoms despite treatment with a PPI.

METHODS

This was a phase II, exploratory, multicenter, randomized, placebo-controlled, double-blind, parallel-group study in patients with GERD who experienced persistent symptoms while taking a stable dose of PPIs (ClinicalTrials.gov identifier: NCT01370863). Patients were randomized to either revexepride (0.5 mg, three times daily) or matching placebo for 4 weeks. Reflux events and associated characteristics were assessed by pH/impedance monitoring and disease symptoms were assessed using electronic diaries and questionnaires.

KEY RESULTS

In total, 67 patients were enrolled in the study. There were no significant differences between study arms in the number, the mean proximal extent or the bolus clearance times of liquid-containing reflux events. Changes from baseline in the number of heartburn, regurgitation, and other symptom events were minimal for each treatment group and no clear trends were observed.

CONCLUSIONS & INFERENCES

No clear differences were seen in reflux parameters between the placebo and revexepride groups.

Intra-gastric pH following single oral administrations of rabeprazole and esomeprazole: double-blind cross-over comparison

Comparisons between the acid inhibitory effects of rabeprazole and esomeprazole after single oral administration with standard doses have not been previously presented. We examined intra-gastric pH after oral administrations of these two proton pump inhibitors using 24-h pH monitoring. Fifty-four normal volunteers not infected by Helicobacter pylori were investigated. Using a cross-over design, we administered 10 mg of rabeprazole or 20 mg of esomeprazole in 27 at 30 min after supper and in the remaining 27 subjects at 15 min before supper, and performed 24-h pH monitoring. Intra-gastric pH data were nearly identical when the proton pump inhibitors were taken after meals. Even if the data were compared in different CYP2C19 genotypes, rabeprazole and esomeprazole did not show the difference. In poor metabolizer, both of the drugs showed stronger acid inhibition. When taken before meals, intra-gastric pH after esomeprazole administration was slightly but not significantly higher than that observed after rabeprazole administration not only in daytime but also in nighttime period. In conclusion, rabeprazole and esomeprazole were similarly effective when administered after a meal.

Overdiagnosis of gastro-esophageal reflux disease and underdiagnosis of functional dyspepsia in a USA community

BACKGROUND

There is symptom overlap between gastro-esophageal reflux disease (GERD) and functional dyspepsia (FD). We aimed to test the hypothesis that FD cases are now more likely mislabeled as GERD.

METHODS

In subjects from Olmsted County, MN seen at Mayo Clinic: (i) Investigation of GERD and FD diagnosis rates between 1985 and 2009. (ii) Assessment of survey-based upper gastrointestinal symptoms between 1988 and 2009. (iii) Analysis of patients reporting GERD and/or FD symptoms and subsequently receiving a consistent diagnosis of GERD and/or FD during a medical encounter. (iv) Assess the association between PPI use and GERD and/or FD symptoms and between actual diagnoses received.

KEY RESULTS

(i) Yearly GERD diagnosis rates rose between 1985 and 2009 (325-1866 per 100 000). FD diagnosis rates rose from 45 in 1985, to 964 in 1999 but decreased to 452 per 100 000 in 2009. (ii) Reported GERD symptoms did not significantly change between three survey waves in the years 1988-2009 (p = 0.052), whereas FD symptoms slightly increased (p = 0.01). (iii) 62.9% of subjects reporting GERD symptoms received a GERD diagnosis, however only 12.5% of subjects reporting FD symptoms received a FD diagnosis. (iv) PPI use was associated with documented GERD diagnosis (p < 0.001), however there was no significant association between GERD symptoms and PPI use (p = 0.078).

CONCLUSIONS & INFERENCES

We have found evidence supporting a systematic bias away from diagnosing FD, favoring a GERD diagnosis.

Refractory gastroesophageal reflux disease: advances and treatment

'Refractory gastroesophageal reflux disease' is one of the most common misnomers in the area of gastroesophageal reflux disease. The term implies reflux as the underlying etiology despite unresponsiveness to aggressive proton pump inhibitor therapy. The term should be replaced with 'refractory symptoms.' We must acknowledge that in many patients symptoms of reflux often overlap with non-GERD causes such as gastroparesis, dyspepsia, hypersensitive esophagus and functional disorders. Lack of response to aggressive acid suppressive therapy often leads to diagnostic testing. In majority of patients these tests are normal. The role of non-acid reflux in this group is uncertain and patients should not undergo surgical fundoplication based on this parameter. In patients unresponsive to acid suppressive therapy GERD is most commonly not causal and a search for non-GERD causes must ensue.

Nrf2 deficiency impairs the barrier function of mouse oesophageal epithelium

OBJECTIVE

As a major cellular defence mechanism, the Nrf2/Keap1 pathway regulates expression of genes involved in detoxification and stress response. Here we hypothesise that Nrf2 is involved in oesophageal barrier function and plays a protective role against gastro-oesophageal reflux disease (GERD).

DESIGN

Human oesophageal biopsy samples, mouse surgical models and Nrf2(-/-) mice were used to assess the role of the Nrf2/Keap1 pathway in oesophageal barrier function. Trans-epithelial electrical resistance (TEER) was measured with mini-Ussing chambers. HE staining and transmission electron microscopy were used to examine tissue morphology, while gene microarray, immunohistochemistry, western blotting and chromatin immunoprecipitation (ChIP) analysis were used to assess gene expression.

RESULTS

Nrf2 was expressed in normal oesophageal epithelium and activated in GERD of both humans and mice. Nrf2 deficiency and gastro-oesophageal reflux in mice, alone or in combination, reduced TEER and increased intercellular space in oesophageal epithelium. Nrf2 target genes and gene sets associated with oxidoreductase activity, mitochondrial biogenesis and energy production were downregulated in the oesophageal epithelium of Nrf2(-/-) mice. Consistent with the antioxidative function of Nrf2, a DNA oxidative damage marker (8OHdG) dramatically increased in oesophageal epithelial cells of Nrf2(-/-) mice compared with those of wild-type mice. Interestingly, ATP biogenesis, Cox IV (a mitochondrial protein) and Claudin 4 (Cldn4) expression were downregulated in the oesophageal epithelium of Nrf2(-/-) mice, suggesting that energy-dependent tight junction integrity was subject to Nrf2 regulation. ChIP analysis confirmed the binding of Nrf2 to Cldn4 promoter.

CONCLUSIONS

Nrf2 deficiency impairs oesophageal barrier function through disrupting energy-dependent tight junction.

New Approaches to Management of PPI-Refractory Gastroesophageal Reflux Disease

OPINION STATEMENT

"Refractory GERD" is one the most common misnomers in the area of gastroesophageal reflux disease. The term implies reflux as the underlying etiology despite unresponsiveness to aggressive, often twice-daily proton pump inhibitor therapy. The term should be replaced with "refractory symptoms." We must acknowledge that in many patients, symptoms of reflux often overlap with non-GERD causes such as gastroparesis, dyspepsia, hypersensitive esophagus, and functional disorders. Lack of response to aggressive acid suppressive therapy often leads to esophagogastroduodenoscopy followed by pH or impedance monitoring. In the majority of patients these tests are normal. The role of non-acid reflux measured by impedance pH testing in this group is uncertain at best and the results from this test alone should not be used to refer patients to surgical fundoplication. In patients unresponsive to acid suppressive therapy, reflux is most commonly not causal and a search for non-GERD causes must ensue.

NFkB and Nrf2 in esophageal epithelial barrier function

The stratified squamous epithelium of the esophagus forms a tight protective barrier. Defects of the barrier function contribute to gastroesophageal reflux disease (GERD), which is manifested as damage to the esophageal epithelium due to exposure to the gastrointestinal refluxate. In this review, we discuss the involvement of NFkB and Nrf2 in esophageal epithelial barrier function. Understanding these molecular pathways in the esophagus may help us develop therapeutic strategies to improve clinical outcomes in patients with GERD.

Proton pump inhibitor resistance, the real challenge in gastro-esophageal reflux disease

Gastro-esophageal reflux disease (GERD) is one of the most prevalent chronic diseases. Although proton pump inhibitors (PPIs) represent the mainstay of treatment both for healing erosive esophagitis and for symptom relief, several studies have shown that up to 40% of GERD patients reported either partial or complete lack of response of their symptoms to a standard PPI dose once daily. Several mechanisms have been proposed as involved in PPIs resistance, including ineffective control of gastric acid secretion, esophageal hypersensitivity, ultrastructural and functional changes in the esophageal epithelium. The diagnostic evaluation of a refractory GERD patients should include an accurate clinical evaluation, upper endoscopy, esophageal manometry and ambulatory pH-impedance monitoring, which allows to discriminate non-erosive reflux disease patients from those presenting esophageal hypersensitivity or functional heartburn. Treatment has been primarily based on doubling the PPI dose or switching to another PPI. Patients with proven disease, not responding to PPI twice daily, are eligible for anti-reflux surgery.

Acid and non-acid reflux in patients refractory to proton pump inhibitor therapy: Is gastroparesis a factor?

AIM: To determine whether an increased number and duration of non-acid reflux events as measured using the multichannel intraluminal impedance pH (MII-pH) is linked to gastroparesis (GP).

METHODS: A case control study was conducted in which 42 patients undergoing clinical evaluation for continued symptoms of gastroesophageal reflux disease (both typical and atypical symptoms) despite acid suppression therapy. MII-pH technology was used over 24 h to detect reflux episodes and record patients’ symptoms. Parameters evaluated in patients with documented GP and controls without GP by scintigraphy included total, upright, and supine number of acid and non-acid reflux episodes (pH < 4 and pH > 4, respectively), the duration of acid and non-acid reflux in a 24-h period, and the number of reflux episodes lasting longer than 5 min.

RESULTS: No statistical difference was seen between the patients with GP and controls with respect to the total number or duration of acid reflux events, total number and duration of non-acid reflux events or the duration of longest reflux episodes. The number of non-acid reflux episodes with a pH > 7 was higher in subjects with GP than in controls. In addition, acid reflux episodes were more prolonged (lasting longer than 5 min) in the GP patients than in controls; however, these values did not reach statistical significance. Thirty-five patients had recorded symptoms during the 24 h study and of the 35 subjects, only 9% (n = 3) had a positive symptom association probability (SAP) for acid/non-acid reflux and 91% had a negative SAP.

CONCLUSION: The evaluation of patients with a documented history of GP did not show an association between GP and more frequent episodes of non-acid reflux based on MII-pH testing.

Therapeutic efficacy of baclofen in refractory gastroesophageal reflux-induced chronic cough

AIM: To evaluate the efficacy and safety of baclofen for treatment of refractory gastroesophageal reflux-induced chronic cough (GERC) unresponsive to standard anti-reflux therapy.

METHODS: Sixteen patients with refractory GERC were given an 8-wk course of baclofen 20 mg three times a day as an add-on therapy to omeprazole. Changes in the cough symptom score, cough threshold to capsaicin, reflux symptom score and possible adverse effects were determined after treatment. The variables of multi-channel intraluminal impedance combined with pH monitoring were compared between responders and non-responders to baclofen.

RESULTS: Twelve of 16 patients completed treatment. Cough disappeared or improved in 56.3% (9/16) of patients, including 6 patients with acid reflux-induced cough (66.7%) and 3 patients with non-acid reflux-induced cough (33.3%). With baclofen treatment, the cough symptom score began to decrease at week 2, was clearly decreased at week 6 and reached a minimum at week 8. At the end of therapy, the lowest concentration of capsaicin required for induction of ≥ 2 and ≥ 5 coughs increased from 0.98 (1.46) to 1.95 (6.82) μmol/L (Z = -2.281, P = 0.024) and from 1.95 (7.31) to 7.8 (13.65) μmol/L (Z = -2.433, P = 0.014), respectively, and the reflux symptom score decreased from 8.0 ± 1.6 to 6.8 ± 0.8 (t = 2.454, P = 0.023). The number of acid reflux episodes was significantly lower in responders than in non-responders. The main adverse effects were somnolence, dizziness and fatigue.

CONCLUSION: Baclofen is a useful, but suboptimal treatment option for refractory GERC.

Predictors of clinical response of acid suppression in Chinese patients with gastroesophageal reflux disease

BACKGROUND

Up to 40% of patients with gastroesophageal reflux disease fail to respond to proton pump inhibitor therapy.

AIMS

To determine predictors of clinical response of proton pump inhibitor therapy.

METHODS

Consecutive patients with gastroesophageal reflux disease were enrolled prospectively. All patients underwent upper endoscopy and 24-h multichannel intraluminal impedance and pH monitoring before receiving esomeprazole 20 mg b.i.d. for 2 months. Multivariate logistic regression analysis was used to determine the independent predictors of clinical response to proton pump inhibitor therapy.

RESULTS

A total of 204 patients with typical reflux symptoms were recruited and screened. Among them 153 patients (mean age 46.3 ± 10.6 years, 51.0% female) completed all the examinations and were assigned to proton pump inhibitor therapy. Ninety-five patients (62.1%) responded to acid suppression after 2 months. Multivariate logistic analysis showed that the predictor for response was pathological distal esophageal acid reflux (P = 0.001). The factors associated with proton pump inhibitor therapy failure were the presence of irritable bowel syndrome alone (P = 0.006), depression (P = 0.005), and overlap of irritable bowel syndrome and functional dyspepsia (P = 0.002).

CONCLUSIONS

The clinical response of acid suppression on gastroesophageal reflux disease could be predicted by clinical and pH parameters rather than impedance data.

The effect of rabeprazole on LES tone in experimental rat model

INTRODUCTION

Despite adequate treatment with proton pump inhibitors (PPIs), symptoms of gastroesophageal reflux disease (GERD) may remain persistent as well as Barrett's esophagus may emerge. It may be proposed that the relaxant effect of PPIs on the smooth muscles may lead to resistance of symptoms. The aim of this study is to investigate effects of rabeprazole on the lower esophageal sphincter (LES) pressure with a rat model.

MATERIALS AND METHODS

Sixteen rats were grouped as control and treatment groups. After obtaining LES tissues followed by a 60 min equilibration period for stabilization, contractile response to carbachol was obtained by application of single dose of carbachol to have a final concentration of 10(-6) M in the organ bath. After the contractions reached a plateau, concentration-response relationships for rabeprazole were obtained in a cumulative manner in the treatment group.

RESULTS

In the carbachol contracted LES preparations; 1.5 × 10(-6) and 1.5×10(-5) M of rabeprazole caused 6.08% and 11.34% relaxations respectively which were not statistically significant. However, mean integral relaxation value for 4.5 × 10(-5) M of rabeprazole was 17.34% and this relaxation was significant compared with controls.

CONCLUSIONS

In the present study, rabeprazole caused no direct significant change in LES tone in the therapeutic dose range applied to the organ bath. However, rabeprazole at the high dose caused a significant decrease in the LES tone.

Histology of symptomatic gastroesophageal reflux disease: is it predictive of response to proton pump inhibitors?

BACKGROUND AND AIM

To examine the differences in esophageal histopathology between non-erosive reflux disease (NERD) and reflux esophagitis (RE), and to investigate whether baseline esophageal histopathology can predict the therapeutic response to proton pump inhibitors (PPIs).

METHOD

The subjects comprised 94 patients with NERD (n = 71) or mild RE (n = 23). Tissue was biopsied from 5 cm above the squamo-columnar junction (SCJ), and the degree or presence of nine histopathological markers was assessed. The patients were treated with rabeprazole (RPZ) 10 mg once daily for 4 weeks. If complete heartburn relief was not achieved, RPZ was increased to 10 mg twice daily for another 2 weeks, and then to 20 mg twice daily for another 2 weeks if heartburn remained.

RESULTS

Features of esophageal histopathology 5 cm above the SCJ differed between NERD and RE patients. The esophageal histopathology in patients unresponsive to RPZ was characterized by Protein Gene Product (PGP) 9.5 negativity in those with NERD, and intraepithelial bleeding in those with RE. In addition, the combination of dilated intercellular spaces (DIS) (+)/PGP 9.5 (-) was indicative of strong resistance to PPI therapy in NERD patients.

CONCLUSION

The therapeutic efficacy of PPI can be predicted from the features of biopsied esophageal tissue. Factors predictive of resistance to treatment with PPI are negativity for PGP 9.5 in NERD patients and intraepithelial bleeding in RE patients.

Step-by-step management of refractory gastresophageal reflux disease

Up to a third of the patients who receive proton pump inhibitor (PPI) once daily will demonstrate lack or partial response to treatment. There are various mechanisms that contribute to PPI failure and they include residual acid reflux, weakly acidic and weakly alkaline reflux, esophageal hypersensitivity, and psychological comorbidity, among others. Some of these underlying mechanisms may coincide in the same patient. Evaluation for proper compliance and adequate dosing time of PPIs should be the first management step before ordering invasive diagnostic tests. Doubling the PPI dose or switching to another PPI is the second step of management. Upper endoscopy and pH testing appear to have limited diagnostic value in patients who failed PPI treatment. In contrast, esophageal impedance with pH testing (multichannel intraluminal impedance MII-pH) on therapy appears to provide the most insightful information about the subsequent management of these patients (step 3). In step 4, treatment should be tailored to the specific underlying mechanism of patient's PPI failure. For those who demonstrate weakly acidic or weakly alkaline reflux as the underlying cause of their residual symptoms, transient lower esophageal sphincter relaxation reducers, endoscopic treatment, antireflux surgery and pain modulators should be considered. In those with functional heartburn, pain modulators are the cornerstone of therapy.

Effect of acid swallowing on esophageal contraction in patients with heartburn related to hypersensitivity

BACKGROUND AND AIM

There are heterogeneous subgroups among those with heartburn, and data on these individuals are relatively scant. We aimed to evaluate the effect of acid challenge on the segmental contractions of esophageal smooth muscle in endoscopy-negative patients with normal esophageal acid exposure.

METHODS

High-resolution esophageal manometry (HRM) was performed on 30 endoscopy-negative patients with heartburn accompanied by normal esophageal acid exposure using 10 water swallows followed by 10 acidic pomegranate juice swallows. Patients were classified into functional heartburn (FH) and hypersensitive esophagus (HE) groups based on the results of 24-hr impedance pH testing. HRM topographic plots were analyzed and maximal wave amplitude and pressure volumes were measured for proximal and distal smooth muscle segments.

RESULTS

The pressure volume of the distal smooth muscle segment in the HE group measured during acidic swallows was higher than during water swallows (2224.1 ± 68.2 mmHg/cm per s versus 2105.6 ± 66.4 mmHg/cm per s, P = 0.027). A prominent shift in the pressure volume to the distal smooth muscle segment was observed in the HE group compared with the FH group (segmental ratio: 2.72 ± 0.08 versus 2.39 ± 0.07, P = 0.005). Manometric measurements during acidic swallows revealed that this shift was augmented in the HE group. The optimal ratio of pomegranate juice swallowing for discrimination of FH from HE was 2.82, with a sensitivity of 88.9% and a specificity of 100%.

CONCLUSIONS

Hypercontractile response of distal smooth muscle segment to acid swallowing was more prominent in the HE group than the FH group.

The relationship between type 2 diabetes mellitus and failure to proton pump inhibitor treatment in gastroesophageal reflux disease

BACKGROUND

There is limited information regarding the contribution of diabetes mellitus (DM) to proton pump inhibitor (PPI) failure in gastroesophageal reflux disease (GERD) patients.

AIM

To determine whether type 2 DM is a risk factor for PPI failure and the potential predictive factors for PPI failure among type 2 DM patients with GERD.

DESIGN

A case-control study was performed using hospital medical records of GERD patients treated with a PPI. The prevalence of type 2 DM and other risk factors (established >1 y before study enrollment) was determined in the PPI failure (treatment with more than once daily PPI) as compared with PPI responders.

RESULTS

A total of 732 GERD patients receiving PPI therapy, including 285 who failed PPI treatment, were included. The overall prevalence of PPI failure was significantly higher in diabetic versus nondiabetic patients. The relationship between PPI failure and type 2 DM depended on body mass index. Only in obese patients the odds ratio of PPI failure was significantly higher in type 2 DM as compared with non-DM patients. In the subgroup of GERD patients with type 2 DM (n=349), PPI failure was significantly associated with female sex, the presence of general comorbidities, and adequate DM control. Duration of DM, type of antidiabetic medication prescribed, and DM-associated complications were not associated with PPI failure.

CONCLUSIONS

PPI failure was significantly associated with type 2 DM in obese patients. Among GERD patients with type 2 DM, failure of PPI treatment was significantly associated with female sex and the presence of general comorbidities.

Healing erosive esophagitis with a proton pump inhibitor: the more the merrier?

Patients with erosive esophagitis (EE) account for 30% of patients with gastroesophageal reflux disease; only a minority of these patients fail to achieve healing on treatment with a proton pump inhibitor (PPI), once-daily, for 8 weeks. For those patients with EE who have failed to heal on a PPI, given once-daily, current practice is to double the PPI dose although there is little published evidence to support this. In this issue of the American Journal of Gastroenterology, authors from Japan have demonstrated that double-dose PPI produced higher healing rates when given as a split, twice-daily dose than as a once-daily dose for patients with EE who had failed initial therapy with rabeprazole 10 mg once-daily. Quadruple-dose PPI, given as a split dose, did not increase the healing rates but did produce better symptom control, albeit limited, compared with double-dose PPI, given twice-daily. Because subjects, initially, received a lower PPI dose than that generally indicated for EE (rabeprazole 20 mg daily), this study does not provide the eagerly awaited justification for double-dose PPI therapy in patients with EE who have failed standard-dose PPI once-daily. However, it does demonstrate the clinical advantage of a split-dose regimen (AM and PM), compared with a once-daily regimen, when doubling the dose of a PPI for patients with residual EE after initial therapy.