Efficacy of rabeprazole on heartburn symptom resolution in patients with non-erosive and erosive gastro-oesophageal reflux disease: a multicenter study from Japan

Different dosages of vonoprazan for gastroesophageal reflux disease: study protocol for a pragmatic, crossover-cluster, randomized controlled trial with patient preference arms

BACKGROUND

Vonoprazan results in more potent acid suppression for gastroesophageal reflux disease (GERD) than proton pump inhibitors. It has only been approved for treating erosive esophagitis in China, but 30-40% of GERD patients cannot achieve the goal of treatment with vonoprazan 20 mg daily. This study aims to investigate whether vonoprazan could relieve the symptoms of Chinese patients with non-erosive reflux disease (NERD) and whether increased dosage or different times of dosing could increase the response rate of GERD.

METHODS

This study is a pragmatic, open-label, crossover-cluster, randomized controlled trial with patient preference arms. Two thousand eight hundred eighty patients with GERD from 48 hospitals in China will be enrolled. These hospitals will be divided into a compulsory randomization cluster (24 hospitals) and a patient preference cluster (24 hospitals). Patients in the compulsory randomization cluster will be randomized to three regimens according to the crossover-cluster randomization. Patients in the patient preference cluster may choose to receive any regimen if they have a preference; otherwise, patients will be randomly assigned. The three treatment regimens will last 4 weeks, including (1) vonoprazan 20 mg p.o. after breakfast, (2) vonoprazan 20 mg p.o. after dinner, and (3) vonoprazan 20 mg p.o. after breakfast and after dinner. Patients will attend a baseline visit, a 4-week e-diary, a fourth-week visit, and a sixth-month visit online. The primary outcome is the symptom relief rate of all patients after 4-week therapy. Secondary outcomes include the healing rate of EE patients, the severity of symptoms, compliance with the therapy at the fourth-week follow-up visit, recurrent symptoms, and the frequency of self-conscious doctor visits at the sixth-month follow-up visit.

DISCUSSION

This trial will explore the effectiveness of different regimens of vonoprazan that will be implemented with GERD patients in China. The randomization with patient preferences considered and the crossover-cluster component may improve the robustness and extrapolation of study conclusions.

TRIAL REGISTRATION

https://www.chictr.org.cn ChiCTR2300069857. Registered on 28 March 2023.

PROTOCOL VERSION

February 18, 2023, Version 2.

Exploring Differences in Pharmacometrics of Rabeprazole between Genders via Population Pharmacokinetic-Pharmacodynamic Modeling

Rabeprazole is a proton pump inhibitor that inhibits gastric acid production and increases gastric pH; it is widely used clinically as a treatment option for gastritis and gastric ulcers. However, information on the inter-individual variability of rabeprazole pharmacometrics, which is a key element in establishing its scientific clinical use, is still lacking. Particularly, the differences in pharmacokinetics between genders and the degree of variation in pharmacodynamics have not been clearly identified. Thus, the main purpose of this study was to explore any differences in rabeprazole pharmacokinetics between genders and to quantitatively predict and compare the effects of any differences in pharmacokinetics between genders on known pharmacodynamics using population pharmacokinetic-pharmacodynamic modeling. To compare pharmacokinetics and modeling data between genders, bioequivalence results were used simultaneously on healthy Korean men and women using the physiological and biochemical parameters derived from each individual. Pharmacodynamic modeling was performed based on the data of previously reported gastric pH changes in response to rabeprazole plasma concentrations, which was co-linked to the central compartmental bioavailable concentration in the population pharmacokinetic model. There was no significant difference in the level of rabeprazole exposure and elimination of plasma between genders following oral administration of 10 mg enteric-coated rabeprazole tablets; however, there was a clear delay in absorption in women compared to men. Additionally, a comparison of pharmacokinetic parameters normalized to body weight between genders showed that the maximum plasma concentrations were significantly higher in women than in men, again suggesting gender differences in rabeprazole absorption. The population pharmacokinetic profiles for rabeprazole were described using a three-sequential multi-absorption with lag time (Tlag) two-compartment model, whereas body surface area and gender were explored as effective covariates for absorption rate constant and Tlag, respectively. The effect of increased gastric pH due to plasma exposure to rabeprazole was explained using the Sigmoid Emax model, with the baseline as a direct response. The significantly longer rabeprazole Tlag in females delayed the onset of an effect by an average of 1.58 times (2.02-3.20 h), yet the overall and maximum effects did not cause a significant difference within 15%. In the relative comparison of the overall efficacy of rabeprazole enteric-coated tablet administration between genders, it was predicted based on the model that males would have higher efficacy. This study will be very useful in broadening the perspective of interpreting drug diversity between individuals and narrowing the gap in knowledge related to scientific precision medicine by presenting new information on gender differences in rabeprazole pharmacometrics that had not been previously identified.

Efficacy of rabeprazole (Razo®) in the treatment of various clinical variants of GERD: results from the GERBERA study

Introduction. Gastroesophageal reflux disease (GERD) is extremely common in the structure of gastroenterological diseases. Aim. To conduct a prospective observational post-marketing study of rabeprazole (Razo®) 20 mg taking once daily in patients with non-erosive reflux disease (NERD) after 2 and 4 weeks of therapy and esophagitis stage A and B after 4 weeks of therapy (GERBERA).

Materials and methods. 75 patients with GERD were included in the study (36 men and 39 women, mean age 41.7 ± 1.5 years). Clinical examination with the completion of standard questionnaires, assessment of the quality of life of patients were performed at three visits: before the start of the treatment, after 2 and 4 weeks of therapy. Fibroesophagogastroduodenoscopy was performed in all patients before treatment and in patients with esophagitis after 4 weeks of therapy. All patients received rabeprazole (Razo®) at a dose of 20 mg once a day for the treatment of GERD. The diagnosis of heartburn and sour eructation was carried out according to the recommendations of the Montreal Consensus, the diagnosis of esophagitis was performed based on the Los Angeles classification.

Results and discussion. Among patients with NERD, 74.1% of patients responded to Razo® therapy after 2 weeks of treatment, after 4 weeks  the proportion of responders increased to 94.4% (p = 0.008). Healing of erosions after  4 weeks  was observed  in 90.5% of patients with esophagitis. Razo® therapy was accompanied by a pronounced improvement in GERD patients in all parameters of quality of life and patient satisfaction with the results of Razo® treatment.

Conclusion. Based on the results of our study, we obtained high efficacy of Razo® at a dose of 20 mg once a day for the treatment of patients with NERD and erosive esophagitis.

2020 Seoul Consensus on the Diagnosis and Management of Gastroesophageal Reflux Disease

Gastroesophageal reflux disease (GERD) is a condition in which gastric contents regurgitate into the esophagus or beyond, resulting in either troublesome symptoms or complications. GERD is heterogeneous in terms of varied manifestations, test findings, and treatment responsiveness. GERD diagnosis can be established with symptomatology, pathology, or physiology. Recently the Lyon consensus defined the “proven GERD” with concrete evidence for reflux, including advanced grade erosive esophagitis (Los Angeles classification grades C and or D esophagitis), long-segment Barrett’s mucosa or peptic strictures on endoscopy or distal esophageal acid exposure time > 6% on 24-hour ambulatory pH-impedance monitoring. However, some Asian researchers have different opinions on whether the same standards should be applied to the Asian population. The prevalence of GERD is increasing in Asia. The present evidence-based guidelines were developed using a systematic review and meta-analysis approach. In GERD with typical symptoms, a proton pump inhibitor test can be recommended as a sensitive, cost-effective, and practical test for GERD diagnosis.

Based on a meta-analysis of 19 estimated acid-exposure time values in Asians, the reference range upper limit for esophageal acid exposure time was 3.2% (95% confidence interval, 2.7-3.9%) in the Asian countries. Esophageal manometry and novel impedance measurements, including mucosal impedance and a post-reflux swallow-induced peristaltic wave, are promising in discrimination of GERD among different reflux phenotypes, thus increasing its diagnostic yield. We also propose a long-term strategy of evidence-based GERD treatment with proton pump inhibitors and other drugs.

Randomised clinical trial: comparison of tegoprazan and placebo in non-erosive reflux disease

BACKGROUND

Tegoprazan is a novel, fast- and long-acting potassium-competitive acid blocker that suppresses gastric acid secretion, which could benefit patients with non-erosive reflux disease (NERD), a type of gastroesophageal reflux disease.

AIM

To evaluate the efficacy and safety profiles of tegoprazan compared with those of a placebo in Korean patients with NERD.

METHODS

In this phase 3, double-blind, placebo-controlled, multicentre study, 324 Korean patients with NERD were randomised into three treatment groups: tegoprazan 50 mg, tegoprazan 100 mg and placebo. These drugs were provided once daily for 4 weeks. The primary endpoint was the proportion of patients with complete resolution of major symptoms (both heartburn and regurgitation) for the last 7 days of the 4-week treatment period. Other outcomes related to efficacy, safety and tolerability were also evaluated.

RESULTS

Among all, 42.5% (45/106), 48.5% (48/99) and 24.2% (24/99) of patients showed complete resolution of major symptoms at week 4 after receiving tegoprazan 50 mg, tegoprazan 100 mg, and placebo, respectively. Both doses of tegoprazan showed superior efficacy than the placebo (P = 0.0058 and P = 0.0004, respectively). The complete resolution rates of heartburn and proportions of heartburn-free days (as other efficacy outcomes) were significantly higher in both tegoprazan groups than in the placebo group (P < 0.05 for all). No significant difference in the incidence of treatment-emergent adverse events were noted.

CONCLUSIONS

Tegoprazan 50 and 100 mg showed superior therapeutic efficacy compared with the placebo, as well as a favourable safety profile in patients with NERD. Registration number: ClinicalTrials.gov identifier NCT02556021.

The early therapeutic response at 2 weeks is a crucial predictor of proton pump inhibitor-refractory gastroesophageal reflux disease

BACKGROUND

In recent years, the prevalence of proton pump inhibitor (PPI)-refractory gastroesophageal reflux disease (GERD) has been increasing, posing a clinical obstacle to improving the management of GERD patients. The ability of known predictive factors to explain therapeutic response to PPI remains insufficient. Therefore, we examined whether the addition of early therapeutic response to PPI as an explanatory variable may increase the predictive power for PPI-refractory GERD.

METHODS

The severity and therapeutic response of GERD symptoms to PPI were evaluated using the GastroEsophageal Reflux and Dyspepsia Therapeutic Efficacy and Satisfaction Test (GERD-TEST) questionnaire at baseline and at 2 and 4 weeks after treatment. The relevance of the therapeutic effect of PPI at 2 weeks compared to that at 4 weeks was examined in 301 patients with GERD. Independent predictive factors for refractory GERD at 4 weeks of PPI therapy were examined in 182 patients. The effect of various clinical factors, including the early response to PPI, was assessed using multiple regression analysis.

RESULTS

The number of PPI-therapy responders increased significantly with the duration of treatment (p < 0.0001). The response to PPI therapy at 2 weeks was significantly correlated with that at 4 weeks (p < 0.0001). Multiple regression analysis revealed that the therapeutic response to PPI at 2 weeks was by far the strongest predictor of the therapeutic effect at 4 weeks among all clinical factors.

CONCLUSIONS

Medication change for PPI-refractory GERD at 2 weeks may be an efficacious therapeutic strategy to improve patients' quality of life.

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 initial and maintenance therapy in reflux esophagitis, nonerosive esophagitis, and proton pump inhibitor-resistant gastroesophageal reflux disease

Proton pump inhibitors (PPIs) have been the first line treatment for gastroesophageal reflux disease (GERD). The aim of this study was to evaluate the efficacy of vonoprazan (VPZ), a potassium-competitive acid blocker for reflux esophagitis (RE), nonerosive reflux disease (NERD), and PPI-resistant GERD patients.An open-label, single-center, observational study in our hospital was performed from August 2016 to August 2017. All patients diagnosed with GERD were asked to self-report a questionnaire of frequency scale for the symptoms of GERD (FSSG) and rate their degree of satisfaction with the treatment of GERD during outpatient visit. A total of 200 (RE 47, NERD 49, PPI-resistant GERD 104) patients were included in the present study. The primary endpoint was the change of FSSG and the proportion of degree of satisfaction with the treatment at the end of the initial therapy. A percentage of improvement (improvement rate) and resolution (resolution rate) at the end of the initial therapy were evaluated. Secondary endpoint included the proportion of patients with symptomatic relapse in the 24-week maintenance phase.FSSG and the degree of satisfaction were significantly improved after the initial therapy in every group. Improvement and resolution rate after the initial therapy were 83.0% and 67.0% in RE, 66.7% and 60.4% in NERD, and 76.0% and 60.4% in PPI-resistant group. There was no significance between after the initial therapy and 24 weeks in improvement and resolution rate. Thirty-two of the total 48 patients did not take VPZ at 24 weeks. Total FSSG score in each group was 1.67 ± 1.97, 2.71 ± 4.91, and 4.0 ± 4.93. The nonrelapse rate at 24 weeks in each group was 66.7%, 60.0%, and 50.0%. The resolution rate at 24 weeks in each group was 38.9%, 45.0%, and 30.0%.The VPZ therapy is effective for initial and maintenance therapy and improves heartburn and patient's satisfaction significantly in all 3 groups. Among patients who stopped taking VPZ during the maintenance period, 42.0% of RE and NERD group and 30% of PPI-resistant group experience complete remission from GERD at 24 weeks by introduction of VPZ.

Efficacy of on-demand therapy using 20-mg vonoprazan for non-erosive reflux disease

BACKGROUND

To evaluate the efficacy of on-demand therapy using 20-mg vonoprazan for non-erosive reflux disease.

METHODS

On-demand therapy by taking one 20-mg tablet of vonoprazan only when reflux symptoms occurred was performed for 8 weeks by 30 patients (11 men, mean age: 67.8) with non-erosive reflux disease who responded well to maintenance therapy using proton pump inhibitor and answered "very satisfied" or "satisfied" to an overall satisfaction survey (5-grade scale). The degree of overall satisfaction with the treatment, score of symptoms, and fasting gastrin levels before breakfast was examined before and after on-demand therapy. The number of vonoprazan tablets taken and the frequency (regular, temporary, rare) of its administration were also investigated.

RESULTS

All patients completed 8-week on-demand therapy with 20-mg vonoprazan. Comparisons of patient satisfaction levels before and after therapy revealed no significant differences in the number of patients who were very satisfied and satisfied with the therapy. Furthermore, there were no significant differences in score of symptoms or gastrin levels before and after therapy. During 8-week on-demand therapy, patients took 11 tablets (median) (7.0-18.0 tablets: 25-75 percentiles), and 30.0% of patients (n = 9) took vonoprazan on a regular basis (at least 2 tablets a week).

CONCLUSION

On-demand therapy with 20-mg vonoprazan exerted equivalent effects to continuous PPI maintenance therapy for patients with non-erosive reflux disease.

Pathogenesis of Potassium-Competitive Acid Blocker-Resistant Non-Erosive Reflux Disease

BACKGROUND

The present study examined the pathogenesis of potassium-competitive acid blocker (P-CAB)-resistant non-erosive reflux disease (NERD).

METHODS

Forty-three patients with NERD, who had persistent reflux symptoms despite the administration of P-CAB, were included in this study. After excluding eosinophilic esophagitis and primary esophageal motility disorders, esophageal impedance-pH monitoring was performed. In symptom index (SI)-positive patients, the mechanism of SI-positivity and percent time with intragastric pH > 4 and with esophageal pH < 4 were investigated according to the presence or absence of Helicobacter pylori infection.

RESULTS

One (2.3%) of 43 patients had a primary esophageal motility disorder (Jackhammer esophagus). Eighteen (41.9%) and 3 (7%) patients were SI-positive for liquid and gas-only reflux, respectively, and the remaining 21 patients who were SI-negative (48.8%) had functional heartburn. All patients SI-positive for liquid reflux were SI-positive for weakly acidic reflux. Gastric acid was sufficiently suppressed by P-CAB, regardless of the presence or absence of H. pylori infection.

CONCLUSIONS

The pathogenesis of -P-CAB-resistant NERD was elucidated in 51% of patients. Symptoms in all patients SI-positive for liquid reflux were related to weakly acidic reflux, and symptoms related to acid reflux may be ruled out by the administration of P-CAB.

Impact of Comorbid Irritable Bowel Syndrome on Treatment Outcome in Non-Erosive Reflux Disease on Long-Term Proton Pump Inhibitor in Japan

BACKGROUND/AIMS

Irritable bowel syndrome (IBS) frequently coexists with non-erosive reflux disease (NERD). Efficacy of long-term proton pump inhibitor (PPI) treatment on NERD with or without IBS is controversial. The impact of comorbid IBS in NERD on quality of life (QOL) remains uncertain. We verified the hypothesis that NERD patients with IBS symptoms demonstrated poor responses to long-term PPI treatments, deteriorated QOL, and high frequency of psychological deviations in Japan.

METHODS

In all, 141 NERD patients who had been taking PPIs for more than 6 months were enrolled and analyzed. Patient profiles were assessed by GerdQ, IBS Severity Index (IBSSI-J)/Gastrointestinal Symptoms Rating Scale (GSRS)/SF-8, and Hospital Anxiety and Depression Scale (HADS).

RESULTS

IBS existed in 37 out of 141 NERD patients. Patients with IBS (the positive-IBS group) demonstrated significantly higher frequencies of extant reflux symptoms than those without IBS (64.9 vs. 40.4%). In the positive-IBS group, 40.5% were classified as middle grade by IBSSI-J. The SF-8 and GSRS scores in this group were significantly lower than those without IBS (the negative-IBS group). Prevalence of depression and anxiety by HADS in the positive-IBS group was significantly higher than that in the negative-IBS group.

CONCLUSION

These results proved the hypothesis that considering comorbid IBS among NERD patients on long-term PPI seems recommended in Japan.

Exploratory Research on Latent Esophageal Motility Disorders in Dysphagia Patients

BACKGROUND/AIMS

High-resolution manometry (HRM) has been applied to assess esophageal motility disorders. However, the frequency and types of motility disorders in patients with dysphagia, which are frequently seen in clinical practice, are not clear. We evaluated latent esophageal motility disorders associated with dysphagia.

METHODS

The study included patients without erosive esophageal mucosal damage and with dysphagia symptoms refractory to at least 8 weeks of standard-dose proton pump inhibitors. After enrolment, HRM was used to evaluate for esophageal motility disorder based on the Chicago classification.

RESULTS

Esophageal motility disorder was found in 58 of 100 patients and was classified based on the causes: achalasia (13%), esophagogastric junction outflow obstruction (16%), distal esophageal spasms (3%), weak peristalsis (14%), frequently failed peristalsis (5%), and hypertensive peristalsis (7%).

CONCLUSION

Primary esophageal motility disorder was found in approximately 50% of cases in dysphagia patients. Therefore, esophageal motility disorder is not an uncommon condition and should be sought for in order to elucidate precisely the cause of dysphagia.

Therapy of gastroesophageal reflux disease and functional dyspepsia overlaps with symptoms after usual-dose proton pump inhibitor: Acotiamide plus usual-dose proton pump inhibitor versus double-dose proton pump inhibitor

BACKGROUND AND AIM

Gastroesophageal reflux disease (GERD) and functional dyspepsia (FD) often coexist or overlap. In this study, the efficacy of acotiamide in combination with a standard dose of rabeprazole for GERD and FD was compared with that of a double dose of rabeprazole.

METHODS

Patients with overlap between GERD and FD experiencing heartburn and epigastric fullness symptoms after standard-dose proton pump inhibitor (PPI) for ≥ 8 weeks were randomized into two groups and received either acotiamide 300 mg/day + rabeprazole 10 mg/day or rabeprazole 20 mg/day for 4 weeks. Efficacy was assessed by reductions in symptom scores using the Izumo scale questionnaire and modified F-scale questionnaire.

RESULTS

As the primary endpoint, three upper gastrointestinal symptoms (heartburn, epigastralgia, and epigastric fullness) were reduced by ≥ 50% in 40.8% and 46.9% of patients in the combination and PPI double-dose groups, respectively, with no significant difference between the two groups. Essentially similar results were obtained for the modified F-scale questionnaire. No serious adverse events were noted.

CONCLUSIONS

Acotiamide 300 mg/day in combination with rabeprazole 10 mg/day or rabeprazole 20 mg/day relieved symptoms in patients with overlap between GERD and FD experiencing heartburn and epigastric fullness symptoms after standard-dose PPI for ≥ 8 weeks, and the efficacies did not differ between the two treatments. The combination therapy may be an alternative option for persistent symptoms in these patients.

Evaluation of the Efficacy and Safety of Vonoprazan in Patients with Nonerosive Gastroesophageal Reflux Disease: A Phase III, Randomized, Double-Blind, Placebo-Controlled, Multicenter Study

BACKGROUND

For many patients, current treatments do not adequately resolve heartburn in nonerosive reflux disease (NERD).

OBJECTIVE

To compare vonoprazan and placebo with respect to the frequency and severity of heartburn in patients with NERD.

METHODS

This Phase III, double-blind, placebo-controlled, parallel-group, multicenter study included patients in Japan aged ≥20 years with Grade N or M NERD and recurrent acid reflux symptoms. Patients were blinded and randomized 1:1:1 to receive placebo or vonoprazan 10 mg or 20 mg. The primary efficacy outcome was the proportion of days without heartburn measured by patient scores during the 4-week treatment period.

RESULTS

Eight hundred twenty-seven patients were randomized (placebo: n = 278, vonoprazan 10 mg: n = 278, and vonoprazan 20 mg: n = 271). Median proportion of days without heartburn was 7.4% (placebo), 10.3% (vonoprazan 10 mg), and 12.0% (vonoprazan 20 mg). Proportion of days without heartburn was not statistically significant between the vonoprazan and placebo groups (P = 0.2310 [10 mg] and P = 0.0504 [20 mg]). Mean severity of heartburn was significantly higher with placebo (median score = 1.070) than with vonoprazan 10 mg (median score = 0.990; P = 0.0440) and 20 mg (median score = 0.960; P = 0.0139). Patients whose symptoms improved at Week 2 experienced significantly increased proportion of days without heartburn and reduced mean severity of heartburn at Week 4 with vonoprazan compared with placebo (proportion of days without heartburn: P = 0.0004 [10 mg] and P = 0.0001 [20 mg] and mean severity: P < 0.0001 [10 mg] and P < 0.0001 [20 mg]). A significant difference in median proportion of days without heartburn was observed for vonoprazan 20 mg compared with placebo in patients with Grade M NERD. Incidence of treatment-emergent adverse events was 32.7% (placebo), 27.7% (vonoprazan 10 mg), and 28.0% (vonoprazan 20 mg).

CONCLUSIONS

Vonoprazan at doses of 10 mg and 20 mg are not superior to placebo with respect to proportion of days without heartburn, whereas the mean severity of heartburn is lower with vonoprazan compared with placebo in patients with NERD. ClinicalTrials.gov identifier: NCT01474369.

Asia-Pacific consensus on the management of gastro-oesophageal reflux disease: an update focusing on refractory reflux disease and Barrett's oesophagus

OBJECTIVE

Since the publication of the Asia-Pacific consensus on gastro-oesophageal reflux disease in 2008, there has been further scientific advancement in this field. This updated consensus focuses on proton pump inhibitor-refractory reflux disease and Barrett's oesophagus.

METHODS

A steering committee identified three areas to address: (1) burden of disease and diagnosis of reflux disease; (2) proton pump inhibitor-refractory reflux disease; (3) Barrett's oesophagus. Three working groups formulated draft statements with supporting evidence. Discussions were done via email before a final face-to-face discussion. We used a Delphi consensus process, with a 70% agreement threshold, using Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria to categorise the quality of evidence and strength of recommendations.

RESULTS

A total of 32 statements were proposed and 31 were accepted by consensus. A rise in the prevalence rates of gastro-oesophageal reflux disease in Asia was noted, with the majority being non-erosive reflux disease. Overweight and obesity contributed to the rise. Proton pump inhibitor-refractory reflux disease was recognised to be common. A distinction was made between refractory symptoms and refractory reflux disease, with clarification of the roles of endoscopy and functional testing summarised in two algorithms. The definition of Barrett's oesophagus was revised such that a minimum length of 1 cm was required and the presence of intestinal metaplasia no longer necessary. We recommended the use of standardised endoscopic reporting and advocated endoscopic therapy for confirmed dysplasia and early cancer.

CONCLUSIONS

These guidelines standardise the management of patients with refractory gastro-oesophageal reflux disease and Barrett's oesophagus in the Asia-Pacific region.

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.

Rapid metabolizer genotype of CYP2C19 is a risk factor of being refractory to proton pump inhibitor therapy for reflux esophagitis

BACKGROUND

Proton pump inhibitors (PPIs) are mainly metabolized by cytochrome P450 2C19 (CYP2C19) and used as the first-line therapy for gastroesophageal reflux disease (GERD). However, while several studies have examined the influence of CYP2C19 polymorphism on GERD treatment with PPIs, most have had small sample sizes and were conducted in a single center. Here, we used meta-analysis to investigate whether or not the CYP2C19 rapid metabolizer (RM) genotype is a risk factor for GERD patients being refractory to PPI therapy.

METHODS

PubMed and other electronic databases were systematically searched up to August 2014 using the following terms: "GERD and CYP2C19", "esophagitis and CYP2C19", and "non-erosive reflux disease and CYP2C19." Searches were limited to publications in English, and two investigators evaluated eligible studies and extracted data.

RESULTS

The total efficacy rate of PPIs for GERD, including reflux esophagitis (RE) and non-erosive reflux disease, was 56.4% (95% confidence interval [CI]; 53.9-58.9%, 870/1543) in intention-to-treat analysis and 63.8% (95%CI; 61.3-66.2%, 950/1489) in per-protocol analysis. Efficacy rates varied significantly between CYP2C19 genotypes (intention-to-treat analysis: RMs, 52.2% [315/604]; intermediate metabolizers, 56.7% [298/526]; poor metabolizers [PMs], 61.3% [138/225]; P = 0.047). Among RE patients, CYP2C19 RMs had an increased risk of being refractory to PPI therapy compared with PMs (odds ratio: 1.661, 95% CI: 1.023-2.659, P = 0.040).

CONCLUSIONS

The present meta-analysis demonstrates that CYP2C19 RMs with RE have an increased risk of being refractory to PPI therapy compared with PMs. Individualized dosing regimen with PPIs based on CYP2C19 genotype might be a valid therapeutic strategy for overcoming insufficient gastric acid inhibition.

Potent Gastric Acid Inhibition Over 24 Hours by 4-Times Daily Dosing of Esomeprazole 20 mg

BACKGROUND

When administered at a standard dose, proton pump inhibitors (PPIs) do not always provide sufficient acid inhibition for all subjects, particularly in extensive metabolizers (EMs) of CYP2C19. Whether esomeprazole at a dose of 20 mg four times daily dosing (q.i.d.) can attain sufficient acid inhibition throughout 24 h in EMs remains unclear. We therefore investigated the efficacy of esomeprazole q.i.d. for acid inhibition.

METHODS

In a randomized cross-over design, 30 Helicobacter pylori-negative healthy young Japanese volunteers received esomeprazole at a dose of 20 mg two times a day (b.i.d.) or q.i.d. for 7 days. A pH monitoring was conducted before the trial as a control and on day 7 of both regimens.

RESULTS

Median pH values in the q.i.d. regimen were significantly higher than those with the b.i.d. regimen in EMs (b.i.d.: 5.3, q.i.d.: 6.6, p = 0.022), intermediate metabolizer (IM) (b.i.d.: 5.5, q.i.d.: 6.8, p = 0.005) and poor metabolizer (PM) (b.i.d.: 6.2, q.i.d.: 7.0, p = 0.047), respectively. Median pH with the b.i.d. regimen differed significantly by CYP2C19 genotypes (p = 0.004), but not the q.i.d. regimen (p = 0.384).

CONCLUSION

Esomeprazole q.i.d. achieved potent acid inhibition in all Helicobacter pylori-negative subjects, irrespective of CYP2C19 genotype, which might be one of the rescue regimens for patients' refractory to PPI treatment.

[Minimal Change Esophagitis]

Gastroesophageal reflux disease (GERD) is defined as a condition which develops when the reflux of gastric contents causes troublesome symptoms and long-term complications. GERD can be divided into erosive reflux disease and non-erosive reflux disease based on endoscopic findings defined by the presence of mucosal break. The Los Angeles classification excludes minimal changes as an evidence of reflux esophagitis because of poor interobserver agreement. In the Asian literature, minimal changes are considered as one of the endoscopic findings of reflux esophagitis, but the clinical significance is still controversial. Minimal change esophagitis is recognized quite frequently among patients with GERD and many endoscopists recognize such findings in their clinical practice. This review is intended to clarify the definition of minimal change esophagitis and their histology, interobserver agreement, and symptom association with GERD.

Improvement of gastroesophageal reflux disease in Japanese patients with spinal kyphotic deformity who underwent surgical spinal correction

BACKGROUND AND AIM

Spinal kyphotic deformity occasionally results in gastroesophageal reflux disease (GERD). The effects of acid reflux on the esophagus in kyphotic patients are unclear, however, and it is unknown whether acid reflux, endoscopic GERD, and reflux-related symptoms improve following surgical spinal correction in these patients. Herein, we investigated the characteristics of GERD in kyphotic patients and the improvement in GERD following surgical correction.

METHODS

In 48 patients with severe kyphotic deformity scheduled for surgical spinal correction, we conducted esophagogastroduodenoscopy, 24-h pH monitoring and three questionnaire surveys, including the frequency scale for the symptoms of GERD (FSSG). We repeated these measurements after surgical correction and compared pre- and post-surgery values.

RESULTS

Of 48 patients, 70.8% [95% CI: 55.9-83.0%, 34/48] had endoscopically evaluated esophageal mucosal injury. Regarding pH before surgery, 64.9% (CI: 47.5-79.8%, 24/37) had abnormal acid reflux (intraesophageal pH < 4 more than 5% of the time). FSSG score was significantly associated with the severity of GERD, and the positive rate was 52.6% (CI: 35.8-69.0%, 20/38). Following surgical correction, esophageal mucosal injury improved endoscopically in 90% of patients, and median total FSSG score significantly decreased from 8 (0-30) to 5 (0-19) (P = 0.005). Regarding pH after surgery, prevalence of abnormal acid reflux decreased from 66.7% (95% CI: 41.0-86.7%) to 33.3% (95% CI: 13.3-59.0%) (P = 0.045).

CONCLUSION

Surgical spinal correction in kyphosis patients improves not only kyphotic deformity-related disorders but also esophageal mucosal injury, abnormal acid reflux, and reflux-related symptoms.

The Nonsteroidal Anti-inflammatory Drug Diclofenac Reduces Acid-Induced Heartburn Symptoms in Healthy Volunteers

BACKGROUND & AIMS

We investigated the effects of diclofenac, a nonsteroidal anti-inflammatory drug that inhibits prostaglandin production, on induction of esophageal sensation by acid perfusion in healthy men.

METHODS

We performed a prospective, double-blind, placebo-controlled, 2-period, cross-over study over 3 visits in 12 healthy men. Diclofenac was given 6 hours and 2 hours before an acid perfusion test. During the test, hydrochloric acid (0.15 mol/L) was perfused into the lower esophagus for 30 minutes; we evaluated upper gastrointestinal symptoms using a validated categoric rating scale. Then, we calculated and assessed the acid perfusion sensitivity score (APSS). Biopsy specimens were collected by endoscopy of the distal esophagus before and after acid perfusion; levels of prostaglandin E2 (PGE2) (pg/mg) were measured in the samples using an enzyme-linked immunosorbent assay.

RESULTS

Compared with placebo, diclofenac significantly reduced the APSS for heartburn (82.2 ± 12.2 for placebo and 47.5 ± 8.9 for diclofenac; P < .01). Of the upper gastrointestinal symptoms, only the APSS for heartburn was reduced significantly by diclofenac. Compared with placebo, diclofenac reduced the overproduction of PGE2 by esophageal tissues after acid perfusion (23.3 ± 5.2 for placebo and 11.4 ± 3.5 for diclofenac; P < .05). APSS correlated with the development of heartburn and esophageal levels of PGE2 (r = 0.53; P < .05 for heartburn vs PGE2).

CONCLUSIONS

Diclofenac attenuated acid-induced heartburn by inhibiting PGE2 overproduction in the esophagus. Esophageal PGE2 might be involved in producing heartburn symptoms. Clinical Trials Registry no: UMIN000014595.

Pathophysiology of functional heartburn based on Rome III criteria in Japanese patients

AIM: To investigate the pathophysiology of functional heartburn (FH) in Japanese patients.

METHODS: A total of 111 patients with proton pump inhibitor (PPI)-refractory non-erosive gastroesophageal reflux disease underwent intraesophageal pressure testing and 24-h multichannel intraluminal impedance-pH (24MII-pH) testing. The patients also completed several questionnaires while they were receiving the PPI treatment, including the questionnaire for the diagnosis of reflux disease (QUEST), the frequency scale for the symptoms of gastroesophageal reflux disease (FSSG), the gastrointestinal symptoms rating scale (GSRS), SF-36, and the Cornell Medical Index (CMI). The subjects were classified into FH and endoscopy-negative reflux disease (ENRD) groups based on the Rome III criteria.

RESULTS: Thirty-three patients with esophageal motility disorder were excluded from this study, while 22 patients with abnormal esophageal acid exposure time (pH-POS) and 34 with hypersensitive esophagus (HE) were included in the ENRD group. The FH group included 22 patients with no reflux involvement. Sex, age, and body mass index did not differ significantly between the groups. The mean SF-36 values were < 50 (normal) for all scales in these groups, with no significant differences. The GSRS scores in these groups were not different and showed overlap with other gastrointestinal symptoms. The QUEST and the FSSG scores did not differ significantly between the groups. Neuroticism was diagnosed using the CMI questionnaire in 17 of the 78 included subjects within the pH-POS (n = 4), HE (n = 8), and FH (n = 5) groups, with no significant differences.

CONCLUSION: Clinical characteristics of the FH and PPI-refractory ENRD groups were similar. Therefore, esophageal function should be examined via manometry and 24MII-pH testing to differentiate between them.

Usefulness of baseline impedance in patients with proton pump inhibitor-refractory nonerosive reflux disease

BACKGROUND AND AIM

Approximately more than half of patients with non-erosive reflux disease (NERD) do not respond to proton pump inhibitor (PPI) therapy. Although NERD is a heterogeneous entity, previous study showed that multichannel intraluminal impedance (MII)-pH monitoring could distinguish reflux-related disease from PPI-refractory NERD. The aim of this study was to examine the usefulness of baseline impedance in PPI-refractory NERD patients.

METHODS

We used MII-pH monitoring to analyze reflux parameters, symptom index (SI), and baseline impedance in 37 PPI-refractory NERD patients on PPI. Reflux was divided into acid (nadir pH ≤ 4) and non-acid (nadir pH > 4). Subjects were classified as having reflux-related disease based on abnormal reflux parameters or positive SI (≥ 50%), or non-reflux-related disease, including functional heartburn, based on negative SI with normal reflux parameters.

RESULTS

A total of 26 of the 37 subjects were diagnosed with reflux-related disease, including eight with acid-reflux type and 18 with non-acid-reflux type, and nine with functional heartburn and two with pseudohypersalivation. There were no significant differences in the clinical characteristics of the acid-reflux type, non-acid-reflux type, and functional heartburn groups. The baseline impedance value in the acid-reflux type (1245 ± 392 Ω) was significantly lower than that in the non-acid-reflux type (2824 ± 1160 Ω) and functional heartburn (3546 ± 1353 Ω) groups. Baseline impedance values inversely correlated with reflux percent time, acid-reflux time, and acid exposure time.

CONCLUSION

Among patients with PPI-refractory NERD, acid-reflux type was associated with lower baseline impedance compared with non-acid-reflux type and functional heartburn.

Pretreatment prediction of symptom response to proton pump inhibitor therapy

BACKGROUND AND AIM

This prospective pilot study investigated whether it is possible to predict the therapeutic response in both the early phase (1 week) and sustained phase (4 weeks) before starting proton pump inhibitor (PPI) therapy for functional dyspepsia (FD) or non-erosive reflux disease (NERD).

METHODS

We administered rabeprazole 10 mg for 4 weeks to NERD/FD patients, who also answered a modified version of the Frequency Scale for Symptoms of gastroesophageal reflux disease (GERD) (FSSG), which added a pain score to the FSSG. Total score (TS), reflux score (RS), dysmotility score (DS), and pain score (PS) were analyzed. Symptom improvement was defined as ≥ 50% improvement in each score.

RESULTS

We enrolled 83 patients (age [mean ± SD] 50.8 ± 15.8 years, 29 males, 54 females), of whom 62 could be classified into four groups: achieved symptom improvement within 1 week and maintained it for 4 weeks (Early-R, 40.3%); achieved symptom improvement within 1 week but lost it after 4 weeks (Temp-R, 9.7%); did not achieve symptom improvement within 1 week but did after 4 weeks (Late-R, 9.7%); and no improvement (Non-R, 40.3%). Mean TS, RS, DS, and PS in the Non-R group were significantly higher than in the Early-R group (23.9, 10.5, 11.0, and 2.4 vs 14.3, 6.8, 6.4, and 1.2). However, the Temp-R, Late-R, and Non-R groups could not be distinguished by TS, RS, or DS.

CONCLUSION

The magnitude of the pretreatment modified FSSG score seemed to be associated with the response at 1 week and 4 weeks.

Refractory gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is a condition that develops when the reflux of stomach contents into the esophagus causes troublesome symptoms, esophageal injury, and/or complications. Use of proton pump inhibitors (PPI) remains the standard therapy for GERD and is effective in most patients. Those whose symptoms are refractory to PPIs should be evaluated further and other treatment options should be considered, according to individual patient characteristics. Response to PPIs could be total (no symptoms), partial (residual breakthrough symptoms), or absent (no change in symptoms). Patients experiencing complete response do not usually need further management. Patients with partial response can be treated surgically or by using emerging endoscopic therapies. Patients who exhibit no response to PPI need further evaluation to rule out other causes.

The role of gastroesophageal reflux in relation to symptom onset in patients with proton pump inhibitor-refractory nonerosive reflux disease accompanied by an underlying esophageal motor disorder

BACKGROUND

The symptom improvement rate is low with proton pump inhibitors (PPIs) in nonerosive reflux disease (NERD). The underlying pathogenic mechanism is complex. Esophageal motility disorders (EMDs) are thought to be a factor, but their prevalence, type, symptoms and the role played by gastroesophageal reflux (GER) in symptom onset have not been fully investigated.

AIM

To investigate the role of GER in symptom onset in PPI-refractory NERD patients with EMDs.

METHODS

This study comprised 76 patients with PPI-refractory NERD. Manometry was performed during PPI treatment and patients were divided into an EMD group and normal motility (non-EMD) group. Then, multichannel intraluminal impedance-pH monitoring was performed and medical interviews were conducted.

RESULTS

Nineteen patients (25%) had an EMD. Data were compared between 17 patients, excluding 2 with achalasia and 57 non-EMD patients. No significant differences were observed between groups in 24-hour intraesophageal pH <4 holding time (HT), mean number of GER episodes or mean number of proximal reflux episodes. The reflux-related symptom index (≥50%) showed a relationship between reflux and symptoms in 70.5% of EMD patients and 75% of non-EMD patients. In the EMD group, the score for FSSG (Frequency Scale for the Symptoms of GERD) question (Q)10 was significantly correlated with the number of GER episodes (r = 0.58, p = 0.02) and the number of proximal reflux episodes (r = 0.63, p = 0.02). In addition, the score for Q9 tended to be correlated with the number of GER episodes (r = 0.44, p = 0.06).

CONCLUSION

Our results suggest that some PPI-refractory NERD patients have EMDs, and that GER plays a role in symptom onset.

Effects of the New Prokinetic Agent DA-9701 Formulated With Corydalis Tuber and Pharbitis Seed in Patients With Minimal Change Esophagitis: A Bicenter, Randomized, Double Blind, Placebo-controlled Study

BACKGROUND/AIMS

DA-9701 (Motilitone) is a new prokinetic agent formulated with Corydalis Tuber and Pharbitis Seed. We assessed the efficacy of DA-9701 in symptomatic patients with minimal change esophagitis.

METHODS

Patients with minimal change esophagitis presenting with reflux or dyspeptic symptoms were randomly assigned to receive either DA-9701 30 mg or placebo t.i.d. (means 3 times a day). After 4 weeks of treatment, the primary efficacy end point determined by changes of the Nepean dyspepsia index questionnaire-Korean version (NDI-K) symptom scores, was analyzed.

RESULTS

Forty-two and 39 patients were assigned to the treatment and control groups, respectively. After 4 weeks, NDI-K symptom scores were reduced from 35.4 to 13.5 (P < 0.001) and from 43.0 to 27.7 (P < 0.001) in the treatment and the control groups, respectively. However, changes in the symptom scores did not differ between the 2 groups (P = 0.741). Although the quality of life scores were significantly improved after 4 weeks in both groups, changes in the quality of life score between the baseline value and that at 4 weeks did not differ between the 2 groups. The reflux symptom score was significantly improved in the treatment group compared to the placebo group in patients aged 65 years or older (P = 0.035).

CONCLUSIONS

Although NDI-K symptom scores and quality of life scores were improved after 4 weeks of treatment compared with baseline values in patients with minimal change esophagitis, DA-9701 did not improve the symptom scores or quality of life scores compared with the placebo.

Comparison of acid inhibition with standard dosages of proton pump inhibitors in relation to CYP2C19 genotype in Japanese

INTRODUCTION

The aim of therapeutic regimens using proton pump inhibitors (PPIs) in patients with acid-related diseases is to potently inhibit acid secretion for the full 24 h. However, optimum treatment is still unclear because the pharmacodynamics of PPIs differ among CYP2C19 genotypes and most of the previous studies have had loss of sample power.

METHODS

Using pH monitoring, we compared acid inhibition at standard dosage of omeprazole (20 mg, 50 times), lansoprazole (30 mg, 68 times), and rabeprazole (10 mg, 65 times) in Helicobacter pylori-negative healthy young Japanese volunteers.

RESULTS

Median pH with rabeprazole was 5.4 (3.3-7.5), which was significantly greater than with either omeprazole [4.4 (2.1-7.3)] or lansoprazole [4.8 (3.5-6.4)] (both P < 0.05). Median 24-h pH differed among the different CYP2C19 genotypes in all three PPIs. In CYP2C19 extensive metabolizers (EMs), the genotype that is refractory to PPI treatment, median pH with omeprazole, lansoprazole, and rabeprazole was 3.8 (2.1-4.4), 4.5 (3.5-5.3) and 4.8 (3.3-7.5), respectively.

DISCUSSION

Treatment with the selected PPIs at their standard dosages had difficulty maintaining acid inhibition for a full 24 h, especially in CYP2C19 EM. However, rabeprazole has the merit of less influence of CYP2C19 genotype compared with the other PPIs.

Effect of rikkunshito on the expression of substance P and CGRP in dorsal root ganglion neurons and voluntary movement in rats with experimental reflux esophagitis

BACKGROUND

While there are reports that the herbal medicine rikkunshito (RKT) relieves upper gastrointestinal disease symptoms, the effect of RKT on primary afferent neurons is unknown.

METHODS

A model of reflux esophagitis (RE) was implemented using male Wistar rats aged 6-7 weeks. Ten days after surgery, the total area of esophageal mucosal erosion sites was determined. Th8-10 dorsal root ganglia (DRG) were dissected out and the expression of substance P (SP), calcitonin gene-related peptide (CGRP), and phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2) was determined in DRG using immunohistochemistry. RKT (0.6%/WV) or omeprazole (OME) (10 mg/kg) was administered for 10 days beginning on the day after surgery. Voluntary movement was measured with an infrared sensor for 22 h each day.

KEY RESULTS

RE rats showed esophageal mucosal erosion and significantly increased number of SP/CGRP- and p-ERK1/2-immunoreactive neurons in DRG. Treatment with OME improved the size of erosive lesions in the esophageal mucosa of RE rats, while RKT did not. Treatment with RKT or OME significantly reduced the expression of SP/CGRP and p-ERK1/2 in DRG, and significantly increased voluntary movement in RE rats.

CONCLUSIONS & INFERENCES

RKT inhibited the activation of ERK1/2 and decreased the expression of SP and CGRP in DRG of RE rats, which may be associated with the observed amelioration of voluntary movement.

A randomized prospective study comparing the efficacy of on-demand therapy versus continuous therapy for 6 months for long-term maintenance with omeprazole 20 mg in patients with gastroesophageal reflux disease in Japan

AIM

To assess the efficacy of continuous therapy (cont) and on-demand therapy (on-demand) as maintenance therapy for gastroesophageal reflux disease (GERD).

METHODS

Patients with upper GI endoscopy (EGD)-proven GERD who completed 8 weeks of initial therapy were randomized to cont (omeprazole 20 mg od) or on-demand (omeprazole 20 mg on-demand) group. Assessments by the Global Overall Symptom (GOS) scale at baseline (at the start of maintenance therapy) and at 8-week, 16-week, and 24-week visits were made and EGD was performed at 24 weeks. Symptom relief was defined as percentages of patients whose GOS score of 1 or 2.

RESULTS

Of the 117 enrolled patients, cont/on-demand was 59/58 and nonerosive reflux disease (NERD)/reflux esophagitis (RE) before the initial therapy was 35/82. Symptom relief in cont/on-demand were 57.6%/48.3% at baseline (n.s.), 66.7%/54.7% at 8 week (n.s.), 64.6%/54.7% at 16 weeks (n.s.), and 66.7%/74.0% at 24 weeks (n.s.). When subjects were divided into NERD and RE, symptom relief in cont/on-demand were 33.3%/41.2% at baseline (n.s.), 43.8%/64.3% at 8 weeks (n.s.), 50.0%/42.9% at 16 weeks (n.s.), and 50.0%/69.2% at 24 weeks (n.s.) in NERD, while those were 68.3%/51.2% at baseline (n.s.), 76.3%/51.3% at 8 weeks (p < 0.05), 70.6%/59.0% at 16 weeks (n.s.), and 72.7%/75.7% at 24 weeks (n.s.) in RE, respectively. At 24-week EGD, all patients in NERD remained as NERD but number of healed patients was significantly higher in cont (85.3%) than in on-demand (44.4%) (p < 0.01) in RE.

CONCLUSIONS

Since NERD is defined by symptoms, as a result of the limited efficacy of continuous therapy, on-demand therapy would be sufficient as maintenance therapy in NERD patients. Regarding RE, continuous therapy would be recommended in terms of reduced symptoms and maintaining mucosal healing.

Acid peptic diseases: pharmacological approach to treatment

Acid peptic disorders are the result of distinctive, but overlapping pathogenic mechanisms leading to either excessive acid secretion or diminished mucosal defense. They are common entities present in daily clinical practice that, owing to their chronicity, represent a significant cost to healthcare. Key elements in the success of controlling these entities have been the development of potent and safe drugs based on physiological targets. The histamine-2 receptor antagonists revolutionized the treatment of acid peptic disorders owing to their safety and efficacy profile. The proton-pump inhibitors (PPIs) represent a further therapeutic advance due to more potent inhibition of acid secretion. Ample data from clinical trials and observational experience have confirmed the utility of these agents in the treatment of acid peptic diseases, with differential efficacy and safety characteristics between and within drug classes. Paradigms in their speed and duration of action have underscored the need for new chemical entities that, from a single dose, would provide reliable duration of acid control, particularly at night. Moreover, PPIs reduce, but do not eliminate, the risk of ulcers in patients taking NSAIDs, reflecting untargeted physiopathologic pathways and a breach in the ability to sustain an intragastric pH of more than 4. This review provides an assessment of the current understanding of the physiology of acid production, a discussion of medications targeting gastric acid production and a review of efficacy in specific acid peptic diseases, as well as current challenges and future directions in the treatment of acid-mediated diseases.

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.

Prostaglandin E(2) mediates acid-induced heartburn in healthy volunteers

Prostaglandin E(2) (PGE(2)) plays a major role in pain processing and hypersensitivity. This study investigated whether PGE(2) levels are increased in the esophageal mucosa after acid infusion and whether increases in PGE(2) are associated with heartburn. Furthermore, expression of the PGE(2) receptor EP1 was investigated in human esophageal mucosa. Fourteen healthy male volunteers were randomized to 30-min lower esophageal acid (1% HCl) or saline perfusion. Before and after acid perfusion, endoscopic biopsies were taken from the distal esophagus. PGE(2) concentration (pg/mg protein) and EP1 mRNA and protein in biopsy samples were measured by ELISA, RT-PCR, and Western blotting. Symptom status of heartburn was evaluated with a validated categorical rating scale with a higher values corresponding to increasing intensity. PGE(2) levels in the esophageal mucosa significantly increased after acid infusion (before vs. after acid infusion: 23.2 ± 8.6 vs. 68.6 ± 18.3, P < 0.05), but not after saline infusion (before vs. after saline infusion: 9.3 ± 2.5 vs. 9.0 ± 3.2, NS). Time to first sensation (min) after acid infusion was less than after saline (saline vs. acid infusion: 22.1 ± 4.1 vs. 5.4 ± 1.5, P < 0.05). Intensity of heartburn in the acid-infusion group was also significantly greater compared with saline (saline vs. acid infusion: 54.3 ± 13.1 vs. 178.5 ± 22.8, P < 0.01). Changes in PGE(2) levels in the esophagus correlated with symptom intensity score (r = 0.80, P = 0.029). EP1 mRNA and protein expression were observed in the normal human esophageal mucosa. Esophageal PGE(2) expression is associated with mucosal acid exposure and heartburn.

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.

Lifestyle factors associated with gastroesophageal reflux disease in the Japanese population

BACKGROUND

We aimed to clarify the lifestyle factors associated with erosive esophagitis and non-erosive reflux disease (NERD) in a Japanese population.

METHODS

Among 886 subjects who underwent health screening, we selected, according to their scores on the FSSG (frequency scale for symptoms of gastroesophageal reflux disease; GERD) questionnaire and the findings of upper gastrointestinal endoscopy, 138 subjects with erosive esophagitis (EE), 148 subjects with NERD (absence of esophagitis, FSSG score ≥8, and acid reflux-related symptoms score ≥4), and 565 control subjects (absence of esophagitis and FSSG score ≤7). We compared clinical characteristics and various lifestyle factors in these three groups.

RESULTS

The lifestyle factors significantly associated with NERD compared with findings in the control group were intake of egg (odds ratio [OR] 1.89, 95% confidence interval [CI] 1.01-3.50), sleep shortage (OR 2.44, 95% CI 1.54-3.88), and strong psychological stress (OR 1.77, 95% CI 1.18-2.62). In male subjects, current smoking (OR 2.06, 95% CI 1.13-3.74; OR 1.87, 95% CI 1.09-3.20) was a significant risk factor for both NERD and EE. Moreover, alcohol >200 kcal/day (OR 3.99, 95% CI 1.03-15.55) and intake of a large quantity of food at supper (OR 7.85, 95% CI 1.66-37.05) were significant risk factors for EE in subjects with hiatal hernia. Intake of a large quantity of food at supper (OR 2.09, 95% CI 1.06-4.13) was more common in the NERD group than in the EE group.

CONCLUSIONS

There were differences in the associated lifestyle factors between patients with NERD and those with EE, and there was also a gender-related difference between these groups.

Arm span-height difference is correlated with gastroesophageal reflux symptoms in aged Japanese subjects

Previous studies have indicated an association between the symptoms of gastroesophageal reflux disease (GERD) and aging plus height. In this study we investigated whether the arm span–height difference was related to GERD symptoms with a focus on aged subjects in the general population, since the arm span reflects the height in young adulthood before decreasing due to vertebral deformities from aging. A total of 285 elderly individuals (105 females) who visited nursing homes for the elderly in Japan were enrolled in this study. The GERD symptoms were evaluated by the Frequency Scale for the Symptoms of GERD (FSSG). The body weight, height and arm span were measured, and information regarding medications and complications were reviewed in each nursing record. 50.5% of women had more than 3 cm of arm span–height difference. In contrast, only 37.3% of men had more than 3 cm of arm span–height difference. The FSSG scores indicated more than 70% of subjects complained of any GERD symptoms. There was a significant correlation between the FSSG score and the arm span–height difference in the subjects with more than 3 cm of arm span-height difference (r = 0.236; p = 0.012). The correlation between the arm span–height difference and the FSSG score was significant only in women in females in the present study. In conclusion, our findings indicate that vertebral deformity evaluated by the arm span–height difference might have some positive relationship to the pathogenesis of GERD symptoms in elderly Japanese individuals.

Clinical symptoms of FSSG in gastroesophageal reflux disease are critical for PPI treatment: Japanese multi-centers with 185 patients

AIM

The main aim of this study was to determine whether questionnaire evaluations of clinical symptoms in gastroesophageal reflux disease were useful to assess proton pump inhibitor therapy.

METHODS

A total of 185 Japanese patients (men, 88; women, 97; age: 55.7 ± 16.1 years) with gastroesophageal reflux disease were enrolled. The patients were divided based on the frequency scale for symptoms of gastroesophageal reflux disease: severe symptoms with scores ≥8 and mild symptoms with scores ≤7. Quality of life was evaluated with the Medical Outcomes Study 8-Item Short-Form Health Survey. All patients were treated with a proton pump inhibitor, rabeprazole (10 mg/day), for 8 weeks.

RESULTS

Patients were classified into four groups: reflux esophagitis with severe symptoms (n = 92, 49.7%); reflux esophagitis with mild symptoms (n = 17, 9.2%); non-erosive reflux disease with severe symptoms (n = 66, 35.7%); and non-erosive reflux disease with mild symptoms (n = 10, 5.4%). The dysmotility score was high in non-erosive reflux disease with severe symptoms compared with reflux esophagitis with severe symptoms (9.1 ± 0.5 vs 6.8 ± 0.5, P < 0.05). The symptom score and quality of life in the severe symptoms groups for both reflux esophagitis and non-erosive reflux disease were significantly improved by rabeprazole treatment. Only the reflux score was improved by rabeprazole in the reflux esophagitis with mild symptoms group; no therapeutic effect was observed for the non-erosive reflux disease with mild symptoms group.

CONCLUSIONS

Low scores on the frequency scale for the symptoms of gastroesophageal reflux disease indicate poor responsiveness to proton pump inhibitor treatment, and high scores indicate good responsiveness.

Rabeprazole 10 mg q.d.s. decreases 24-h intragastric acidity significantly more than rabeprazole 20 mg b.d. or 40 mg o.m., overcoming CYP2C19 genotype

BACKGROUND

Standard dosing (i.e. once daily) of proton pump inhibitors (PPIs) cannot inhibit acid secretion for a full 24 h. Better therapeutic regimens using PPIs are required to sustain potent acid inhibition for the full 24 h in all patients with acid-related diseases.

AIM

To evaluate acid inhibitory effects by different dosing times of a PPI at the same daily dosage, in a study involving 70 rounds of pH monitoring.

METHODS

Using pH monitoring, we evaluated the efficacy of different divided treatment regimens with the same total daily dose of rabeprazole (40 mg o.m., 15 rounds; 20 mg b.d., 20 rounds; 10 mg q.d.s., 35 rounds) on day 7 or 8 of PPI dosing.

RESULTS

In the study of divided treatment, the median pH (when administered once, twice or four times to achieve a daily dose of 40 mg) was 4.8 (3.6-6.4), 5.7 (4.1-7.4), 6.6 (4.9-8.4), respectively. When comparing the median pHs at the same CYP2C19 genotype among different dosing times of rabeprazole, the median pH attained with 10 mg q.d.s. was significantly higher than that in 40 mg o.m. or 20 mg b.d. Increase in the frequency of dosing effectively increased pH [median percent time of pH > 4.0 with q.d.s. therapy: 95.5% (63.2-100.0%)], irrespective to CYP2C19 genotype.

CONCLUSION

Four times daily dosing with rabeprazole 10 mg achieved potent acid inhibition, including during the night-time, suggesting its potential usefulness as a regimen for patients who are refractory to standard once daily PPI treatment.

Efficacy of adding sodium alginate to omeprazole in patients with nonerosive reflux disease: a randomized clinical trial

Nonerosive reflux disease (NERD) is the most common form of gastroesophageal reflux disease. Patients with NERD have a lower response rate to proton pump inhibitors (PPIs) than patients with erosive esophagitis when gauged from relief of heartburn. Sodium alginate decreases the acidity of refluxate and protects the esophageal mucosa. However, whether the addition of sodium alginate to PPI therapy can improve NERD symptoms remains unknown. Accordingly, the aim of this study was to evaluate the efficacy of adding sodium alginate to basal PPI therapy for NERD. Patients who had experienced heartburn on at least 2 days per week during the 1-month period before entering the study and had no endoscopic mucosal breaks (grade M or N according to Hoshihara's modification of the Los Angeles classification) were randomized to one of two treatments for 4 weeks: omeprazole (20 mg once daily) plus sodium alginate (30 mL four times a day) (group A) or omeprazole (20 mg once daily) alone (group B). Eighty-seven patients were enrolled, and 76 patients were randomly assigned to group A (n = 36) or group B (n = 40). Complete resolution of heartburn for at least 7 consecutive days by the end of treatment was significantly more common in group A (56.7%) than in group B (25.7%). One patient from group A had mild drug-related diarrhea that was not clinically serious. In conclusion, omeprazole combined with sodium alginate was better than omeprazole alone in Japanese patients with NERD.

A study on the efficacy of rebamipide for patients with proton pump inhibitor-refractory non-erosive reflux disease

BACKGROUND AND AIM

Reflux symptoms in patients with non-erosive reflux disease (NERD) cannot be easily controlled by treatment with proton pump inhibitors (PPI). The anti-inflammatory function of rebamipide may be effective for protecting the esophageal mucosa. This prospective randomized multicenter placebo-controlled study was performed to clarify the efficacy of rebamipide for NERD patients whose reflux symptoms were refractory to PPI treatment.

METHODS

One hundred forty-nine patients were enrolled on the basis of a QUEST score of over 6 and absence of endoscopically proven esophageal mucosal breaks. All the patients were initially administered 15 mg of lansoprazole for 4 weeks, and the symptoms were then assessed using QUEST and GSRS. PPI-refractory patients were randomly assigned to administration of rebamipide or placebo t.i.d. for 4 weeks.

RESULTS

Three of the 149 patients were lost to follow-up, and 60 among the remaining 146 patients were found to be PPI-refractory. Among these PPI-refractory patients, 31 were randomly assigned to a rebamipide group and 29 to a placebo group. At the end of drug administration, the QUEST and GSRS scores did not differ between the rebamipide and placebo groups, although a significantly higher proportion of patients in the rebamipide group showed amelioration of abdominal pain and diarrhea.

CONCLUSION

Administration of rebamipide cannot effectively control reflux symptoms in NERD patients whose symptoms are refractory to PPI therapy.

Efficacy of esomeprazole in treating acid-related diseases in Japanese populations

Esomeprazole (Nexium^®; AstraZeneca), the S-isomer of omeprazole, is the first proton pump inhibitor (PPI) to be developed as an optical isomer. Compared with omeprazole, esomeprazole has an improved pharmacokinetic profile with regards to CYP2C19 (S-mephenytoin 4′-hydroxylase) genotype, showing increased systemic exposure and less interindividual variability. Further, esomeprazole is a more potent acid inhibitor than other currently available PPIs and is therefore used as a first-line drug for acid-related diseases. While esomeprazole has been available in a number of countries worldwide, the compound only received authorized permission to be marketed in Japan in September 2011. The standard esomeprazole dose in Japan for the treatment of peptic ulcers and gastroesophageal reflux disease (GERD) is 20 mg. Other advised dosages are 10 mg for nonerosive reflux disease and 20 mg twice-daily dosing for eradication of Helicobacter pylori. In Japanese, the effective rate of esomeprazole 20 mg during 24 weeks for GERD patients is 92.0% (88.0%–96.0%), while the prevention of peptic ulcer development using 20 mg for 24 weeks in patients treated with nonsteroidal anti-inflammatory drugs is 96.0% (92.8%–99.1%). Although clinical data are limited, the usefulness of esomeprazole is expected in Japanese subjects given the reduced prevalence of CYP2C19 rapid metabolizers in Japan compared with Western countries.

Predicting the efficacy of proton pump inhibitors in patients with non-erosive reflux disease before therapy using dual-channel 24-h esophageal pH monitoring

BACKGROUND AND AIM

We aimed to determine whether reflux- and symptom-related parameters can predict the efficacy of proton pump inhibitors (PPI) in non-erosive reflux disease (NERD).

METHODS

Twenty-seven NERD patients who had experienced heartburn more than once a week within the previous month were enrolled. Intraesophageal pH before therapy was measured simultaneously at 5 and 15 cm above the esophagogastric junction (EGJ) for 24 h. The PPI rabeprazole was administered at a dose of 10 mg once daily for 4 weeks. In the event that heartburn was not relieved, the dose was increased to 10 mg twice daily for an additional 2 weeks, and again to 20 mg twice daily for another 2 weeks.

RESULTS

Univariate analysis demonstrated no significant associations between any reflux- or symptom-related parameters at either site and complete heartburn relief after 4 weeks, or cumulative complete heartburn relief after 8 weeks. However, post-hoc analysis demonstrated more satisfactory heartburn relief after 4 weeks in patients with a high symptom index compared with those with a low symptom index, at 5 cm above the EGJ (P = 0.009). Cumulative satisfactory heartburn relief after 8 weeks was also greater in patients with a high total number of acid reflux episodes compared with those with a low total number of episodes, at 15 cm above the EGJ (P = 0.037).

CONCLUSIONS

Pre-therapeutic pH monitoring in the lower and mid-esophagus is useful for predicting the efficacy of PPI in NERD patients.

Pathogenesis of proton-pump inhibitor-refractory non-erosive reflux disease according to multichannel intraluminal impedance-pH monitoring

BACKGROUND AND AIM

Proton-pump inhibitor (PPI) therapy is the first-line treatment for gastroesophageal reflux disease; however, there are some reports of PPI failure in cases of non-erosive reflux disease (NERD). Among the pathogenic factors associated with PPI-refractory NERD, reflux other than acid reflux can not be detected by conventional pH monitoring. The purpose of this study was to clarify the usefulness of multichannel intraluminal impedance-pH (MII-pH) monitoring for PPI-refractory NERD patients and examine the pathogenesis.

METHODS

We used MII-pH monitoring to examine 29 PPI-refractory NERD patients on PPI treatment. Reflux parameters, symptom index (SI: positive if ≥ 50%), and proximal migration were analyzed. The acidity of the reflux was divided into acid (nadir pH ≤ 4) and non-acid (nadir pH > 4). Subjects were classified into reflux-related disease (abnormal reflux parameters or positive SI) and non-reflux-related disease (normal reflux parameters and negative SI).

RESULTS

Of the 29 subjects, 21 were diagnosed with reflux-related disease, including 6 with acid reflux type and 15 with non-acid reflux type, and 8 were diagnosed with non-reflux-related disease. Of the total 1816 liquid reflux episodes, 834 showed proximal migration, which was more common in symptomatic reflux than in asymptomatic reflux.

CONCLUSIONS

MII-pH monitoring could distinguish reflux-related disease (especially non-acid type) from PPI-refractory NERD. Proximal migration was associated with symptomatic reflux in PPI-refractory NERD patients.

Investigation of pretreatment prediction of proton pump inhibitor (PPI)-resistant patients with gastroesophageal reflux disease and the dose escalation challenge of PPIs-TORNADO study: a multicenter prospective study by the Acid-Related Symptom Research Group in Japan

BACKGROUNDS

Some non-erosive reflux disease (NERD) and reflux esophagitis (RE) patients are unresponsive to a proton pump inhibitor (PPI) at standard dose. We investigated the predictive marker of the efficacy of PPI for GERD patients including NERD and RE treated with standard and increased doses of a PPI.

METHODS

Patients with symptomatic gastroesophageal reflux disease (GERD) (NERD and RE) were treated with rabeprazole (RPZ) 10 mg once daily for 4 weeks. The RPZ dosage was increased to 10 mg twice daily for an additional 2 weeks and again to 20 mg twice daily for another 2 weeks if heartburn was not relieved. Baseline characteristics and efficacy of RPZ were assessed on the basis of a heartburn diary and frequency scale for symptoms of GERD (FSSG).

RESULTS

Complete heartburn relief rates after 4 weeks were 42.5% (31/73) and 67.9% (19/28) in NERD and RE groups, respectively, which rose to 68.9 and 91.7% after dose escalation. Multivariate analysis revealed that parameters associated with resistance to RPZ 10 mg once daily were female, non-smoking, frequent heartburn, low score for question 4 (Q4) of the FSSG (subconsciously rubbing the chest), and high scores for Q3 (heavy stomach after meal) and Q7 (unusual sensation in the throat). Frequent heartburn and a high score for Q7 were associated with resistance to RPZ 20 mg twice daily. FSSG scores of patients resistant to RPZ were significantly higher in comparison with responders before and during treatment.

CONCLUSIONS

FSSG could predict response to a PPI for symptomatic GERD. Increase of RPZ dose is useful for treatment of GERD refractory to the standard dose of RPZ.

Ilaprazole, a new proton pump inhibitor, is primarily metabolized to ilaprazole sulfone by CYP3A4 and 3A5

Ilaprazole is a new proton pump inhibitor, designed for treatment of gastric ulcers, and developed by Il-Yang Pharmaceutical Co (Seoul, Korea). It is extensively metabolised to the major metabolite ilaprazole sulfone. In the present study, several in vitro approaches were used to identify the cytochrome P450 (CYP) enzymes responsible for ilaprazole sulfone formation. Concentrations of ilaprazole sulfone were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Incubation of ilaprazole with cDNA-expressed recombinant CYPs indicated that CYP3A was the major enzyme that catalyses ilaprozole to ilaprazole sulfone. This reaction was inhibited significantly by ketoconazole, a CYP3A inhibitor, and azamulin, a mechanism-based inhibitor of CYP3A, while no substantial effect was observed using selective inhibitors for eight other P450s (CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP2E1). In addition, the formation of ilaprazole sulfone correlated well with CYP3A-catalysed testosterone 6β-hydroxylation and midazolam 1'-hydroxylation in 20 different human liver microsome panels. The intrinsic clearance of the formation of ilaprazole sulfone by CYP3A4 was 16-fold higher than that by CYP3A5. Collectively, these results indicate that the formation of the major metabolite of ilaprazole, ilaprazole sulfone, is predominantly catalysed by CYP3A4/5.

Acid-suppressive effect of rabeprazole 5 mg and 10 mg once daily by 24-hour esophageal pH monitoring in patients with non-erosive reflux disease in Japan: a multicenter, randomized, parallel-group, double-blind pharmacodynamic study

BACKGROUND

Acid suppression induced by rabeprazole 5 mg in patients with NERD has not been reported in the literature.

AIMS

The objective of this study was to investigate gastroesophageal acid suppression in NERD patients by rabeprazole 5 mg and 10 mg/day.

METHODS

Subjects were grade M (minimal changes) NERD patients. Twenty-two patients not responding to open label antacid therapy entered a double-blind treatment phase in which rabeprazole 5 mg or 10 mg/day for four weeks were compared. Twenty-four-hour esophageal pH monitoring was performed before and on treatment (at week 4) to assess the pharmacodynamic effect of these doses of rabeprazole.

RESULTS

The frequency of heartburn episodes and the number of acid reflux episodes in the esophagus corresponded well in grade M NERD patients (r=0.44, P=0.042). Median percentage of time at pH<4 was 4.3% before treatment and 1.1% on treatment with rabeprazole 5 mg (change from baseline; -2.5%), whereas the median percentage of time at pH<4 in the rabeprazole 10 mg group was 7.4% before treatment and 0.5% on treatment (change from baseline; -6.6%). Likewise, treatment-related changes of median number of reflux episodes were -18.0 with rabeprazole 5 mg and -44.0 with rabeprazole 10 mg. For each esophageal pH data, no significant differences were observed between the two groups (P=0.377, P=0.077).

CONCLUSIONS

Administration of 5 mg and 10 mg rabeprazole sufficiently inhibited pathological gastroesophageal acid reflux and relieved heartburn episodes in NERD patients who did not respond to an antacid. Further investigation would be necessary to determine proper usage of the two doses.

Causes of, and therapeutic approaches for, proton pump inhibitor-resistant gastroesophageal reflux disease in Asia

Proton pump inhibitors (PPIs) are the most widely used drugs for treatment of gastroesophageal reflux disease. However, approximately 20% of patients with reflux esophagitis and 40% of those with nonerosive reflux diseases complain of troublesome symptoms, even during treatment with PPIs. In patients with reflux esophagitis, dose escalation and co-administration with a histamine H(2)-receptor antagonist are potential approaches, since the major cause of PPI resistance is incomplete suppression of gastric acid secretion. On the other hand, for patients with nonerosive reflux disease, switching from PPIs to pain modulators is often necessary for improvement of symptoms, since 25% of patients with nonerosive reflux disease have symptoms not caused by gastroesophageal acid reflux. Therapeutic approaches for PPI-resistant patients with reflux esophagitis and nonerosive reflux diseases are considered according to pathogenesis.

Characteristics of non-erosive gastroesophageal reflux disease refractory to proton pump inhibitor therapy

AIM: To investigate whether potent acid inhibition is effective in non-erosive reflux disease (NERD) refractory to standard rabeprazole (RPZ) treatment.

METHODS: We treated 10 Japanese patients with NERD resistant to standard dosages of RPZ: 10 mg or 20 mg od, 20 mg bid, or 10 mg qid for 14 d. All patients completed a frequency scale for symptoms of gastroesophageal reflux disease questionnaire frequency scale for the symptoms of GERD (FSSG); and underwent 24 h pH monitoring on day 14.

RESULTS: With increased dosages and frequency of administration of RPZ, median intragastric pH significantly increased, and FSSG scores significantly decreased. With RPZ 10 mg qid, potent acid inhibition was attained throughout 24 h. However, five subjects were refractory to RPZ 10 mg qid, although the median intragastric pH in these subjects (6.6, range: 6.2-7.1) was similar to that in the remaining five responsive subjects (6.5, range: 5.3-7.3). With baseline RPZ 10 mg od, FSSG scores in responsive patients improved by > 30%, whereas there was no significant decrease in the resistant group.

CONCLUSION: NERD patients whose FSSG score fails to decrease by > 30% after treatment with RPZ 10 mg od for 14 d are refractory to higher dosage.