Pathophysiology of Potassium-competitive Acid Blocker-refractory Gastroesophageal Reflux and the Potential of Potassium-competitive Acid Blocker Test

Differences Between Patients with Heartburn Refractory to Vonoprazan and Those Refractory to Proton Pump Inhibitors

BACKGROUND

Vonoprazan, a potassium-competitive acid blocker, demonstrates more potent acid inhibition than proton pump inhibitors (PPIs). This study aimed to evaluate the effect of vonoprazan in patients with unproven gastroesophageal reflux disease (GERD) by comparing patients with vonoprazan-refractory heartburn with those with PPI-refractory heartburn.

METHODS

This study included 104 consecutive patients with vonoprazan- or PPI-refractory heartburn (52 patients each), no erosive esophagitis on endoscopy and who underwent combined multichannel intraluminal impedance-pH (MII-pH) testing with vonoprazan/PPI discontinuation. Patients' backgrounds, symptom scores from four questionnaires, MII-pH results and high-resolution manometry results were compared between the two groups.

RESULTS

The vonoprazan group demonstrated significantly higher GERD symptoms and scores of abdominal pain and diarrhea on the Gastrointestinal Symptom Rating Scale questionnaire. MII-pH results revealed that the vonoprazan group demonstrated 40.4%, 17.3%, and 42.3% and the PPIs group exhibited 26.9%, 17.3%, and 55.8% of abnormal acid reflux [true non-erosive reflux disease (NERD)], reflux hypersensitivity and functional heartburn, respectively. The vonoprazan group demonstrated higher true NERD rates but with no significant difference (p = 0.307). Among the vonoprazan group, eight patients with true NERD underwent another MII-pH test on vonoprazan, and all cases demonstrated normal acid exposure times (0.0% [0.0-0.3]).

CONCLUSION

Patients with unproven GERD with vonoprazan-refractory heartburn demonstrated more symptoms, including not only GERD symptoms but also functional dyspepsia and irritable bowel syndrome symptoms, than those with PPI-refractory heartburn.

The crystal structure of 1-[5-(2-fluorophenyl)-1-(pyridine-3-sulfonyl)-1H-pyrrol-3-yl]-N-methylmethanaminium 3-carboxyprop-2-enoate, C21H20FN3O6S

C21H20FN3O6S, monoclinic, P21/n (no. 14), a = 7.8502(4) Å, b = 7.9892(4) Å, c = 34.9707(19) Å, β = 92.500(1)°, V = 2191.2(2) Å3, Z = 4, R gt (F) = 0.0502, wR ref(F 2) = 0.1361, T = 296(2) K.

Efficacy of rikkunshito in patients with functional heartburn: a prospective pilot study

BACKGROUND

Although the efficacy of rikkunshito in patients with treatment-resistant non-erosive gastroesophageal reflux disease (NERD) has been reported, it is unclear for which subgroups of NERD patients (per the Rome IV criteria) rikkunshito is effective. The objective of this study was to investigate the efficacy of rikkunshito in patients with functional heartburn.

METHODS

Ten patients with functional heartburn who experienced symptoms of dyspepsia were enrolled. The patients were administered rikkunshito for 8 weeks. The frequency scale for the symptoms of GERD (FSSG), Japanese translation of quality of life in reflux and dyspepsia questionnaire (QOLRAD-J), and hospital anxiety and depression scale (HADS) were evaluated before and 4 and 8 weeks after administration. Overall treatment efficacy (OTE) was evaluated 8 weeks after administration.

RESULTS

One patient was discontinued 4 weeks after administration because of voluntary withdrawal. Total FSSG score was significantly (P = 0.039) lower 8 weeks after treatment or at discontinuation (13.2 ± 8.0) than before treatment (18.3 ± 10.7). Although QOLRAD-J score tended to increase 8 weeks after treatment or at discontinuation compared with before treatment, no significant difference was observed. HADS score did not decrease significantly 8 weeks after treatment or at discontinuation compared with before treatment. However, a correlation was found between total FSSG and HADS anxiety scores (correlation coefficient: 0.684, P = 0.027).

CONCLUSIONS

This was the first study to investigate the efficacy of rikkunshito in patients with functional heartburn. Rikkunshito may be effective in these patients.

Long-term vonoprazan therapy is effective for controlling symptomatic proton pump inhibitor-resistant gastroesophageal reflux disease

Vonoprazan, a novel potassium-competitive acid blocker, results in greater inhibition of gastric acid secretion than proton pump inhibitors (PPI). The aim of this study was to assess the long-term outcomes of patients with PPI-resistant gastroesophageal reflux disease (GERD) treated with vonoprazan. The medical records of patients with symptomatic GERD treated with vonoprazan for 1 year were retrospectively reviewed. Changes in abdominal symptoms were assessed using the Izumo scale, a self-reported questionnaire which is useful in evaluating the symptoms of GERD, epigastric pain, postprandial distress, constipation and diarrhea, and is commonly used in routine clinical practice. A total of 30 patients were included and stratified into a non-erosive (n=22) and erosive group (n=8). At baseline, postprandial distress symptoms were significantly greater in the non-erosive group compared with the erosive group (P=0.013). Even with vonoprazan therapy, symptoms of GERD in the non-erosive group were refractory compared with the erosive group, and required additional treatment in a larger proportion of patients (45 vs. 13%). GERD symptoms in the non-erosive group significantly improved from baseline and remained better after 1 year of vonoprazan therapy, similar to the erosive group. In addition, vonoprazan improved epigastric pain and postprandial distress symptoms in the non-erosive group, and 1 year of vonoprazan therapy did not aggravate constipation or diarrhea. In conclusion, 1 year of vonoprazan therapy improves GERD symptoms in patients with PPI-resistant GERD.

The Impact of COVID-19 on Gastrointestinal Motility Testing in Asia and Europe

Background: The new coronavirus disease (COVID-19) has high infection and mortality rates, and has become a pandemic. The infection and mortality rates are lower in Asian countries than in European countries. This study aimed to conduct a survey on the effects of COVID-19 on the capacity to perform gastrointestinal motility tests in Asian countries compared with European countries. Methods: We used the questionnaire previously established by our team for researchers in European countries. The correlation between the decreased rate of gastrointestinal motility and function tests, and the infection/mortality rates of COVID-19 and stringency of a government’s interventions in each country was analysed and protective measures were assessed. Results: In total, 58 gastroenterologists/motility experts in Asian countries responded to this survey. The infection/mortality rates of COVID-19 and Stringency Index had a significant impact on the testing capacity of oesophageal manometry and catheter-based pH monitoring. In European countries, most facilities used filtering facepiece 2/3 (FFP2/3) masks during oesophageal motility studies. Meanwhile, in Asian countries, most facilities used surgical masks. Conclusion: The total infection and mortality rates of COVID-19 can affect the rate of gastrointestinal motility testing and the type of protective equipment that must be used.

A comparison between dexlansoprazole modified release-based and lansoprazole-based nonbismuth quadruple (concomitant) therapy for first-line Helicobacter pylori eradication: a prospective randomized trial

Purpose

Steadily maintaining high intra-gastric PH is the major factor for successful Helicobacter pylori (H.pylori) eradication. It is important to search for a stronger PPI. Dexlansoprazole MR is a dual delayed release formulation PPI taken once daily which is capable of maintaining longer duration of high intra-gastric PH. It is very effective in treating gastroesophageal disease but reports on H, pylori eradication is very rare. This study sought to compare dexlansoprazole MR-based concomitant treatment and lansoprazole-based concomitant treatment in H. pylori infection and to investigate the factors that affect the eradication rates.

Methods

Two hundred two participants with H. pylori infection were included and randomly assigned to seven days of dexlansoprazole MR-based concomitant therapy (dexlansoprazole MR 60 mg once daily, clarithromycin 500 mg twice daily, amoxicillin 1 g twice daily and metronidazole 500 mg twice daily; DACM group) or a seven days of lansoprazole-based concomitant therapy (lansoprazole 30 mg twice daily, clarithromycin 500 mg twice daily, amoxicillin 1 g twice daily, and metronidazole 500 mg twice daily; LACM group). The participants were asked to perform urea breath tests eight weeks later.

Results

The eradication rates in the DACM group were 86.1% [95% confidence interval (CI): 77.8%–92.2%] in the ITT analysis and 90.6% (95% CI: 82.9%–95.6%) in the PP analysis, respectively, as compared with 90.1% (95% CI: 82.6%–95.2%) and 92.6% (95% CI: 85.5%–96.9%) (p=0.384 and p=0.572, respectively) in the LACM group for the same analyses. The adverse event rates were 11.5% in the DACM group and 10.2% in the LACM group (p=0.779).

Conclusion

As a first-line H. pylori treatment regimen, dexlansoprazole MR-based concomitant therapy attained a successful eradication rate of 90%, which was non inferior to that of lansoprazole-based concomitant treatment.

ClinicalTrials.gov identifier

NCT03829150.

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