Intragastric pH Research Articles

Effects of vonoprazan on gastric PH and clinical course after gastric ESD: A retrospective and prospective study

BackgroundVonoprazan has been more widely used for artificial ulcers after endoscopic submucosal dissection (ESD) for early gastric cancer; however, no reports have examined intragastric pH during ESD. The present study aimed to measure gastric pH at the time of ESD and the clinical course afterwards for patients treated with vonoprazan the night before undergoing ESD. Materials and methodsWe examined medication status regarding gastric acid secretion and antithrombotic drugs, post-ESD bleeding as a perioperative complication, and the timing of upper gastrointestinal endoscopy after ESD and ulcer healing in 156 patients who underwent gastric ESD at our hospital from January 2014 to December 2019. The gastric pH was measured at the time of ESD after administration of 20 mg vonoprazan on the night before gastric ESD. ResultsThere were 14 cases of post-ESD bleeding in patients treated with proton-pump inhibitors (PPIs), including oozing during second-look endoscopy compared to only 1 case of bleeding with vonoprazan administration (p < 0.05). Vonoprazan was also associated with better post-ESD ulcer healing than PPIs. Gastric pH during ESD after vonoprazan administration on the night before gastric ESD was ≥6.96 in all 11 patients. ConclusionPost-ESD bleeding was reduced, and ulcer healing was improved in patients treated with vonoprazan the night before their procedure. Our results suggest high gastric pH during ESD due to vonoprazan administration may be beneficial for hemostasis and ulcer healing following ESD.

Capsule endoscopy detects insufficient treatment of gastric bleeding in a dog with chronic hepatitis

A five-year-old dog was presented for a chronic non-regenerative anaemia, copper-associated chronic hepatitis and suspected portal hypertension. The anaemia was suspected to be from gastrointestinal (GI) bleeding and persisted despite...

Intragastric pH of foals admitted to the intensive care unit.

BackgroundIntragastric pH profiles of neonatal foals admitted to the intensive care unit (ICU) remain poorly characterized.Hypothesis/ObjectivesTo determine intragastric pH profiles and clinical parameters associated with intragastric pH in foals admitted to the ICU.AnimalsForty‐two neonatal foals admitted to the ICU and requiring placement of an indwelling nasogastric tube for nutritional management were included.MethodsIntragastric pH was measured for 24 hours from the time of admission. Mean pH, % time pH <4, and % time pH >4 were determined for each foal. History, clinical findings, and clinicopathological data recorded at the time of presentation were collected.ResultsThe mean pH of included foals was 5.5 ± 1.8. The median % time pH <4 was 6.3% (range: 0‐99). A history of placentitis was associated with greater mean pH (median 5.3 (range: 0.9‐7.8) versus median 7.2 (5.9‐11.3); P = .002) and less % time pH <4 (median 13 (0‐99.6) versus median 0.1 (0‐7.2); P = .01). Foals with diarrhea had a greater % time pH <4 (median 4.6% (0‐99) versus median 28.8% (1.4‐57.48); P = .02). Foals with a pH >4 for >50% recording time had a lower PaO2 (mean difference 25.0 mm Hg; 95% confidence interval [CI], 14.4‐35.6; P = .03) and higher PaCO2 (mean difference 14.9 mm Hg; 95% CI, 4.7‐25.2; P = .02). Surviving foals had a lower mean median hourly pH (P = .02).Conclusions and Clinical ImportanceIntragastric pH profiles were unpredictable and mostly >4 for >80% of the recording time. This study does not support the indiscriminate administration of acid suppressive treatment.

Alternations of Gastric Microbiota with Mucosal Atrophy and Intestinal Metaplasia

Atrophic gastritis (AG) and intestinal metaplasia (IM) are regarded as precancerous lesions of gastric cancer. Helicobacter pylori (H. pylori) infection is a major cause of AG and IM. Although stomach is a hostile environment for most bacteria, increased microbial diversity with the predominance of Proteobacteria and Actinobacteria is frequently observed in H. pylori-uninfected healthy stomach; however, dysbiosis with H. pylori predominance occurs in individuals with H. pylori-associated active chronic gastritis. H. pylori disappear in cases of severe AG and IM or in an environment with high intragastric pH, and consequently, the microbial diversity increases; however, the bacterial composition of these patients differs from that of the individuals with no history of H. pylori infection. According to previous studies, the relative abundance of Firmicutes, such as Streptococcus, Lactobacillus, and Lactococcus, was increased with mucosal atrophy and metaplasia. Oral cavity flora, such as Fusobacterium and Veillonella as well as nitrosating or nitrate-reducing bacteria, other than H. pylori could increase in individuals with severe AG and IM. Alternations of the gastric microbiota following mucosal atrophy and metaplasia may play a pivotal role in gastric carcinogenesis. Nevertheless, more well-designed studies with larger sample size focusing on the gastric mucosa-associated microbial profiles of H. pylori-negative healthy gastric mucosa, H. pylori-infected gastritis, AG, IM with or without H. pylori, and gastric cancer are necessary in the future. Key words: Helicobacter pylori; Gastritis, atrophic; Intestinal metaplasia; Microbiota

Comparative analysis of the effect of PO administered acid suppressants on gastric pH in healthy cats.

BackgroundProton pump inhibitors (PPIs) are among the most commonly prescribed medications for esophagitis and upper gastrointestinal erosion and ulceration in cats. Newer PPIs such as lansoprazole and esomeprazole are believed to be effective in cats, but the effect of many of these PPIs on gastric pH in cats has not been explored.Hypothesis/ObjectivesTo evaluate the efficacy of PO esomeprazole, dexlansoprazole, and lansoprazole on intragastric pH in healthy cats. We hypothesized that esomeprazole and lansoprazole would provide superior acid suppression compared to dexlansoprazole and reach pH goals extrapolated from people for the treatment of esophagitis and duodenal ulceration.AnimalsTwelve healthy research cats.MethodsRandomized, 3‐way crossover study. Cats were given esomeprazole and lansoprazole at a dosage of 1 mg/kg PO q12h or dexlansoprazole at 6 mg/kg PO q12h. Intragastric pH was recorded at baseline and for 4 days of treatment. Mean pH and the mean percentage time (MPT) intragastric pH was ≥3 or ≥4 were compared among and within treatment groups.ResultsCats treated with lansoprazole had a lower MPT ± SD of intragastric pH ≥3 (8.8 ± 6.8%) and mean ± SD pH (1.6 ± 0.5) than did cats treated with dexlansoprazole (41.2 ± 34.6% and 3.11 ± 1.6, respectively) or esomeprazole (54 ± 33.8% and 4.1 ± 3.9, respectively;P ≤ .04). Esomeprazole was the only treatment that achieved the goals defined for people for the treatment of duodenal ulceration by Day 4 of treatment (MPT ± SD of intragastric pH ≥4 of 77.1 ± 29.2%).Conclusions and Clinical ImportanceOrally administered esomeprazole might be a superior acid suppressant in cats compared to PO lansoprazole or dexlansoprazole.

Comparative study of H.pylori eradication rates of high and frequent dose of Omeprazole and Amoxicillin dual therapy versus standard triple therapy in children

Objectives and Study: With increasing prevalence of clarithromycin and metronidazole resistant H. pylori strains, eradication rates with triple therapy have fallen below 80% worldwide. Unlike that to clarithromycin or metronidazole, H.pylori resistance to amoxicillin(AMO) remains uncommon. AMO is also unique in that its bactericidal effect against H. pylori is time dependent (6-8 h after administration) and can be amplified by increasing the maximum intragastric pH(>6.5) using high-dose proton pump inhibitor( PPI) .High-dose dual therapy, of a PPI and …

Postprandial proximal gastric acid pocket and its association with gastroesophageal acid reflux in patients with short-segment Barrett's esophagus.

To determine the characteristics of postprandial proximal gastric acid pockets (PPGAPs) and their association with gastroesophageal acid reflux in patients with Barrett's esophagus (BE). Fifteen patients with BE (defined by columnar lined esophagus of ≥1 cm) and 15 healthy individuals that were matched for age, gender, and body mass index, were recruited. The fasting intragastric pH and the appearance time, length, lowest pH, and mean pH of the PPGAP were determined using a single pH electrode pull-through experiment. For BE patients, a gastroesophageal reflux disease questionnaire (GerdQ) was completed and esophageal 24-h pH monitoring was carried out. The PPGAP was significantly longer (5 (3, 5) cm vs. 2 (1, 2) cm) and the lowest pH (1.1 (0.8, 1.5) vs. 1.6 (1.4, 1.9)) was significantly lower in patients with short-segment BE than in healthy individuals. The PPGAP started to appear proximally from the gastroesophageal pH step-up point to the esophageal lumen. The acidity of the PPGAP was higher in the distal segment than in the proximal segment. In short-segment BE patients, there were significant correlations between the acidity and the appearance time and length of the PPGAP. The length and acidity of the PPGAP were positively associated with gastroesophageal acid reflux episodes. The acidity of the PPGAP was associated with the DeMeester scores, the GerdQ scores, and the fasting intragastric pH. In patients with short-segment BE, a PPGAP is commonly seen. Its length and acidity of PPGAP are associated with gastroesophageal acid reflux, the DeMeester score, and the GerdQ score in patients with short-segment BE.

The Effect of the Food Matrix on the In Vitro Bio-Accessibility and IgE Reactivity of Peanut Allergens.

Factors such as food processing, the food matrix, and antacid medication may affect the bio-accessibility of proteins in the gastrointestinal tract and hence their allergenic activity. However, at present they are poorly understood. Roasted peanut flour was incorporated into either a chocolate dessert or cookie matrix and bio-accessibility were assessed using an in vitro digestion system comprising a model chew and simulated gastric and duodenal digestion. Protein digestion was monitored by SDS-PAGE and immunoreactivity analyzed by immunoblotting and immunoassay. IgE reactivity was assessed by immunoassay using serum panels from peanut-allergic subjects. Roasted peanut flour proteins proved highly digestible following gastro-duodenal digestion even when incurred into a food matrix, with only low molecular weight polypeptides of Mr < 8kDa remaining. When gastric digestion was performed at pH 6.5 (simulating the effect of antacid medication), peanut proteins are not digested; subsequent duodenal digestion is also limited. IgE reactivity of the major peanut allergens Ara h 1, Ara h 2, and Ara h 6, although reduced, was retained after oral-gastro-duodenal digestion irrespective of digestion conditions employed. Peanut allergen bio-accessibility is unaffected by the dessert or cookie matrices whilst high intra-gastric pH conditions render allergens more resistant to digestion.

Exploring the impact of Crohn's disease on the intragastric environment of fasted adults.

We explored the potential impact of Crohn’s disease on the intragastric environment of fasted adults with a view to potential effects on intragastric performance of orally administered drugs in the fasted state. Data were collected from 15 healthy individuals and 15 patients with Crohn’s disease. All subjects remained fasted for at least 12h prior to gastroscopy. Intragastric resting volume and pH were measured upon aspiration. Osmolality, surface tension, pepsin activity, and content of six bile acids were measured within 4 months upon sample collection. Unlike intragastric volumes, intragastric osmolality was significantly increased by Crohn’s disease. However, mean osmolality value in patients was only slightly higher than in healthy individuals (293 vs. 257 mOsmol/kg, respectively), therefore, unlikely to affect intragastric drug product performance. Primarily due to the high variability of data in healthy individuals, the potential effects on intragastric pH and surface activity could not be evaluated on a statistical basis. However, based on average (mean and median) values, even if they are statistically significant, it seems unlikely to be of clinical significance. Inter-subject variability of pepsin activity, and total bile acids content was high in both the healthy and the patients’ groups. Statistical investigation of the potential impact of Crohn’s disease on these parameters requires prior designation of the minimum differences to be detected; such differences will determine the minimum sample size required of relevant investigations.

The Impact of Gastric Juice pH on the Intraluminal Therapy for Helicobacter pylori Infection.

Background: Helicobacter pylori (H. pylori) can be topically eradicated in stomach lumen on endoscopic examination. The procedures of intraluminal therapy for H. pylori infection (ILTHPI) include the control of intragastric pH, mucolytic irrigation of the gastric mucosal surface, and a single-dose medicament containing antimicrobial agents. Aims: To detect gastric juice pH and evaluate its impact on the success rate of ILTHPI. Methods: We enrolled 324 patients with upper abdominal discomfort for endoscopic examinations. Among them, 13C-urea breath test was positive in 218 patients, where 100 underwent ILTHPI, and negative in 106. All patients had their gastric juice pH detected and set into three ranges, including normal acidity (pH < 4.0), low-level hypoacidity (pH 4.0–5.5), and high-level hypoacidity (pH ≥ 6.0). The impact of gastric juice pH on the success rate of ILTHPI was evaluated. Results: Distribution of pH level showed no significant difference between two groups of H. pylori-infected patients (p = 0.942). The eradication rate of ILTHPI is significantly lower in patients with gastric juice pH below 4 (p < 0.001). Conclusions: Detection of gastric juice pH in ILTHPI is extremely important. Rapid control of stomach pH at or above 4 for patients prior to ILTHPI is strongly recommended. (NCT03124420).

P0863TYPE OF PROTON PUMP INHIBITOR AND RISK OF IRON DEFICIENCY IN RENAL TRANSPLANT RECIPIENTS

Abstract Background and Aims Use of proton-pump inhibitors (PPIs) is common practice in renal transplant recipients (RTRs). Emerging data suggest several adverse effects of use of PPIs, including development of iron deficiency (ID). Although the latter has been shown with respect to PPIs, specific analyses for different types of PPIs and the associated risk of ID have not been performed. Method We used data from the TransplantLines Biobank and Cohort study, an ongoing prospective cohort study among all types of solid organ transplant recipients. For the current study, we used data from stable RTRs with a functional graft for more than 1 year post transplantation (n=795). We excluded RTRs who used any form of iron supplementation (n=54) and EPO-stimulating agents (n=24), resulting in 728 RTRs eligible for analyses. Use of PPIs was subdivided in different types of PPIs, i.e. omeprazole, esomeprazole, pantoprazole, and rabeprazole. ID was defined as TSAT&amp;lt;20% and ferritin &amp;lt;300 µg/L. Logistic regression analysis was used to assess the associations between PPIs and ID. Results We included 728 RTRs (age 56±13 years, 61% males), with a mean eGFR of 53±18 ml/min/1.73m2, a median [interquartile range] ferritin level of 96 (44 – 191) µg/L and mean TSAT of 24±10%. PPIs were used by 504 (69%) of the included RTRs, of which 398 (79%), 55 (11%), 49 (10%), and 2 (0.4%) respectively used omeprazole, pantoprazole, esomeprazole, and rabeprazole. Use of PPIs was strongly associated with ID (OR, 2.20; 95%CI 1.48 – 3.28; P&amp;lt;0.001), independent of adjustment for age, sex, BMI, eGFR, hs-CRP, smoking, alcohol use, use of calcineurine inhibitors, prednisolone, antiplatelet drugs, and antihypertensives. When subdividing the PPIs into the different types, both omeprazole (OR, 1.98; 95%CI 1.39 – 2.83; P&amp;lt;0.001) and esomeprazole (OR, 2.11; 95%CI 1.09 – 4.07; P=0.03) were independently associated with iron deficiency, whereas pantoprazole was not associated (OR, 0.89; 95%CI 0.47 – 1.70; P=0.73). Conclusion Omeprazole and esomeprazole, but not pantoprazole, are associated with an increased risk of ID. Our results are in line with previous reports that pantoprazole has the lowest potency with least increase in intragastric pH, thereby possibly interfering less with reduction of ferric to ferrous iron, and subsequently iron absorption. Future studies are warranted to confirm our present findings.

Pharmacokinetic-Based Drug-Drug Interactions with Anaplastic Lymphoma Kinase Inhibitors: A Review.

Anaplastic lymphoma kinase (ALK) inhibitors are important treatment options for non-small-cell lung cancer (NSCLC), associated with ALK gene rearrangement. Patients with ALK gene rearrangement show sensitivity to and benefit clinically from treatment with ALK tyrosine kinase inhibitors (ALK-TKIs). To date, crizotinib, ceritinib, alectinib, brigatinib, lorlatinib, and entrectinib have received approval from the US Food and Drug Administration and/or the European Medicines Agency for use during the treatment of ALK-gene-rearrangement forms of NSCLC. Although the oral route of administration is convenient and results in good compliance among patients, oral administration can be affected by many factors, such as food, intragastric pH, cytochrome P450 enzymes, transporters, and p-glycoprotein. These factors can result in increased risks for serious adverse events or can lead to reduced therapeutic effects of ALK-TKIs. This review characterizes and summarizes the pharmacokinetic parameters and drug–-drug interactions associated with ALK-TKIs to provide specific recommendations for oncologists and clinical pharmacists when prescribing ALK-TKIs.

Omeprazole vs Lansoprazole in the Management of Gastroesophageal Reflux Disease: A Systematic Literature Review

Objective: To evaluate the effectiveness and safety of omeprazole compared to lansoprazole in Gastroesophageal reflux disease patients (GERD).&#x0D; Methods: A systematic search of MEDLINE, EMBASE (inception to December 2019) and CENTRAL (January 2011 to December 2019) was conducted to identify the relevant articles. A detailed inclusion-exclusion criterion was developed and implemented to screen the abstracts. Full texts of the selected abstracts were then assessed to establish their inclusion or exclusion in our review. Cochrane risk of bias criterion was used to assess the methodological quality of the included studies. All relevant data were extracted and the results were summarised narratively.&#x0D; Results: 9 studies met our inclusion-exclusion criteria and were included in this review. In all three trials reporting on heartburn and regurgitation, both omeprazole and lansoprazole were found to be effective in relieving the symptoms of heartburn and regurgitation; however, there was no evidence that one is better than the other. Five out of six studies reporting on intragastric pH provided the evidence of omeprazole’s superiority over lansoprazole in controlling gastric pH. Omeprazole lowered intragastric pH faster and the results lasted longer compared to lansoprazole. The results were statistically significant.&#x0D; Conclusion: There is no significant difference in the clinical effectiveness of omeprazole and lansoprazole in relieving symptoms of heartburn and regurgitation. However, omeprazole is more effective in reducing gastric acidity than lansoprazole.

Comparison of the effects of esomeprazole 40 mg, rabeprazole 20 mg, lansoprazole 30 mg, and pantoprazole 40 mg on intragastrıc pH in extensive metabolizer patients with gastroesophageal reflux disease.

Studies on the therapeutic efficacy of proton pump inhibitors (PPIs) in patients with gastroesophageal reflux disease (GERD) have been recently published. In most of these studies, comparison of only two PPIs have been made. There are few studies on the comparison of four or more PPIs. We aimed to compare the acid inhibitory effects of esomeprazole 40 mg, rabeprazole 20 mg, lansoprazole 30 mg, and pantoprazole 40 mg on days 1 and 5 of treatment in patients with GERD, who were extensive metabolizers in regard to the CYP2C19 genotype. Helicobacter pylori-negative with typical symptoms of GERD patients were randomly divided into four treatment groups. Efficacy analysis on days 1 and 5 were performed on the four groups which comprised 10 (esomeprazole), 11 (rabeprazole), 10 (lansoprazole), and 10 (pantoprazole) patients. On day 1 of PPI treatment, the mean percentage of time with intragastric Ph>4 were 54%, 58%, 60%, and 35% for the groups, respectively, and on day 5, these values were 67%, 60%, 68%, and 59%, respectively. Esomeprazole, rabeprazole, and lansoprazole were found to be superior to pantoprazole on the first day of treatment. Pantoprazole is a less potent proton pump inhibitor than the other PPIs tested on the first day of treatment. When the time needed to raise the intragatric pH to over 4 was evaluated, esomeprazole was found to have the most rapid action, followed by lansoprazole and rabeprazole.

The Ameliorating Effect of Switching to Vonoprazan: A Novel Potassium-Competitive Acid Blocker in Patients with Proton Pump Inhibitor Refractory Non-Erosive Reflux Disease

Introduction: Weakly acidic reflux has been reported to be the major cause of symptoms in patients with proton pump inhibitor (PPI)-refractory nonerosive reflux disease (NERD) undergoing PPI treatment. We previously reported that reflux at pH 4–5 was the main factor that induced symptoms in such patients. The present study aimed to elucidate the symptom-ameliorating effect of vonoprazan (VPZ) by evaluating the change in the pH value of the refluxate using multichannel intraluminal impedance and pH (MII-pH) monitoring. Methods: We retrospectively evaluated the records of MII-pH monitoring in 29 symptom index (SI) and/or symptom association probability (SAP)-positive patients with PPI-refractory NERD. After switching to VPZ 20 mg/day, we performed MII-pH monitoring again. We assessed the change in the score of the frequency scale for the symptoms of gastroesophageal reflux disease (FSSG), the pH value of the refluxate, and the percent times of intragastric pH <4 or <5 before and after switching. We divided the patients into the following 2 groups according to the FSSG score after switching: effective and noneffective groups. Results: Among of the 29 SI/SAP-positive patients, 16 underwent switching to VPZ. Furthermore, of these 16 patients, 10 underwent MII-pH monitoring again after switching. The FSSG score decreased, the pH value of the refluxate increased, and the percent times of intragastric pH <4 or <5 reduced after switching when compared with the findings before switching. In the effective group, both the proportion of reflux at pH <4 and that of reflux at pH 4–5 decreased while taking VPZ when compared with the findings while taking double-dose PPI. In the noneffective group, the proportion of reflux at pH <4 decreased but that of reflux at pH 4–5 increased and that of reflux at pH <5 did not change overall while taking VPZ. In addition, the percent times of intragastric pH <5 values were low in the effective group. Conclusion: Symptom suppression appears to be inadequate in patients with persistent reflux at pH 4–5 even with VPZ 20 mg/day. Strong acid suppressive therapy with VPZ to increase the pH value of the refluxate to ≥5 is useful for symptom improvement.

Comparative analysis of the effect of IV administered acid suppressants on gastric pH in dogs.

BackgroundUpper gastrointestinal (GI) ulceration and bleeding in critically ill dogs can cause severe anemia and increase morbidity. Acid suppressants using proton pump inhibitors or histamine‐2 receptor blockers administered IV is commonly recommended.Hypothesis/ObjectivesTo evaluate the efficacy of IV administered esomeprazole, pantoprazole, and famotidine constant rate infusion (CRI) on increasing the intragastric pH of dogs. We hypothesized that esomeprazole and famotidine CRI would provide superior acid suppression compared to pantoprazole and reach pH goals for the treatment of GI bleeding.AnimalsNine healthy research Beagles.MethodsRandomized, 3‐way crossover. Dogs received pantoprazole or esomeprazole at 1 mg/kg IV q12h and famotidine with a loading dose of 1 mg/kg followed by 8 mg/kg IV CRI daily for 3 consecutive days. The intragastric pH was recorded at baseline and for 72 hours of treatment. The mean pH and the mean percentage time (MPT) the intragastric pH was ≥3 or ≥4 were compared among and within treatment groups.ResultsSignificant increases in mean pH (P < 0.0001), MPT ≥3 (P < 0.001), and MPT ≥4 (P = 0.0006) were noted over time with all 3 treatments. The time effect did not differ by treatment for mean pH, MPT ≥3, and MPT ≥4 (P = .29, .56, and .37, respectively); however, only esomeprazole and famotidine CRI achieved the goals established for the treatment of gastroduodenal ulceration in people.Conclusions and Clinical ImportanceFamotidine CRI and esomeprazole might be superior acid suppressants compared to standard doses of pantoprazole for the first 72 hours of treatment.

Intragastric pH in non-feeding or feeding horses with omeprazole treatment

Intragastric pH in non-feeding or feeding horses with omeprazole treatment

Feasibility of gastric endoscopic submucosal dissection without using proton pump inhibitor injection: a propensity score analysis.

Purpose: Endoscopic submucosal dissection is a promising method for the resection of superficial gastric neoplasms. To date, several institutions have used proton pump inhibitor injections over the perioperative period. However, there is very little evidence regarding their efficacy. To overcome this limitation, we compared procedural outcomes and the prevention of adverse events of proton pump inhibitor injection with an orally administered active potassium-competitive acid blocker alone.Participants and Methods: We enrolled a total of 150 patients treated for superficial gastric neoplasms at a single institution between April 2015 and December 2018. Patients treated for 2 days with proton pump inhibitor injections following 12 days of oral potassium-competitive acid blocker (proton pump inhibitor group=80) were compared with patients treated for 14 days orally with potassium-competitive acid blocker alone (potassium-competitive acid blocker group=70) using propensity score analysis. We evaluated intragastric pH levels prior to endoscopic submucosal dissection, frequency of intraoperative major bleeding, procedure time, en bloc resection rate, curability, ulcer reduction rate 14 days after endoscopic submucosal dissection, and adverse events (including perforation and postoperative bleeding).Results: Propensity score analysis yielded 43 matched pairs. The comparison demonstrated similar values for the outcomes. For all cases, we observed intragastric pH levels >6.4 prior to endoscopic submucosal dissection. Postoperative bleeding rates were 2.3% (1/43) in the proton pump inhibitor group and 0.0% (0/43) in the potassium-competitive acid blocker group (P=0.315).Conclusions: Oral potassium-competitive acid blocker alone was as effective as proton pump inhibitor injection, with a low incidence of adverse events. Based on these results, proton pump inhibitor injection might be omitted during gastric endoscopic submucosal dissection.

Temporal changes in postprandial intragastric pH: Comparing measurement methods, food structure effects, and kinetic modelling

Intragastric pH greatly affects food disintegration and the release of nutrients in the gut. Here, the behaviour of two liquid meals (soymilk, pea emulsion) and two solid meals (tofu, seitan) was tested in miniature pigs fitted with gastric cannula. For 5 h, intragastric pH was recorded using one of three methods: ex vivo measurements of chyme samples, in situ measurements using pH catheters, or in situ measurements using wireless pH capsules, both inserted through a pig's cannula. The pH values obtained with the two in situ methods were highly correlated. The liquid and solid foods yielded distinct pH kinetics. For the solids, pH simply decreased exponentially. For the liquids, pH increased rapidly and then plateaued for 2 h before dropping Food macrostructure and, to a lesser extent, food buffering capacity clearly had an impact on intragastric pH. We modelled changes in intragastric pH over time with food-dependent nonlinear equations.

Comparison of the gastric acid inhibition function among lansoprazole, pantoprazole, and their respective stereoisomers in healthy Chinese subjects .

This study was conducted to evaluate the difference in acid inhibition function among lansoprazole (LPZ), pantoprazole (PPZ), and their respective stereoisomers following single and multiple intravenous doses in healthy Chinese subjects. The dosage groups were set as follows: 30mg single and multiple intravenous administrations of LPZ or R-LPZ, 40mg single and multiple intravenous administrations of PPZ or S-PPZ. Subjects received an intravenous infusion of LPZ, R-LPZ, PPZ, or S-PPZ injection in sterile saline solution (100mL/h, 60minutes), respectively. The intragastric pH was sampled every second for 24 hours at baseline and for 24 hours after drug administration. The baseline-adjusted pharmacodynamic (PD) parameters include ΔMean (pH), ΔMedian (pH), ΔTpH≥3 (%), ΔTpH≥4 (%), ΔTpH≥6 (%), and ΔAUECph-tτ1-τ2. The PD parameters were evaluated in different time intervals (0-24 hours, 0-4 hours and 14-24 hours). After a single dose, the ΔTpH≥4 (%) of R-LPZ, LPZ, S-PPZ and PPZ was 56.6 ± 19.6, 53.1 ± 23.3, 35.6 ± 24.9 and 26.8 ± 30.2, respectively. The ΔTpH≥6 (%) was 50.7 ± 26.1, 41.4 ± 26.2, 25.4 ± 24.9 and 22.1 ± 27.6, respectively. The ΔAUECph-τ1-τ was 45,564 ± 16,107, 41,798 ± 16,153, 31,914 ± 17,304 and 20,744 ± 21,500, respectively. Statistically significant differences were found with R-LPZ vs. S-PPZ, R-LPZ vs. PPZ, LPZ vs. S-PPZ and LPZ vs. PPZ. The average TpH≥4 of R-LPZ, LPZ, S-PPZ, and PPZ was (47.2 ± 26.1) minutes, (49.6 ± 19.3) minutes, (56.1 ± 23.7) minutes, and (72.1 ± 27.3) minutes, respectively. Statistically significant differences were found with R-LPZ vs. PPZ (p=0.009) and LPZ vs. PPZ (p=0.019). After multiple doses, the ΔTpH≥4 (%) of R-LPZ, LPZ, S-PPZ, and PPZ was 71.7 ± 20.2, 63.5 ± 19.4, 59.5 ± 17.8 and 64.0 ± 22.4, respectively. The ΔTpH≥6 (%) was 64.0 ± 22.2, 52.0 ± 19.2, 49.6 ± 20.4 and 50.9 ± 23.8, respectively. The ΔAUECph-τ1-τ was 326,149 ± 94,839, 288,565 ± 93,279, 296,189 ± 83,412 and 300,960 ± 108,057, respectively. No statistically significant differences were found in baseline-adjusted PD parameters during all time periods after multiple doses. After a single dose, the mean gastric pH inhibition value of R-LPZ was the highest, followed by LPZ, then S-PPZ and PPZ. R-LPZ and LPZ provided significantly better pH control compared with PPZ and S-PPZ in healthy subjects. The onset time of R-LPZ was the fastest and R-LPZ can provide better acid inhibition during sleeping time. After multiple doses, the mean values in all PD parameters of R-LPZ were the highest, the values of LPZ, S-PPZ, and PPZ were similar. However, no significant difference was found in acid inhibition among these four drugs after multiple doses.