Effect of Helicobacter pylori status on intragastric pH during treatment with omeprazole

Predicting Surface pH in Unbuffered Conditions for Acids, Bases, and Their Salts - A Review of Modeling Approaches and Their Performance

Dissolution of ionizable drugs and their salts is a function of drug surface solubility driven by the surface pH, i.e., the microenvironmental pH at the solid/liquid interface, which will deviate from bulk pH when there is an acid-base reaction occurring at the solid/liquid interface. In this work, we first present a brief overview of the modeling approaches available in the literature, classified according to the rate-determining step assumed in the dissolution process. In the second part, we present and evaluate the prediction performance of two different modeling approaches for surface pH. The first method relies only on thermodynamic equilibria, while the second method accounts for transport phenomena of charged compounds through the diffusional boundary layer using the Nernst - Planck equation. Model outcomes are compared with experimental data taken from the literature and obtained during this work. In terms of surface pH predictions, the models provide identical values for weak acids or weak bases. The models' outcomes for bases are in good agreement with experimental data in acidic conditions (bulk pH 1-4), while overpredictions are observed in the 5-7 bulk pH range in a system-dependent manner. Deviations can be related to the effect of surface dissolution (also referred to as surface reaction), which may become a controlling mechanism and slow the replenishment of the unionized drug at the surface of the crystal. Surface pH predictions for acids are generally in good agreement with experiments, with a slight underestimation for some drug examples, which could be related to errors in intrinsic solubility determination or to the assumption of thermodynamic equilibrium at the surface of the drug. A good agreement is also observed for salts with the thermodynamic model except for mesylate salts, suggesting that other phenomena, not currently included in the thermodynamic equilibrium model, may determine the surface pH.

Vonoprazan versus lansoprazole in erosive esophagitis - A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Proton-pump inhibitors (PPIs) are the mainstay of treatment in erosive esophagitis (EE). An alternative to PPIs in EE is Vonoprazan, a potassium competitive acid blocker. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing vonoprazan to lansoprazole.

METHODS

Multiple databases searched through November 2022. Meta-analysis was performed to assess endoscopic healing at two, four and eight weeks, including for patients with severe EE (Los Angeles C/D). Serious adverse events (SAE) leading to drug discontinuation were assessed. The quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology.

RESULTS

Four RCTs with 2208 patients were included in the final analysis. Vonoprazan 20 mg once-daily was compared to lansoprazole 30 mg once-daily dosing. Among all patients, at two and eight weeks post-treatment, vonoprazan resulted in significantly higher rates of endoscopic healing as compared to lansoprazole, risk ratios (RR) 1.1, p<0.001 and RR 1.04, p=0.03. The same effect was not observed at four weeks, RR 1.03 (CI 0.99-1.06, I2=0%) following therapy. Among patients with severe EE, vonoprazan resulted in higher rates of endoscopic healing at two weeks, RR 1.3 (1.2-1.4, I2=47%), p=<0.001, at four weeks, RR 1.2 (1.1-1.3, I2=36%), p=<0.001 and at eight weeks post-treatment, RR 1.1 (CI 1.03-1.3, I2=79%), p=0.009. We found no significant difference in the overall pooled rate of SAE and pooled rate of adverse events leading to drug discontinuation. Finally, the overall certainty of evidence for our main summary estimates was rated as high (grade A).

CONCLUSION

Based on limited number of published non-inferiority RCTs, our analysis demonstrates that among patients with EE, vonoprazan 20 mg once-daily dosing achieves comparable and in those with severe EE, higher endoscopic healing rates as compared to lansoprazole 30 mg once-daily dosing. Both drugs have a comparable safety profile.

Vonoprazan Versus Lansoprazole for Healing and Maintenance of Healing of Erosive Esophagitis: A Randomized Trial

BACKGROUND & AIMS

For decades, proton pump inhibitors (PPIs) have been the mainstay of treatment for erosive esophagitis. The potassium-competitive acid blocker vonoprazan provides more potent acid inhibition than PPIs, but data on its efficacy for erosive esophagitis are limited.

METHODS

Adults with erosive esophagitis were randomized to once-daily vonoprazan, 20 mg, or lansoprazole, 30 mg, for up to 8 weeks. Patients with healing were rerandomized to once-daily vonoprazan, 10 mg, vonoprazan, 20 mg, or lansoprazole, 15 mg, for 24 weeks. Primary end points, percentage with healing by week 8 endoscopy, and maintenance of healing at week 24 endoscopy, were assessed in noninferiority comparisons (noninferiority margins, 10%), with superiority analyses prespecified if noninferiority was demonstrated. Analyses of primary and secondary end points were performed using fixed-sequence testing procedures.

RESULTS

Among 1024 patients in the healing phase, vonoprazan was noninferior to lansoprazole in the primary analysis and superior on the exploratory analysis of healing (92.9 vs 84.6%; difference, 8.3%; 95% confidence interval [CI], 4.5%-12.2%). Secondary analyses showed vonoprazan was noninferior in heartburn-free days (difference, 2.7%; 95% CI, -1.6% to 7.0%), and superior in healing Los Angeles Classification Grade C/D esophagitis at week 2 (difference, 17.6%; 95% CI, 7.4%-27.4%). Among 878 patients in the maintenance phase, vonoprazan was noninferior to lansoprazole in the primary analysis and superior on the secondary analysis of maintenance of healing (20 mg vs lansoprazole: difference, 8.7%; 95% CI, 1.8%-15.5%; 10 mg vs lansoprazole: difference, 7.2%; 95% CI, 0.2%-14.1%) and secondary analysis of maintenance of healing Grade C/D esophagitis (20 mg vs lansoprazole: difference, 15.7%; 95% CI, 2.5%-28.4%; 10 mg vs lansoprazole: difference, 13.3%; 95% CI, 0.02%-26.1%).

CONCLUSIONS

Vonoprazan was noninferior and superior to the PPI lansoprazole in healing and maintenance of healing of erosive esophagitis. This benefit was seen predominantly in more severe erosive esophagitis. (ClinicalTrials.gov: NCT04124926).

Pharmacokinetics and Pharmacodynamics of Esomezol DR, a New Dual Delayed-Release Formulation of Esomeprazole 20 Mg or 40 Mg, in Healthy Subjects

Background

Esomeprazole, a proton pump inhibitor (PPI), is widely used to treat acid-related disorders, but it has short plasma half-life which can cause insufficient gastric acid suppression, such as nocturnal acid breakthrough. A new dual delayed-release (DR) formulation of esomeprazole (Esomezol DR), was developed to extend the duration of gastric acid suppression.

Purpose

This study aimed to evaluate the pharmacokinetics (PKs) and pharmacodynamics (PDs) of esomeprazole for the DR formulation compared to a conventional enteric-coated (EC) formulation (Nexium) in healthy male subjects.

Methods

Two randomized, open-label, multiple-dose, two-way crossover studies with esomeprazole 20 mg and 40 mg were conducted. Subjects received the DR formulation or the EC formulation once daily for 7 days in each period with a 7-day washout. Serial blood samples were collected up to 24 hours after the 1st dose, and 24-hour intragastric pH was continuously monitored before the 1st dose as baseline and after the 1st and the 7th dose.

Results

In 20 mg and 40 mg dose groups, 38 and 44 subjects completed the study, respectively. The DR formulation exhibited the dual-release pattern of esomeprazole, resulting in more sustained plasma concentration-time profiles compared to the EC formulation. The systemic exposure of esomeprazole for the DR formulation was comparable to that for the EC formulation, showing the similar area under the plasma concentration-time curve. The 24-hour gastric acid suppression was also similar between the two formulations, while the inhibition during night-time (22:00-06:00) showed a better tendency in the DR formulation.

Conclusion

The sustained exposure of esomeprazole in the DR formulation led to well-maintained and higher acid inhibition compared to the EC formulation, especially during the night-time. These results suggest that the DR formulation can be an alternative formulation to the conventional EC formulation, expecting the potential of relieving nocturnal acid-related symptoms.

Pharmacokinetics and Pharmacodynamics of YYD601, a Dual Delayed-Release Formulation of Esomeprazole, Following Single and Multiple Doses in Healthy Adult Volunteers Under Fasting and Fed Conditions

Background

YYD601 was developed as a novel dual delayed release (DDR) formulation of esomeprazole to prolong the plasma esomeprazole concentration and extend the duration of acid suppression.

Purpose

The pharmacokinetic (PK) and pharmacodynamics (PD) characteristics of YYD601 after single and multiple oral administrations were investigated in healthy Korean adults under fasting and fed conditions, and compared with the original esomeprazole capsule.

Methods

In the single-center, randomized, open-label, parallel-design, two-period study, thirty two volunteers were enrolled into four dosing groups, including esomeprazole 40-mg (group A), YYD60130-mg (group B), YYD601 40-mg (group C), and YYD601 60-mg (group D) once daily for 5 days. Blood samples were collected for PK analysis, before and up to 24 h after dosing. For PD characteristics of YYD601, the percentages of time with intragastric pH > 4 over a 24-h period and during night-time following multiple oral administrations were evaluated.

Results

A total of 27 subjects completed the study. YYD601 showed a dual-peak PK profile under fasting condition, with delayed T_max, compared with conventional formulation. There were no significant differences in the AUC values adjusted for dose between the three YYD601 dosage groups and the conventional esomeprazole 40 mg. The esomeprazole AUC following single and multiple administration decreased with food intake by approximately 33%. YYD601 showed a linear pharmacokinetic profile in the dose range studied. There was no statistically significant difference in increase in mean percentage of time with intragastric pH > 4 for 24-hour and during night-time between the three different doses of YYD601 and the conventional formulation. The treatments were well-tolerated during the study and no serious adverse events were observed.

Conclusion

YYD601 30 mg has a comparable effect on gastric acid inhibition as conventional esomeprazole 40 mg following once daily oral administration. Single and multiple oral dosing of YYD601 up to 60 mg were safe and well-tolerated throughout the study.

Clinical Trial Registry

http://clinicaltrials.gov, NCT03558477 (date of registration: June 15, 2018; study period: between October 2017 and February 2018).

Proton Pump Inhibitors and Gastric Cancer

Concerns have been raised regarding the long-term use of proton pump inhibitors (PPIs) as an important risk factor for gastric cancer in clinical practice. PPIs can cause hypergastrinemia at clinical doses, and hypergastrinemia has been reported to induce malignant neoplasms in the stomach in previous animal studies. In humans, the proliferation of enterochromaffin-like (ECL) cells induced by hypergastrinemia is suspected as a potential mechanism of gastric cancer. Meanwhile, persistent Helicobacter pylori (H. pylori) infection causes gastric atrophic change, which itself is a major cause of gastric cancer, and it can further increase the risk of gastric cancer by strengthening corpus atrophy through interaction with PPIs. Recent epidemiologic studies have reported an important link between long-term PPI intake and gastric cancer risk even after successful eradication of H. pylori. However, due to the methodological limitations of observational clinical studies, the causal relationship is still not clear, and a recent big data-based study reported that long-term PPI use was not related to gastric cancer incidence. Taken together, despite the potential detrimental effects of PPIs, it is currently difficult to draw a definite conclusion about its association with gastric cancer. To minimize the possibility of gastric cancer in H. pylori-infected patients or precancerous lesions in long-term PPI users, long-term PPI administration should be limited to the minimum effective dose, and antibacterial treatment for H. pylori should be considered.

Use of Proton Pump Inhibitors vs Histamine 2 Receptor Antagonists for the Risk of Gastric Cancer: Population-Based Cohort Study

INTRODUCTION

Proton pump inhibitors (PPIs) are commonly prescribed medications. Long-term use of PPIs has been suspected to have a provocative effect on gastric cancer. This study was to determine the association between PPI vs histamine 2 receptor antagonist (H2RA) use and the risk of gastric cancer in a region where the risk of this malignancy is high.

METHODS

A population-based cohort study using the Korean National Health Insurance Services Database. The participants with first prescription of PPIs and H2RA with normal esophagogastroduodenoscopy finding from 2004 through 2015 were collected. Among them, 50% of participants were systematic stratified randomly sampled. There were 122,118 users of PPIs or H2RAs who use medication more than cumulative defined daily dose of 180 days. The users were followed up from long-term use threshold until gastric cancer, death from non-gastric cancer cause, gastric surgery, or study end (December 2017).

RESULTS

After calculating propensity score weights, we included 39,799 PPI and 38,967 H2RA users. Among the new PPI and H2RA users, we identified 411 cases of incident gastric cancer from 182,643 person-years of follow-up observation and 397 cases from 178,846 person-years of follow-up observation, respectively. Compared with H2RA users, PPI users did not experience significantly different gastric cancer incidence (adjusted hazard ratio, 1.01; 95% confidence interval, 0.88-1.16; P = 0.89). Sensitivity analyses confirmed that gastric cancer incidence did not differ between PPI and H2RA users.

DISCUSSION

In this large study, long-term treatment with PPIs vs H2RAs did not show higher risk of gastric cancer even in a high-risk region.

Relationship between long-term use of proton pump inhibitors and risk of gastric cancer: A systematic analysis

BACKGROUND AND AIM

This study aims to systematically analyze the effect of long-term therapy with proton pump inhibitors (PPIs) on the risk of gastric cancer.

METHODS

PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure (CNKI), and China biomedical literature database (CBM) were searched for studies before February 2019. We evaluated the quality of the included articles through the Newcastle-Ottawa Scale and gathered relevant data to calculate the pooled odds ratio (OR) through Stata14.0.

RESULTS

Seven relevant articles conformed to the inclusion criteria; 943 070 patients were included. The pooled OR was 2.50; 95% CI (1.74, 3.85); the subgroup analysis results showed that patients who had used PPIs for more than 36 months were most likely to develop gastric cancer, and an increased risk was observed among patients after Helicobacter pylori eradication. Noncardia gastric cancer was more likely to develop.

CONCLUSIONS

Long-term use of PPIs can possibly increase the risk of gastric cancer even among patients after H. pylori eradication; in particular, for noncardia gastric cancer, the risk increases with longer durations of PPI use. Due to the limited number of studies, more high-quality studies are required to be designed.

Long-term use of proton-pump inhibitors and risk of gastric cancer: a review of the current evidence

Gastric cancer remains one of the leading cancers in the world with a high mortality, particularly in East Asia. Helicobacter pylori infection accounts for the majority of the noncardia gastric cancers by triggering gastric inflammation and subsequent neoplastic progression. Eradication of H. pylori can reduce, but not totally eliminate, subsequent risk of developing gastric cancer. Proton-pump inhibitors (PPIs) are one of the most widely prescribed medications worldwide. With their profound gastric-acid suppression, there are concerns about a possible carcinogenic role in gastric cancer, due to induced hypergastrinemia, gastric atrophy and bacterial overgrowth in the stomach. While randomized clinical trials to establish causality between long-term PPI use and gastric cancer are lacking, current evidence based on observational studies suggests PPIs are associated with an increased gastric cancer risk. However, opinions on causality remain divergent due to unmeasured and possible residual confounding in various studies. Our recent study has showed that even after H. pylori eradication, long-term PPI use is still associated with an increased risk of gastric cancer by more than twofold. Hence, long-term PPIs should be used judiciously after considering individual's risk-benefit profile, particularly among those with history of H. pylori infection. Further well-designed prospective studies are warranted to confirm the potential role of PPIs in gastric cancer according to baseline gastric histology and its interaction with other chemopreventive agents like aspirin, statins and metformin.

Proton pump inhibitor-refractory gastroesophageal reflux disease: challenges and solutions

A significant percentage of patients with gastroesophageal reflux disease (GERD) will not respond to proton pump inhibitor (PPI) therapy. The causes of PPI-refractory GERD are numerous and diverse, and include adherence, persistent acid, functional disorders, nonacid reflux, and PPI bioavailability. The evaluation should start with a symptom assessment and may progress to imaging, endoscopy, and monitoring of esophageal pH, impedance, and bilirubin. There are a variety of pharmacologic and procedural interventions that should be selected based on the underlying mechanism of PPI failure. Pharmacologic treatments can include antacids, prokinetics, alginates, bile acid binders, reflux inhibitors, and antidepressants. Procedural options include laparoscopic fundoplication and LINX as well as endoscopic procedures, such as transoral incisionless fundoplication and Stretta. Several alternative and complementary treatments of possible benefit also exist.

A novel K+ competitive acid blocker, YH4808, sustains inhibition of gastric acid secretion with a faster onset than esomeprazole: randomised clinical study in healthy volunteers

BACKGROUND

YH4808, a K⁺ -competitive acid blocker, is under clinical development for the treatment of acid-related disorders, such as gastroesophageal reflux disease.

AIMS

To determine the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of YH4808, compared to placebo and esomeprazole.

METHODS

This double-blind, randomised, placebo- and active comparator (esomeprazole)-controlled study was conducted with 123 healthy male volunteers. We evaluated YH4808 (30-800 mg) properties, administered in single (N=55) and multiple (N=24) oral doses, and recorded the effects on 24-hour intragastric acidity. Results were compared to placebo (N=20) and esomeprazole 40 mg (N=24).

RESULTS

Plasma YH4808 exposure increased dose-proportionally and declined in a multi-phasic manner. YH4808 ≥200 mg/d maintained intragastric acidity at pH >4 for longer times than esomeprazole during both day and night (%Time at pH >4: >70% vs 58% of a 24-hour period, respectively; and >50% vs 33% of a 9-hour night respectively). A twice-daily regimen of YH4808 more effectively controlled intragastric pH at night than a once-daily regimen. In evaluating the mean areas under the intragastric pH-time curves in 15-minute intervals for 2 hours after dosing, we found that YH4808 had a faster onset than esomeprazole. Moreover, unlike esomeprazole, YH4808 PK and PD were not significantly affected by the CYP2C19 genotype of the subjects. YH4808 was well-tolerated at all doses administered.

CONCLUSION

This study showed that YH4808 produced a rapid, sustained suppression of gastric secretion with good tolerability. The results at YH4808 ≥200 mg/d provide a rationale for further clinical investigations in populations with acid-related diseases.

Acid Inhibitory Effect of a Combination of Omeprazole and Sodium Bicarbonate (CDFR0209) Compared With Delayed-Release Omeprazole 40 mg Alone in Healthy Adult Male Subjects

CDFR0209, a combination of an immediate-release formulation of omeprazole 40 mg and sodium bicarbonate 1100 mg, has been developed to treat acid-related disorders. We compared the acid inhibitory effects of CDFR0209 and delayed-release omeprazole (omeprazole-DR, Losec 40 mg) after repeated dosing in Helicobacter pylori-negative healthy adult male subjects. In this 2-period crossover study, 30 subjects were randomized to CDFR0209 or omeprazole-DR daily for 7 days. An ambulatory continuous 24-hour intragastric pH recording was performed at baseline and on days 1 and 7 of each administration period. Integrated gastric acidity was calculated from time-weighted average hydrogen ion concentrations at each hour of the 24-hour record. An analysis of variance model was used to test the pharmacodynamic equivalence of CDFR0209 and omeprazole-DR, using the natural logarithmic transformation of the percent decrease from baseline in integrated gastric acidity for the 24-hour interval after the seventh dose of each omeprazole formulation. The geometric least-squares mean ratios (CDFR0209/omeprazole-DR) of the percent decrease from baseline in integrated gastric acidity was 0.98 (90%CI, 0.93-1.07). Both CDFR0209 and omeprazole-DR are equally effective in decreasing integrated gastric acidity at steady state.

Use of Proton Pump Inhibitors and Risks of Fundic Gland Polyps and Gastric Cancer: Systematic Review and Meta-analysis

BACKGROUND & AIMS

There have been increasing numbers of case reports and observational studies of adverse events in patients receiving long-term therapy with proton pump inhibitors (PPIs). The effects of PPI therapy on risks of fundic gland polyps (FGPs) and gastric cancer have received considerable attention. We performed a systematic review with a meta-analysis of randomized controlled trials and observational studies that assessed these risks.

METHODS

We searched the PUBMED, EMBASE, and Cochrane Central Register of Controlled Trials databases for relevant studies published through July 2015. We calculated pooled odds ratio for FGPs and the risk ratio for gastric cancer in PPI users compared with PPI nonusers using fixed- and random-effects models.

RESULTS

We analyzed data from 12 studies, comprising more than 87,324 patients: 1 randomized controlled trial reporting the effect of PPIs on gastric polyps (location not specified), 6 cohort and 1 case-control studies on FGPs, and 1 cohort and 3 case-control studies on gastric cancer. Pooled odds ratios for FGPs were 1.43 (95% confidence interval, 1.24-1.64) and 2.45 (95% confidence interval, 1.24-4.83) from fixed- and random-effects models, respectively. The pooled risk ratio for gastric cancer was 1.43 (95% confidence interval, 1.23-1.66) from each model. We observed significant heterogeneity among studies reporting on FGPs, but not among studies reporting on gastric cancer.

CONCLUSIONS

Based on a systematic review with meta-analysis, long-term use of PPIs (≥12 months) is associated with an increased risk of FGPs. PPI therapy might also increase the risk of gastric cancer, but this association could be biased, because of the limited number of studies and possible confounding factors.

Pharmacokinetic and Pharmacodynamic Modeling Analysis of Intravenous Esomeprazole in Healthy Volunteers

Esomeprazole is one of the most commonly used drugs to treat gastroesophageal reflux disease and peptic ulcers, but the quantitative relationships among the pharmacokinetics (PK), pharmacodynamics (PD), and pharmacogenomics (PG) of the drug are not fully understood in special patient populations. A clinical PK/PD/PG study of intravenous (IV) esomeprazole in 5 dosing regimens was conducted in 20 healthy Chinese volunteers, who were categorized into Helicobacter pylori (HP)-negative and HP-positive subgroups. Plasma esomeprazole concentration and intragastric H(+) concentration were monitored for 24 hours postdosing. Population PK (PopPK) models were tested based on elimination characteristics and other data. For a single-dose IV esomeprazole regimen, a 2-compartment model with nonlinear elimination characteristics fitted the PK data well. The elimination of esomeprazole was found to be significantly linked to CYP2C19 genotype by 11% to 29%. A mechanism-based PD model was first tested to mimic the irreversible inhibition of H(+) /K(+) -ATPase by esomeprazole using a cell-killing mechanism and models of gastric H(+) secretion that included the effects of an asymmetric circadian rhythm and food effects. Results from this PD model showed that the turnover rate of H(+) /K(+) -ATPase was significantly different between HP-negative and HP-positive subgroups. In conclusion, the PopPK model quantitatively identified the effects of the CYP2C19 genotype on esomeprazole elimination in healthy subjects for the first time. In addition, the effects of HP status on drug effect, H(+) /K(+) -ATPase turnover, and circadian rhythm amplitude were preliminarily explored using a mechanism-based PD model.

A toolkit of thread-based microfluidics, sensors, and electronics for 3D tissue embedding for medical diagnostics

Threads, traditionally used in the apparel industry, have recently emerged as a promising material for the creation of tissue constructs and biomedical implants for organ replacement and repair. The wicking property and flexibility of threads also make them promising candidates for the creation of three-dimensional (3D) microfluidic circuits. In this paper, we report on thread-based microfluidic networks that interface intimately with biological tissues in three dimensions. We have also developed a suite of physical and chemical sensors integrated with microfluidic networks to monitor physiochemical tissue properties, all made from thread, for direct integration with tissues toward the realization of a thread-based diagnostic device (TDD) platform. The physical and chemical sensors are fabricated from nanomaterial-infused conductive threads and are connected to electronic circuitry using thread-based flexible interconnects for readout, signal conditioning, and wireless transmission. To demonstrate the suite of integrated sensors, we utilized TDD platforms to measure strain, as well as gastric and subcutaneous pH in vitro and in vivo.

An Appropriate Cutoff Value for Determining the Colonization of Helicobacter pylori by the Pyrosequencing Method: Comparison with Conventional Methods

BACKGROUND

Sequencing of 16S ribosomal RNA (rRNA) gene has improved the characterization of microbial communities. It enabled the detection of low abundance gastric Helicobacter pylori sequences even in subjects that were found to be H. pylori negative with conventional methods. The objective of this study was to obtain a cutoff value for H. pylori colonization in gastric mucosa samples by pyrosequencing method.

MATERIALS AND METHODS

Gastric mucosal biopsies were taken from 63 subjects whose H. pylori status was determined by a combination of serology, rapid urease test, culture, and histology. Microbial DNA from mucosal samples was amplified by PCR using universal bacterial primers. 16S rDNA amplicons were pyrosequenced. ROC curve analysis was performed to determine the cutoff value for H. pylori colonization by pyrosequencing. In addition, temporal changes in the stomach microbiota were observed in eight initially H. pylori-positive and eight H. pylori-negative subjects at a single time point 1-8 years later.

RESULTS

Of the 63 subjects, the presence of H. pylori sequences was detected in all (28/28) conventionally H. pylori-positive samples and in 60% (21/35) of H. pylori-negative samples. The average percent of H. pylori reads in each sample was 0.67 ± 1.09% in the H. pylori-negative group. Cutoff value for clinically positive H. pylori status was approximately 1.22% based on ROC curve analysis (AUC = 0.957; p < .001). Helicobacter pylori was successfully eradicated in five of seven treated H. pylori-positive subjects (71.4%), and the percentage of H. pylori reads in these five subjects dropped from 1.3-95.18% to 0-0.16% after eradication.

CONCLUSION

These results suggest that the cutoff value of H. pylori sequence percentage for H. pylori colonization by pyrosequencing could be set at approximately 1%. It might be helpful to analyze gastric microbiota related to H. pylori sequence status.

Effects of Esomeprazole on the Pharmacokinetics of Lapatinib in Breast Cancer Patients

The aqueous solubility of lapatinib declines significantly at pH >4, suggesting that its bioavailability might be lowered by acid-reducing drugs. A study was therefore conducted to assess the effects of esomeprazole on lapatinib pharmacokinetics (PK). Women with metastatic human epidermal growth factor receptor 2 positive (HER2(+) ) breast cancer were enrolled. Patients received 1,250 mg lapatinib once daily (QD) in the morning on Days 1-7 (Period 1) and Days 8-14 (Period 2) with 40 mg esomeprazole QD at bedtime 3 hours after dinner on Days 8-14. Lapatinib PK sampling occurred during the 24-hour steady-state dosing intervals on Day 7 (lapatinib alone) and Day 14 (lapatinib with esomeprazole). Esomeprazole treatment resulted in decreased lapatinib bioavailability (mean 26%, range 6-49%) that was inversely associated with patient age as a significant covariate.

The role of Helicobacter pylori and CagA in response to treatment in Iranian Gastroesophageal Reflux Diseases patients

AIM

This study was conducted to evaluate the influence H. pylori infection and anti-CagA status on the efficacy of Omeperazole 20 m.g. b.d. for patients with endoscopic oesophagitis.

BACKGROUND

The influence of Helicobacter pylori (H. pylori) infection and its virulent strain (cytotoxin-associated gene A: CagA) has not been evaluated on efficacy of treatment for patients with erosive oesophagitis in Iran.

PATIENTS AND METHODS

One hundred and ten patients (55 H. Pylori positive and 55 H. Pylori negative) with endoscopic evidence of oeosphagitis were enrolled in this interventional study and treated with Omeprazole 20 m.g. b.d. Healing was assessed at repeat endoscopy after 8 weeks of treatment. H. Pylori infection and anti-CagA-IgG (immunoglobulin G) antibodies were determined for each subject by the rapid urease test, pathological assessment and ELISA.

RESULTS

At repeat endoscopy, following 8 weeks of Omeprazole 20 m.g. b.d. therapy, endoscopic healing of oesophagitis had occurred in 32 % of the HP +ve patients and 23 % of the HP -ve patients (chi square p < 0.01). Among the HP +ve endoscopic healing occurred resolved in 11 (32.4 %) of the CagA +ve patients and 19 (90.5 %) of the CagA -ve patients. This difference was significant (chi-square p <0.001).

CONCLUSION

H. pylori infection and the CagA virulence factor are associated with an increased rate of healing amongst patients with endoscopic oesophagitis treated with Omperazole 20 m.g. b.d. compared to patients without H. pylori infection.

Vitamin C, gastritis, and gastric disease: a historical review and update

The discovery of Helicobacter pylori as the cause of gastritis and peptic ulcers ushered in the modern era of research into gastritis and into acid-peptic diseases and rekindled interest in the role of ascorbic acid in the pathophysiology and treatment of gastritis and peptic ulcer disease. Here, we review historic and modern studies on ascorbic acid and gastric diseases with an emphasis on H. pylori gastritis and its sequelae. The relationship of ascorbic acid and gastritis and peptic ulcer and its complications was extensively studied during the 1930s through the 1950s. Much of this extensive literature has been effectively "lost." Ascorbic acid deficiency was associated with all forms of gastritis (e.g., autoimmune, chemical, and infectious) due in varying degrees to insufficient intake, increased metabolic requirements, and destruction within the GI tract. Importantly, gastritis-associated abnormalities in gastric ascorbic acid metabolism are reversed by H. pylori-eradication and potentially worsened by proton pump inhibitor therapy. Diets rich in naturally occurring ascorbic acid are associated with protection of the gastric corpus from atrophy and a reduction in the incidence of gastric cancer possibly through the ability of ascorbic acid to reduce oxidative damage to the gastric mucosa by scavenging carcinogenic N-nitroso compounds and free radicals and attenuating the H. pylori-induced inflammatory cascade. Ascorbic acid supplementation was possibly associated with a decreased incidence of bleeding from peptic ulcer disease. Pharmacologic doses of ascorbic acid also may improve the effectiveness of H. pylori-eradication therapy. Occasionally, looking back can help plot the way forward.

Helicobacter pylori requires TlpD-driven chemotaxis to proliferate in the antrum

Different disease outcomes of Helicobacter pylori infection correlate with distinct inflammation patterns. These different inflammatory distributions may be initiated by differences in bacterial localization. One H. pylori property known to affect murine stomach localization is chemotaxis, the ability to move in response to chemical cues. In this report, we used nonchemotactic mutants (Che(-)) to analyze whether chemotaxis is required for initial colonization of particular stomach regions or for subsequent growth therein. We found that H. pylori behaves differently in the corpus, antrum, and corpus-antrum transition zone subregions of the stomach. This outcome suggests that these regions contain unique chemotactic signals. In the corpus, H. pylori utilizes chemotaxis for initial localization but not for subsequent growth. In contrast, in the antrum and the corpus-antrum transition zone, chemotaxis does not help initial colonization but does promote subsequent proliferation. To determine which chemoreceptor is responsible for the corpus-antrum phenotypes, we infected mice with strains lacking each chemoreceptor. Strains lacking TlpA, TlpB, or TlpC displayed only modest deviations from the wild-type phenotype, while strains lacking TlpD resembled the Che(-) mutant in their antral colonization defect and fared even worse than the Che(-) mutant in the corpus. Additional analysis showed that inflammation is worse in the antrum than in the corpus in both wild-type and Che(-) mutant infections. These results suggest that chemotaxis, specifically, that controlled by TlpD, is necessary for H. pylori to survive or grow in the environment of increased inflammation in the antrum.

Effects of long-term PPI treatment on producing bowel symptoms and SIBO

BACKGROUND

Gastroesophageal reflux disease (GERD), including erosive reflux disease and non-erosive reflux disease (NERD), is a chronic disease with a significant negative effect on quality of life. State-of-the-art treatment involves proton pump inhibitors (PPIs). However, relapse of symptoms occurs in the majority of the patients who require recurrent or continuous therapy. Although PPIs are well tolerated, little information is available about gastrointestinal side effects.

AIM

To evaluate the effects of long-term PPI treatment on development of bowel symptoms and/or small intestinal bacterial overgrowth (SIBO).

METHODS

Patients with NERD not complaining of bowel symptoms were selected by upper endoscopy, 24-h pH-metry and a structured questionnaire concerning severity and frequency of bloating, flatulence, abdominal pain, diarrhoea and constipation. Patients were treated with esomeprazole 20 mg bid for 6 months. Prior to and after 8 weeks and 6 months of therapy, patients received the structured questionnaire and underwent evaluation of SIBO by glucose hydrogen breath test (GHBT).

RESULTS

Forty-two patients with NERD were selected out of 554 eligible patients. After 8 weeks of PPI treatment, patients complained of bloating, flatulence, abdominal pain and diarrhoea in 43%, 17%, 7% and 2%, respectively. After 6 months, the incidence of bowel symptoms further increased and GHBT was found positive in 11/42 (26%) patients. By a post hoc analysis, a significant (P < 0·05) percentage of patients (8/42) met Rome III criteria for irritable bowel syndrome.

CONCLUSIONS

Prolonged PPI treatment may produce bowel symptoms and SIBO; therefore, the strategy of step-down or on-demand PPI therapy should be encouraged in GERD.

Increased incidence of small intestinal bacterial overgrowth during proton pump inhibitor therapy

BACKGROUND & AIMS

Proton pump inhibitors (PPIs) can cause diarrhea, enteric infections, and alter the gastrointestinal bacterial population by suppressing the gastric acid barrier. Among patients that received long term PPI treatment, we evaluated the incidence of small intestinal bacterial overgrowth (SIBO; assessed by glucose hydrogen breath test [GHBT]), the risk factors for development of PPI-related SIBO and its clinical manifestations, and the eradication rate of SIBO after treatment with rifaximin.

METHODS

GHBTs were given to 450 consecutive patients (200 with gastroesophageal reflux disease who received PPIs for a median of 36 months; 200 with irritable bowel syndrome [IBS], in absence of PPI treatment for at least 3 years; and 50 healthy control subjects that had not received PPI for at least 10 years). Each subject was given a symptoms questionnaire.

RESULTS

SIBO was detected in 50% of patients using PPIs, 24.5% of patients with IBS, and 6% of healthy control subjects; there was a statistically significant difference between patients using PPIs and those with IBS or healthy control subjects (P < .001). The prevalence of SIBO increased after 1 year of treatment with PPI. The eradication rate of SIBO was 87% in the PPI group and 91% in the IBS group.

CONCLUSIONS

SIBO, assessed by GHBT, occurs significantly more frequently among long term PPI users than patients with IBS or control subjects. High dose therapy with rifaximin eradicated 87%-91% of cases of SIBO in patients who continued PPI therapy.

Adverse effects of proton pump inhibitors

Proton pump inhibitors (PPI) are very effective drugs used largely in acid related disorders. During the last years concern have been raised regarding their overutilisation in benign condition, such as gastroesophageal reflux disease. The debate focussed also on the risk of adverse events related to long term use of PPI. Apart of the case of Helicobacter Pylori (H. Pylori) positive patients, in whose long term acid suppression lead to the development of corpus predominant atrophic gastritis, precursor of cancer; the other assumed adverse events, have never been demonstrated in prospective studies. The attention should move towards the appropriate prescription of PPI, rather than the fear adverse effects of PPI. In fact, in clinical practise, PPI are often prescribed in patients without a specific acid related disease and continued long term based on their safety profile. This review focus on the main adverse events related to long term PPI use.

[Guidelines of treatment for non-bleeding peptic ulcer disease]

Over the past century, since the introduction of non steroidal anti-inflammatory drugs (NSAID), antacid, histamine H2-receptor antagonists (H2RA), proton pump inhibitors (PPI), and discovery of Helicobacter pylori infection, the paradigm of peptic ulcer disease has changed with marked decrease in morbidity and mortality. However, peptic ulcer disease still occupies a position as a major health problem with increase of aged population and NSAIDs usage. In daily general practice, the management of peptic ulcer disease is directed according to the presence of bleeding or not. For non-bleeding peptic ulcer disease, proper acid suppression and the correction of underlying causes such as Helicobacter pylori infection and NSAID use is the main stay of treatment. Though a complete understanding of pathophysiology and a perfect treatment strategy are still a challenge, this guideline aims to provide practical recommendations based on evidences or consensus of experts through in-depth literature review and expert meeting.

Peptic ulcer disease

Peptic ulcer disease had a tremendous effect on morbidity and mortality until the last decades of the 20th century, when epidemiological trends started to point to an impressive fall in its incidence. Two important developments are associated with the decrease in rates of peptic ulcer disease: the discovery of effective and potent acid suppressants, and of Helicobacter pylori. With the discovery of H pylori infection, the causes, pathogenesis, and treatment of peptic ulcer disease have been rewritten. We focus on this revolution of understanding and management of peptic ulcer disease over the past 25 years. Despite substantial advances, this disease remains an important clinical problem, largely because of the increasingly widespread use of non-steroidal anti-inflammatory drugs (NSAIDs) and low-dose aspirin. We discuss the role of these agents in the causes of ulcer disease and therapeutic and preventive strategies for drug-induced ulcers. The rare but increasingly problematic H pylori-negative NSAID-negative ulcer is also examined.

Review article: Helicobacter pylori-negative duodenal ulcer disease

BACKGROUND

Helicobacter pylori infection rates in duodenal ulcer (DU) patients may be lower than previously estimated.

AIM

To review the real prevalence of H. pylori-negative DUs and its possible causes.

METHODS

Bibliographical searches in MEDLINE looking for the terms 'H. pylori' and 'duodenal ulcer'.

RESULTS

Mean prevalence of H. pylori infection in DU disease, calculated from studies published during the last 10 years including a total of 16 080 patients, was 81%, and this figure was lower (77%) when only the last 5 years were considered. Associations with H. pylori-negative DU were: (1) False negative results of diagnostic methods, (2) NSAID use (21% in studies with <90% infection rate), (3) Complicated DU (bleeding, obstruction, perforation), (4) Smoking, (5) Isolated H. pylori duodenal colonization, (6) Older age, (7) Gastric hypersecretion, (8) Diseases of the duodenal mucosa, (9) Helicobacter'heilmanii' infection and (10) Concomitant diseases.

CONCLUSION

In patients with H. pylori-negative DU disease, one should carefully confirm that the assessment of H. pylori status is reliable. In truly H. pylori-negative patients, the most common single cause of DU is, by far, the use of NSAIDs. Ulcers not associated with H. pylori, NSAIDs or other obvious causes should, for the present, be viewed as 'idiopathic'. True idiopathic DU disease only exceptionally exists.

Long-term safety concerns with proton pump inhibitors

Proton pump inhibitors (PPIs) are among the most widely prescribed medications worldwide. Their use has resulted in dramatic improvements in treatment of peptic ulcer disease and gastroesophageal reflux disease. Despite an acceptable safety profile, mounting data demonstrate concerns about the long-term use of PPIs. To provide a comprehensive review regarding the concerns of long-term PPI use, a literature search was performed to identify pertinent original and review articles. Despite study shortcomings, the collective body of information overwhelmingly suggests an increased risk of infectious complications and nutritional deficiencies. Data regarding any increased risk in gastric or colon malignancy are less convincing. PPIs have revolutionized the management and complications of acid-related disorders with a high margin of safety; however, with the data available, efforts to reduce the dosing of or discontinue the use of PPIs must be reassessed frequently.

Optimal dose of intravenous pantoprazole in patients with peptic ulcer bleeding requiring endoscopic hemostasis in Korea

BACKGROUND AND AIM

The lowest effective dose of proton pump inhibitors (PPI) for prevention of peptic ulcer rebleeding remains unclear. The objective of the present study was to evaluate whether low-dose PPI has a similar efficacy to high-dose i.v. administration for maintaining intragastric pH above 6.

METHODS

Sixty-one patients with bleeding ulcers were randomized into one of three groups after endoscopic hemostasis: pantoprazole 80 mg bolus followed by 8 mg/h; 40 mg, 4 mg/h infusion; and bolus injection of 40 mg every 24 h. Intragastric pH values and rebleeding rates were measured. In addition, pharmacokinetic parameters and association with CYP2C19 polymorphisms and H. pylori infection were assessed.

RESULTS

Mean percentage of time with intragastric pH > 6, and the proportion of patients with pH > 6 for more than 60% of the time were significantly higher in the 40 mg, 4 mg/h infusion group compared to the 40 mg bolus injection. There was no significant difference between the 80 mg, 8 mg/h and the 40 mg, 4 mg/h groups. In the H. pylori (-) group, only 40% of patients that received continuous infusion reached the target pH > 6 for more than 60% of the time; this was significantly lower than the H. pylori (+) group, 87.5% (P = 0.026).

CONCLUSIONS

A continuous infusion, regardless of high or low dose, was more effective for acid suppression than a 40 mg bolus PPI injection in Korea. H. pylori infection was an important factor for the maintenance of an intragastric pH > 6.

Clinical trial: factors associated with freedom from relapse of heartburn in patients with healed reflux oesophagitis--results from the maintenance phase of the EXPO study

BACKGROUND

Ability to predict freedom from heartburn relapse during maintenance therapy for healed reflux oesophagitis may facilitate optimal treatment choices for individual patients.

AIM

To determine factors predicting freedom from heartburn relapse during maintenance proton pump inhibitor therapy in patients with healed reflux oesophagitis.

METHODS

This post-hoc analysis used data from the maintenance phase of the EXPO study (AstraZeneca study code: SH-NEG-0008); 2766 patients with healed reflux oesophagitis and resolved heartburn received once-daily esomeprazole 20 mg or pantoprazole 20 mg for 6 months. Multiple logistic regression analysis determined factors associated with freedom from heartburn relapse.

RESULTS

Heartburn relapse rates were lower with esomeprazole than pantoprazole in all subgroups analysed. Esomeprazole treatment was the factor most strongly associated with freedom from heartburn relapse (odds ratio 2.08; P < 0.0001). Other factors significantly associated with freedom from heartburn relapse were Helicobacter pylori infection, greater age, non-obesity, absence of epigastric pain at baseline, pre-treatment nonsevere heartburn and GERD symptom duration < or =5 years.

CONCLUSIONS

Several factors predict freedom from heartburn relapse during maintenance proton pump inhibitor therapy for healed reflux oesophagitis, the strongest being choice of proton pump inhibitor. These findings outline the importance of optimizing acid control and identifying predictors of relapse for effective long-term symptom management in reflux oesophagitis patients.

Helicobacter pylori-negative nonsteroidal anti-inflammatory drug-negative ulcer

The most important clinical point for dyspeptic H pylori-negative NSAID-absent negative ulcers is to adequately ensure that these common risk factors are indeed absent. Once that is done, further investigations to include the rare causes of ulcer disease need to be performed and exclusion of underlying malignancy ensured. The possibility of the Zollinger Ellison syndrome should be considered, remembering that proton pump inhibitor therapy will mitigate its classical, clinical features.

Clinical trial: factors associated with resolution of heartburn in patients with reflux oesophagitis--results from the EXPO study

BACKGROUND

The ability to predict symptom response to reflux oesophagitis-healing therapy may optimize treatment decisions.

AIM

To identify factors associated with heartburn resolution in patients receiving acid-suppressive therapy for reflux oesophagitis.

METHODS

In this multicentre, randomized, double-blind trial (EXPO; AstraZeneca study code: SH-NEG-0008), patients with endoscopically confirmed reflux oesophagitis and reflux symptoms received once-daily proton pump inhibitor therapy [esomeprazole 40 mg (n = 1562) or pantoprazole 40 mg (n = 1589)] for >or=4 weeks. Factors associated with heartburn resolution after 4 weeks were identified by multiple logistic regression analysis.

RESULTS

Esomeprazole therapy, positive Helicobacter pylori status and greater age were associated with an increased likelihood of heartburn resolution [odds ratio (95% confidence interval): 1.31 (1.12, 1.54), 1.44 (1.19, 1.74) and 1.013 (1.007, 1.019) per year, respectively; all P < 0.001]. Men and patients with no acid regurgitation or epigastric pain pre-treatment were also more likely to achieve heartburn resolution (all P < 0.05).

CONCLUSIONS

The use of esomeprazole rather than pantoprazole increases the probability of achieving resolution of heartburn during reflux oesophagitis-healing therapy. Other factors, including H. pylori status, age, gender and symptom profile may be helpful in determining the likelihood of heartburn resolution in such patients.

Effect of proton pump inhibitors on vitamins and iron

Vitamin C is actively secreted in human gastric juice. Proton pump inhibitor therapy lowers the concentration of vitamin C in gastric juice and the proportion of the vitamin in its active antioxidant form i.e., ascorbic acid. This has secondary effects on intragastric nitrite chemistry, resulting in a rise in gastric juice nitrite levels. There is also some evidence that proton pump inhibitors may reduce the bioavailability of ingested vitamin C. The effect of proton pump inhibitors on vitamin C and nitrite chemistry is more marked in Helicobacter pylori-infected subjects. Proton pump inhibitors also reduce the absorption of vitamin B(12) probably by inhibiting intragastric proteolysis and, thus, its release from food required prior to binding to R-proteins and gastric intrinsic factor. Under certain circumstances, the treatment may lower serum vitamin B(12) levels. Proton pump inhibitor therapy reduces the absorption of non-heme iron and this effect has been employed in the management of hemochromatosis. It may also retard clinical response to iron supplementation.

How I manage H. pylori-negative, NSAID/aspirin-negative peptic ulcers

The first and most important action on encountering a patient with unexplained gastric or duodenal ulceration is to double check that they are truly H. pylori negative and also not taking any ulcerogenic medicines. Once the patient is confirmed to be H. pylori negative and NSAID negative, ensure that biopsies of the ulcer-whether gastric or duodenal-and of the surrounding gastric and duodenal mucosa are obtained to exclude underlying malignancy/lymphoma, Crohn's disease, and unusual infectious agents. If the etiology of the ulceration remains unexplained, an underlying gastrinoma should be considered and excluded. Patients with idiopathic ulcers should be maintained on proton pump inhibitor therapy, and higher doses may be required to control acid secretion and prevent ulcer relapse in these H. pylori-uninfected subjects.

Refractory GERD: what is it?

Refractory gastroesophageal reflux disease (GERD) is very common and may affect up to 40% of patients who use a proton pump inhibitor (PPI) once daily. Refractory GERD can present as incomplete or lack of response to PPI therapy. The disorder is clearly driven by patients, who present with a wide range of symptom severity and frequency while on PPI treatment. Poor compliance and improper timing of PPI consumption should always be excluded before further evaluation of this patient population. The putative mechanisms for refractory GERD include weakly acidic reflux, duodenogastroesophageal/bile reflux, visceral hypersensitivity, delayed gastric emptying, psychological comorbidity, and concomitant functional bowel disorders. Reduced PPI bioavailability, rapid PPI metabolism, PPI resistance, nocturnal reflux, and Helicobacter pylori infection status have very limited roles in refractory GERD. The contribution of eosinophilic esophagitis to refractory GERD is still unknown. Pill-induced esophagitis, Zollinger-Ellison syndrome, achalasia, and other disorders are rarely responsible for PPI failure and usually are not confused with GERD.

Relative potency of proton-pump inhibitors-comparison of effects on intragastric pH

AIM

Comparative potency of proton-pump inhibitors (PPIs) is an important clinical issue. Most available trials have compared the different PPIs at one or a few selected specific dosages, making it difficult to derive quantitative equivalence dosages. Here we derived PPI dose equivalents based on a comprehensive assessment of dose-dependent effects on intragastric pH.

METHODS

All available clinical studies reporting the effects of PPIs on mean 24-h intragastric pH were sought from electronic databases including Medline. Studies included were restricted to those targeting the Caucasian population, and healthy volunteers or gastroesophageal reflux disease (GERD) patients. The dose-effect relationships for mean 24-h intragastric pH and for percentage of time with pH > 4 in 24 h were analyzed for each PPI using pharmacodynamic modeling with NONMEM and a model integrating all available data.

RESULTS

Fifty-seven studies fulfilled the inclusion criteria. Based on the mean 24-h gastric pH, the relative potencies of the five PPIs compared to omeprazole were 0.23, 0.90, 1.00, 1.60, and 1.82 for pantoprazole, lansoprazole, omeprazole, esomeprazole, and rabeprazole, respectively. Compared with healthy volunteers, patients with GERD needed a 1.9-fold higher dose and Helicobacter pylori-positive individuals needed only about 20% of the dose to achieve a given increase in mean 24-h intragastric pH.

CONCLUSION

The present meta-analysis provides quantitative estimates on clinical potency of individual PPIs that may be helpful when switching between PPIs and for assessing the cost-effectiveness of specific PPIs. However, our estimates must be viewed with caution because only a limited dose range has been tested and not exactly the same study conditions were applied for the different substances.

[Reasons for proton-pump-inhibitor failure in the treatment of gastroesophageal reflux disease]

The introduction of proton pump inhibitors (PPI) has facilitated the successful management of patients with gastroesophageal reflux disease (GERD). In a minor, but still relevant proportion of patients with GERD-like symptoms, PPI therapy has also proved to be ineffective. In such cases, the first question to be answered is if the symptoms and complaints are related to GERD indeed, or another disorder should be searched for. If GERD is still the most likely diagnosis, patients' compliance should be thoroughly investigated before any further diagnostic and therapeutic measure is taken. If PPI failure is not a result of inadequate management of GERD, there are several other disorders to be ruled out. In our review, we summarize the most important differential diagnostic issues of PPI failure.

Esomeprazole in acute and maintenance treatment of reflux oesophagitis: a multicentre prospective study

INTRODUCTION

The aim of this study was to assess the efficacy and safety of esomeprazole 40 mg once daily (q.d.) in healing reflux oesophagitis at 4 and 8 weeks, and the efficacy of esomeprazole 20 mg q.d. for 12 weeks in the maintenance of remission.

METHODS

A total of 235 patients with endoscopically proven reflux oesophagitis were enrolled in this study, which consisted of two phases (healing and maintenance therapy). Patients who showed complete endoscopic and symptomatic healing at the end of 4 or 8 weeks were switched to maintenance treatment with esomeprazole 20 mg q.d. for 12 weeks. The primary efficacy endpoint was healing of reflux oesophagitis at week 8. Secondary assessments included the proportion of patients with symptomatic relapse in the maintenance phase.

RESULTS

At the end of week 8, 88% (95% life-table confidence intervals [CI]: 84%, 92%) of patients were healed endoscopically and 90.6% of the patients were asymptomatic. Patient age, gender and Helicobacter pylori status had no effect on the efficacy of treatment. During the 12-week maintenance treatment phase, symptomatic relapse ratios were 0.5%, 2.2%, and 0%, for the first, second, and third 4-week periods, respectively. The proportions of patients satisfied with treatment were 95% and 99.4% at the end of acute and maintenance treatment, respectively. The most common adverse effects were headache, upper respiratory tract infection and abdominal pain.

CONCLUSIONS

Esomeprazole is effective in the healing of reflux oesophagitis, the resolution of heartburn, and in maintaining symptomatic remission. The effectiveness of esomeprazole in patients with gastroesophageal reflux disease is not affected by the presence of H. pylori.

Refractory gastrooesophageal reflux disease

The introduction of proton pump inhibitors (PPIs) has facilitated the treatment of gastrooesophageal reflux disease (GORD) enormously; however, treatment of GORD still fails in a small proportion of patients. This small proportion of therapy-resistant patients encompasses a substantial part of the working load of physicians and has become a common clinical problem. A strong variability in acid-suppressive effect of PPI treatment exists depending on compliance, Helicobacter pylori status and genotype. Nocturnal acid breakthrough does not seem to be a major determinant of refractory GORD. Recent data, however, show that PPI-refractory GORD can result from nonacid reflux episodes. It is wise to reconsider the diagnosis of GORD in patients who are PPI-refractory. Most patients in whom a PPI is not effective do not have GORD, instead they suffer from other disorders such as functional dyspepsia. If after a thorough history is taken the suspicion of GORD is still high, the next step would be to perform upper endoscopy and reflux monitoring. In case patients truly have PPI-refractory GORD, therapy can be aimed at oesophageal hypersensitivity or a surgical solution can be sought.

Proton-pump inhibitor therapy in patients with gastro-oesophageal reflux disease: putative mechanisms of failure

Proton-pump inhibitor (PPI) failure in gastro-oesophageal reflux disease (GORD) patients has become the main reason for referral of these patients to gastroenterology specialists. It is estimated that 30% of GORD patients requiring a PPI once daily will experience treatment failure. Patients with non-erosive reflux disease are the most common GORD-related group in which once-daily PPI therapy fails. Various mechanisms have been suggested to underlie PPI failure in GORD patients. The most pertinent include weakly acidic reflux, duodenogastro-oesophageal reflux, visceral hyperalgesia, delayed gastric emptying, psychological co-morbidity and concomitant functional bowel disorders, as well as others. Because of the importance of PPI failure as a target for future drug development, further understanding of the most relevant underlying mechanisms is needed.

Helicobacter pylori infection and severity of reflux-induced esophageal disease in a cohort of patients with columnar-lined esophagus

The relationship between Helicobacter pylori infection and reflux-induced esophageal diseased is controversial. We examined esophageal disease severity in patients with columnar-lined esophagus and compared results between patients with and without Helicobacter pylori infection. Medical records of 1000 patients diagnosed with columnar-lined esophagus were examined. Endoscopic and histological findings of reflux-induced esophageal disease were compared between H. pylori-positive and H. pylori-negative patients. Four hundred twenty-nine patients (42.9%) showed evidence of H. pylori status, of whom 239 (55.7%) were positive and 190 (44.3%) negative. There were no significant differences in length of columnar-lined segment (P = 0.305), frequency of associated esophagitis (P = 0.583), or presence of gastroduodenal inflammation (P = 0.335, P = 0.131) between the two groups. Histological grade of esophageal disease severity was similar between them, with no statistically significant differences (P = 0.231). We conclude that in patients with established columnar-lined esophagus, there appears to be no difference in severity of reflux-induced esophageal disease between those with and those without H. pylori infection.

A review of esomeprazole in the treatment of gastroesophageal reflux disease (GERD)

Proton-pump inhibitors (PPIs) are the drugs of choice for the treatment of gastroesophageal reflux disease (GERD). Esomeprazole is the latest PPI and was developed as the S-isomer of omeprazole as an attempt to improve its pharmacokinetic properties. Esomeprazole has been reported to have a somewhat higher potency in acid inhibition than other PPIs. Despite some controversy, data from clinical trials and meta-analyses indicate that esomeprazole 40 mg od for up to 8 weeks provided higher rates of healing of erosive GERD and a greater proportion of patients with sustained resolution of heartburn, than omeprazole 20 mg, lansoprazole 30 mg, or pantoprazole 40 mg od. Esomeprazole 20 mg od has also been shown to be more effective in maintaining healing of erosive GERD compared with lansoprazole 15 mg od or pantoprazole 20 mg od. However, it is not clear whether these statistically significant differences are of major clinical importance. Esomeprazole 20 mg od is superior to placebo for treatment of non-erosive reflux disease (NERD) but clinical trials have not shown any significant differences in efficacy between esomeprazole 20 mg and omeprazole 20 mg or pantoprazole 20 mg od. Lastly, although esomeprazole treatment in GERD has been reported to result in improvement of health-related quality of life (QoL) indices, no clinical trials have evaluated the possible differential effects of different PPIs on QoL in GERD.

Proton pump inhibitors and Helicobacter pylori gastritis: friends or foes?

H. pylori gastritis and gastric acid closely interact. In H. pylori-positive patients, profound acid suppressive therapy induces a corpus-predominant pangastritis, which is associated with accelerated corpus gland loss and development of atrophic gastritis. Both corpus-predominant and atrophic gastritis have been associated with an increased risk of development of gastric cancer. H. pylori eradication leads to resolution of gastritis and may induce partial regression of pre-existent gland loss. H. pylori eradication does not aggravate GERD nor does it impair the efficacy of proton pump inhibitor maintenance therapy for this condition. This is the background of the advise within the European guidelines for the management of H. pylori infection to offer an H. pylori test and treat policy to patients who require proton pump inhibitor maintenance therapy for GERD. As such a policy fully reverses H. pylori pangastritis even in patients who have been treated for years with proton pump inhibitors, there is no need to eradicate H. pylori before the start of proton pump inhibitors. In fact, the somewhat slower initial response of H. pylori-negative GERD patients to proton pump inhibitor therapy and the fact that many GERD patients will only require short-term therapy suggests to first start the proton pump inhibitor, and only test and treat when maintenance therapy needs to be prescribed. Such considerations prevent the persistent presence of active corpus-predominant gastritis in proton pump inhibitor-treated reflux patients without impairing the clinical efficacy of treatment.

Effect of intravenous application of esomeprazole 40 mg versus pantoprazole 40 mg on 24-hour intragastric pH in healthy adults

BACKGROUND

It has been demonstrated that therapy with proton pump inhibitors reduces recurrence of bleeding following initial endoscopic treatment of bleeding peptic ulcers.

AIM

This study compared the effects of esomeprazole 40 mg and pantoprazole 40 mg on intragastric acid control. Both substances were administered intravenously as 15-min infusion and as bolus injection.

METHODS

Healthy men and women volunteers were enrolled in this single-center, open, randomized, three-way crossover study. After administration of esomeprazole 40 mg and pantoprazole 40 mg intravenously as 15-min infusion, and pantoprazole 40 mg intravenously as bolus injection, continuous 24-h intragastric pH monitoring was carried out.

RESULTS

pH data were available for 21 Helicobacter pylori-negative and seven H. pylori-positive volunteers. In H. pylori-negative volunteers, esomeprazole 40 mg intravenously resulted in 11.8 h with an intragastric pH>4 compared with 5.6 h for pantoprazole 40 mg intravenously as infusion (P<0.0001), and 7.2 h for pantoprazole 40 mg intravenously as bolus injection (P<0.001). During the first 6 h of administration, the corresponding values were 3.4, 1.1 (P<0.000001), and 2.1 h (P<0.001), respectively.

CONCLUSIONS

In H. pylori-negative patients, a single dose of esomeprazole 40 mg intravenously provides an intragastric acid control that is faster and more pronounced than administration of pantoprazole 40 mg intravenously.