Review article: acid-related disease--what are the unmet clinical needs?

Association between proton pump inhibitors and rhabdomyolysis risk: a post-marketing surveillance using FDA adverse event reporting system (FAERS) database

Background

This research aims to explore and compare the signals of rhabdomyolysis from the use of Proton pump inhibitors (PPIs) using the United States Food and Drug Administration Adverse Event Reporting System (FAERS) database.

Methods

Rhabdomyolysis and related terms submitted between 2013 and 2021 were retrieved from the FAERS database. The data were analyzed using the reporting odds ratio (ROR), proportional reporting ratio (PRR), Empirical Bayes Geometric Mean (EBGM) and the information component (IC). The signals of rhabdomyolysis associated with PPIs use were detected in both 3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) utilizers and non-utilizers.

Results

A total of 7,963,090 reports were retrieved and analyzed. Fifty-seven reports linked PPIs to rhabdomyolysis out of 3670 reports from other drugs (non-statin included). The association of rhabdomyolysis and PPIs was significant in both statins included, and non-statin-included reports, although with varying degrees of association. The ROR was 2.5 (95% confidence interval [CI] 1.9-3.2) for PPIs in non-statin-included reports and 2 (95% CI: 1.5-2.6) for PPIs in statin-included reports.

Conclusion

Significant signals of rhabdomyolysis were associated with PPIs. However, its signals were higher in non-statin-included reports compared to statin-included reports.

Plain Language Summary

Plain language summaryProton Pump Inhibitors and rhabdomyolysis risk Background: The FDA created the FDA Adverse Event Reporting System (FAERS) database to support post-marketing surveillance programs. The FAERS is a computerized database with more than nine million adverse event reports, including all reports from 1969 to the present. This research aims to explore and compare the signals of rhabdomyolysis from the use of proton pump inhibitors (PPIs) using the United States Food and Drug Administration Adverse Event Reporting System (FAERS) database.Research design and methods: We retrieved rhabdomyolysis and related terms submitted between 2013 and 2021 from the FAERS database. Then, we analyzed the data that we found. We detected the signals of rhabdomyolysis associated with PPIs use in both statins utilizers and non-utilizers.Results: We retrieved and analyzed a total of 7,963,090 reports. We found 57 reports linked PPIs to rhabdomyolysis out of 3670 reports from other drugs (non-statin included). The association of rhabdomyolysis and PPIs was significant in both statins included, and non-statin-included reports, although with varying degrees of association.Conclusion: Significant signals of rhabdomyolysis were associated with PPIs. However, its signals were higher in non-statin-included reports than in statin-included reports.

GERD-related chronic cough: Possible mechanism, diagnosis and treatment

GERD, or gastroesophageal reflux disease, is a prevalent medical condition that affects millions of individuals throughout the world. Chronic cough is often caused by GERD, and chronic cough caused by GER is defined as GERD-related chronic cough (GERC). It is still unclear what the underlying molecular mechanism behind GERC is. Reflux theory, reflex theory, airway allergies, and the novel mechanism of esophageal motility disorders are all assumed to be linked to GERC. Multichannel intraluminal impedance combined with pH monitoring remains the gold standard for the diagnosis of GERC, but is not well tolerated by patients due to its invasive nature. Recent discoveries of new impedance markers and new techniques (mucosal impedance testing, salivary pepsin, real-time MRI and narrow band imaging) show promises in the diagnosis of GERD, but the role in GERC needs further investigation. Advances in pharmacological treatment include potassium-competitive acid blockers and neuromodulators (such as Baclofen and Gabapentin), prokinetics and herbal medicines, as well as non-pharmacological treatments (such as lifestyle changes and respiratory exercises). More options have been provided for the treatment of GERC other than acid suppression therapy and anti-reflux surgery. In this review, we attempt to review recent advances in GERC mechanism, diagnosis, and subsequent treatment options, so as to provide guidance for management of GERC.

A randomized, double-blind, placebo-controlled pilot study to evaluate the efficacy and tolerability of a novel oral bioadhesive formulation for the treatment of nonerosive reflux disease-related symptoms

OBJECTIVE

The use of antisecretory drugs can provide symptomatic relief in 70-80% of patients suffering from gastro-oesophageal reflux disease (GORD), although this benefit is reduced by 20-30% in the case of nonerosive reflux disease (NERD). The current study evaluates the efficacy and safety of a patented oral formulation (liquid sachets containing hyaluronic acid, a mixture of amino acids including proline, hydroxyl-proline and glutamine, and rice extract dispersed in a bioadhesive polymer matrix) for relieving the symptoms of NERD.

METHODS

A single-centre, randomized, double-blind, parallel group, placebo-controlled clinical study was performed. Patients who experienced at least three episodes of moderate-severity heartburn during the 7-day run-in period were included and treated with three liquid sachets per day for 14 days. The primary objective was to evaluate the proportion of patients with at least a three-point reduction in the total symptom score (TSS).

RESULTS

Overall, 20 patients were randomized to receive the investigational product and 20 to receive the placebo. At the end of treatment, a three-point reduction in the TSS was achieved by 95% of patients treated with the investigational product and by 20% of patients treated with placebo (P < 0.0001). No adverse events were reported.

CONCLUSION

The investigational product showed a statistically significant superiority to the placebo in relieving common symptoms in patients with NERD. Future studies will be aimed at clarifying the hypothesis that this symptomatic benefit is related to the strengthening of the oesophageal barrier against the damage induced by gastric contents.

Esophageal reflux hypersensitivity: Non-GERD or still GERD?

The most recent iteration of the classifications for functional esophageal disorders, Rome IV, proposed relevant modifications of the previous definitions for Rome III. They specifically considered increased esophageal acid exposure as the marker of gastroesophageal reflux disease (GERD), including the remaining part of non-erosive reflux disease patients with normal acid in the group with functional alterations, considering both reflux hypersensitivity and functional heartburn. However, recent pathophysiological and therapeutic data suggest the need for a return to including reflux hypersensitivity in the GERD spectrum. Indeed, physiologic alterations in esophageal mucosal integrity and chemical clearance, the presence of microscopic esophagitis, and strict symptom-reflux association support the concept that reflux hypersensitivity pertains to GERD. Surgical anti-reflux therapy has resulted in positive outcomes, even in the long term, in patients with reflux hypersensitivity and not in those with functional heartburn. Moreover, clinical trials using neuromodulators have been scarce and provided conflicting results. As a result, the real progress of the Rome IV classifications is in dispute. This article aims to summarize the most recent knowledge of non-erosive reflux disease and reflux hypersensitivity to discuss the utility of Rome IV criteria in the identification and management of functional esophageal disorders.

Pharmacologic treatment of GERD: Where we are now, and where are we going?

The introduction of acid inhibition in clinical practice has revolutionized the management of acid-related diseases, leading to the virtual abolition of elective surgery for ulcer disease and relegating antireflux surgery to patients with gastroesophageal reflux disease (GERD) not adequately managed by medical therapy. Proton pump inhibitors (PPIs) are the antisecretory drugs of choice for the treatment of reflux disease. However, these drugs still leave some unmet clinical needs in GERD. PPI-refractoriness is common, and persistent symptoms are observed in up to 40-55% of daily PPI users. Potassium-competitive acid blockers (P-CABs) clearly overcome many of the drawbacks and limitations of PPIs, achieving rapid, potent, and prolonged acid suppression, offering the opportunity to address many of the unmet needs. In recent years, it has been increasingly recognized that impaired mucosal integrity is involved in the pathogenesis of GERD. As a consequence, esophageal mucosal protection has emerged as a new, promising therapeutic avenue. When P-CABS are used as add-on medications to standard treatment, a growing body of evidence suggests a significant additional benefit, especially in the relief of symptoms not responding to PPI therapy. On the contrary, reflux inhibitors are considered a promise unfulfilled, and prokinetic agents should only be used on a case-by-case basis.

Different Traditional Herbal Medicines for the Treatment of Gastroesophageal Reflux Disease in Adults

Background/Aims

Traditional Herbal Medicines (THM) have been being used for gastroesophageal reflux disease (GERD) for a long time, but clinical evidence is still scarce. We evaluated different THM prescriptions for GERD in adults.

Methods

Data added to nine online databases from their inception to November 30, 2019, were systematically searched. All relevant randomized controlled trials (RCTs) were included and were combined with Bayesian network analysis. The Cochrane Collaboration’s risk of bias tool and GRADE profiler version 3.6 were respectively employed to evaluate the quality of evidence of outcomes.

Results

Seventeen publications involving 1441 participants were retrieved. The results of our analysis suggested that Jianpi therapy+proton pump inhibitors (PPIs) and Ligan Hewei therapy respectively ranked first in overall clinical efficacy and efficacy under gastroscope; Ligan Hewei therapy+PPIs was the optimum intervention in the improvement of acid regurgitation and heartburn.

Conclusion

This research indicates that Ligan Hewei therapy and Jianpi therapy, or these therapies separately combined with PPIs, should be recommended as appropriate complementary and alternative treatments based on the specific characteristics of GERD. However, additional well-designed RCTs with high methodological quality are still needed for future research.

The Physiology of the Gastric Parietal Cell

Parietal cells are responsible for gastric acid secretion, which aids in the digestion of food, absorption of minerals, and control of harmful bacteria. However, a fine balance of activators and inhibitors of parietal cell-mediated acid secretion is required to ensure proper digestion of food, while preventing damage to the gastric and duodenal mucosa. As a result, parietal cell secretion is highly regulated through numerous mechanisms including the vagus nerve, gastrin, histamine, ghrelin, somatostatin, glucagon-like peptide 1, and other agonists and antagonists. The tight regulation of parietal cells ensures the proper secretion of HCl. The H+-K+-ATPase enzyme expressed in parietal cells regulates the exchange of cytoplasmic H+ for extracellular K+. The H+ secreted into the gastric lumen by the H+-K+-ATPase combines with luminal Cl- to form gastric acid, HCl. Inhibition of the H+-K+-ATPase is the most efficacious method of preventing harmful gastric acid secretion. Proton pump inhibitors and potassium competitive acid blockers are widely used therapeutically to inhibit acid secretion. Stimulated delivery of the H+-K+-ATPase to the parietal cell apical surface requires the fusion of intracellular tubulovesicles with the overlying secretory canaliculus, a process that represents the most prominent example of apical membrane recycling. In addition to their unique ability to secrete gastric acid, parietal cells also play an important role in gastric mucosal homeostasis through the secretion of multiple growth factor molecules. The gastric parietal cell therefore plays multiple roles in gastric secretion and protection as well as coordination of physiological repair.

Development of Dexlansoprazole Delayed-Release Capsules, a Dual Delayed-Release Proton Pump Inhibitor

Proton pump inhibitors (PPIs) are widely used for treating acid-related disorders. For an "ideal PPI," achieving maximal absorption and sustaining pharmacodynamic effects through the 24-h dosing cycle are critical features. Dexlansoprazole offers a relevant case study on how an improved PPI was developed capitalizing on the rational optimization of a precursor molecule-in this case, using lansoprazole as a starting point, leveraging its chemical properties on pharmacokinetics, and exploring optimized formulations. Dexlansoprazole is the R(+)-enantiomer of lansoprazole and shows stereoselective differences in absorption and metabolism compared with the racemic mixture of lansoprazole. The formulation was further refined to use pulsate-type granules with enteric coating to withstand acidic gastric conditions, while allowing prolonged absorption in the proximal and distal small intestine. As a result, the dual delayed-release formulation of dexlansoprazole has a plasma concentration-time profile characterized by 2 distinct peaks, leading to an extended duration of therapeutic plasma drug concentrations compared with the conventional delayed-release lansoprazole formulation. The dual delayed-release formulation maintains plasma drug concentrations longer than the lansoprazole delayed-release formulation at all doses.

The potential role of potassium-competitive acid blockers in the treatment of gastroesophageal reflux disease

PURPOSE OF REVIEW

Gastroesophageal reflux disease (GERD) is primarily a motor disorder, but its pathogenesis is multifactorial. Although gastric acid secretion is usually normal in GERD patients, treatment with proton pump inhibitors (PPIs) has become the standard of care, despite increasing awareness of their shortcomings. In this article, a new class of antisecretory drugs (namely potassium-competitive acid blockers, P-CABs), developed to overcome these limitations, is discussed.

RECENT FINDINGS

P-CABs block the K exchange channel of the proton pump, resulting in rapid, competitive, reversible inhibition of acid secretion. These drugs offer a more rapid elevation of intragastric pH than PPIs, while maintaining similar antisecretory effect, the duration of which is dependent on half-life and can be prolonged with extended release formulations. Thus, P-CABs offer advances in the treatment of GERD including rapid heartburn relief, faster and more reliable healing of severe grades of erosive esophagitis, as a consequence of better control of nighttime acid secretion than PPIs.

SUMMARY

P-CABs overcome many of the drawbacks of PPIs. The unique antisecretory effects of vonoprazan might be especially useful in the long-term treatment of patients with Barrett's esophagus.

Mucosal Two-Step Pathogenesis in Gastroesophageal Reflux Disease: Repeated Weakly Acidic Stimulation and Activation of Protease-Activated Receptor-2 on Mucosal Interleukin-8 Secretion

BACKGROUND

Activation of protease-activated receptor-2 (PAR2) is involved in the mucosal immune pathogenesis of gastroesophageal reflux disease (GERD) that is characterized by proinflammatory cytokines such as interleukin-8 (IL-8). PAR2 activation on epithelial cells induces epithelial IL-8 secretion and initiates mucosal inflammation.

METHODS

A human primary esophageal epithelial cell model was established to investigate the effects of repeated stimulation with weakly acidic solutions and subsequent PAR2 activation. After creating a monolayer, cells were incubated under weakly acidic conditions for 7 h followed by 17 h at pH 7.4. This short-term exposure was repeated once. After weakly acidic stimulation, PAR2 activation was achieved by a synthetic agonist at pH 7.4.

RESULTS

After repeated weakly acidic incubation, PAR2 transcript levels were 3.6-fold upregulated (p = 0.001) and IL-8 transcripts were 2.4-fold enhanced (p = 0.034) compared to nonstimulated controls, while IL-8 protein in the cell pellet and supernatant was not increased. Only the additional PAR2 activation upon pH stimulation led to increased IL-8 secretion into the supernatant.

CONCLUSIONS

We propose a 2-step mechanism in which repeated weakly acidic exposure leads to the upregulation of epithelial PAR2 expression. The subsequent activation of upregulated PAR2 contributes to the initiation of mucosal inflammation, which underlies the important role of esophageal epithelium in GERD pathogenesis.

Safety, tolerability, pharmacodynamics and pharmacokinetics of DWP14012, a novel potassium-competitive acid blocker, in healthy male subjects

BACKGROUND

A novel potassium-competitive acid blocker, DWP14012, is in clinical development as a potential alternative to proton pump inhibitors for the treatment of acid-related diseases.

AIMS

To evaluate the safety, tolerability, pharmacodynamics and pharmacokinetics of DWP14012 in humans.

METHODS

A randomised, double-blind, double-dummy, placebo- and active-controlled, single- and multiple-ascending dose (SAD and MAD, respectively) study was conducted in healthy male subjects without Helicobacter pylori infection. Subjects randomly received a single oral dose of 10-320 mg DWP14012, esomeprazole (active comparator) or placebo in the SAD study (n = 72) and once daily doses of 20-160 mg DWP14012, esomeprazole or placebo for 7 days in the MAD study (n = 48; 8:2:2). Tolerability was evaluated using a microRNA-122 assay. Pharmacodynamics were evaluated through 24-hour gastric pH monitoring, and pharmacokinetics were evaluated plasma and urine DWP14012 concentrations.

RESULTS

DWP14012 was generally well tolerated. The liver toxicity of DWP14012 was not higher than that of placebo after multiple oral administrations. DWP14012 showed rapid and sustained suppression of gastric acid secretion for 24 hours after dosing. Clear dose-response and exposure-response relationships were observed. Plasma concentrations of DWP14012 increased in a dose-proportional manner in the MAD study, whereas in the SAD study, DWP14012 did not significantly accumulate in the plasma.

CONCLUSIONS

DWP14012 was well tolerated, and showed a rapid and long-lasting gastric acid suppression effect in healthy subjects. These results justify further investigation of DWP14012 in patients with acid-related disorders.

Proton pump inhibitors: from CYP2C19 pharmacogenetics to precision medicine

Introduction: Proton Pump inhibitors (PPIs) are commonly used for a variety of acid related disorders. Despite the overall effectiveness and safety profile of PPIs, some patients do not respond adequately or develop treatment related adverse events. This variable response among patients is in part due to genotype variability of CYP2C19, the gene encoding the CYP450 (CYP2C19) isoenzyme responsible for PPIs metabolism.

Areas covered: This article provides an overview of the pharmacokinetics and mechanism of action of the currently available PPIs, including the magnitude of CYPC19 contribution to their metabolism. Additionally, the role of CYP2C19 genetic variability in the therapeutic effectiveness or outcomes of PPI therapy is highlighted in details, to provide supporting evidence for the potential value of CYP2C19 genotype-guided approaches to PPI drug therapy.

Expert opinion: There is a large body of evidence describing the impact of CYP2C19 variability on PPIs and its potential role in individualizing PPI therapy, yet, CYP2C19 pharmacogenetics has not been widely implemented into clinical practice. More data are needed but CYP2C19 genotype-guided dosing of PPIs is likely to become increasingly common and is expected to improve clinical outcomes, and minimize side effects related to PPIs.

Acid-Suppressive Therapy and Risk of Infections: Pros and Cons

This narrative review summarises the benefits, risks and appropriate use of acid-suppressing drugs (ASDs), proton pump inhibitors and histamine-2 receptor antagonists, advocating a rationale balanced and individualised approach aimed to minimise any serious adverse consequences. It focuses on current controversies on the potential of ASDs to contribute to infections-bacterial, parasitic, fungal, protozoan and viral, particularly in the elderly, comprehensively and critically discusses the growing body of observational literature linking ASD use to a variety of enteric, respiratory, skin and systemic infectious diseases and complications (Clostridium difficile diarrhoea, pneumonia, spontaneous bacterial peritonitis, septicaemia and other). The proposed pathogenic mechanisms of ASD-associated infections (related and unrelated to the inhibition of gastric acid secretion, alterations of the gut microbiome and immunity), and drug-drug interactions are also described. Both probiotics use and correcting vitamin D status may have a significant protective effect decreasing the incidence of ASD-associated infections, especially in the elderly. Despite the limitations of the existing data, the importance of individualised therapy and caution in long-term ASD use considering the balance of benefits and potential harms, factors that may predispose to and actions that may prevent/attenuate adverse effects is evident. A six-step practical algorithm for ASD therapy based on the best available evidence is presented.

A Meta-Analysis and Systematic Review of the Efficacy of Twice Daily PPIs versus Once Daily for Treatment of Gastroesophageal Reflux Disease

Background

To investigate whether PPIs BID is superior to QD for treatment of GERD in a short time.

Methods

We searched PubMed, Cochrane Library, Scopus, EMBASE, Ovid, EBSCO, and Web of Science databases (from 1998 to May 2016) to select RCTs, which compared the efficacy of PPIs BID versus QD for GERD. The primary outcomes were symptom relief or esophageal mucosal healing at weeks 4 and 8. The M-H method with fixed-effect or random-effect model was used to calculate RR and 95% CIs.

Results

Seven RCTs were enrolled. The esophageal healing rates were higher in PPIs BID group (P = 0.01), and rabeprazole 20 mg BID can achieve better mucosal healing than 20 mg QD after 8 weeks (P < 0.05). However, no significant differences were observed in heartburn relief (P = 0.27), sustained symptom relief rates at week 4 (P = 0.05), 24 h pH monitoring after treatment (P = 0.11), endoscopic response at week 4 (P = 0.22), and adverse events (P = 0.18).

Conclusion

PPIs BID more effectively improve endoscopic healing rate at week 8 than PPIs QD. But there are no significant differences in symptom relief, 24 h pH monitoring, sustained symptom relief, and endoscopic response at week 4.

Randomised clinical trial: mucosal protection combined with acid suppression in the treatment of non-erosive reflux disease - efficacy of Esoxx, a hyaluronic acid-chondroitin sulphate based bioadhesive formulation

BACKGROUND

Several studies have shown that patients with non-erosive reflux disease (NERD) are less responsive to proton pump inhibitors (PPIs) than those with erosive disease as they belong to different subgroups, in whom factors other than acid can trigger symptoms.

AIM

To evaluate whether combined therapy (mucosal protection plus acid suppression) would improve symptom relief compared to PPI treatment alone.

METHODS

In a multicenter, randomised, double-blind trial, 154 patients with NERD were randomised to receive Esoxx (Alfa Wassermann, Bologna, Italy), a hyaluronic acid-chondroitin sulphate based bioadhesive formulation, or placebo, in addition to acid suppression with standard dose PPIs for 2 weeks. Symptoms (heartburn, acid regurgitation, retrosternal pain and acid taste in the mouth) and health-related quality of life (HRQL) were evaluated before and after treatment. The primary endpoint was the proportion of patients with at least a 3-point reduction in the total symptom score.

RESULTS

At the end of treatment, the primary endpoint was reached by 52.6% of patients taking Esoxx compared to 32.1% of those given placebo (P < 0.01). The same was true also for HRQL, evaluated by means of the Short Form-36 questionnaire, which improved with both treatments, but some items were significantly better after Esoxx plus PPI therapy.

CONCLUSION

The synergistic effect of Essox with PPI treatment suggests that mucosal protection added to acid suppression could improve symptoms and HRQL in NERD patients.

Risk of dementia from proton pump inhibitor use in Asian population: A nationwide cohort study in Taiwan

Introduction

Concerns have been raised regarding the potential association between proton pump inhibitor (PPI) use and dementia.

Objective

This study aimed to examine this association in an Asian population.

Methods

Patients initiating PPI therapy between January 1, 2000 and December 31, 2003 without a prior history of dementia were identified from Taiwan’s National Health Insurance Research Database. The outcome of interest was all-cause dementia. Cox regression models were applied to estimate the hazard ratio (HR) of dementia. The cumulative PPI dosage stratified by quartiles of defined daily doses and adjusted for baseline disease risk score served as the primary variables compared against no PPI use.

Results

We analyzed the data of 15726 participants aged 40 years or older and free of dementia at baseline. PPI users (n = 7863; average follow-up 8.44 years) had a significantly increased risk of dementia over non—PPI users (n = 7863; average follow-up 9.55 years) (adjusted HR [aHR] 1.22; 95% confidence interval: 1.05–1.42). A significant association was observed between cumulative PPI use and risk of dementia (P for trend = .013). Subgroup analysis showed excess frequency of dementia in PPI users diagnosed with depression (aHR 2.73 [1.91–3.89]), hyperlipidemia (aHR 1.81 [1.38–2.38]), ischemic heart disease (aHR 1.55 [1.12–2.14]), and hypertension (aHR 1.54 [1.21–1.95]).

Conclusions

An increased risk for dementia was identified among the Asian PPI users. Cumulative PPI use was significantly associated with dementia. Further investigation into the possible biological mechanisms underlying the relationship between dementia and PPI use is warranted.

Post-fundoplication symptoms and complications: Diagnostic approach and treatment

Laparoscopic Nissen fundoplication is currently considered the surgical treatment of choice for gastroesophageal reflux disease (GERD) and its long-term effectiveness is above 90%. Adequate patient selection and the experience of the surgeon are among the predictive factors of good clinical response. However, there can be new, persistent, and recurrent symptoms after the antireflux procedure in up to 30% of the cases. There are numerous causes, but in general, they are due to one or more anatomic abnormalities and esophageal and gastric function alterations. When there are persistent symptoms after the surgical procedure, the surgery should be described as "failed". In the case of a patient that initially manifests symptom control, but the symptoms then reappear, the term "dysfunction" could be used. When symptoms worsen, or when symptoms or clinical situations appear that did not exist before the surgery, this should be considered a "complication". Postoperative dysphagia and dyspeptic symptoms are very frequent and require an integrated approach to determine the best possible treatment. This review details the pathophysiologic aspects, diagnostic approach, and treatment of the symptoms and complications after fundoplication for the management of GERD.

Dexlansoprazole: delayed-release orally disintegrating tablets for the treatment of heartburn associated with non-erosive gastroesophageal reflux disease and the maintenance of erosive esophagitis

Gastroesophageal reflux disease (GERD) is a common condition afflicting millions of patients, whose prevalence continues to rise owing to the aging population and increasing burden of comorbid conditions, such as obesity. Currently, the mainstay of therapy for GERD is treatment with proton pump inhibitors (PPIs), which have proven efficacy, safety, and tolerability. Despite this, a considerable number of patients have refractory symptoms to PPI therapy. Dexlansoprazole is a new addition to the class of PPIs, which has a unique dual delayed drug release system, which aims to address the current limitations of acid suppressive therapy by offering extended acid suppression and improved ease of administration. Areas covered: This manuscript covers the pharmacokinetics, pharmacodynamics, clinical efficacy, and regulatory approval of dexlansoprazole. Additionally, there is further discussion concerning the current market settings and the potential future impact of dexlansoprazole. Expert commentary: Overall, dexlansoprazole offers benefits in its ease of administration and proven efficacy in the healing, maintenance of erosive esophagitis, and symptomatic non-erosive GERD. Long-term, dexlansoprazole will likely find a niche market among patients who fail other acid suppressive therapy or who desire simplified administration for compliance concerns, but will likely come at a higher out of pocket expense than comparable generic PPIs.

Proton pump inhibitors for the treatment of patients with erosive esophagitis and gastroesophageal reflux disease: current evidence and safety of dexlansoprazole

Gastroesophageal reflux disease is the most common upper gastroenterology disorder in the US. It is associated with a variety of complications and significantly impacts quality of life. Proton pump inhibitors are the most effective treatment. Dexlansoprazole modified release (MR) is a proton pump inhibitor that employs a novel release formulation that prolongs its absorption and allows for more flexibility in dosing. Dexlansoprazole MR can be dosed without regard to food intake or time of day, and once-daily dosing may replace twice-daily dosing of other agents. Dexlansoprazole MR is effective for healing and maintenance of erosive esophagitis, and for the treatment of nonerosive disease, including nocturnal gastroesophageal reflux disease. Dexlansoprazole MR is safe and well tolerated, and can improve quality of life.

Managing gastroesophageal reflux disease - comparative efficacy and outcomes of dexlansoprazole MR

The management of gastroesophageal reflux disease (GERD) has been revolutionized with the development of proton pump inhibitors (PPIs). Unfortunately, due to the inherent pharmacokinetic and pharmacodynamic profiles of conventional PPIs, many patients continue to suffer from symptoms related to GERD despite appropriate use of PPIs. Dexlansoprazole MR is a PPI with a unique dual delayed-release delivery system that has been designed to address the unmet needs in GERD management. Specifically, dexlansoprazole MR addresses limitations with short plasma half-life and need for meal-associated dosing, characteristic of conventional PPIs. In addition, dexlansoprazole MR has been shown to be effective in several specific clinical situations. These include coadministration with clopidogrel, healing of all grades of erosive esophagitis, improvement in reflux-related quality of life, step down to once-per-day dosing, and treatment of Helicobacter pylori infections. Furthermore, dexlansoprazole MR has been found to induce symptom improvement in patients with nonerosive esophageal reflux disease, nocturnal heartburn and GERD-related sleep disturbance, and regurgitation. Overall, dexlansoprazole MR is a unique and useful tool in the management of GERD.

Potassium-Competitive Acid Blockers (P-CABs): Are They Finally Ready for Prime Time in Acid-Related Disease?

The need for new acid suppressing agents with improved pharmacology and superior antisecretory effects to address unmet clinical needs in acid-related disorders has been evident for over a decade. Recent new antisecretory drugs (IR-omeprazole and MR-dexlansoprazole) only provide a small incremental advance in control of acid secretion over the delayed-release proton pump inhibitors. Vonoprazan (a new potassium-competitive acid blocker) displays more potent and extended 24 h acid suppression and preliminary Japanese trials translate this into meaningful clinical benefits in gastro-esophageal reflux disease and Helicobacter pylori eradication. We review the vonoprazan information to date and the indications, benefits, and concerns of more effective therapeutic control of acid secretion.

Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Single Rising TAK-438 (Vonoprazan) Doses in Healthy Male Japanese/non-Japanese Subjects

OBJECTIVES:

To evaluate safety, tolerability, pharmacokinetics, and pharmacodynamics of TAK-438 (vonoprazan, a potassium-competitive acid blocker) in healthy male subjects.

METHODS:

In two phase I, randomized, double-blind, placebo-controlled, single rising-dose studies, healthy male subjects (Japan N=84; UK N=63) received a single TAK-438 dose (1–120 mg in Japan and 1–40 mg in the UK). Assessments included safety, tolerability, pharmacokinetics, and pharmacodynamics (intragastric pH).

RESULTS:

Plasma concentration–time profiles of TAK-438 at all dose levels showed rapid absorption (median T_max up to 2 h). Estimated mean elimination half-life was up to 9 h. Exposure was slightly greater than dose proportional. No clear difference in TAK-438 pharmacokinetics was observed between Japanese and non-Japanese subjects. Acid suppression was dose dependent and similar in both studies. The 24-h intragastric pH ≥4 holding time ratio with 40 mg TAK-438 was 92% in Japan and 87% in the UK. TAK-438 was well tolerated, with no adverse events reported in Japanese subjects; 10 of 63 UK subjects experienced 12 treatment-emergent adverse events (non-serious). Increases in serum gastrin and pepsinogen I and II concentrations were observed at doses ≥10 mg, but there were no changes in alanine aminotransferase concentrations.

CONCLUSIONS:

Single oral doses of TAK-438 20–120 mg caused rapid, profound, and 24-h suppression of gastric acid secretion in healthy male subjects, regardless of geographical region, and TAK-438 was well tolerated at all doses studied, making it a potential alternative to proton pump inhibitors for the treatment of acid-related disorders.

Gastric acid secretion: changes during a century

The advances in knowledge of gastric physiology within the past century have been the most exciting and important in this area of interest for many decades. The aim of this presentation consists of a comprehensive review of the extensive recent literature on this topic in order to highlight milestones in the field of gastric physiology, in particular in gastric acid secretion, gastric pathophysiology, acid-related diseases and use of acid regulatory drugs. Moreover, in the 21st century there have been many epidemiologic changes as well as a decrease of Helicobacter pylori infection and gastric cancer together with an increase of gastroesophageal reflux disease and the related increase of pomp proton inhibitor wide use.

Acid peptic diseases: pharmacological approach to treatment

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

Poor effectiveness of proton pump inhibitors in non-erosive reflux disease: the truth in the end!

Despite acid secretion being normal in the majority of patients with gastro-esophageal reflux disease (GERD) or Barrett's esophagus, acid inhibition represents the mainstay of treatment for both these conditions, with the aim of reducing the aggressive nature of the refluxate toward the esophageal mucosa. Proton pump inhibitors (PPIs) represent, therefore, the first choice medical treatment for GERD, in that they are able to provide an 80-85% healing rate for esophageal lesions, a 56-76% symptom relief and also reduce the incidence of complications, such as strictures as well as dysplasia and adenocarcinoma in Barrett's esophagus. According to a widely quoted systematic review, compared to patients with erosive esophagitis, patients with non-erosive reflux disease (i.e., NERD) display a reduced symptom relief with PPIs, with about 20% reduction of therapeutic gain. In this issue of NeuroGastroenterology & Motility, Weijenborg et al. address for the first time the PPI efficacy in subpopulations of patients with NERD. The study shows clearly that, when the diagnosis is accurately made by including a functional test, NERD patients respond to PPI therapy in a similar way to those with erosive disease. Although not as frequent as previously suggested, however, PPI-refractory heartburn does exist. Some 20% (range: 15-27%) of correctly diagnosed and appropriately treated patients do not respond to PPI treatment at standard doses. Although the pathophysiology underlying PPI failure in GERD is complex and likely multifactorial, acid (be it the sole component of refluxate or not) still remains a major causative factor. A better and more predictable form of acid suppression should therefore be pursued.

Chemoprevention of esophageal adenocarcinoma

The incidence of esophageal adenocarcinoma (EAC) is rising rapidly in Western countries, and effective chemoprevention for this malignancy is lacking. Endoscopic surveillance of patients with Barrett's esophagus is currently employed to diagnose EAC at earlier stages, but this strategy has several limitations. Non-steroidal anti-inflammatory drugs and proton pump inhibitors are the most promising agents for prevention of EAC, and a randomized controlled trial of aspirin and esomeprazole is ongoing. Other agents under investigation include green tea, berries, and antioxidants. Cost-effectiveness analyses have shown that chemopreventive agents need to be highly effective at preventing EAC in order to have benefit beyond endoscopic surveillance.

Dexlansoprazole: A proton pump inhibitor with a dual delayed-release system

BACKGROUND

Dexlansoprazole, the dextrorotatory enantiomer of lansoprazole, is a proton pump inhibitor (PPI) formulated to have dual delayed-release properties. It is indicated for healing all grades of esophagitis, maintaining the healing of erosive esophagitis (EE), and treating heartburn associated with nonerosive gastroesophageal reflux disease.

OBJECTIVE

This article reviews the pharmacology, pharmacokinetics, and pharmacodynamics of dexlansoprazole, as well as its clinical efficacy and tolerability.

METHODS

MEDLINE (1966-April 2010) and International Pharmaceutical Abstracts (1970-April 2010) were searched for original research and review articles published in English using the terms dexlansoprazole and TAK-390MR. The reference lists of identified articles were reviewed for additional pertinent publications. Abstracts from 2007-2009 American College of Gastroenterology and Digestive Disease Week meetings were searched using the same terms.

RESULTS

By irreversibly binding to H(+)K(+)-ATPase, dexlansoprazole inhibits acid production by the parietal cell. Its dual delayed-release formulation provides 2 distinct releases of medication, prolonging the mean residence time compared with lansoprazole (5.56-6.43 vs 2.83-3.23 hours, respectively). In 2 identical Phase III trials of the healing of EE, there were no significant differences in rates of complete healing after 8 weeks between dexlansoprazole 60 and 90 mg once daily and lansoprazole 30 mg once daily. In 2 studies of the maintenance of healing of EE, rates of healing at 6 months were significantly higher with dexlansoprazole 30, 60, and 90 mg once daily compared with placebo (P < 0.001). Patients with nonerosive reflux disease who received dexlansoprazole 30 or 60 mg once daily had significantly more 24-hour heartburn-free days compared with those who received placebo (P < 0.001). Dexlansoprazole was well tolerated compared with placebo or lansoprazole in all studies.

CONCLUSIONS

In the studies reviewed, dexlansoprazole was well tolerated and effective in the healing and maintenance of EE, and in the treatment of nonerosive reflux disease. However, most of the available evidence involved comparisons with placebo, making it difficult to draw meaningful conclusions about the place of dexlansoprazole among PPIs. More head-to-head comparative trials with other PPIs are needed to determine whether the unique formulation of dexlansoprazole translates into a clinically meaningful improvement in outcomes.

Weakly acidic reflux

The advent of multichannel intraluminal impedance-pH (MII-pH) monitoring has generated interest in the role of weakly acidic reflux in persistent symptoms in patients with gastroesophageal reflux disease (GERD). Emerging evidence suggests that MII-pH may be superior to conventional pH testing under certain circumstances in the detection of reflux and expert opinions have been put forth advocating a central role for pH impedance monitoring in the detection of GERD. However the clinical relevance of an impedance-based diagnosis of reflux and its impact on clinically relevant outcomes is less clear. This review appraises the role of weakly acidic reflux in health and in GERD patients and the clinical utility of detecting weakly acidic reflux in the management of GERD.

Safety of proton pump inhibitor exposure

Proton pump (H(+)/K(+)-adenosine triphosphatase) inhibitors (PPIs) are widely used to treat patients with acid-related disorders because they are generally perceived to be safe and effective. However, as with any pharmacologic agent, they have the potential for side effects. Many studies have examined the side effects of long-term or short-term PPI exposure. We review the mechanism of action of PPIs, focusing on recently released products that might have greater risks of adverse effects than older products because of increased potency and/or duration of action. We summarize the data available on the putative adverse effects of PPI therapy and propose guidelines for clinicians who prescribe these agents to limit the potential for adverse outcomes in users of these effective therapeutic agents.

1-[5-(2-Fluorophenyl)-1-(pyridin-3-ylsulfonyl)-1H-pyrrol-3-yl]-N-methylmethanamine monofumarate (TAK-438), a novel and potent potassium-competitive acid blocker for the treatment of acid-related diseases

Proton pump inhibitors (PPIs) are widely used in the treatment of acid-related diseases. However, several unmet medical needs, such as suppression of night-time acid secretion and rapid symptom relief, remain. In this study, we investigated the pharmacological effects of 1-[5-(2-fluorophenyl)-1-(pyridin-3-ylsulfonyl)-1H-pyrrol-3-yl]-N-methylmethanamine monofumarate (TAK-438), a novel potassium-competitive acid blocker (P-CAB), on gastric acid secretion in comparison with lansoprazole, a typical PPI, and SCH28080 [3-(cyanomethyl)-2-methyl,8-(phenylmethoxy)imidazo(1,2-a)pyridine], a prototype of P-CAB. TAK-438, SCH28080, and lansoprazole inhibited H(+),K(+)-ATPase activity in porcine gastric microsomes with IC(50) values of 0.019, 0.14, and 7.6 μM, respectively, at pH 6.5. The inhibitory activity of TAK-438 was unaffected by ambient pH, whereas the inhibitory activities of SCH28080 and lansoprazole were weaker at pH 7.5. The inhibition by TAK-438 and SCH28080 was reversible and achieved in a K(+)-competitive manner, quite different from that by lansoprazole. TAK-438, at a dose of 4 mg/kg (as the free base) orally, completely inhibited basal and 2-deoxy-d-glucose-stimulated gastric acid secretion in rats, and its effect on both was stronger than that of lansoprazole. TAK-438 increased the pH of gastric perfusate to a higher value than did lansoprazole or SCH28080, and the effect of TAK-438 was sustained longer than that of lansoprazole or SCH28080. These results indicate that TAK-438 exerts a more potent and longer-lasting inhibitory action on gastric acid secretion than either lansoprazole or SCH28080. TAK-438 is a novel antisecretory drug that may provide a new option for the patients with acid-related disease that is refractory to, or inadequately controlled by, treatment with PPIs.

Delayed release dexlansoprazole in the treatment of GERD and erosive esophagitis

Although proton pump inhibitors (PPI) have a record of remarkable effectiveness and safety in the management of gastroesophageal reflux disease (GERD), several treatment challenges with PPI have emerged. Dexlansoprazole MR is the (R)-enantiomer of lansoprazole contained in a formulation that produces two distinct releases of drug and significantly extends the duration of active plasma concentrations and % time pH > 4 beyond that of conventional single-release PPI. Dexlansoprazole MR can be administered without regard to meals or the timing of meals in most patients. Dexlansoprazole MR 60 mg demonstrated similar efficacy for healing of erosive esophagitis at 8 weeks compared with lansoprazole 30 mg, and dexlansoprazole MR 30 mg was superior to placebo for maintenance of healed erosive esophagitis at 6 months with 99% of nights and 96% of days heartburn-free over 6 months in patients taking dexlansoprazole MR 30 mg. Superior relief of heartburn occurred in patients taking dexlansoprazole MR 30 mg (55% heartburn-free 24-hour periods) vs placebo (14%) for symptomatic nonerosive GERD. The safety profile of dexlansoprazole MR is similar to that of lansoprazole. The extended pharmacodynamic effects, added convenience, and efficacy and safety of dexlansoprazole MR offer a novel approach to gastric pH control in patients with acid-related disorders.

[Gastro-esophageal reflux through gastric antisecretory drugs]

During the 20th century, gastro-esophageal reflux moved from the status of a rare and severe disease to that of a frequent disease occurring mostly, in the absence of any significant lesions. Proton pump inhibitors (PPIs) are the mainstay of its therapy and are prescribed mainly in an empirical way. Extradigestive manifestations require more accurate diagnostic tests and therapeutic management. The modalities of prescription of the PPIs quickly progressed toward the on-demand therapy and over-the-counter PPIs should become widespread. The relative failures of PPIs led to a profusion of new antisecretory agents but clinical improvements are presently disappointing and the rationale of this escalation is questionable. The concept of non acid gastro-esophageal reflux opens more innovative diagnostic and therapeutic perspectives which, however, must be validated. In this respect, endoscopic treatment needs more reliable techniques and more rigorous trials. Gastro-esophageal reflux refractory to PPIs corresponds mainly to functional esophageal disorders that need diagnostic and therapeutic improvements. Barrett's esophagus constitutes a major challenge for the next few years. Its screening and its prevention seem, for the moment, inaccessible. Its survey and the prevention of its complications should benefit from progress of diagnostic and interventional endoscopy.

Evolving issues in the management of reflux disease?

PURPOSE OF REVIEW

Gastroesophageal reflux disease (GERD) is a common chronic disorder often successfully treated, although there are several evolving issues in management. We reviewed the issues related to unmet needs over the past 12 months.

RECENT FINDINGS

A substantial number of patients fail to respond adequately to once or even twice daily proton pump inhibitor (PPI). There is no standard definition of PPI failure in GERD; a universally accepted definition for treatment success is also not available. Differentiation between erosive esophagitis and nonerosive reflux disease can be made but requires endoscopy; but studies still confuse functional heartburn and nonerosive reflux disease, which impacts management. Acid reflux plays an important role in GERD pathogenesis and the precise role of acid requires more studies of differences between erosive esophagitis and nonerosive reflux disease symptom generation and the implication of nocturnal acidification. Several possible mechanisms may explain GERD refractory to PPIs.

SUMMARY

Management of PPI nonresponders remains a challenge. Objective and precise evaluation of symptoms and treatment response requires study in high-quality trials. New therapeutic approaches are under investigation to answer unmet needs and improve erosive esophagitis healing rates and symptom control.

Review article: dual delayed release formulation of dexlansoprazole MR, a novel approach to overcome the limitations of conventional single release proton pump inhibitor therapy

BACKGROUND

Proton pump inhibitors (PPIs) provide the most effective pharmacotherapy for treating acid-related disorders. However, PPIs do not completely control acid over 24 h with once-daily dosing.

AIMS

To discuss limitations inherent in the pharmacokinetics (PK) and pharmacodynamics of conventional PPI formulations, which provide a single drug release. Also, to consider approaches to extending the duration of acid suppression focusing on dexlansoprazole MR, a PPI with a novel Dual Delayed Release (DDR) formulation.

METHOD

We reviewed the available literature regarding marketed and investigational PPIs.

RESULTS

Non-standard dosing of currently marketed PPIs has produced incremental advances in acid control. Multiple approaches are being evaluated to enhance acid suppression with PPIs. Dexlansoprazole MR is a DDR formulation of dexlansoprazole, an enantiomer of lansoprazole, with two distinct drug release periods to prolong the plasma dexlansoprazole concentration-time profile and extend duration of acid suppression. Clinical studies show that dexlansoprazole MR produces a dual-peak PK profile that maintains therapeutic plasma drug concentrations longer than lansoprazole, with a single-peak PK profile, and increases the percentage of time that intragastric pH >4.

CONCLUSIONS

Novel drug delivery platforms, including the dexlansoprazole MR DDR formulation, may improve acid suppression and offer benefits over conventional single release PPI formulations.

Medical management of gastroesophageal reflux disease

Antisecretory therapies that raise intragastric pH provide the best healing of the esophageal mucosal damage that occurs in gastroesophageal reflux disease. Continuous maintenance therapy is also effective to reduce the likelihood of recurrence of esophagitis and control symptoms in the long term. Proton pump inhibitor (PPI) therapy is an effective approach for healing esophagitis and controlling symptoms. Endoscopic and surgical treatments may provide an option for patients who are refractory to PPIs in whom reflux has been clearly demonstrated. Long-term antireflux medication is often needed after surgical treatment because of persisting or recurrent pathologic reflux and symptoms. An alternative approach to controlling transient lower esophageal sphincter relaxations, such as the GABA-B agonists, deserves further study.