Ilaprazole for the treatment of gastro-esophageal reflux

Introduction: Despite the undoubted benefit of proton pump inhibitors (PPIs), they have several shortcomings, such as a slow onset of action and a remarkable inter-individual variability, that limit the complete success of these drugs. Recently, a new PPI, ilaprazole, has been developed and used in GERD patients.

Areas covered: The present review provides an update on the following points: current knowledge of GERD mechanisms; limitations of actual therapies; pharmacokinetic profile and metabolism of ilaprazole; initial studies on the therapeutic efficacy of ilaprazole in GERD.

Expert opinion: Compared with all other approved PPIs, ilaprazole has shown an extended plasma half-life, a metabolism not significantly influenced by CYP2C19 genetic polymorphism and similar safety. This characteristics account for a low inter-individual variability, particularly in Asian populations, a higher suppression of gastric acid secretion, a more rapid acid control and consequent quicker symptom relief and a better effect on nocturnal acidity. However, clinical investigations assessing the efficacy of ilaprazole in the management of GERD are lacking and therefore the potential improvements achievable with ilaprazole in the current standard of care for acid-suppressing treatment must be confirmed in large and randomly controlled clinical trials enrolling patients with both erosive and non-erosive reflux disease.     

Vonoprazan for treatment of gastroesophageal reflux: pharmacodynamic and pharmacokinetic considerations

Introduction: About 30–40% of GERD patients report an inadequate response to proton pump inhibitors (PPIs) due to their suboptimal pharmacological profiles. Recently, a new synthesized P-CABs, vonoprazan, showed higher suppression of gastric acid secretion as compared to lansoprazole.

Areas covered: This review provides an update on the pharmacokinetic properties of vonoprazan and their correlates with pharmacodynamics; preliminary data on the therapeutic efficacy of vonoprazan as compared to lansoprazole in GERD patients

Expert opinion: At variance from all available PPIs, vonoprazan acts directly on H+,K+-ATPase irrespectively of its activity, providing a fast onset of action without requiring acid activation and specific administration timing. Clinical and pharmacological investigations have confirmed a more rapid, potent and prolonged inhibition of acid secretion, including a better nighttime acid control, and a less antisecretory variability, as compared with PPIs. Preliminary data in patients with erosive esophagitis (EE) have shown the non-inferiority of vonoprazan to lansoprazole in terms of symptom relief and healing rate. Since these pharmacokinetic advantages, it is expected that it will have a significant favorable impact on GERD management. However, the clinical use of vonoprazan raises also some issues about its efficacy and safety in the long-term that deserve verification and careful investigation.     

Randomised clinical trial: twice daily esomeprazole 40 mg vs. pantoprazole 40 mg in Barrett's oesophagus for 1 year

Aliment Pharmacol Ther 2011; 33: 1019–1027

Summary

Background Barrett’s oesophagus is regarded as the most important risk factor for development of oesophageal adenocarcinoma. According to current guidelines, treatment should be limited to symptomatic Barrett’s oesophagus. Aim To evaluate the expression of Ki67, cyclooxygenase‐2 (COX‐2) and apoptosis in Barrett’s oesophagus after 12 months of double‐dose proton pump inhibitor therapy. The effectiveness of esomeprazole and pantoprazole was also compared. Methods Seventy‐seven nondysplastic Barrett’s oesophagus patients underwent baseline upper endoscopy. Patients were then randomised into two groups: one group was allocated to receive esomeprazole 40 mg b.d. and the other group pantoprazole 40 mg b.d. for 12 months. A follow‐up endoscopy was performed at the end of treatment. Sixty‐five of 77 patients agreed to undergo oesophageal manometry and 24‐h pH‐metry. Barrett’s oesophagus biopsies, obtained at baseline and after treatment, were analysed using immunohistochemistry to assess Ki67 and COX‐2 expression; apoptosis was evaluated using TUNEL. Results In the esomeprazole group, a significant decrease in Ki67 and COX‐2 expression, as well as an increase in apoptosis, were observed (P < 0.05). By contrast, in the pantoprazole group Ki67, COX‐2 and apoptosis did not vary significantly from baseline. By 24‐h oesophageal pH‐monitoring, a normal acid exposure time was recorded in patients treated with esomeprazole, while those allocated to pantoprazole displayed abnormal acid exposure (P < 0.05). Conclusions Treatment of Barrett’s oesophagus patients with high‐dose esomeprazole, but not pantoprazole, promoted a decrease in proliferative markers, concomitantly with a decrease in apoptotic cell death. Moreover, esomeprazole allowed a better oesophageal acid control than pantoprazole.     

Overlap of functional heartburn and gastroesophageal reflux disease with irritable bowel syndrome

Several studies indicate a significant degree of overlap between irritable bowel syndrome(IBS)and gastroesophageal reflux disease(GERD).Likewise,both functional heartburn(FH)and IBS are functional digestive disorders that may occur in the same patients.However,data establishing a solid link between FH and IBS are lacking,mainly because the clinical definition of FH has undergone substantial changes over the years.The available literature on the overlap between GERD or FH and IBS highlights considerable heterogeneity in terms of the criteria and diagnostic procedures used to assess heartburn and IBS.In particular,several epidemiological studies included patients with concomitant IBS and GERD without any attempt to distinguish FH(as defined by the RomeⅢcriteria)from GERD via pathophysiological investigations.Independent of these critical issues,there is preliminary evidence supporting a significantdegree of FH-IBS overlap.This underscores the need for studies based on updated diagnostic criteria and accurate pathophysiological classifications,particularly to distinguish FH from GERD.This distinction would represent an essential starting point to achieving a better understanding of pathophysiology in the subclasses of patients with GERD and FH and properly assessing the different degrees of overlap between IBS and the subcategories of heartburn.The present review article intends to appraise and critically discuss current evidence supporting a possible concomitance of GERD or FH with IBS in the same patients and to highlight the pathophysiological relationships between these disorders.     

Lower pH values of weakly acidic refluxes as determinants of heartburn perception in gastroesophageal reflux disease patients with normal esophageal acid exposure

Multichannel impedance pH monitoring has shown that weakly acidic refluxes are able to generate heartburn. However, data on the role of different pH values, ranging between 4 and 7, in the generation of them are lacking. The aim of this study was to evaluate whether different pH values of weakly acidic refluxes play a differential role in provoking reflux symptoms in endoscopy‐negative patients with physiological esophageal acid exposure time and positive symptom index and symptom association probability for weakly acidic refluxes. One hundred and forty‐three consecutive patients with gastroesophageal reflux disease, nonresponders to proton pump inhibitors (PPIs), were allowed a washout from PPIs before undergoing: upper endoscopy, esophageal manometry, and multichannel impedance pH monitoring. In patients with both symptom index and symptom association probability positive for weakly acidic reflux, each weakly acidic reflux was evaluated considering exact pH value, extension, physical characteristics, and correlation with heartburn. Forty‐five patients with normal acid exposure time and positive symptom association probability for weakly acidic reflux were identified. The number of refluxes not heartburn related was higher than those heartburn related. In all distal and proximal liquid refluxes, as well as in distal mixed refluxes, the mean pH value of reflux events associated with heartburn was significantly lower than that not associated. This condition was not confirmed for proximal mixed refluxes. Overall, a low pH of weakly acidic reflux represents a determinant factor in provoking heartburn. This observation contributes to better understand the pathophysiology of symptoms generated by weakly acidic refluxes, paving the way toward the search for different therapeutic approaches to this peculiar condition of esophageal hypersensitivity.     

Esophageal testing: What we have so far

Gastroesophageal reflux disease(GERD) is a common disorder of the gastrointestinal tract. In the last few decades, new technologies have evolved and have been applied to the functional study of the esophagus, allowing for the improvement of our knowledge of the pathophysiology of GERD. High-resolution manometry(HRM) permits greater understanding of the function of the esophagogastric junction and the risks associated with hiatal hernia. Moreover, HRM has been found to be more reproducible and sensitive than conventional water-perfused manometry to detect the presence of transient lower esophageal sphincter relaxation. Esophageal 24-h p H-metry with or without combined impedance is usually performed in patients with negative endoscopy and reflux symptoms who have a poor response to anti-reflux medical therapy to assess esophageal acid exposure and symptom-reflux correlations. In particular, esophageal 24-h impedance and p H monitoring can detect acid and non-acid reflux events. Endo FLIP is a recent technique poorly applied in clinical practice, although it provides a large amount of information about the esophagogastric junction. In the coming years, laryngopharyngeal symptoms could be evaluated with up and coming non-invasive or minimally invasive techniques, such as pepsin detection in saliva or pharyngeal p H-metry. Future studies are required of these techniques to evaluate their diagnostic accuracy and usefulness, although the available data are promising.