Pharmacological and Safety Profile of Dexlansoprazole: A New Proton Pump Inhibitor - Implications for Treatment of Gastroesophageal Reflux Disease in the Asia Pacific Region

A Comprehensive Review of Xanthan Gum-Based Oral Drug Delivery Systems

Xanthan gum (XG) is an exopolysaccharide synthesized by the aerobic fermentation of simple sugars using Xanthomonas bacteria. It comprises a cellulosic backbone with a trisaccharide side chain connected to alternative glucose residues in the main backbone through α (1→3) linkage. XG dissolves readily in cold and hot water to produce a viscous solution that behaves like a pseudoplastic fluid. It shows excellent resistance to enzymatic degradation and great stability throughout a broad temperature, pH, or salt concentration range. Additionally, XG is nontoxic, biocompatible, and biodegradable, making it a suitable carrier for drug delivery. Furthermore, the carboxylic functions of pyruvate and glucuronic acid offer a considerable opportunity for chemical modification to meet the desired criteria for a specific application. Therefore, XG or its derivatives in conjunction with other polymers have frequently been studied as matrices for tablets, nanoparticles, microparticles, and hydrogels. This review primarily focuses on the applications of XG in various oral delivery systems over the past decade, including sustained-release formulations, gastroretentive dosage forms, and colon-targeted drug delivery. Source, production methods, and physicochemical properties relevant to drug delivery applications of XG have also been discussed.

Structural characterization of the optical isomers esomeprazole and omeprazole using the JADER and FAERS databases

BACKGROUND

It is unclear whether the s (-) form of esomeprazole (EPZ) has an improved safety profile when compared with its racemic form omeprazole (OPZ). We assessed the potential complications of these optical isomers when combined with cilostazol, clopidogrel, and prasugrel, which are frequently used concomitant medications.

METHODS

Using two adverse event spontaneous reporting databases, Japanese Adverse Drug Event Report (JADER) and FDA Adverse Event Reporting System (FAERS), adverse event names for hemorrhage, venous/arterial embolization, and thrombus were obtained from the Medical Dictionary for Regulatory Activities. Reported odds ratios were calculated using a 2 × 2 contingency table, and a signal was considered present if the lower limit of the 95% confidence interval was >1.

RESULTS

In combination with cilostazol, a hemorrhagic signal for OPZ in JADER and arterial emboli and thrombus signals for EPZ were detected in both databases. In combination with clopidogrel, OPZ showed arterial emboli and thrombus signals in JADER and venous/arterial emboli and thrombus signals in FAERS, while EPZ displayed arterial emboli and thrombus signals in FAERS. In contrast, when in combination with prasugrel, there were no adverse event signals in either database.

CONCLUSION

This study has confirmed using big data, that EPZ, the optical isomer and racemic form of omeprazole, has the beneficial characteristics of being less sensitive to CYP, as was intended by its design.

Conversion of Racemic Alkyl Aryl Sulfoxides into Pure Enantiomers Using a Recycle Photoreactor: Tandem Use of Chromatography on Chiral Support and Photoracemization on Solid Support

Chiral sulfoxides are valuable in the fields of medicinal chemistry and organic synthesis. A recycle photoreactor utilizing the concept of deracemization, where a racemate is converted into a pure enantiomer, is developed and successfully applied in the syntheses of chiral alkyl aryl sulfoxides. The recycling system consists of rapid photoracemization using an immobilized photosensitizer and separation of the enantiomers via chiral high-performance liquid chromatography, and the desired pure chiral sulfoxides are obtained after 4-6 cycles. The key to the success of the system is the photoreactor site, wherein the photosensitizer 2,4,6-triphenylpyrylium is immobilized on the resin and irradiated (405 nm) to enable the rapid photoracemizations of the sulfoxides. As the green recycle photoreactor requires no chiral components, it should be a useful alternative system for application in producing chiral compounds.

Nocturnal acid breakthrough and esophageal acidification during treatment with dexlansoprazole as compared to omeprazole in patients with gastroesophageal reflux disease

BACKGROUND

Nocturnal acid breakthrough (NAB) may differ based on duration of proton pump inhibitor (PPI) action and Helicobacter pylori (H. pylori) infection; NAB may influence esophageal acidification (EA) and mucosal damage. Dexlansoprazole, a long-acting PPI, was not compared with omeprazole for NAB, gastric acid suppression, and EA in relation to H. pylori infection.

METHODS

In this prospective open-label comparative observational study, gastroesophageal reflux disease (GERD) patients were evaluated using 24-h dual-channel pH-impedance monitoring while on dexlansoprazole (60 mg, n = 39) and omeprazole (20 mg, n = 41) to study the degree of gastric acid suppression, esophageal acid exposure, and NAB (primary outcome measures). H. pylori was detected by rapid urease test and histology.

RESULTS

NAB tended to be frequent with omeprazole than dexlansoprazole (33/41 [80.5%] vs. 23/39 [59%]; p = 0.06). Though nocturnal mean esophageal pH was comparable between the dexlansoprazole and omeprazole groups, its duration was less with the former (181.5 [15.2-334.2] vs. 283 [158-366] min, p = 0.03). NAB was as frequent in the H. pylori-infected than the non-infected group (11/19 [57.9%] vs. 45/61 [73.8%]; p = 0.1). The nocturnal gastric and esophageal pH in the H. pylori-infected group was higher than in the non-infected group (4.6 ± 1.7 vs. 4 ± 1.6, p = 0.157; 6.1 ± 0.6 vs. 5.8 ± 0.6, p = 0.128). Dexlansoprazole tended to increase 24-h and nocturnal mean gastric pH among H. pylori-infected more than omeprazole (5.9 ± 1.1 vs. 4.2 ± 1.7, p = 0.023; 5.7 ± 1.2 vs. 3.8 ± 1.5, p = 0.006).

CONCLUSION

Dexlansoprazole is more effective than omeprazole in suppressing gastric acid secretion, resulting in lesser EA and NAB, particularly in the presence of H. pylori.

Comparing Efficacy and Safety of Empirical vs. Guided Therapy for Non-cardiac Chest Pain: A Pragmatic Randomized Trial

Background: Non-cardiac chest pain is common with two-thirds due to gastroesophageal reflux disease (GERD).

Objective: To evaluate the effectiveness and safety of guided vs. empirical therapy in non-cardiac chest pain.

Methods: Adults with normal angiogram or stress test were randomized into either a guided or empirical group. In the guided group, after the ambulatory pH-impedance test, if GERD then dexlansoprazole 30 mg/day for 8 weeks, but if functional or hypersensitive chest pain, then theophylline SR 250 mg/day for 4 weeks. In the empirical group, dexlansoprazole 60 mg/day was given for 2 weeks. The primary outcome was global chest pain visual analog score (VAS) and secondary outcomes were Quality of Life in Reflux and Dyspepsia (QOLRAD), GERD questionnaire (GERDQ), and pH parameters, all determined at baseline, 2nd and 8th weeks.

Results: Of 200 screened patients, 132 were excluded, and of 68 randomized per-protocol, 33 were in the guided group and 35 in the empirical group. For between-group analysis, mean global pain scores were better with guided vs. empirical group at 8th week (P = 0.005) but not GERDQ or QOLRAD or any of pH measures (all P > 0.05). For within-group analysis, mean QOLRAD improved earliest at 8th week vs. baseline (P = 0.006) in the guided group and 2nd week vs. baseline (P = 0.011) in the empirical group but no differences were seen in other secondary outcomes (P > 0.05). No serious adverse events were reported.

Conclusions: Guided approach may be preferred over short-term empirical therapy in symptom response, however QOLRAD, acid-related symptoms, or pH measures are not significantly different (trial registration ID no. NCT03319121).

Efficacy and safety of 7 days versus 10 days triple therapy based on levofloxacin-dexlansoprazole for eradication of Helicobacter pylori: A pilot randomized trial

BACKGROUND

Levofloxacin-based triple therapies are considered the standard regimen for eradication of Helicobacter pylori (H. pylori) due to decreased sensitivity to clarithromycin and the optimal duration of therapy is still controversial. Besides, there is no complete evidence about dexlansoprazole efficacy in the eradication of H. pylori.

AIM

Our study aimed to determine the effectiveness of triple therapy based on levofloxacin-dexlansoprazole as a standard treatment for H. pylori infection and estimate the effect of H. pylori on lipid profile and hemoglobin (Hb).

MATERIALS AND METHODS

A pilot prospective randomized trial of a triple therapy based on levofloxacin-dexlansoprazole for H. pylori eradication was conducted at Damanhour Medical National Institute, Egypt; 66 participants with H. pylori infection received levofloxacin (500 mg/day) plus amoxicillin (1 g/12 h) plus dexlansoprazole (60 mg/day). All medications administrated orally for either 7 days or 10 days. Four weeks after treatment, the eradication was assessed by the stool antigen test.

RESULTS

The rate of eradication was 63.6% in levofloxacin, amoxicillin, and dexlansoprazole (LAD) 7-day group, and 90.9% in LAD 10-day group. In addition, laboratory test results showed a significant difference in Hb, low-density lipoprotein, high-density lipoprotein, triglyceride, and total cholesterol levels before and after treatment (P < 0.05).

CONCLUSION

LAD 10 days is the least duration that provides maximum efficacy for H. pylori in Egyptian participants. In addition, successful treatment of H. pylori infection may reduce the risk of anemia and dyslipidemia. Furthermore, all members of the patient's family should be screened for H. pylori to prevent recurrent infection.

Phase 4 Study in Patients From Asia With Gastroesophageal Reflux Disease Treated With Dexlansoprazole

Background/Aims

Since the use of dexlansoprazole in Asian subjects with gastroesophageal reflux disease (GERD) has not been adequately characterized, this study was conducted to evaluate the efficacy and safety of dexlansoprazole modified-release in Asian subjects with non-erosive reflux disease (NERD) and erosive esophagitis (EE).

Methods

In this phase 4, open-label, non-randomized, uncontrolled, multicenter, multi-country study sponsored by Takeda, subjects aged ≥ 20 years with persistent typical GERD symptoms for at least 6 months underwent endoscopy. Based on endoscopic findings, they were assigned to either dexlansoprazole modified-release 30 mg once-daily for 4 weeks (NERD group) or dexlansoprazole modified-release 60 mg once-daily for 8 weeks (EE group). The primary endpoint was the percentage of days that subjects did not experience any 24-hour heartburn or acid regurgitation.

Results

Of the 445 subjects screened from Hong Kong, South Korea, and Taiwan, 208 were enrolled in the NERD group (mean age: 53.6 years, male: 34.6%) and 88 in the EE group (mean age: 51.7 years, male: 55.7%). Over the treatment period, the median percentage of days that subjects did not experience any 24-hour heartburn or acid regurgitation was 26.9% and 65.5% in the NERD and EE groups, respectively; for nighttime heartburn or acid regurgitation the proportions were 59.3% and 83.3%, respectively. The treatment was well tolerated with low incidence of treatment-related adverse events in NERD and EE groups (6.7% and 5.7%, respectively).

Conclusion

In Asian patients with GERD, treatment with dexlansoprazole modified-release indicates a favorable efficacy and safety profile in relieving heartburn and acid regurgitation symptoms.

Advantages and Disadvantages of Long-term Proton Pump Inhibitor Use

Proton pump inhibitors (PPIs) potently inhibit gastric acid secretion and are widely used for treatment of acid-related diseases including gastroesophageal reflux disease and secondary prevention of aspirin/NSAID-induced ulcers. Although clinically important adverse effects of PPIs can occur, just as with other drugs, those are not frequently observed during or after administration. Thus, PPIs are regarded as relatively safe and considered to be clinically beneficial. Recently, PPIs have become frequently administered to patients with functional gastrointestinal diseases or primary prevention of drug-related gastroduodenal damage, even though their beneficial effects for those conditions have not been fully confirmed. PPIs tend to be given for conditions in which the necessity of the drug has not been clarified, thus otherwise rare adverse effects are presented as clinically relevant. Although several PPI-related adverse effects have been reported, their clinical relevance is not yet clear, since the evidence reported in those studies is not at a high enough level, as the majority are based on retrospective observational studies and the reported hazard ratios are low. It is important to administer PPIs only for patients who will gain a substantial clinical benefit and to continue to investigate their adverse effects with high quality prospective studies.

Pantoprazole Does Not Reduce the Antiplatelet Effect of Clopidogrel: A Randomized Controlled Trial in Korea

Background/Aims

Concerns that proton pump inhibitors (PPIs) diminish the efficacy of clopidogrel could hamper the appropriate prescription of PPIs. We evaluated the influence of pantoprazole on the antiplatelet effect of clopidogrel compared with ranitidine, which is regarded as safe, after stratification of the population according to the presence of a cytochrome (CYP) 2C19 polymorphism in Korea.

Methods

Forty patients who underwent dual antiplatelet therapy were randomized to receive pantoprazole (n=20) or ranitidine (n=20). Platelet aggregation was evaluated by impedance aggregometry at baseline (D0) and 8 days after acid-lowering treatments (D9). CYP2C19 was genotyped by polymerase chain reaction restriction fragment length polymorphism.

Results

After co-treatment, the percentage of clopidogrel low-response was 11.1% (2/18) in the pantoprazole group and 10.5% (2/19) in the ranitidine group (p=0.954). The impedance values with adenosine diphosphate stimulus after acid-lowering treatments did not significantly differ between the two groups. In a multiple regression analysis, only ST-elevation myocardial infarction was marginally associated with a reduced antiplatelet effect (odds ratio, 12.07; 95% confidence interval, 0.84 to 173.78). However, pantoprazole use did not affect the antiplatelet effect after correction for the CYP2C19 polymorphism.

Conclusions

This study showed that pantoprazole does not increase platelet aggregation in patients receiving dual antiplatelet therapy (ClinicalTrials.gov number: NCT02733640).

A Double-blind, Randomized, Multicenter Clinical Trial Investigating the Efficacy and Safety of Esomeprazole Single Therapy Versus Mosapride and Esomeprazole Combined Therapy in Patients with Esophageal Reflux Disease

Background/Aims

We aim to evaluate the efficacy and safety of combination therapy in erosive reflux disease (ERD) patients by comparing endoscopic healing rates according to the Los Angeles classification for esomeprazole alone, and esomeprazole plus mosapride.

Methods

A total of 116 ERD patients were randomized to receive esomeprazole 40 mg once daily plus mosapride 5 mg 3 times daily (E+M group), or esomeprazole plus placebo (E only group) for 8 weeks. Patients recorded gastroesophageal reflux disease (GERD) symptom questionnaire at weeks 4 and 8. The primary endpoint was the endoscopic healing rate of ERD after 8 weeks of treatment.

Results

Endoscopic healing rates according to the Los Angeles classification was 32 (66.7%) in the E+M group and 26 (60.5%) in the E only group, but there was no statistically significant difference between the groups. Only at 4 weeks, the total GERD symptom score changes relative to the baseline significantly improved in the E+M group than that of the E only group (−13.4 ± 14.7 vs −8.0 ± 12.3, P = 0.041), and upper abdominal pain and belching score changes showed significantly improved in the E+M group than that of the E only group (P = 0.018 and P = 0.013, respectively).

Conclusions

The combination of a proton pump inhibitor with mosapride shows a tendency for upper abdominal pain, belching, and total GERD symptoms scores to improve more rapidly. This suggests that combination therapy with esomeprazole and mosapride will be useful for rapid improvement of specific GERD symptoms, such as upper abdominal pain and belching in ERD patients.

Efficacy and Safety of Modified Banxia Xiexin Decoction (Pinellia Decoction for Draining the Heart) for Gastroesophageal Reflux Disease in Adults: A Systematic Review and Meta-Analysis

Modified Banxia Xiexin decoction (MBXD) is a classical Chinese herbal formula in treating gastroesophageal reflux disease (GERD) for long time, but the efficacy of it is still controversial. This study is to evaluate the efficacy and safety of MBXD for the treatment of GERD in adults. The search strategy was carried out for publications in seven electronic databases. RevMan software version 5.3 and the Cochrane Collaboration's risk of bias tool were performed for this review. Twelve RCTs were included for the analysis. The results of overall clinical efficacy and efficacy under gastroscope demonstrated that MBXD was superior to conventional western medicine. Meanwhile, the results of subgroup analysis showed clinical heterogeneity between the two groups. However, there was no statistically significant difference in acid regurgitation between the two groups. But in the improvement of heartburn and sternalgia, the results showed statistically significant differences for the comparison between two groups. In addition, the adverse reactions of the experiment groups were not different from those of the control groups. This systematic review indicates that MBXD may have potential effects on the treatment of patients with GERD. But because the evidence of methodological quality and sample sizes is weak, further standardized researches are required.

Pharmacogenomics of proton pump inhibitors

At present, proton pump inhibitors (PPIs), as a class of strong antacid agents, are widely used in the clinical treatment of gastrointestinal diseases. PPIs achieved a strong effect of acid suppression with high specificity and long duration. However, the issue of PPI abuse exists worldwide because of the lack of relevant knowledge. Due to tremendous inter-individual differences in uptake, the clinical application of PPIs appears to be limited. Therefore, rational use of PPIs in daily clinical practice is an important research topic. In addition, PPIs were found with many side effects. CYP2C19, as one of the most important enzymes in cytochrome P450 enzyme family, is responsible for the metabolism of over 10% of drugs. The bioavailability and metabolism of PPIs are mainly affected by drug-metabolizing enzymes CYP2C19 and CYP3A4, which are located in the liver. By suppressing cytochrome P450 isoenzyme, PPIs may affect the metabolism of multiple drugs, thus leading to unwanted side effects in case of combined medication. What's more, the individual difference in PPI administration is derived from distinct molecular mechanisms mediated by CYP3A4 and/or CYP2C19. Non-genetic factors, such as combined medication and food pyramid, also impact on the effectiveness of PPIs. Gene mutations can also alter the enzymatic activity of CY2C19, thereby resulting in different blood concentrations of drugs metabolized by CYP2C19. In conclusion, PPIs have the advantages of safety and effectiveness; however, the problem of drug resistance still exists, which indicates their selective application in clinical practice. In this paper, we review the advances in pharmacogenomics of PPIs, with an aim to provide reference to individualized clinical medication.

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.