Effect of CYP2C19 genetic polymorphisms on the efficacy of proton pump inhibitor-based triple therapy for Helicobacter pylori eradication: a meta-analysis

Quadruple therapy with vonoprazan 20 mg daily as a first-line treatment for Helicobacter pylori infection: A single-center, open-label, noninferiority, randomized controlled trial

BACKGROUND

Although vonoprazan has been proven to be a highly potent drug for Helicobacter pylori eradication, there have been no randomized trials comparing the effectiveness of regimens containing vonoprazan 20 mg daily with alternative standard strategies. We aimed to assess the efficacy, tolerance, and cost-effectiveness of quadruple therapy with vonoprazan 20 mg daily as a first-line therapy for H. pylori eradication.

MATERIALS AND METHODS

We conducted a single-center, open-label, noninferiority, randomized controlled study in Zhejiang, China. Treatment-naive H. pylori-positive participants (n = 234) were randomly assigned to three groups in a 1:1:1 ratio: vonoprazan 20 mg daily with amoxicillin 1000 mg, furazolidone 100 mg and colloidal bismuth 200 mg each given twice a day for 10 days (V10) or 14 days (V14), or esomeprazole 20 mg with amoxicillin 1000 mg, furazolidone 100 mg and colloidal bismuth 200 mg each given twice a day for 14 days (E14). The primary endpoint was the eradication rates in each group. The secondary endpoints were the incidence of adverse events (AEs) and compliance.

RESULTS

The eradication rates in the V10, V14 and E14 groups were 96.2% (89.2-99.2%), 94.9% (87.4-98.6%), and 93.6% (85.7-97.9%) in the intention-to-treat analysis, and 98.6% (92.7-100.0%), 97.4% (90.8-99.7%), and 94.8% (87.2-98.6%) in the per-protocol analysis, respectively. Quadruple therapy with vonoprazan 20 mg daily was noninferior to the esomeprazole-based regimen (Farrington and Manning test: margin 10%, significance level 2.5%). The adverse event rates were 12.8% versus 3.8% versus 6.4% in the V10, V14, and E14 groups, respectively. All regimens were well tolerated without significant differences (p = 0.096). The cost-effectiveness ratio was 1.32, 1.88, and 3.06 for the V10, V14, and E14 groups in the intention-to-treat analysis, respectively. (NCT04907747).

CONCLUSIONS

Vonoprazan (20 mg daily) was as effective as esomeprazole (20 mg twice a day) in quadruple therapies for the eradication of H. pylori, was more economical, and was well tolerated. In addition, the 10-day regimen of vonoprazan (20 mg daily) was comparable to the 14-day regimen.

Effects of CYP2C19 genetic polymorphisms on the cure rates of H. pylori in patients treated with the proton pump inhibitors: An updated meta-analysis

Background: The cure rates of Helicobacter pylori (H. pylori) treatment using a proton pump inhibitor (PPI) are gradually decreasing due to antibiotic resistance, poor compliance, high gastric acidity, and cytochrome P450 2C19 (CYP2C19) polymorphism, and the effects of PPI depend on metabolic enzymes, cytochrome P450 enzymes. The aim of this meta-analysis was to determine whether CYP2C19 polymorphisms affect H. pylori cure rates in patients treated with different proton pump inhibitors (PPIs) according to stratified analysis.

Materials and methods: The literature was searched with the key words “H. pylori” and “CYP2C19” in PubMed, CNKI, and Wanfang up to 31 May 2022, and the studies were limited to clinical observational or randomized controlled trials (RCTs). Finally, seven RCTs and 29 clinical observational studies met the inclusion criteria and were used for the meta-analysis via STATA version 16.

Results: The cure rates were significantly different between genotypes of homozygous extensive metabolizers (EM) and poor metabolizers (PM) (OR = 0.58, 95% CI: 0.47–0.71) and between EM and heterozygous extensive metabolizers (IM) (OR = 0.71, 95% CI: 0.59–0.86), but not between IM and PM. Moreover, there was a significantly lower H. pylori cure rate in EM subjects than that in IM subjects when treated with omeprazole (66.4% vs. 84.1%), lansoprazole (76.1% vs. 85.6%), but not rabeprazole, esomeprazole, or pantoprazole. In addition, there was a significantly lower H. pylori cure rate in EM subjects than that in IM subjects when treated with a PPIs for 7 days (77.4% vs. 82.1%), but not 14 days (85.4% vs. 90.0%).

Conclusion: Carriers of CYP2C19 loss-of-function variant alleles (IM and PM) exhibit a significantly greater cure rate of H. pylori than noncarriers (EM) regardless of other factors (84.7% vs. 79.2%). In addition, pantoprazole- and rabeprazole-based quadruple therapy for H. pylori treatment is less dependent on the CYP2C19 genotype and should be prioritized in Asian populations with H. pylori.

Clinical Factors Implicated in Antibiotic Resistance in Helicobacter pylori Patients

Helicobacter pylori is a common gastric pathogen associated with multiple clinical syndromes, including cancer. Eradication rates of H. pylori remain suboptimal despite the progress made in the past few decades in improving treatment strategies. The low eradication rates are mainly driven by antibiotic resistance of H. pylori. Non-invasive molecular testing to identify patients with antibiotic-resistant H. pylori represents a promising therapeutic avenue, however this technology currently remains limited by availability, costs, and lack of robust validation. Moreover, there is insufficient evidence to demonstrate that resistance-testing-based treatment approaches are superior to appropriately designed empiric strategies. Consensus guidelines recommend use of proven locally effective regimens; however, eradication data are inconsistently generated in several regions of the world. In this review, we describe several clinical factors associated with increased rates of antibiotic resistant H. pylori, including history of previous antibiotic exposure, increasing age, female gender, ethnicity/race, extent of alcohol use, and non-ulcer dyspepsia. Assessment of these factors may aid the clinician in choosing the most appropriate empiric treatment strategy for each patient. Future study should aim to identify locally effective therapies and further explore the clinical factors associated with antibiotic resistance.

Effect of major CYP2C19 genetic polymorphisms on Helicobacter pylori eradication based on different treatment regimens

Helicobacter pylori (H. pylori) infection is a global issue. Its eradication in affected individuals is important to prevent several further complications that may occur if left untreated. Proton pump inhibitors (PPIs) serve an important role in the eradication regimens of H. pylori. PPIs are metabolized primarily through the CYP2C19 enzyme in the liver. Inter-individual variation in the response to eradication treatment may partly be due to variations in the metabolism of PPIs. The aim of this study was to determine whether there was any association between CYP2C19 genetic polymorphisms and the response to eradication therapy amongst Jordanians infected with H. pylori receiving lansoprazole-based regimens. The present study was approved by the Institutional Review Board of The University of Jordan Hospital. A total of 141 patients infected with H. pylori were genotyped for the polymorphisms CYP2C19^*2 and CYP2C19^*17 using the PCR-restriction fragment length polymorphism assay method. Patients received lansoprazole-based triple or sequential therapy. The assessment of eradication was performed using either a H. pylori stool antigen test or from feedback from patients regarding their improvement. Eradication rates were 84.6% and 64.5% in the intermediate-metabolizer and extensive-metabolizer group, respectively. This difference was not statistically significant. Moreover, no significant association was found between the carriers of the CYP2C19^*17 polymorphism and the response to eradication therapy. These findings suggest that there was no significant association between the CYP2C19 genotype and the response to eradication therapy amongst Jordanians infected with H. pylori.

Host Genetic Determinants Associated With Helicobacter pylori Eradication Treatment Failure: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Helicobacter pylori infects approximately 50% of individuals worldwide. Successful H pylori eradication is associated with reduced risk of gastric cancer and peptic ulcer disease, among other conditions. We hypothesized that host genetic determinants, especially those affecting gastric pH, might contribute to eradication therapy failure, particularly when treatment adherence and antibiotic susceptibility are confirmed. We aimed to conduct a meta-analysis of host genetic variants associated with H pylori eradication failure.

METHODS

We searched the literature for studies comparing posttreatment H pylori eradication failure vs success (outcome) according to host genetic polymorphisms (exposure). Reference groups were defined according to genotypes (or corresponding phenotypes) hypothesized to be associated with successful eradication. We pooled estimates using a random-effects model and performed comprehensive sensitivity analyses.

RESULTS

We analyzed 57 studies from 11 countries; the vast majority analyzed CYP2C19 polymorphisms. Among individuals prescribed eradication regimens with proton pump inhibitors predominantly CYP2C19 metabolized, enhanced vs poor metabolizer phenotypes were associated with a 2.52-fold significantly higher likelihood of eradication failure and 4.44-fold significantly higher likelihood when treatment adherence and H pylori clarithromycin susceptibility (if relevant) were confirmed. There was no association between CYP2C19 variants and eradication failure if proton pump inhibitors less metabolized by or that bypass CYP2C19 metabolism were used. IL1B polymorphisms that are vs are not associated with less gastric acid suppression were associated with 1.72-fold significantly higher likelihood of eradication failure. There was no association between MDR1 polymorphisms and H pylori eradication failure. The certainty of evidence was moderate.

CONCLUSION

Based on meta-analysis, we identified host genetic polymorphisms significantly associated with H pylori eradication failure; host genetics might underlie eradication failure among treatment-adherent individuals with confirmed H pylori antibiotic susceptibility.

The effect of CYP2C19 gene polymorphism on the eradication rate of Helicobacter pylori by proton pump inhibitors-containing regimens in Asian populations: a meta-analysis

Premise: The effects of proton pump inhibitors (PPI) depend on metabolic enzyme CYP2C19 that has different activity due to gene polymorphism. The purpose of this meta-analysis is to determine the potential effects of CYP2C19 polymorphism on the efficiency of PPI-based treatment. Materials & methods: The PubMed, EMBASE, Cochrane Library, etc. were searched for relevant articles published in English or Chinese from inception to 31 May 2020. Finally, 26 randomized controlled trials and 15 cohort studies met the inclusion criteria and used for the meta-analysis via STATA version 15. Results: Poor metabolizer (PM) genotype Helicobacter pylori eradication rates were highest for Asian individuals receiving triple or quadruple first-line therapy based on PPIs (p < 0.05). CYP2C19 polymorphism could influence H. pylori eradication rate only in Mainland China and Japan (p < 0.05). Conclusion: PM genotype facilitates the elimination of H. pylori in Asian populations. Rabeprazole-, esomeprazole- and pantoprazole-based eradication program was less affected by the CYP2C19 polymorphism.

Three-Decade Failure to the Eradication of Refractory Helicobacter pylori Infection and Recent Efforts to Eradicate the Infection

BACKGROUND

Helicobacter pylori causes dangerous and deadly diseases such as gastric cancer and duodenal ulcers. Eradication and treatment of this bacterium are very important due to the deadly diseases caused by H. pylori and the high cost of treatment for countries.

METHODS

Thus, we present a complete list of the most important causes of failure in the treatment and eradication of H. pylori, and address new therapeutic methods that may be effective in controlling this bacterium in the future.

RESULTS

Many efforts have been made to control and eradicate this bacterium over the years, but no success has been achieved since its eradication is a complex process affected by the bacterial properties and host factors. Previous studies have shown that various factors are involved in the failure to eradicate H. pylori, such as new genotypes of the bacterium with higher pathogenicity, inappropriate patient cooperation, mutations, biofilm formation and dormant forms that cause antibiotic resistance, acidic stomach pH, high bacterial load, smoking, immunosuppressive features and intracellular occurrence of H. pylori. On the other hand, recent studies reported that the use of probiotics, nanoparticles, antimicrobial peptides, natural product and vaccines can be helpful in the treatment and eradication of H. pylori infections.

CONCLUSION

Eradication of H. pylori is crucial for the treatment of important diseases such as gastric cancer. Therefore, it seems that identifying the failure causes of treating this bacterium can be helpful in controlling the infections. Besides, further studies on new therapeutic strategies may help eradicate H. pylori in the future.

Application of Visual Gene Clip-Based Tailored Therapy for the Eradication of Helicobacter pylori

Background

Helicobacter pylori eradication with therapies employing a proton pump inhibitor (PPI) and antimicrobial agents is mainly achieved via bacterial susceptibility to antimicrobial agents and the magnitude of acid secretion inhibition. However, annual eradication rates have greatly declined in Mainland China, and therefore, tailored H. pylori eradication regimens that inhibit acid secretion and employ optimal antimicrobial agents determined based on gene clip testing may improve eradication rates. This study was aimed at evaluating the efficacy of tailored H. pylori eradication therapy guided by visual gene clip testing for antibiotic resistance and PPI metabolism genotypes.

Methods

This prospective study included 244 patients (141 men and 103 women aged 20-79 years) receiving initial treatment for H. pylori infection. Visual gene clip testing using gastric mucosal specimens was performed to detect antibiotic resistance to clarithromycin conferred by the A2142G and A2143G point mutations of the H. pylori 23S rRNA gene and to levofloxacin conferred by the Asn87 and Asp91 point mutations of the H. pylori gyrA gene. Patients received a 14-day bismuth quadruple therapy regimen guided by testing for antibiotic resistance and CYP2C19 polymorphisms, and primary H. pylori eradication was assessed at least 4 weeks after therapy.

Results

H. pylori strains were successfully isolated from the gastric mucosa tissues of 244 patients. Antibiotic resistant isolates were identified in 63 patients, with clarithromycin resistance observed in 50 patients, levofloxacin resistance in 7 patients, and dual resistance in 6 patients. The PPI metabolic genotype of CYP2C19 was detected in 242 of 244 cases, and 97 cases were categorized as extensive metabolizers, 141 as intermediate metabolizers, and 4 as poor metabolizers. Among the 242 patients who received tailored therapy, the H. pylori eradication rate was 90.9% (95% confidence interval 87.3%~94.6%) in the intention-to-treat analysis and 96.9% (95% confidence interval 94.7%~99.2%) in the per protocol analysis.

Conclusions

Tailored therapy for H. pylori infection guided by determination of antibiotic resistance and CYP2C19 polymorphism using visual gene chip technology may provide high clinical effectiveness as initial H. pylori eradication therapy.

CYP2C19 Polymorphisms in Indonesia: Comparison among Ethnicities and the Association with Clinical Outcomes

Simple Summary

CYP2C19 is known as an enzyme primarily responsible for metabolizing various drugs, such as proton pump inhibitor, antiplatelet, anti-epileptic, and anticoagulant. CYP2C19 is known to be polymorphic and can result in the clinical efficacy of drugs. To examine the prevalence and the distribution of the CYP2C19 genetic polymorphisms in Indonesia, we performed polymerase chain reaction-restriction fragment length polymorphism to the genomic DNA of Indonesian participants. In addition, we also analyzed the distribution of CYP2C19 polymorphisms among ethnicities and clinical outcomes. We found that the prevalence of intermediate metabolizers were the highest in Indonesia, followed by rapid metabolizers and poor metabolizers, respectively. The distribution of metabolizer groups were different between ethnic groups in Indonesia. Therefore, dosage adjustment should be considered when administering drugs-affected by CYP2C19 in Indonesia. The results presented in this study showed the distribution of CYP2C19 variant alleles at the population level in Indonesia and might be used as a consideration for providing personalized treatment in clinical practice.

Abstract

CYP2C19 polymorphisms are important factors for proton pump inhibitor-based therapy. We examined the CYP2C19 genotypes and analyzed the distribution among ethnicities and clinical outcomes in Indonesia. We employed the polymerase chain reaction-restriction fragment length polymorphism method to determine the CYP2C19 genotypes and evaluated inflammation severity with the updated Sydney system. For CYP2C19*2, 46.4% were the homozygous wild-type allele, 14.5% were the homozygous mutated allele, and 39.2% were the heterozygous allele. For CYP2C19*3, 88.6% were the homozygous wild-type allele, 2.4% were the homozygous mutated allele, and 9.0% were the heterozygous allele. Overall, the prevalence of rapid, intermediate, and poor metabolizers in Indonesia was 38.5, 41.6, and 19.9%, respectively. In the poor metabolizer group, the frequency of allele *2 (78.8%) was higher than the frequency of allele *3 (21.2%). The Papuan had a significantly higher likelihood of possessing poor metabolizers than the Balinese (OR 11.0; P = 0.002). The prevalence of poor metabolizers was lower compared with the rapid and intermediate metabolizers among patients with gastritis and gastroesophageal reflux disease. Intermediate metabolizers had the highest prevalence, followed by rapid metabolizers and poor metabolizers. Dosage adjustment should therefore be considered when administering proton pump inhibitor-based therapy in Indonesia.

The appropriate cutoff gastric pH value for Helicobacter pylori eradication with bismuth-based quadruple therapy

BACKGROUND

This study aimed to investigate whether an increased proton pump inhibitor (PPI) dose enhanced the efficacy of Helicobacter pylori (H. pylori) eradication and determine the appropriate cutoff intragastric pH value that could predict H. pylori eradication with bismuth-based quadruple therapy.

MATERIALS AND METHODS

A total of 207 H. pylori infected, treatment naive patients were enrolled in this prospective, open-label, randomized controlled trial. Patients were randomly allocated into Eso40-group (esomeprazole 40 mg bid) and Eso20-group (esomeprazole 20 mg bid), and their CYP2C19 genotyping status was assessed. The 24-h intragastric pH monitoring on day 7 was performed, and percentage of time gastric pH ≥ 3, ≥4, ≥5, and ≥6 (pH holding time ratios; HTRs) were measured. H. pylori eradication was evaluated using ¹³ C-urea breath test.

RESULTS

No significant difference in the eradication rates was observed between two groups. The median 24-h intragastric pH value was not significant different between two groups but the Eso40 Group had a significant higher pH4 HTRs (91.11% [95%CI: 87.50%-95.83%] vs. 95.83% [95.83%-100%]; p = .002). Additionally, the median 24-h intragastric pH value showed significantly difference between two groups in EM genotype (Eso20 Group 6.00 [95%CI; 5.75-6.15] vs. Eso40 Group 6.30 [6.05-6.30]; p = .019). Similar results were observed in pH4 HTRs. There were significant differences in intragastric pH value (6.10 [95%CI: 4.40-7.00] vs. 5.65 [4.85-5.95], p = .038) and in pH4 HTRs (96% [95%CI: 92.00%-96.00%] vs. 87.5% [67.00%-100.0%], p = .019) between eradication-successful and eradication-failed patients. Statistical analysis suggested that the median intragastric pH = 5.7 could identify the success of H. pylori eradication.

CONCLUSIONS

Bismuth-based quadruple therapy resulted in high H. pylori eradication rates either in PPI standard or double doses. Double dose of esomeprazole is associated with better intragastric acid suppression. A median 24-h intragastric pH of 5.7 could be appropriate cutoff value for predicting the successful H. pylori eradication.

Prevalence of CYP2C19 polymorphism in Bogotá, Colombia: The first report of allele *17

INTRODUCTION

Proton pump inhibitors (PPIs) are a group of drugs that are essential for the treatment of acid-related disorders, such as gastroesophageal reflux (GERD), dyspepsia, gastric ulcers and Helicobacter pylori (H. pylori) infection. PPIs such as omeprazole, esomeprazole, pantoprazole and lansoprazole are metabolized by the CYP2C19 enzyme, which is encoded by a polymorphic gene. Four polymorphisms have an impact on the speed of PPI metabolism: CYP2C19*1/*1 (extensive metabolizers), CYP2C19*2/*2 (intermediate metabolizers), CYP2C19*3/*3 (poor metabolizers) and CYP2C19*17/*17 (ultrarapid metabolizers). Extensive and ultrarapid metabolizers inactivate PPIs quickly, which consequently causes low plasma concentrations of PPIs, while intermediate or poor metabolizers have higher plasma concentrations of PPIs and, therefore, PPIs have greater therapeutic efficacy in individuals with these polymorphisms.

OBJECTIVE

To determine the frequency of genetic polymorphisms of the CPY2C19 enzyme in Bogotá, Colombia.

METHODS

This observational study was conducted in Bogotá between 2012 and 2015 and was part of a clinical trial (ID: NCT03650543). It included 239 subjects with dyspepsia, H. pylori infection, or GERD symptoms. CYP2C19 genotyping was performed on gastric biopsy samples. Polymorphisms *1, *2, and *3 were analyzed by real-time PCR (Roche®), and PCR-RFLP was used to determine the presence of polymorphism *17.

RESULTS

The distribution of different types of PPI metabolizers was as follows: extensive (70.7%), ultrarapid (12.9%), intermediate (8.8%) and poor (0.8%).

CONCLUSION

The population studied consisted mainly of extensive and ultrarapid PPI metabolizers. These findings show that it is necessary to increase PPI doses in this group of subjects or to use PPIs that are not metabolized by CYP2C19 (rabeprazole). This is the first Colombian work to identify ultrarapid metabolizers.

Susceptibility-guided quadruple therapy is not superior to medication history-guided therapy for the rescue treatment of Helicobacter pylori infection: A randomized controlled trial

OBJECTIVE

In this study we aimed to compare the efficacy and safety of two personalized rescue therapies for Helicobacter pylori infection.

METHODS

An open-label, single-center, randomized controlled trial was conducted. Patients who had failed one or two regimens for H. pylori infection were randomized to receive a 14-day bismuth-containing quadruple therapy guided by antimicrobial susceptibility testing (AST) or personal medication history (PMH). In the AST group, either two of amoxicillin, clarithromycin, metronidazole or levofloxacin were prescribed according to the AST. In the PMH group, amoxicillin plus either levofloxacin or furazolidone were prescribed based on the patient's history of quinolone use. The primary outcomes were eradication rates confirmed by an urea breath test 6 weeks after treatment. The secondary outcomes were adherence, incidence of adverse events (AE) and cost-effectiveness.

RESULTS

Altogether 164 with a positive culture received AST-guided therapy and 192 received PMH-guided therapy, respectively. Both AST- and PMH-guided therapies achieved comparable eradication rate (intention-to-treat analysis: 78.10% vs 74.29%, P = 0.42; per-protocol analysis: 87.10% vs 88.64%, P = 0.80). The AST clarithromycin regimen had a lower per-protocol eradication rate than the levofloxacin (75.47% vs 96.30%, P = 0.03) or furazolidone-containing regimen (75.47% vs 92.75%, P = 0.02). Both groups had high compliance with low incidences of AE, and PMH-guided therapy had a lower medical cost.

CONCLUSIONS

AST-guided therapy was not superior to PMH-guided therapy as a second- or third-line treatment for H. pylori infection. Considering the cost-effectiveness, PMH therapy is clinically more favorable.

The prolongation effect of ilaprazole-based standard triple therapy for Helicobacter pylori

BACKGROUND

Helicobacter pylori (HP) infection causes many diseases, such as peptic ulcers, gastritis and gastric cancer, and MALToma. It has been gradually accepted that all HP-infected patients should be treated because HP is regarded as an infection. Therefore, the importance of selecting the optimal treatment regimen has increased. Although the 14-day standard triple therapy (STT) is recommended in the current guidelines, prolonging treatment duration is controversial in real practice because of inconsistent results from previous data and the risk of adverse effects. Additionally, the effect of STT using ilaprazole has not been reported until now. We aimed to compare the eradication rate between 7 and 10 days STT using ilaprazole.

METHODS

A prospective randomized controlled trial was conducted, which was divided into 2 treatment groups: the control group was 7 days of STT, and the test group was 10 days of STT. The eradication regimen was 10 mg ilaprazole, 500 mg clarithromycin, and 1000 mg amoxicillin twice daily. We included patients who were diagnosed with positive results of H pylori examination. We compared the HP eradication rate according to treatment duration, CYP2C19 subtype and endoscopic diagnosis.

RESULTS

We enrolled a total of 254 patients consisting of 127 patients in each treatment arm. The eradication rates of the control and test groups were 65.4% (82/127) and 74.8% (95/127), respectively, in the intention-to-treat analysis (P = .1). In the per-protocol analysis, 70.3% (83/118) and 82.6% (94/115) were eradicated in each group, which was statistically significant (P = .027). The CYP2C19 subtype was examined in 230 patients. The eradication rate was 79.2% (57/72), 75.4% (92/122), and 72.2% (26/36) in each group, which was not significantly different (P = .704).

CONCLUSION

Ten-day STT was more effective than 7-day STT for HP eradication. The eradication rate was not affected by the CYP2C19 genotype.

Characterization of metabolic activity, isozyme contribution and species differences of bavachin, and identification of efflux transporters for bavachin-O-glucuronide in HeLa1A1 cells

Objectives

Bavachin is a bioactive natural flavonoid with oestrogen-like activity. Here, we aimed to investigate its metabolic and disposal fates involving in CYPs, UGTs and efflux transporters.

Methods

Phase I metabolism and glucuronidation were performed by human liver microsomes (HLM). Reaction phenotyping and activity correlation analysis were performed to identify the main CYP and UGT isozymes. Chemical inhibition and gene knock-down approaches were employed to explore the function of BCRP and MRPs.

Key findings

Five phase I metabolites (M1–M5) and three glucuronides (G1–G3) were identified. The CLint values for M4 and G1 by HLM were 127.99 and 1159.07 μl/min per mg, respectively. Reaction phenotyping results suggested CYP1A1 (208.85 μl/min per mg) and CYP2C9 (107.51 μl/min per mg), and UGT1A1 (697.19 μl/min per mg), UGT1A7 (535.78 μl/min per mg), UGT1A8 (247.72 μl/min per mg) and UGT1A9 (783.68 μl/min per mg) all participated in the metabolism of bavachin. In addition, activity correlation analysis also supported the results above. Furthermore, the metabolism exhibited marked species differences, and rabbits were the appropriate model animals. Moreover, MRP4 was identified as the main contributor based on chemical inhibition and gene silencing approaches.

Conclusions

CYP1A1 and CYP2C9, UGT1A1, UGT1A7, UGT1A8 and UGT1A9, and MRP4 all played important roles in the metabolism and disposition of bavachin.

Proton Pump Inhibitor Switching Strategy after Failure of Standard Triple Therapy for Helicobacter pylori Infection

Background/Aims: It is still unknown whether cytochrome P450 (CYP) 2C19 polymorphisms influence <i>Helicobacter pylori</i> (<i>H. pylori</i>) eradication, especially in eastern Asia. We aimed to evaluate how changes in proton pump inhibitor (PPI) strategies could be used to overcome the effects of CYP2C19 polymorphism on <i>H. pylori</i> eradication rate when it is used as the second-line regimen after the failure of standard triple therapy.Materials and Methods: We performed a retrospective observation study of 675 patients in whom standard triple therapy for <i>H. pylori</i> infection was not effective between January 2009 to December 2018. All patients underwent a classic bismuth-containing quadruple therapy (10 to 14-day regimen), and their eradication rates were evaluated for several years. We compared the eradication rates in patients with or without the second-line PPI switch. Further, we assessed differences in eradication rates with or without the strategy using esomeprazole and rabeprazole, which are not influenced significantly by CYP2C19 genetic polymorphism.Results: The eradication rate was 81.0% in individuals who received the second-line PPI switch, but it was 74.8% without switching (<i>P</i>=0.14). In the strategy using esomeprazole and rabeprazole, the eradication rate was 84.6%, compared to 76.5% in the control group (<i>P</i>=0.03). Finally, in the group of patients who switched to rabeprazole, the eradication rates were 85.6%, compared to 77.6% in the group who switched to pantoprazole (<i>P</i>=0.05).Conclusions: Switching to PPI, which is not influenced by CYP2C19 genetic polymorphism, increases the efficiency of eradication after the failure of standard triple therapy.

Role of Genetic Polymorphisms of Cytochrome P450 2C19 in Pantoprazole Metabolism and Pantoprazole-based Helicobacter pylori Eradication Regimens

BACKGROUND

Cytochrome P450 (CYP450) enzymes play an important role in the metabolism of 70-80% of the currently used medications, including proton pump inhibitors. There are some data analyzing the impact of gene polymorphisms of CYP450 enzymes on most widely used PPIs, such as omeprazole, however, the data on pantoprazole are highly lacking.

OBJECTIVE

To summarize the most recent publications and studies on the role of polymorphisms of the genes encoding CYP450 enzyme 2C19 in the metabolism of pantoprazole and pantoprazole based Helicobacter pylori eradication regimens.

METHODS

We performed a non-systematic search of the available literature on the selected topic.

RESULTS AND CONCLUSION

The data on cytochrome P450 gene polymorphisms and their role in pantoprazole metabolism and pantoprazole based Helicobacter pylori eradication remain conflicting. Individual differences in pantoprazole metabolism might be partly related to genetic polymorphisms of CYP450 enzymes. Most of the studies support the observation that cytochrome 2C19 polymorphisms have an impact on the pharmacokinetics of pantoprazole and its therapeutic effects: poor metabolizers of PPIs are more likely to have a better response to pantoprazole therapy and achieve better H. pylori eradication rates compared to rapid metabolizers. The determination of alleles that are associated with decreased (e.g., *2, *3 alleles) or increased (e.g., *17 allele) cytochrome 2C19 enzyme activity might be used as predictive factors for the potential of acid suppression and the success of Helicobacter pylori eradication. Overall, currently available data do not provide robust evidence, therefore, the application of genetic polymorphisms of cytochrome enzymes in clinical practice still cannot be recommended as routine practice for personalized pantoprazole prescription strategies.

Metabolism and disposition of corylifol A from Psoralea corylifolia: metabolite mapping, isozyme contribution, species differences and identification of efflux transporters for corylifol A-O-glucuronide in HeLa1A1 cells

Corylifol A (CA), a phenolic compound from Psoralea corylifolia, possessed several biological properties but poor bioavailability. Here we aimed to investigate the roles of cytochromes P450s (CYPs), UDP-glucuronosyltransferases (UGTs) and efflux transporters in metabolism and disposition of CA.Metabolism of CA was evaluated in HLM, expressed CYPs and UGTs. Chemical inhibitors and shRNA-mediated gene silencing of multidrug resistance-associated proteins (MRPs) and breast cancer resistance protein (BCRP) were performed to assess the roles of transporters in CA disposition.Three oxidated metabolites (M1-M3) and two glucuronides (M4-M5) were detected. The intrinsic clearances (CL_int) values of M1 and M4 in HLM were 48.10 and 184.03 μL/min/mg, respectively. Additionally, CYP1A1, 2C8 and 2C19 were identified as main contributors with CL_int values of 13.01-49.36 μL/min/mg, while UGT1A1, 1A7, 1A8 and 1A9 were with CL_int values ranging from 85.01 to 284.07 μL/min/mg. Furthermore, activity correlation analysis proved CYP2C8, UGT1A1 and 1A9 were the main active hepatic isozymes. Besides, rats and monkeys were appropriate model animals. Moreover, dipyridamole and MK571 both could significantly inhibit M4 efflux. Gene silencing results also indicated MRP4 and BCRP were major contributors in HeLa1A1 cells.Taken together, CYPs, UGTs, MRP4 and BCRP were important determinants of CA pharmacokinetics.

Reevaluation of the Efficacy of First Line Regimen for Helicobacter pylori

Background

Helicobacter pylori is a common cause of gastritis, peptic ulcer disease, and non-ulcer dyspepsia, and is also associated with gastric adenocarcinoma and mucosa associated lymphoid tissue lymphoma. Despite being known about for more than 30 years, finding an effective therapeutic strategy against it remains a challenge.

Aim

There are no US studies evaluating the efficacy of a Levofloxacin based therapy for H. pylori infection. We here intend to study the efficacy of Levofloxacin based triple antibiotic regimen as compared to Clarithromycin based triple therapy and Bismuth based quadruple therapy in our patient population.

Methods

This is a retrospective single center observational study. Patients with Helicobacter pylori infection who underwent treatment for H. pylori with one of the three therapies, i.e. Clarithromycin triple, Bismuth Quadruple or Levofloxacin triple, were included in the study and the eradication rates were compared. The confirmation of the H. pylori was done 4 weeks after the completion of anti-microbial therapy.

Results

A total of 177 individuals underwent the H. pylori treatment in our retrospective review. Of these, 54% (n=97) of patients were treated with Clarithromycin based triple therapy (Group 1), 35% (n=63) were treated with Levofloxacin based regimen (Group 2), and the remaining 11% (n=17) were treated with Bismuth based quadruple therapy (Group 3). The eradication rates were significantly higher in patients treated with Clarithromycin based triple therapy as compared to Levofloxacin based triple therapy and Bismuth quadruple therapy (78.3% vs 49.2% vs 41.1% P=0.001).

Conclusion

In conclusion, our study shows significantly lower eradication rates with Levofloxacin triple therapy among a selected US population. Thus, it may not be a good first-line therapy among this US population and the Clarithromycin based regimen may still be used successfully.

Association between parental history of Helicobacter pylori treatment failure and treatment failure in the offspring

BACKGROUND AND AIM

Both clarithromycin-resistant Helicobacter pylori and CYP2C19 polymorphisms may be passed down for generations and are known risk factors for the failure of H. pylori eradication therapy. However, no study has evaluated the risk of clarithromycin triple therapy failure in patients with a parental history of such failure. This study investigated the association between a history of clarithromycin triple therapy failure in parents and clarithromycin triple therapy failure in the offspring.

METHODS

This cross-sectional study was conducted using a large administrative claims database of 3 100 000 insured individuals. We identified 404 patients who had both personal and parental records of prescriptions for first-line clarithromycin triple therapy between January 2005 and February 2018. Failure of clarithromycin triple therapy was defined as treatment with second-line therapy after having received first-line clarithromycin triple therapy. A parental history of clarithromycin triple therapy failure was defined as failure of clarithromycin triple therapy by either the father or the mother. Odds ratios were estimated using logistic regression models adjusted for age, sex, diabetes mellitus, and peptic ulcer.

RESULTS

The incidence of clarithromycin triple therapy failure was 22.5% (91/404). Based on univariate analysis (odds ratio [95% confidence interval], 1.90 [1.10-3.29]) and multivariable analysis (odds ratio [95% confidence interval], 1.93 [1.10-3.39]), parental history of clarithromycin triple therapy failure was associated with failure of clarithromycin triple therapy in the offspring.

CONCLUSION

A parental history of clarithromycin triple therapy failure is a risk factor for failure of clarithromycin triple therapy in the offspring.

Role of Acid Suppression in Acid-related Diseases: Proton Pump Inhibitor and Potassium-competitive Acid Blocker

Proton pump inhibitors are commonly utilized for the treatment of gastric acid-related diseases, such as gastroesophageal reflux disease, peptic ulcer disease, and Helicobacter pylori infection, and for the prevention of low-dose aspirin or nonsteroidal anti-inflammatory drug-induced peptic ulcers. Vonoprazan is a first-in-class potassium-competitive acid blocker, which has distinct advantages compared to other conventional proton pump inhibitors in terms of the efficacy for acid suppression. Due to its strong gastric acid suppression capabilities, vonoprazan serves as an effective drug for the treatment of gastroesophageal reflux disease and H. pylori infection.

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.

Association between CYP2C19 extensive metabolizer phenotype and childhood anti-reflux surgery following failed proton pump inhibitor medication treatment

When pediatric gastroesophageal reflux disease (GERD) that is refractory to proton pump inhibitor (PPI) medication treatment is identified in clinical practice and anti-reflux surgery (ARS) is being considered, genetic factors related to PPI metabolism by the CYP2C19 enzyme are currently not part of the clinical decision-making process. Our objective was to test the hypothesis that the distribution of the extensive metabolizer (EM) phenotypes among children undergoing ARS after failing PPI therapy would differ compared to controls (children with no history of ARS). We conducted a case-control study between children across the Nemours Health System from 2000 to 2014 who received ARS after failing PPI therapy and a control group comprised of healthy children. Our results demonstrated 2.9% of ARSs vs 20.8% of controls were poor metabolizers (PMs), 55.9% of ARSs vs 49.0% of controls were normal metabolizers (NMs), and 41.2% of ARSs vs 30.2% of controls were EMs; p = 0.035. Next, we performed a multiple-regression model to account for race as a potential confounding variable and the EM group was significantly associated with ARS compared to controls (OR 9.78, CI 1.25-76.55, p < 0.03).

CONCLUSION

Among children with medically refractory GERD despite PPI therapy, carriage of CYP2C19*17 allele corresponding to the EM phenotype was associated with ARS. Prospective comparative personalized medicine effectiveness studies are needed to determine if CYP2C19 genotype-guided dosing improves response to PPI therapy without a corresponding increase in adverse effects in children. What is known: • Anti-reflux surgery (ARS) is one of the most common surgical procedures performed in children for the indication of refractory gastroesophageal reflux disease (GERD). What is new: • Individualizing PPI medication dosing based on CYP2C19 diplotype may avoid GERD treatment failures and reduce the need for anti-reflux surgery (ARS).

Cytochrome P450 in Pharmacogenetics: An Update

Interindividual variability in drug disposition is a major cause of lack of efficacy and adverse effects of drug therapies. The majority of hepatically cleared drugs are metabolized by cytochrome P450 (CYP) enzymes, mainly in families CYP1, CYP2, and CYP3. Genes encoding these enzymes are highly variable with allele distribution showing considerable differences between populations. Genetic variability of especially CYP2C9, CYP2C19, CYP2D6, and CYP3A5 is known to have clear clinical impact on drugs that are metabolized by these enzymes. CYP1A2, CYP2A6, CYP2B6, CYP2C8, and CYP3A4 all show variability that affects pharmacokinetics of drugs as well, but so far the evidence regarding their clinical implications is not as conclusive. In this review, we provide an up-to-date summary of the pharmacogenetics of the major human drug-metabolizing CYP enzymes, focusing on clinically significant examples.

Efficacy and tolerability of culture-guided treatment for Helicobacter pylori infection

OBJECTIVE

The aim of this study was to evaluate the efficacy/tolerability of a culture-guided approach in the eradication of Helicobacter pylori and identify factors associated with antibiotic resistance/treatment failure.

PATIENTS AND METHODS

This retrospective single-center study included patients who underwent culture-guided treatment for H. pylori infection, after two ineffective eradication attempts, between October 2012 and December 2016. We assessed the following demographic and clinical data of the patients: sex, age, BMI, alcohol and tobacco consumption, history of dyspepsia, peptic ulceration and first-degree relatives with gastric cancer, antibiotic susceptibility results, treatment composition, tolerability, and success. The treatment success was confirmed by a monoclonal stool antigen test.

RESULTS

Culture-guided treatment was performed in 42 patients (57% women, mean age±SD: 48.9±11.4 years). The rates of antibiotic resistance were as follows: clarithromycin 86%, metronidazole 67%; levofloxacin 52%, tetracycline 2%, and amoxicillin and rifampicin 0%. Double resistance to clarithromycin and metronidazole was found in 59.5% of the patients. Most patients showed resistance to less than three antibiotics, but 31% were resistant to three or more. Intention-to-treat and per-protocol eradication rates were 59.5 and 61.5%. Adverse events occurred in 15 (35.7%) patients, but only two (4.8%) patients did not complete treatment because of adverse events. Only age more than 50 years was associated with resistance to three or more antibiotics. Having a first-degree relative with gastric cancer was associated with treatment failure and having a BMI of at least 25 kg/m protected from failure.

CONCLUSION

Third-line culture-guided treatment often fails to eradicate H. pylori infection. We need to find factors other than in-vitro antibiotic resistance to explain these suboptimal results.

Association Between CYP2C19*17 Alleles and pH Probe Testing Outcomes in Children With Symptomatic Gastroesophageal Reflux

Esophageal pH monitoring remains a primary diagnostic tool for detecting gastroesophageal reflux disease (GERD). GERD that is refractory to proton pump inhibitor (PPI) medications may be related to CYP2C19 variants. Current PPI dosing practices in children do not take into account CYP2C19 allelic variants, which may lead to underdosing and subsequently to a misperception of PPI therapy failure. We hypothesized that pH probe acid exposure outcomes associate with CYP2C19*17 alleles among children with clinical concern for GERD. We identified a retrospective cohort of 74 children (age range 0.71-17.1 years, mean 8.5, SD 4.6) with stored endoscopic tissue samples and who had also undergone esophageal pH testing while on PPI therapy. These individuals were genotyped for common CYP2C19 alleles and were dichotomized to either CYP2C19*17 allelic carriers without corresponding loss of function alleles as cases vs controls. Associations between pH probe acid exposure outcomes and CYP2C19*17 alleles were investigated. Compared to controls, children who carry CYP2C19*17 alleles without corresponding loss-of-function alleles demonstrated statistically significant longer times with pH < 4 (76.46 vs 33.47 minutes, P = .03); and higher percent of time with pH < 4.0 (5.71 vs 2.67 minutes, P = .04). These findings remained statistically significant using multiple-regression modeling with test duration, PPI dose, and race as confounding variables. PPI therapy in children with *17 alleles may be better optimized with CYP2C19 genotype-guided dosing prior to pH probe testing.

Optimization strategies aimed to increase the efficacy of H. pylori eradication therapies

BACKGROUND

As with any other infectious disease, we should aim for treatments offering ≥90% Helicobacter pylori eradication rates in clinical practice.

AIM

To summarize optimization strategies aimed to increase the efficacy of H. pylori eradication therapies.

METHODS

A systematic bibliographic search (in PubMed up to August 2016) was designed to identify studies investigating optimization strategies aimed to increase the efficacy of H. pylori eradication therapies.

RESULTS

The most direct way to optimize a treatment is using higher doses of drugs unless it has been shown that lower doses are equally effective. Similarly, prescriptions should use 14-day duration unless a shorter scheme has been shown locally to be equally effective. Double-dose proton-pump inhibitor therapy is recommended for triple therapy and may probably increase the efficacy of nonbismuth concomitant regimen as well. The efficacy of triple therapies in the presence of resistance can be significantly improved by the addition of bismuth salts, which offer an additive effect in combination with antibiotics. Overall, probiotics seem to reduce antibiotic side effects, but the increase in eradication rates is not so evident; therefore, they cannot be generally recommended for clinical practice yet.

CONCLUSIONS

Using potent acid inhibition and/or higher antibiotic doses-especially by increasing the number of daily intakes-and lengthening treatments up to 14 days improves efficacy in most regimens and should be generally recommended. Triple therapies can be efficiently improved by the addition of bismuth salts, turning them into quadruple therapies. Finally, some treatments will require a combination of optimization strategies to significantly improve results.

Effects of Histamine 2-receptor Antagonists and Proton Pump Inhibitors on the Pharmacokinetics of Gefitinib in Patients With Non-small-cell Lung Cancer

INTRODUCTION

In this study, we investigated the degree of drug interactions between gefitinib and gastric acid suppressants (ie, histamine 2-receptor antagonists [H2RAs] or proton pump inhibitors [PPIs]) with a clinical standard dose in Japanese patients with non-small-cell lung cancer.

METHODS

Retrospectively, 47 patients were divided into 3 groups: gefitinib therapy with a PPI (15 patients) or an H2RA (8 patients) or gefitinib therapy alone (24 patients). On day 15 after beginning gefitinib therapy (administration at 08:00) with or without H2RA (administration twice daily at 08:00 and 18:30) or PPI (administration once daily at 08:00 or 18:30), whole blood samples were collected just prior to and at 1, 2, 4, 6, 8, 12, and 24 hours after administration.

RESULTS

The total area under the observed plasma concentration-time curve (AUC_0-24) and the maximum and trough plasma concentrations of gefitinib with the PPI were significantly lower than those without the PPI. The AUC_0-24 of gefitinib with PPI administration in either the morning or evening were significantly lower than those without PPI administration (P = .015 and .049, respectively); however, there were no significant differences in gefitinib AUC_0-24 between patients taking PPI in the morning and evening. No significant differences were observed in gefitinib exposure among the 3 CYP2C19 genotypes. The AUC_0-24 of gefitinib with H2RA tended to be lower than that without H2RA.

CONCLUSION

If the plasma concentrations of gefitinib cannot be monitored, the combination of gefitinib and PPI should be avoided, and an H2RA should also be used carefully.

Efficacy and Safety of the Triple Therapy Containing Ilaprazole, Levofloxacin, and Amoxicillin as First-Line Treatment in Helicobacter pylori Infections

Background and Aims. To establish the efficacy and safety of ilaprazole, levofloxacin, and amoxicillin as a first-line eradication treatment for Helicobacter pylori. Methods. Patients with gastric ulcer, duodenal ulcer, or gastritis, as detected by esophagogastroduodenoscopy with confirmed H. pylori infection between September 2014 and November 2015, were enrolled in the study. All participants received ilaprazole (10 mg bid), levofloxacin (500 mg bid), and amoxicillin (1000 mg bid) for 10 days. H. pylori eradication was confirmed by a ¹³C-urea breath test at 6–8 weeks after the end of treatment. Results. Of 84 patients included in the analysis, the eradication rate was 88.8% in the per protocol group (n = 80). Demographic factors such as age, gender, body mass index (BMI), alcohol, smoking, hypertension, diabetes mellitus, and peptic ulcer did not affect the eradication rate. However, multivariate analysis showed that overweight patients and patients with cerebrovascular accident (CVA) had a significantly lower eradication rate than patients with normal BMI and without CVA. Laboratory test results did not change significantly after treatment. A total of six (7.5%) patients developed eight adverse reactions. Conclusions. A 10-day triple therapy containing ilaprazole, levofloxacin, and amoxicillin is a safe alternative first-line eradication treatment for H. pylori.

Effect of Multiple Oral Doses of the Potent CYP3A4 Inhibitor Clarithromycin on the Pharmacokinetics of a Single Oral Dose of Vonoprazan: A Phase I, Open-Label, Sequential Design Study

BACKGROUND AND OBJECTIVES

This phase I, open-label, sequential design study assessed the effect of multiple oral doses of the potent cytochrome P450 (CYP) 3A4 inhibitor clarithromycin on the pharmacokinetics of a single oral dose of vonoprazan.

METHODS

During the 10-day treatment period, 16 healthy male subjects received vonoprazan 40 mg on days 1 and 8, and clarithromycin 1000 mg on days 3-9, with the pharmacokinetics of both examined. Primary endpoints included the maximum observed plasma concentration (C _max) and area under the plasma concentration-time curve (AUC) of vonoprazan and its major metabolites (M-I, M-II, M-III, and M-IV-Sul). Safety was also assessed.

RESULTS

Following administration, vonoprazan was rapidly absorbed (time to reach C _max, 2 h), consistent with its known pharmacokinetic profile. This was unchanged in the presence of clarithromycin. Plasma concentrations declined thereafter, with a mean apparent terminal elimination half-life of 7.2 h on day 1 and 9.4 h on day 8. Small-to-moderate increases (1.6- and 1.4-fold) in mean AUC and C _max of vonoprazan, respectively, were observed following clarithromycin. In contrast, AUC and C _max for vonoprazan metabolites decreased, except for M-IV-Sul, which increased approximately 2.1- and 1.5-fold, respectively. Overall, vonoprazan was well tolerated, with mild or moderate treatment-emergent adverse events occurring in six (37.5%) subjects receiving either vonoprazan and/or clarithromycin.

CONCLUSIONS

Modest increases in plasma concentrations of the potent CYP3A4 inhibitor clarithromycin and vonoprazan were observed during coadministration, however these differences were not considered clinically significant. Vonoprazan had a favorable safety and tolerability profile, and no serious adverse events were reported. CLINICALTRIALS.GOV: NCT02774902.

Management of Helicobacter pylori infection-the Maastricht V/Florence Consensus Report

Important progress has been made in the management of Helicobacter pylori infection and in this fifth edition of the Maastricht Consensus Report, key aspects related to the clinical role of H. pylori were re-evaluated in 2015. In the Maastricht V/Florence Consensus Conference, 43 experts from 24 countries examined new data related to H. pylori in five subdivided workshops: (1) Indications/Associations, (2) Diagnosis, (3) Treatment, (4) Prevention/Public Health, (5) H. pylori and the Gastric Microbiota. The results of the individual workshops were presented to a final consensus voting that included all participants. Recommendations are provided on the basis of the best available evidence and relevance to the management of H. pylori infection in the various clinical scenarios.

Randomized Trial Comparing Esomeprazole and Rabeprazole in First-line Eradication Therapy for Helicobacter pylori Infection based on the Serum Levels of Pepsinogens

Objective CYP2C19 metabolic activity influences the efficacy of Helicobacter pylori eradication therapies comprising PPIs. Rabeprazole (RPZ) and esomeprazole (EPZ) are PPIs not extensively metabolized by CYP2C19. The aim of this study was to elucidate whether or not first-line triple therapies using RPZ or EPZ are equally effective in Japanese patients with different CYP2C19 genotypes. Methods Two-hundred patients infected with H. pylori were randomized to receive one of the following regimens: amoxicillin (750 mg), clarithromycin (200 mg), and either esomeprazole (20 mg) (EAC group) or rabeprazole (10 mg) (RAC group), twice a day for one week. The CYP2C19 polymorphisms were determined by polymerase chain reaction and the serum level of pepsinogens was measured. Results The eradication rates of the EAC and RAC regimens were 79.8% (95% confidential interval: 71.7-89.0%) and 74.7% (66.0-83.4%), respectively, in a per protocol (PP) analysis (p=0.488). The eradication rates of the EAC and RAC regimens were not significantly different between patients with the homo EM genotype (p=0.999) or hetero IM or PM genotypes (p=0.286). A lower PG I/II ratio was associated with lower eradication rates (p=0.025). Conclusion Although the eradication rate was less than 80%, the EAC and RAC regimens were equally effective in each CYP2C19 genotype group. The PG I/II ratio was associated with the results of EAC and RAC therapy in this series of patients.

Comparison of Helicobacter pylori Eradication Rates of 2-Week Levofloxacin-Containing Triple Therapy, Levofloxacin-Containing Bismuth Quadruple Therapy, and Standard Bismuth Quadruple Therapy as a First-Line Regimen

OBJECTIVE

The aim of this study was to compare the efficacy and safety of 2-week levofloxacin-containing triple therapy, levofloxacin-containing bismuth quadruple therapy, and standard bismuth-containing quadruple therapy as a first-line regimen for the eradication of Helicobacter pylori.

METHODS

A total of 329 patients with H. pylori infection were randomly divided into 3 groups to receive one of the following regimens: (a) levofloxacin-containing bismuth quadruple therapy, RBAL (rabeprazole 20 mg, b.i.d., bismuth subsalicylate 562 mg, b.i.d., amoxicillin 1 g, b.i.d, levofloxacin 500 mg, once daily), (b) standard bismuth quadruple therapy, RBMT (rabeprazole 20 mg, b.i.d, subsalicylate 562 mg, b.i.d., metronidazole 500 mg, t.i.d, tetracycline 500 mg, q.i.d), or (c) levofloxacin-containing triple therapy, RAL (rabeprazole 20 mg, b.i.d., amoxicillin 1 g, b.i.d, levofloxacin 500 mg, once daily). The primary outcome was the eradication rate in the intention-to-treat (ITT) and per protocol (PP) analysis.

RESULTS

The eradication rates of the above 3 groups using ITT analysis were RBAL 83.8%, RBMT 88.3%, and RAL 74.8% compared with 91.2, 92.5, and 79.2%, respectively, using PP analysis. The eradication rate using RBMT was significantly higher than that of RAL (p = 0.029 in ITT analysis and p = 0.017 in PP analysis). Several side effects occurred in 156 patients (54.1%) in the RBAL group, 215 (52.3%) in the RBMT group, and 56 (26.2%) in the RAL group (p > 0.05, RBAL vs. RBMT; p < 0.001, RBMT vs. RAL; p < 0.001, RBAL vs. RAL).

CONCLUSION

All bismuth-containing quadruple therapies had acceptable eradication rates, but levofloxacin-containing triple therapy was not as good as quadruple therapies. Hence, quadruple therapies should be considered the preferred first-line therapy for H. pylori infections.

Current status of Helicobacter pylori infection and evolution of treatment strategy in China

Infection with Helicobacter pylori (H. pylori) has become a common digestive disease and the prevalence of H. pylori infection remains high in the Chinese population. Recently, the Kyoto global consensus report on H. pylori gastritis and the Toronto consensus for the treatment of H. pylori infection in adults were issued. Therefore, it is essential to discuss the prevention and control of H. pylori infection in China. Due to severe resistance to antibiotics, toxic and host factors, the eradication rate in China has currently became lower than before. Therefore, whether to intervene H. pylori infection in the asymptomatic population and enlarge the indication for eradication and the cost-effect for this new strategy should be discussed. In addition, the implementation of the "test and treat" policy or not in China is debatable. Developing optimal treatment strategy has become a major challenge that clinicians face. This review focuses on the current H. pylori infection situation and the evolution of treatment strategies in China.

A Comparison of Five Different Treatment Regimens as the First-Line Treatment of Helicobacter pylori in Turkey

BACKGROUND

The H. pylori eradication success is low in countries with high antibiotic resistance to H. pylori.

OBJECTIVE

We retrospectively assessed the eradication rates achieved by five different regimens and aimed to compare the efficiency of bismuth enhanced sequential therapy and other treatments in a gastroenterology outpatient clinic a university-affiliated hospital.

DESIGN

Our study was carried out with a retrospective cohort design.

SETTING

This study assessed the gastroscopy examinations of patients.

PATIENTS

A total of 621 patients were included in the study. There were 122 patients in the quadruple treatment group, 168 patients in the classical sequential treatment group, 130 patients in the bismuth enhanced sequential therapy, 113 patients in the sequential treatment with levofloxacin, and 88 patients in the hybrid treatment.

MEASUREMENTS

Eradication rates of different regimens was analyzed by performing Chi-square and Tukey's honest significant difference test.

RESULTS

Eradication rates by ITT and PP analysis achieved by treatment groups were 74.6 and 75.6% in the quadruple treatment; 70.2 and 70.4% in the sequential treatment with clarithromycin, 88.5 and 90.3% in the bismuth enhanced sequential therapy, 77.9 and 78.5% in the sequential treatment with levofloxacin, and 76.1 and 76.2% in the hybrid treatment.

LIMITATIONS

The main limitation of our study was its retrospective nature. Different proton pump inhibitors were used in the treatment arms.

CONCLUSIONS

Bismuth-enhanced sequential therapy can be recommended to overcome resistance.

Antibiotic resistance and CYP2C19 polymorphisms affect the efficacy of concomitant therapies for Helicobacter pylori infection: an open-label, randomized, single-centre clinical trial

OBJECTIVES

We evaluate the efficacy of concomitant therapy for Helicobacter pylori infection and the associated factors that influence it in China, where it has not previously been investigated.

METHODS

In this prospective study, 374 consecutive patients with H. pylori infection were randomly assigned to 10 day regimens of concomitant therapy with different proton pump inhibitors: esomeprazole (20 mg)/omeprazole (20 mg), amoxicillin (1000 mg), clarithromycin (500 mg) and metronidazole (400 mg). All drugs were administered twice daily. A [(13)C]urea breath test was performed at least 4 weeks after the completion of treatment. Gene polymorphisms and antimicrobial susceptibility were determined.

RESULTS

A total of 374 patients with active, uncomplicated duodenal ulcer disease were enrolled in the study (187 cases in each group). The overall eradication rate resulting from concomitant therapy was 90.7% (PP) and 86.1% (ITT) and the eradication rate was significantly higher in the group that received an esomeprazole-based regimen compared with the group that received an omeprazole-based regimen [95.4% versus 86.0%, respectively, P = 0.003 (PP) and 89.8% versus 82.4%, P = 0.036 (ITT), respectively]. Moreover, the omeprazole-based regimen was an independent risk factor for treatment failure (P = 0.039), as were CYP2C19 extensive metabolizer (P = 0.005), clarithromycin (P = 0.000) and metronidazole resistance (P = 0.000). In addition, CYP2C19 polymorphisms and antibiotic resistance had a synergistic effect on eradication rates. The majority of side effects were mild and none was serious.

CONCLUSIONS

The 10 day concomitant therapy yielded an eradication rate of nearly 90%. Antibiotic resistance, CYP2C19 polymorphisms and their interactions were closely associated with regimen efficacy.

Tailored Therapy Versus Empiric Chosen Treatment for Helicobacter pylori Eradication: A Meta-Analysis

Although various regimens are empirically accepted for Helicobacter pylori eradication, the efficacy might be declined by multiple individual factors. The necessity of a personalized eradication therapy still remains controversial. The aim of the study was to compare tailored therapy with empiric chosen regimens. Databases of PUBMED, EMBASE, and MEDLINE were searched for eligible studies, published up to October 2015. All relevant controlled clinical trials were included. A random-effect model was applied to compare pooled relative risk (RR) with related 95% confidence intervals (CIs).Thirteen controlled clinical trials integrating 3512 participants were assessed. Overall, the pooled eradication rates of tailored groups were higher than those of empiric ones (intention-to-treat: RR = 1.16, 95% CI 1.10-1.22; preprotocol: RR = 1.14, 95% CI 1.08-1.21). In subgroup analysis, tailored therapy was superior to 7-day standard triple therapy (RR = 1.22, 95% CI 1.16-1.29) and bismuth-quadruple therapy (RR = 1.14, 95% CI 1.07-1.22) on eradication rates; first-line tailored therapy achieved higher eradication rates than first-line empirical regimens (pooled RR = 1.18, 95%CI 1.14-1.22), whereas tailored rescue regimen showed no difference with empirical ones (pooled RR = 1.16, 95% CI 0.96-1.39). Moreover, among different tailored designs, susceptibility-guided tailored therapy obtained higher eradication rates than empiric groups, independent of CYP2C19 genotype detection (with CYP: RR = 1.16, 95% CI 1.09-1.23; without CYP: RR = 1.14, 95% CI 1.01-1.28). Both molecular test-based and culture-based tailored groups were better on eradication rates than empiric groups (molecular: RR = 1.23, 95% CI 1.11-1.35; culture: RR = 1.13, 95% CI 1.06-1.20). Compared with empiric chosen treatments, tailored therapy is a better alternative for H pylori eradication.

High antibiotic resistance rate: A difficult issue for Helicobacter pylori eradication treatment

Helicobacter pylori (H. pylori) infection is associated with a variety of upper gastrointestinal diseases, including gastric cancer. With the wide application of antibiotics in H. pylori eradication treatment, drug-resistant strains of H. pylori are increasing. H. pylori eradication treatment failure affects the outcome of a variety of diseases of the upper gastrointestinal tract. Therefore, antibiotic resistance that affects H. pylori eradication treatment is a challenging situation for clinicians. The ideal H. pylori eradication therapy should be safe, effective, simple, and economical. The eradication rate of triple antibiotic therapy is currently less than 80% in most parts of the world. Antibiotic resistance is the main reason for treatment failure, therefore the standard triple regimen is no longer suitable as a first-line treatment in most regions. H. pylori eradication treatment may fail for a number of reasons, including H. pylori strain factors, host factors, environmental factors, and inappropriate treatment.

Antibiotic treatment for Helicobacter pylori: Is the end coming?

Infection with the Gram-negative pathogen Helicobacter pylori (H. pylori) has been associated with gastro-duodenal disease and the importance of H. pylori eradication is underscored by its designation as a group I carcinogen. The standard triple therapy consists of a proton pump inhibitor, amoxicillin and clarithromycin, although many other regimens are used, including quadruple, sequential and concomitant therapy regimens supplemented with metronidazole, clarithromycin and levofloxacin. Despite these efforts, current therapeutic regimens lack efficacy in eradication due to antibiotic resistance, drug compliance and antibiotic degradation by the acidic stomach environment. Antibiotic resistance to clarithromycin and metronidazole is particularly problematic and several approaches have been proposed to overcome this issue, such as complementary probiotic therapy with Lactobacillus. Other studies have identified novel molecules with an anti-H. pylori effect, as well as tailored therapy and nanotechnology as viable alternative eradication strategies. This review discusses current antibiotic therapy for H. pylori infections, limitations of this type of therapy and predicts the availability of newly developed therapies for H. pylori eradication.

Long-Term Loss of Response in Proton Pump Inhibitor-Responsive Esophageal Eosinophilia Is Uncommon and Influenced by CYP2C19 Genotype and Rhinoconjunctivitis

OBJECTIVES

Proton pump inhibitor-responsive esophageal eosinophilia (PPI-REE) is diagnosed in at least one-third of patients with suspected eosinophilic esophagitis (EoE). We aimed to evaluate the durability and factors influencing long-term efficacy of PPI therapy.

METHODS

Retrospective multicenter cohort study of patients with PPI-REE who had at least 12 months of follow-up. PPI therapy was tapered to the lowest dose, which maintained clinical remission. Primary outcomes were the proportion of patients with loss of histological response (<15 eos/HPF) and predictors of loss of response. CYP2C19 polymorphisms were determined from blood samples in a subset of patients.

RESULTS

Seventy-five PPI-REE patients were included (mean follow-up 26 months (12-85)), of whom fifty-five (73%) had sustained histological remission on low-dose PPI therapy. Loss of response was significantly higher in those patients with a CYP2C19 rapid metabolizer genotype (36% vs. 6%, P = 0.01) and with rhinoconjunctivitis (40% vs. 13%, P = 0.007). On the multivariate analysis, a CYP2C19 rapid metabolizer genotype (odds ratio (OR) 12.5; 95% confidence interval (CI): 1.3-115.9) and rhinoconjunctivitis (OR 8.6; 95% CI: 1.5-48.7) were independent predictors of loss of response. Among relapsing patients, eosinophilia was limited to the distal esophagus in 14/20 (70%). Nine of ten relapsers, with distal eosinophilia, all showing a CYP2C19 rapid metabolizer genotype, regained histological remission after PPI dose intensification.

CONCLUSIONS

Most PPI-REE patients remain in long-term remission on low-dose PPI therapy. CYP2C19 rapid metabolizer genotypes and rhinoconjunctivitis were independent predictors of loss of response to PPI, but patients frequently responded to PPI dose escalation.

Treatment of Helicobacter Pylori infection: optimization strategies in a high resistance era

INTRODUCTION

Treatment of Helicobacter pylori (H. pylori) infection is paramount for the management of prevalent gastrointestinal disorders and in the prevention of gastric cancer. Due to increasing antimicrobial resistance, performance of standard triple therapies has now declined to unacceptably low levels.

AREAS COVERED

In this article: i) we critically revise optimization tools aiming to improve the outcome of standard treatments; ii) we provide updated evidence on the efficacy and rationale for the use of several non-bismuth quadruple regimens in clinical practice, recommended as preferred empirical therapies in areas of high clarithromycin resistance.

EXPERT OPINION

Prolonged (14-day) treatment duration may boost the efficacy of standard triple therapy by approximately 5%. Use of a high-dose PPI and/or new-generation PPIs, rabeprazole and esomeprazole, might improve eradication rates, particularly in regions where the CYP2C19 rapid metabolizer phenotype is prevalent. Adjunctive probiotics may be considered to improve treatment tolerability, though more data are required to better define their role in H. pylori eradication. Among non-bismuth quadruple regimens, both concomitant and sequential therapies are appropriate options for high-resistance settings; however, concomitant therapy appears to be less impaired by dual clarithromycin/metronidazole resistance. Hybrid therapy is a promising new alternative which seems not to be inferior to concomitant therapy.

Practical Aspects in Choosing a Helicobacter pylori Therapy

Cure rates greater than 90%-95% should be expected with an antimicrobial therapy for Helicobacter pylori infection. Standard triple therapy does not guarantee these efficacy rates in most settings worldwide anymore. The choice of eradication regimen should be dictated by factors that can predict the outcome: (1) H. pylori susceptibility; (2) patients' history of prior antibiotic therapy; and (3) local data, either resistance patterns or clinical success. Currently, the preferred first-line choices are 14-day bismuth quadruple and 14-day non-bismuth quadruple concomitant therapy. Bismuth quadruple (if not used previously), fluoroquinolone-, furazolidone- and rifabutin-containing regimens might be effective rescue treatments.

Pharmacogenomics of antimicrobial agents

Antimicrobial efficacy and toxicity varies between individuals owing to multiple factors. Genetic variants that affect drug-metabolizing enzymes may influence antimicrobial pharmacokinetics and pharmacodynamics, thereby determining efficacy and/or toxicity. In addition, many severe immune-mediated reactions have been associated with HLA class I and class II genes. In the last two decades, understanding of pharmacogenomic factors that influence antimicrobial efficacy and toxicity has rapidly evolved, leading to translational success such as the routine use of HLA-B*57:01 screening to prevent abacavir hypersensitivity reactions. This article examines recent advances in the field of antimicrobial pharmacogenomics that potentially affect treatment efficacy and toxicity, and challenges that exist between pharmacogenomic discovery and translation into clinical use.

[Inadequate response to proton pump inhibitor therapy: causes and patient management tactics]

The past decade has been marked by a considerable increase in the number of patients with gastroesophageal reflux disease and gastroduodenal ulcer who show an inadequate response to proton pump inhibitor (PPI) therapy. At the present time, most of the causes diminishing the response have been elucidated. Unfortunately, they cannot always be eliminated by drug therapy; nonetheless, rabeprazole has a number of advantages over other PPIs. The major causes of an inadequate response to PPI therapy are low treatment motivation; nocturnal gastric acid breakthroughs; genetically determined CYP polymorphism; chiefly nighttime symptoms of gastroesophageal reflux disease; non-acid refluxes; hypersensitive esophagus; overweight and obesity.