Efficacy of metronidazole as second-line drug for the treatment of Helicobacter pylori Infection in the Japanese population: a multicenter study in the Tokyo Metropolitan Area

Managing Helicobacter pylori as an Infectious Disease: Implementation of Antimicrobial Stewardship

Helicobacter pylori is prevalent globally and implicated in various gastric diseases and malignancies. Rising antibiotic resistance has increasingly compromised the effectiveness of standard H. pylori eradication therapies. This review explores the role of antimicrobial stewardship (AMS) as a structured approach to optimizing H. pylori management through the "5D" strategy: Diagnosis-utilizing advanced diagnostic tools to accurately detect bacterial resistance; Drug-selecting antibiotics tailored to resistance profiles and patient-specific factors; Dosage-optimizing dosing and frequency based on pharmacokinetic properties to maximize efficacy; Duration-employing shorter treatment courses where supported by evidence; and Discontinuation-balancing the benefits and risks of repeated antibiotic treatments. We discuss recent advances in diagnostic technologies, such as polymerase chain reaction and next-generation sequencing, and their impact on therapeutic decision-making. Additionally, we evaluate treatment regimens, with a particular focus on emerging alternatives such as regimens containing potassium-competitive acid blockers. Given the growing global resistance and limited pipeline for new antibiotics, we advocate for a more strategic and resource-conscious approach to H. pylori management, integrating AMS principles within the "One Health" framework to address the pathogen's transmission across humans, animals, and the environment. With advancements in resistance testing and diagnostics, H. pylori therapies are likely to become increasingly personalized and precise. To achieve this, effective AMS implementation necessitates interdisciplinary collaboration to maximize therapeutic outcomes, minimize adverse effects, combat resistance, and reduce healthcare costs.

Long-term Response of Helicobacter pylori Antibody Titer After Eradication Treatment in Middle-aged Japanese: JPHC-NEXT Study

BACKGROUND

Helicobacter pylori (H. pylori) is an established causative factor of gastric cancer. Although the expansion of insurance coverage has led to an increase in the number of patients treated for H. pylori, the population impact of eradication treatment for H. pylori has been scarcely investigated. This study aimed to clarify the long-term responses of H. pylori antibody titer after eradication treatment using large scale cross-sectional data from the Japan Public Health Center-based Prospective Study for the Next Generation (JPHC-NEXT Study).

METHODS

A total of 55,282 Japanese participants aged 40 to 74 years residing in 16 areas provided blood samples from 2011 through 2016. From these, treated (n = 6,276) and untreated subjects who were seropositive for H. pylori or had serological atrophy (n = 22,420) formed the study population (n = 28,696). Seropositivity was defined as an anti-H. pylori IgG titer of ≥10 U/mL. Antibody level was compared among subjects according to self-reported treatment history as untreated, and treated for less than 1 year (<1Y), 1 through 5 years (1-5Y), and 6 or more years ago (6Y+).

RESULTS

Median serum antibody titer was 34.0 U/mL, 7.9 U/mL, 4.0 U/mL, and 2.9 U/mL for the untreated, <1Y, 1-5Y, and 6Y+ groups, respectively. While those treated for H. pylori within the previous year had a 76.8% lower antibody titer compared to untreated subjects, approximately 41% of subjects were still seropositive.

CONCLUSION

A significant reduction in H. pylori antibody titer occurs within 1 year after eradication treatment, but that a long period is needed to achieve complete negative conversion.

Randomized controlled study on the effects of triple therapy including vonoprazan or rabeprazole for the second-line treatment of Helicobacter pylori infection

BACKGROUND AND AIM

Inhibition of gastric acid secretion is important for eradicating Helicobacter pylori. Vonoprazan (VPZ) is a strong, long-lasting inhibitor of gastric acid secretion. Studies that examined the effectiveness of VPZ-based triple therapy in second-line treatment have been performed. However, there have been no randomized controlled studies to compare the effect between VPZ-based triple therapy and proton pump inhibitor (PPI)-based triple therapy in second-line treatment, and it is not known which is more effective between VPZ-based and PPI-based therapies. This study aimed to compare the effectiveness of second-line triple therapies including VPZ or rabeprazole (RPZ) as the PPI.

METHODS

Eligible patients with H. pylori infection who failed first-line triple therapy were assigned randomly to the VPZ [VPZ40 mg/day, amoxicillin (AMPC) 1500 mg/day, metronidazole (MNZ) 500 mg/day] or RPZ (RPZ20 mg/day, AMPC1500 mg/day, MNZ500 mg/day) group. A ¹³C-urea breath test result of less than 2.5% was considered as successful eradication.

RESULTS

In total, 46 and 41 patients were analyzed as intention to treat (ITT) and per protocol (PP), respectively. Eradication rates in the VPZ and RPZ groups were 73.9% [95% confidence interval (CI) 51.6-89.8%] and 82.6% (95% CI 61.2-95.0%) based on ITT analysis, respectively (p = 0.72). Based on PP analysis, the eradication rates in the VPZ and RPZ groups were 89.5% (95% CI 66.9-98.7%) and 86.4% (95% CI 65.1-97.1%), respectively (p = 1.00). Two patients in the VPZ group and one in the RPZ group discontinued treatment due to side effects (p = 1.00).

CONCLUSION

There were no significant differences in efficacy and safety between second-line therapies including VPZ or RPZ.

Guidelines for the management of Helicobacter pylori infection in Japan: 2016 Revised Edition

BACKGROUND

Since "Helicobacter pylori (H. pylori) infection" was set as the indication in the Japanese Society for Helicobacter Research (JSHR) Guidelines 2009, eradication treatment for H. pylori gastritis is covered under insurance since 2013 in Japan, and the number of H. pylori eradication has rapidly increased. Under such circumstances, JSHR has made the third revision to the "Guidelines for diagnosis and treatment of H. pylori infection" for the first time in 7 years.

METHODS

The Guideline Committee held 10 meetings. Articles published between the establishment of the 2009 Guidelines and March 2016 were reviewed and classified according to the evidence level; the statements were revised on the basis of this review. After inviting public comments, the revised statements were finalized using the Delphi method.

RESULTS

There was no change in the basic policy that H. pylori infectious disease is an indication for eradication. Other diseases presumed to be associated with H. pylori infection were added as indications. Serum pepsinogen level, endoscopic examination, and X-ray examination were added to the diagnostic methods. The effects of 1-week triple therapy consisting of potassium-competitive acid blocker (P-CAB), amoxicillin, and clarithromycin have improved, and high eradication rates can also be expected with proton pump inhibitors (PPI) or P-CAB combined with amoxicillin and metronidazole. If the susceptibility test is not performed, the triple PPI or P-CAB/amoxicillin/metronidazole therapy should be chosen, because the PPI/amoxicillin/metronidazole combination demonstrated a significantly higher eradication rate than PPI/amoxicillin/clarithromycin. In the proposal for gastric cancer prevention, we divided gastric cancer prevention measures by age from adolescent to elderly, who are at an increased gastric cancer risk, and presented measures for gastric cancer prevention primarily based on H. pylori eradication.

CONCLUSION

We expect the revised guidelines to facilitate appropriate interventions for patients with H. pylori infection and accomplish its eradication and prevention of gastric cancer.

Systematic review, meta-analysis, and meta-regression: Successful second-line treatment for Helicobacter pylori

BACKGROUND

Multiple Helicobacter pylori second-line schedules have been described as potentially useful. It remains unclear, however, which are the best combinations, and which features of second-line treatments are related to better cure rates. The aim of this study was to determine that second-line treatments achieved excellent (>90%) cure rates by performing a systematic review and when possible a meta-analysis. A meta-regression was planned to determine the characteristics of treatments achieving excellent cure rates.

METHODS

A systematic review for studies evaluating second-line Helicobacter pylori treatment was carried out in multiple databases. A formal meta-analysis was performed when an adequate number of comparative studies was found, using RevMan5.3. A meta-regression for evaluating factors predicting cure rates >90% was performed using Stata Statistical Software.

RESULTS

The systematic review identified 115 eligible studies, including 203 evaluable treatment arms. The results were extremely heterogeneous, with 61 treatment arms (30%) achieving optimal (>90%) cure rates. The meta-analysis favored quadruple therapies over triple (83.2% vs 76.1%, OR: 0.59:0.38-0.93; P = .02) and 14-day quadruple treatments over 7-day treatments (91.2% vs 81.5%, OR; 95% CI: 0.42:0.24-0.73; P = .002), although the differences were significant only in the per-protocol analysis. The meta-regression did not find any particular characteristics of the studies to be associated with excellent cure rates.

CONCLUSION

Second-line Helicobacter pylori treatments achieving>90% cure rates are extremely heterogeneous. Quadruple therapy and 14-day treatments seem better than triple therapies and 7-day ones. No single characteristic of the treatments was related to excellent cure rates. Future approaches suitable for infectious diseases-thus considering antibiotic resistances-are needed to design rescue treatments that consistently achieve excellent cure rates.

Meta-analysis: High-dose vs. low-dose metronidazole-containing therapies for Helicobacter pylori eradication treatment

Objective

The purpose of this study was to evaluate the efficacy of high dose of metronidazole in the treatment of Helicobacter pylori (H. pylori) infection.

Methods

Studies were identified from databases (Pubmed, Embase, Cochrane Library, ClinicalTrials.gov) searched from January 1990 to September 2017 using a battery of keywords. We included randomized controlled trials (RCTs) of H. pylori treatment comparing the high-dose and low-dose metronidazole-containing therapies (high-dose and low-dose therapies). Two reviewers independently selected studies, extracted relevant data and assessed study quality. A meta-analysis was performed by using Review Manager 5.3. Dichotomous data were pooled to obtain the relative risk (RR) of the eradication rate, with 95% confidence intervals (CIs).

Results

Four randomized controlled trials, a total of 612 patients with a diagnosis of H. pylori infection were included. Overall the meta-analysis showed that both high-dose and low-dose therapies achieved similar efficacy of intention-to-treat (ITT) eradication rate 82% vs. 76%, RR 1.12 (95%CI: 0.96 to 1.30), P = 0.15, and adherence 94% vs. 94%, RR 1.00 (95%CI: 0.97 to 1.04), P = 0.81, but side effects were more likely in high-dose therapies [32% vs. 17%, RR 1.84 (95%CI: 1.17 to 2.88), P = 0.008]. In subgroup analysis, increasing the dose of metronidazole enhanced eradication rates in areas with high metronidazole resistance [74% vs 52%, RR 1.40 (95%CI: 1.08 to 1.82), P = 0.01] and in individuals with metronidazole-resistant strains [71% vs. 46%, RR 1.50 (95%CI: 1.02 to 2.19), P = 0.04].

Conclusions

Both high-dose and low-dose therapies can achieve similar eradication rates and adherence and generally low-dose therapies cause fewer side effects. In populations with high metronidazole resistance, high dose of metronidazole can increase the eradication rates of H. pylori infection.

Cost-Effectiveness Analysis of Helicobacter pylori Diagnostic Methods in Patients with Atrophic Gastritis

Background. There are several diagnostic methods for Helicobacter pylori (H. pylori) infection. A cost-effective analysis is needed to decide on the optimal diagnostic method. The aim of this study was to determine a cost-effective diagnostic method in patients with atrophic gastritis (AG). Methods. A decision-analysis model including seven diagnostic methods was constructed for patients with AG diagnosed by esophagogastroduodenoscopy. Expected values of cost and effectiveness were calculated for each test. Results. If the prevalence of H. pylori in the patients with AG is 85% and CAM-resistant H. pylori is 30%, histology, stool H. pylori antigen (SHPAg), bacterial culture (BC), and urine H. pylori antibody (UHPAb) were dominated by serum H. pylori IgG antibody (SHPAb), rapid urease test (RUT), and urea breath test (UBT). Among three undominated methods, the incremental cost-effective ratios (ICER) of RUT versus SHPAb and UBT versus RUT were $214 and $1914, respectively. If the prevalence of CAM-sensitive H. pylori was less than 55%, BC was not dominated, but its H. pylori eradication success rate was 0.86. Conclusions. RUT was the most cost-effective at the current prevalence of CAM-resistant H. pylori. BC could not be selected due to its poor effectiveness even if CAM-resistant H. pylori was more than 45%.

Systematic review and meta-analysis: triple therapy combining a proton-pump inhibitor, amoxicillin and metronidazole for Helicobacter pylori first-line treatment

BACKGROUND

Due to clarithromycin resistance, the current efficacy of Helicobacter pylori first-line triple therapies including clarithromycin is low. It seems reasonable to explore alternative clarithromycin-free therapies.

OBJECTIVES

The objective of this study was to evaluate the efficacy of triple therapy including a proton-pump inhibitor (PPI), amoxicillin and metronidazole (PAM) as first-line H. pylori therapy by systematic review and meta-analysis.

METHODS

Studies evaluating PAM in adult patients were included. Meta-analyses comparing PAM with other treatments were performed. The primary endpoint was the ITT eradication rate for H. pylori first-line treatment. In addition, sensitivity analyses ascertained the effects of treatment schedule, dosage and duration on cure rates.

RESULTS

Ninety-four studies (8061 patients) were included. Meta-analyses comparing PAM versus clarithromycin-including triple therapies showed a significant difference in favour of PPI, amoxicillin and clarithromycin (PAC) (70% versus 77.1%; OR = 0.70, 95% CI = 0.56-0.88) and PPI, metronidazole and clarithromycin (PMC) therapy (66.4% versus 77.7%; OR = 0.55, 95% CI = 0.39-0.76). Sensitivity analyses showed a similar efficacy of PAM versus PAC when drugs were administered for 14 days (80% versus 84%; OR = 0.70, 95% CI = 0.44-1.12). There were not enough studies to perform further comparisons. Number of antibiotic doses (P = 0.012), length of treatment (P < 0.001) and use of high metronidazole doses (P = 0.021) were related to higher cure rates in the sensitivity analysis including observational studies.

CONCLUSIONS

PAM was less efficacious than clarithromycin-including triple therapies. However, its efficacy was similar to that of PAC when drugs were administered for 14 days, although ITT cure rates did not reach 90%. Use of 14 day, thrice daily and high-metronidazole-dose PAM treatments markedly increased the cure rate.

Engineering bioinspired bacteria-adhesive clay nanoparticles with a membrane-disruptive property for the treatment of Helicobacter pylori infection

We present a bioinspired design strategy to engineer bacteria-targeting and membrane-disruptive nanoparticles for the effective antibiotic therapy of Helicobacter pylori (H. pylori) infection. Antibacterial nanoparticles were self-assembled from highly exfoliated montmorillonite (eMMT) and cationic linear polyethyleneimine (lPEI) via electrostatic interactions. eMMT functions as a bioinspired 'sticky' building block for anchoring antibacterial nanoparticles onto the bacterial cell surface via bacteria-secreted extracellular polymeric substances (EPS), whereas membrane-disruptive lPEI is able to efficiently lyse the bacterial outer membrane to allow topical transmembrane delivery of antibiotics into the intracellular cytoplasm. As a result, eMMT-lPEI nanoparticles intercalated with the antibiotic metronidazole (MTZ) not only efficiently target bacteria via EPS-mediated adhesion and kill bacteria in vitro, but also can effectively remain in the stomach where H. pylori reside, thereby serving as an efficient drug carrier for the direct on-site release of MTZ into the bacterial cytoplasm. Importantly, MTZ-intercalated eMMT-lPEI nanoparticles were able to efficiently eradicate H. pylori in vivo and to significantly improve H. pylori-associated gastric ulcers and the inflammatory response in a mouse model, and also showed superior therapeutic efficacy as compared to standard triple therapy. Our findings reveal that bacterial adhesion plays a critical role in promoting efficient antimicrobial delivery and also represent an original bioinspired targeting strategy via specific EPS-mediated adsorption. The bacteria-adhesive eMMT-lPEI nanoparticles with membrane-disruptive ability may constitute a promising drug carrier system for the efficacious targeted delivery of antibiotics in the treatment of bacterial infections.

Efficacy of 10-day Sitafloxacin-Containing Third-Line Rescue Therapies for Helicobacter pylori Strains Containing the gyrA Mutation

BACKGROUND AND AIM

Sitafloxacin-containing Helicobacter pylori eradication therapy is a promising third-line therapeutic approach, but there is no previous studies between gyrA mutation status of H. pylori strains and the efficacy of 10-day sitafloxacin-containing regimens. Here, we assessed the efficacy of 2 different 10-day sitafloxacin-containing rescue regimens.

METHODS

Patients who failed first- and second-line eradication therapies were enrolled. The minimum inhibitory concentrations (MICs) of sitafloxacin, amoxicillin, and metronidazole and the gyrA mutation status of the H. pylori strains were determined before treatment. The patients were randomized to receive a 10-day triple therapy containing either esomeprazole (20 mg, b.i.d.), amoxicillin (500 mg, q.i.d.), and sitafloxacin (100 mg, b.i.d.) (EAS regimen) or esomeprazole (20 mg, b.i.d.), metronidazole (250 mg, b.i.d.), and sitafloxacin (100 mg, b.i.d.) (EMS regimen). Eradication rates were evaluated by the [13C] urea breath test or the H. pylori stool antigen test.

RESULTS

All patients with gyrA mutation-negative strains (24 in EAS and 16 in EMS) showed successful eradication, irrespective of the regimen they received. In patients with gyrA mutation-positive strains, we found eradication rates of 70.3% (26/37) and 66.7% (26/39) in the EAS and EMS groups in per-protocol population, respectively (p = .81). According to logistic regression analyses, the MICs of sitafloxacin, which were strongly associated with gyrA mutation status, were independently associated with successful eradication in both groups. This study was registered in the UMIN Clinical Trials Registry as UMIN000006483.

CONCLUSION

There is no significant difference in the eradication rates between EAS and EMS, regardless of the gyrA mutation status of the H. pylori strains. GyrA mutation status was an important factor in predicting successful eradication with sitafloxacin-containing rescue therapies.

Low efficacy of levofloxacin-doxycycline-based third-line triple therapy for Helicobacter pylori eradication in Italy

AIM: To evaluate a levofloxacin-doxycycline-based triple therapy with or without a susceptibility culture test in non-responders to Helicobacter pylori (H. pylori) eradication.

METHODS: A total of 142 (99 women, 43 men; mean 53.0 ± 12.7 years) non-responders to more than two H. pylori eradication therapies underwent susceptibility culture tests or were treated with a seven-day triple therapy consisting of esomeprazole, 20 mg b.i.d., levofloxacin, 500 mg b.i.d., and doxycycline, 100 mg b.i.d., randomly associated with (n = 71) or without (n = 71) Lactobacillus casei DG. H. pylori status was checked in all patients at enrollment and at least 8 wk after the end of therapy. Compliance and tolerability of regimens were also assessed.

RESULTS: H. pylori eradication was achieved in < 50% of patients [per prototol (PP) = 49%; intention to treat (ITT) = 46%]. Eradication rate was higher in patients administered probiotics than in those without (PP = 55% vs 43%; ITT = 54% vs 40%). Estimated primary resistance to levofloxacin was 18% and multiple resistance was 31%. Therapy was well tolerated, and side effects were generally mild, with only one patient experiencing severe effects.

CONCLUSION: Third-line levofloxacin-doxycycline triple therapy had a low H. pylori eradication efficacy, though the success and tolerability of this treatment may be enhanced with probiotics.

Efficacy of Levofloxacin Based Triple and High-Dose PPI-Amoxicillin Dual Eradication Therapy for Helicobacter pylori after Failures of First- and Second-Line Therapies

Objectives. The aim of this study was to investigate and compare the eradication rate of Helicobacter pylori as the third-line triple therapy with rabeprazole (RPZ) + amoxicillin (AMPC) + levofloxacin (LVFX) and high-dose RPZ + AMPC. Methods. 51 patients who failed Japanese first-line (proton pump inhibitor (PPI) + AMPC + clarithromycin) and second-line (PPI + AMPC + metronidazole) eradication therapy were randomly assigned at a 1 : 1 ratio to one of the following third-line eradication groups: (1) RAL group: RPZ 10 mg (b.i.d.), AMPC 750 mg (b.i.d.), and LVFX 500 mg (o.d.) for 10 days; (2) RA group: RPZ 10 mg (q.i.d.) and AMPC 500 mg (q.i.d.) for 14 days. Patients who failed to respond to third-line eradication therapy received salvage therapy. Results. The rates of eradication success, based on intention to treat (ITT) analysis, were 45.8% in the RAL group and 40.7% in the RA group. The overall eradication rates were 73.9% in the RAL group and 64.0% in the RA group. There was no significant difference between the two groups. Conclusions. The third-line triple therapy with RPZ, AMPC, and LVFX was as effective as that with high-dose RPZ and AMPC.

[Ideal treatment for Helicobacter pylori: a systematic review]

BACKGROUND

The success rates of therapies for treating Helicobacter pylori vary greatly worldwide and the ideal treatment has yet to be clearly established.

AIMS

A systematic review was carried out to evaluate the effectiveness of current first and second-line therapies in treating H.pylori infection.

METHODS

Two researchers independently carried out Internet search engine reviews (PUBMED, EMBASE, MEDLINE) of clinical trials on adults published between 1990 and 2012 in both English and Spanish.

RESULTS

Forty-three (n=8,123) clinical trials were evaluated that included first and second-line triple, quadruple, and sequential therapies. The eradication rates of the standard triple therapy are unacceptable (≤80%) in countries where H.pylori is highly resistant to clarithromycin and metronidazole. Administration of the standard triple therapy for more than 7 days does not improve its effectiveness. No statistically significant differences were observed between the eradication rates of the quadruple therapy with bismuth and the standard triple therapy. Even though the sequential and concomitant therapies are equally successful regimens, the triple therapy with levofloxacin offers the best results as first and second-line treatment, but quinolone resistance can diminish its effectiveness. The triple therapy with levofloxacin and the sequential and concomitant treatments were superior to the standard triple regimen as first-line therapy.

CONCLUSIONS

Currently there is no ideal first or second-line treatment for achieving 100% eradication. The therapeutic order should be carried out according to the initial treatment and local antimicrobial resistance studies.

Molecular approaches and modern clinical strategies for the management of Helicobacter pylori infection in Japan

Thirty years have passed since Warren and Marshall's discovery of Helicobacter pylori (H. pylori). Since then, not only peptic ulcer diseases and chronic gastritis but also non-cardia gastric cancers have been recognized as diseases originating from H. pylori infection. Several combination therapies consisting of multiple antibiotics have been developed as first- or second-line regimens to eradicate H. pylori infection. Our extensive experience in the field of anti-H. pylori medicine suggests that clinicians should consider a possible role for unidentified, invisible pathogens to elucidate the pathogenesis and improve the treatment of refractory diseases of unknown etiology.

Multi-center randomized controlled study to establish the standard third-line regimen for Helicobacter pylori eradication in Japan

BACKGROUNDS

The present study sought to establish a standard third-line eradication regimen for Helicobacter pylori in Japan.

METHODS

Subjects were 204 patients with H. pylori infection in whom the standard Japanese first- and second-line eradication therapies had proven unsuccessful. Patients were randomly assigned to one of the following third-line eradication therapy groups: (1) LA group: lansoprazole (LPZ) 30 mg 4 times a day (qid) + amoxicillin (AMPC) 500 mg qid for two weeks; (2) LAL group: LPZ 30 mg twice a day (bid) + AMPC 750 mg bid + levofloxacin (LVFX) 300 mg bid for one week; (3) LAS group: LPZ 30 mg bid + AMPC 750 mg bid + sitafloxacin (STFX) 100 mg bid for one week. Patients for whom these therapies failed underwent a crossover fourth-line eradication regimen. Drug sensitivity was also tested for AMPC, clarithromycin (CAM), MNZ, LVFX, and STFX.

RESULTS

Drug resistance rates prior to third-line eradication therapy were 86.4 % for CAM, 71.3 % for MNZ, 57.0 % for LVFX, 8.2 % for AMPC, and 7.7 % for STFX. Intention-to-treat analysis of third-line eradication therapy eradication rates showed a significantly higher rate in the LAS group (70.0 %) compared with the LA group (54.3 %; p < 0.05) and the LAL group (43.1 %; p < 0.001). The significantly lower rate in the LAL group than the LAS group was caused by bacterial resistance to LVFX.

CONCLUSIONS

The findings suggest that triple therapy with PPI, AMPC, and STFX for one week would be an effective standard third-line eradication regimen for H. pylori in Japan.

Delay of second-line eradication therapy for Helicobacter pylori can increase eradication failure

BACKGROUND AND AIM

The interval between first-line Helicobacter pylori eradication treatment and second-line treatment may be critical to the second-line therapeutic effect. We attempted to assess the association between the second-line eradication rates and the treatment interval.

METHODS

Data of patients, who were administered the second-line H. pylori eradication regimen at Tokyo Medical Center between 2008 and 2012, were reviewed.

RESULTS

Of the 148 patients enrolled, one patient dropped out. The eradication rates were 88.6% (intention-to-treat [ITT]) and 89.3% (per-protocol [PP]) for early eradication group (eradication interval < 180 days, patients number 132) and 68.8% (ITT and PP) for delayed eradication group (eradication interval ≥ 180 days, patients number 16). The eradication rate in the delayed eradication group was significantly lower than in the early eradication group (P = 0.027 [ITT] and 0.021 [PP]). The eradication interval in the subjects showing eradication failure (124.0 ± 96.8 days, patients number 19) was significantly longer than those showing successful eradication (85.8 ± 56.9 days, patients number 128, P = 0.008).

CONCLUSION

Our results suggest that the delay of second-line treatment should be avoided.

A review of rescue regimens after clarithromycin-containing triple therapy failure (for Helicobacter pylori eradication)

INTRODUCTION

Helicobacter pylori infection is generally treated with therapies that include a proton pump inhibitor (PPI) and, at least, two antibiotics being clarithromycin one of the most used. Antibiotic resistance, mainly to clarithromycin, seems to be increasing in many geographical areas, and this factor is considered a main cause leading to a treatment failure when the later therapies contain this antibiotic again. As clarithromycin is a key antibiotic in the eradication of H. pylori, the election of the rescue treatment is a matter of debate.

AREAS COVERED

The aim of this study is to systematically review the efficacy of the second-line rescue therapies after the failure of a first-line clarithromycin-containing regimen, and to link this information with the previous first-line treatment. Also, authors performed meta-analyses and inverse variance analyses with studies that met the inclusion criteria: first-line treatment must specify type and dosage; diagnosis and eradication confirmation must be performed by generally accepted tests; and second-line treatment must not be assigned depending on the antibiotic susceptibility or resistance.

EXPERT OPINION

In a routine clinical practice setting, the most adequate second-line treatment consists in a 10-day regimen of levofloxacin- amoxicillin-PPI given twice daily, unless regional or new data show high quinolone resistance. Other good options are the bismuth quadruple regimen and a metronidazole-amoxicillin-PPI therapy.

Efficacy of 2-week, second-line Helicobacter pylori eradication therapy using rabeprazole, amoxicillin, and metronidazole for the Japanese population

BACKGROUND

Following the failure of first-line Helicobacter pylori eradication therapy using a proton pump inhibitor, amoxicillin, and clarithromycin, second-line therapy is conducted for 1 week using metronidazole instead of clarithromycin in Japan. Recent studies indicate that metronidazole-containing therapy has a higher eradication rate with prolonged treatment duration, even with metronidazole resistance. The aim of this study was to reveal the efficacy of 2-week metronidazole-containing second-line therapy.

METHODS

Eighty-two consecutive outpatients who had failed in the first-line eradication therapy were enrolled and second-line therapy was initiated with 10 mg rabeprazole, 750 mg amoxicillin, and 250 mg metronidazole twice daily. After they had been screened by hematological examination 1 week after initiation, the treatment was continued for 2 weeks after initiation in patients without hematological abnormality. Cure was essentially confirmed by the urea breath test.

RESULTS

After one patient was lost, hematological examination showed elevated serum aminotransferase in 14 of 81 patients. Although it was mild without clinical issues, they were ethically excluded from this study. In the remaining 67 patients and the lost patient, the eradication rate with 2-week therapy was 65/68 (96%, 95% confidence interval: 88-98%) by intention to treat analysis and 65/65 (100%, 94-100%) by per protocol analysis. The main adverse event was soft stools (39%), and no serious adverse event was observed.

CONCLUSION

This 2-week metronidazole-containing second-line therapy provides high efficacy in Japan where metronidazole resistance is rare.

Changes in 12-Year First-Line Eradication Rate of Helicobacter pylori Based on Triple Therapy with Proton Pump Inhibitor, Amoxicillin and Clarithromycin

A triple therapy based on a proton pump inhibitor (PPI), amoxicillin (AMPC), and clarithromycin (CAM) is recommended as a first-line therapy for Helicobacter pylori (H. pylori) eradication and is widely used in Japan. However, a decline in eradication rate associated with an increase in prevalence of CAM resistance is viewed as a problem. We investigated CAM resistance and eradication rates over time retrospectively in 750 patients who had undergone the triple therapy as first-line eradication therapy at Nagoya City University Hospital from 1995 to 2008, divided into four terms (Term 1: 1997-2000, Term 2: 2001-2003, Term 3: 2004-2006, Term 4: 2007-2008). Primary resistance to CAM rose significantly over time from 8.7% to 23.5%, 26.7% and 34.5% while the eradication rate decreased significantly from 90.6% to 80.2%, 76.0% and 74.8%. Based on the PPI type, significant declines in eradication rates were observed with omeprazole or lansoprazole, but not with rabeprazole. A decrease in the H. pylori eradication rate after triple therapy using a PPI + AMPC + CAM has been acknowledged, and an increase in CAM resistance is considered to be a factor. From now on, a first-line eradication regimen that results in a higher eradication rate ought to be investigated.

Helicobacter pylori eradication therapy

Helicobacter pylori infection is the main cause of gastritis, gastroduodenal ulcers and gastric cancer. H. pylori eradication has been shown to have a prophylactic effect against gastric cancer. According to several international guidelines, the first-line therapy for treating H. pylori infection consists of a proton pump inhibitor (PPI) or ranitidine bismuth citrate, with any two antibiotics among amoxicillin, clarithromycin and metronidazole, given for 7-14 days. However, even with these recommended regimens, H. pylori eradication failure is still seen in more than 20% of patients. The failure rate for first-line therapy may be higher in actual clinical practice, owing to the indiscriminate use of antibiotics. The recommended second-line therapy is a quadruple regimen composed of tetracycline, metronidazole, a bismuth salt and a PPI. The combination of PPI-amoxicillin-levofloxacin is a good option as second-line therapy. In the case of failure of second-line therapy, the patients should be evaluated using a case-by-case approach. European guidelines recommend culture before the selection of a third-line treatment based on the microbial antibiotic sensitivity. H. pylori isolates after two eradication failures are often resistant to both metronidazole and clarithromycin. The alternative candidates for third-line therapy are quinolones, tetracycline, rifabutin and furazolidone; high-dose PPI/amoxicillin therapy might also be promising.

Second-line rescue therapy of helicobacter pylori infection

Helicobacter pylori infection is the main known cause of gastritis, gastroduodenal ulcer disease and gastric cancer. After more than 20 years of experience in H. pylori treatment, however, the ideal regimen to treat this infection has still to be found. Nowadays, apart from having to know well first-line eradication regimens, we must also be prepared to face treatment failures. Therefore, in designing a treatment strategy we should not focus on the results of primary therapy alone, but also on the final (overall) eradication rate. The choice of a 'rescue' treatment depends on which treatment is used initially. If a first-line clarithromycin-based regimen was used, a second-line metronidazole-based treatment (quadruple therapy) may be used afterwards, and then a levofloxacin-based combination would be a third-line 'rescue' option. Alternatively, it has recently been suggested that levofloxacin-based 'rescue' therapy constitutes an encouraging second-line strategy, representing an alternative to quadruple therapy in patients with previous PPI-clarithromycin-amoxicillin failure, with the advantage of efficacy, simplicity and safety. In this case, quadruple regimen may be reserved as a third-line 'rescue' option. Finally, rifabutin-based 'rescue' therapy constitutes an encouraging empirical fourth-line strategy after multiple previous eradication failures with key antibiotics such as amoxicillin, clarithromycin, metronidazole, tetracycline, and levofloxacin. Even after two consecutive failures, several studies have demonstrated that H. pylori eradication can finally be achieved in almost all patients if several 'rescue' therapies are consecutively given. Therefore, the attitude in H. pylori eradication therapy failure, even after two or more unsuccessful attempts, should be to fight and not to surrender.

Second Asia-Pacific Consensus Guidelines for Helicobacter pylori infection

The Asia-Pacific Consensus Conference was convened to review and synthesize the most current information on Helicobacter pylori management so as to update the previously published regional guidelines. The group recognized that in addition to long-established indications, such as peptic ulcer disease, early mucosa-associated lymphoid tissue (MALT) type lymphoma and family history of gastric cancer, H. pylori eradication was also indicated for H. pylori infected patients with functional dyspepsia, in those receiving long-term maintenance proton pump inhibitor (PPI) for gastroesophageal reflux disease, and in cases of unexplained iron deficiency anemia or idiopathic thrombocytopenic purpura. In addition, a population 'test and treat' strategy for H. pylori infection in communities with high incidence of gastric cancer was considered to be an effective strategy for gastric cancer prevention. It was recommended that H. pylori infection should be tested for and eradicated prior to long-term aspirin or non-steroidal anti-inflammatory drug therapy in patients at high risk for ulcers and ulcer-related complications. In Asia, the currently recommended first-line therapy for H. pylori infection is PPI-based triple therapy with amoxicillin/metronidazole and clarithromycin for 7 days, while bismuth-based quadruple therapy is an effective alternative. There appears to be an increasing rate of resistance to clarithromycin and metronidazole in parts of Asia, leading to reduced efficacy of PPI-based triple therapy. There are insufficient data to recommend sequential therapy as an alternative first-line therapy in Asia. Salvage therapies that can be used include: (i) standard triple therapy that has not been previously used; (ii) bismuth-based quadruple therapy; (iii) levofloxacin-based triple therapy; and (iv) rifabutin-based triple therapy. Both CYP2C19 genetic polymorphisms and cigarette smoking can influence future H. pylori eradication rates.

Helicobacter pylori and gastric cancer

Helicobacter pylori is now well known as an important pathogen related to the development of gastric cancer. However, some clinicians still doubt the causal association of H. pylori with the development of gastric cancer. To summarize the recent clinical data on the link between H. pylori and gastric cancer, we reviewed related articles published over the past 3 years, after the award of the Nobel Prize for Physiology or Medicine to Drs. J.R. Warren and B.J. Marshall for the first culture and isolation of H. pylori and the investigation of their relevance to peptic ulcer disease. This updated summary of the relationship between H. pylori and gastric cancer highlights the strong link between the organism and the development of gastric cancer, and suggests eradication of this bacterial infection as a possible prophylactic measure against the development of this lethal malignancy. At present, clinicians and researchers in the field emphasize the strong need for H. pylori eradication from the human stomach.

In vitro antibacterial activity of acyl-lysyl oligomers against Helicobacter pylori

The gastric pathogen Helicobacter pylori has developed resistance to virtually all current antibiotics; thus, there is a pressing need to develop new anti-H. pylori therapies. The goal of this work was to evaluate the antibacterial effect of oligo-acyl-lysyl (OAK) antimicrobial peptidomimetics to determine if they might represent alternatives to conventional antibiotic treatment of H. pylori infection. A total of five OAK sequences were screened for growth-inhibitory and/or bactericidal effects against H. pylori strain G27; four of these sequences had growth-inhibitory and bactericidal effects. The peptide with the highest efficacy against strain G27, C12K-2beta12, was selected for further characterization against five additional H. pylori strains (26695, J99, 7.13, SS1, and HPAG1). C12K-2beta12 displayed MIC and minimum bactericidal concentration (MBC) ranges of 6.5 to 26 microM and 14.5 to 90 microM, respectively, across the six strains after 24 h of exposure. G27 was the most sensitive H. pylori strain (MIC = 6.5 to 7 microM; MBC = 15 to 20 microM), whereas 26695 was the least susceptible strain (MIC = 25 to 26 microM; MBC = 70 to 90 microM). H. pylori was completely killed after 6 to 8 h of incubation in liquid cultures containing two times the MBC of C12K-2beta12. The OAK demonstrated strong in vitro stability, since efficacy was maintained after incubation at extreme temperatures (4 degrees C, 37 degrees C, 42 degrees C, 50 degrees C, 55 degrees C, 60 degrees C, and 95 degrees C) and at low pH, although reduced killing kinetics were observed at pH 4.5. Additionally, upon transient exposure to the bacteria, C12K-2beta12 showed irreversible and significant antibacterial effects and was also nonhemolytic. Our results show a significant in vitro effect of C12K-2beta12 against H. pylori and suggest that OAKs may be a valuable resource for the treatment of H. pylori infection.

Quinolone-Based Third-Line Therapy for Helicobacter pylori Eradication

Currently, a standard third-line therapy for Helicobacter pylori (H. pylori) eradication remains to be established. Quinolones show good oral absorption, no major side effects, and marked activity against H. pylori. Several authors have studied quinolone-based third-line therapy and reported encouraging results, with the reported H. pylori cure rates ranging from 60% to 84%. Resistance to quinolones is easily acquired, and the resistance rate is relatively high in countries with a high consumption rate of these drugs. We recently reported a significant difference in the eradication rate obtained between patients infected with gatifloxacin-susceptible and gatifloxacin-resistant H. pylori, suggesting that the selection of quinolones for third-line therapy should be based on the results of drug susceptibility testing. As other alternatives of third-line rescue therapies, rifabutin-based triple therapy, high-dose proton pump inhibitor/amoxicillin therapy and furazolidone-based therapy have been suggested.

Gatifloxacin-based triple therapy as a third-line regimen for Helicobacter pylori eradication

BACKGROUND AND AIM

This study was designed to investigate the efficacy of gatifloxacin (GAT)-based triple therapy as a third-line treatment for Helicobacter pylori (H. pylori) eradication, according to the assessment of the susceptibility to GAT and gyrA mutation.

METHODS

Fourteen patients who had eradication failure following both clarithromycin-based triple therapy and metronidazole-based triple therapy, or who were infected with H. pylori isolates that were resistant to both clarithromycin and metronidazole after failure of clarithromycin-based triple therapy, were enrolled. These patients were randomly assigned to two groups: (i) rabeprazole and amoxicillin (RA) and (ii) rabeprazole, amoxicillin, and GAT for 7 days (RAG). The minimal inhibitory concentrations were determined by the agar dilution method. The gyrA gene was examined by sequencing.

RESULTS

The eradication rate was 0% in the RA group and 75% in the RAG group. The eradication rate in the RAG group was 100% in patients infected with GAT-susceptible bacteria and/or bacteria without gyrA mutations, but was only 33.3% in those infected with GAT-resistant bacteria or bacteria with gyrA mutations.

CONCLUSION

Although GAT may be a promising candidate for third-line therapy, its selection must be based on the results of drug susceptibility testing or gyrA analyses.

“Rescue” regimens after Helicobacter pylori treatment failure

Helicobacter pylori (H pylori) infection is the main cause of gastritis, gastroduodenal ulcer disease, and gastric cancer. After more than 20 years of experience in H pylori treatment, in my opinion, the ideal regimen to treat this infection is still to be found. Currently, apart from having to know first-line eradication regimens well, we must also be prepared to face treatment failures. Therefore, in designing a treatment strategy we should not focus on the results of primary therapy alone, but also on the final (overall) eradication rate. The choice of a “rescue” treatment depends on which treatment is used initially. If a clarithromycin-based regimen was used initially, a subsequent metronidazole-based treatment (quadruple therapy) may be used afterwards, and then a levofloxacin-based combination would be a third “rescue” option. Alternatively, it has recently been suggested that levofloxacin-based rescue therapy constitutes an encouraging second-line strategy, representing an alternative to quadruple therapy in patients with previous PPI-clarithromycin-amoxicillin failure, with the advantage of efficacy, simplicity and safety. In this case, a quadruple regimen may be reserved as a third-line rescue option. Finally, rifabutin-based rescue therapy constitutes an encouraging empirical fourth-line strategy after multiple previous eradication failures with key antibiotics such as amoxicillin, clarithromycin, metronidazole, tetracycline, and levofloxacin. Even after two consecutive failures, several studies have demonstrated that H pylori eradication can finally be achieved in almost all patients if several rescue therapies are consecutively given. Therefore, the attitude in H pylori eradication therapy failure, even after two or more unsuccessful attempts, should be to fight and not to surrender.

Comparison of three different second-line quadruple therapies including bismuth subcitrate in Turkish patients with non-ulcer dyspepsia who failed to eradicate Helicobacter pylori with a 14-day standard first-line therapy

BACKGROUND AND AIM

Many studies have reported poor results with standard first-line treatment for Helicobacter pylori. Second-line regimens that may overcome bacterial resistance can minimize side-effects and optimize compliance. The aim of this study was to evaluate the efficacy of proton pump inhibitor (PPI) and bismuth subcitrate-based quadruple therapy, after failure of a PPI plus clarithromycin and amoxicillin as first-line therapy.

METHODS

Patients who failed to eradicate the infection after initial therapy were randomly separated into three groups. The first group received lansoprazole, bismuth subcitrate, metronidazole and amoxicillin (LBMA); in the second group metronidazole was replaced by tetracycline (LBTA); and the third group was given metronidazole and tetracycline in addition to same doses of lansoprazole and bismuth subcitrate (LBMT).

RESULTS

In the LBMA group, the eradication rate was 74.7% and was significantly related to sex, with no relationship to age. In the LBTA group the eradication rate was 81.5% with similar rates in males and females. No relation to sex or age was observed. In the LBMT group the eradication rate was 82.1% with no difference between women and men and it was not related to age, either. Eradication rates in study groups were similar (P > 0.05).

CONCLUSION

A-14-day regimen of lansoprazole, bismuth subcitrate and antibiotic pairs, tetracycline-amoxicillin and tetracycline-metronidazole, is an effective quadruple therapy after one failed course of standard triple therapy. The evaluation of tolerability of and compliance with quadruple therapy needs further studies.

Dual therapy with high doses of rabeprazole and amoxicillin versus triple therapy with rabeprazole, amoxicillin, and metronidazole as a rescue regimen for Helicobacter pylori infection after the standard triple therapy

BACKGROUNDS AND AIMS

Development of safe and effective rescue regimens for eradication failure of Helicobacter pylori infection by standard regimens is an urgent task. We designed the prospective study to compare the efficacy of two rescue regimens after eradication failure by the standard triple therapy.

METHODS

One hundred and thirty-two patients in whom eradication of H. pylori infection failed initial triple therapy with lansoprazole 30 mg b.i.d, amoxicillin 750 mg b.i.d. and clarithromycin 400 mg b.i.d. for 1 week were randomized to either the 1-week triple therapy with rabeprazole 10 mg b.i.d., amoxicillin 750 mg b.i.d., and metronidazole 250 mg b.i.d. (RAM) or the 2-week dual therapy with rabeprazole 10 mg q.i.d. and amoxicillin 500 mg q.i.d. (RA). Eradication of H. pylori was judged by (13)C-urea breath test 1 month later.

RESULTS

The intention-to-treat and per-protocol-based eradication rates were 92.4% (95% CI: 83.2-97.5) and 95.3% (95% CI: 86.9-99.0) for the RAM therapy and 90.9% (95% CI: 81.2-96.6) and 93.8% (95% CI: 84.8-98.3), respectively, for the RA therapy (P > 0.2 for both). No clinically recognizable adverse events were observed with either regimen.

CONCLUSION

RA as well as RAM therapy are safe and effective rescue regimens for H. pylori infection after eradication failure by the standard triple therapy.

Rapid detection of clarithromycin-resistant Helicobacter pylori in patients with dyspepsia by fluorescent in situ hybridization (FISH) compared with the E-test

BACKGROUND

Clarithromycin is the antibiotic of choice for treatment of H.pylori-related dyspepsia, but unfortunately, resistance to clarithromycin is not rare. Detection of resistant strains takes 2 to 4 days by conventional methods. In this report, we applied the FISH technique for rapid detection of H.pylori in biopsies of dyspeptic patients.

METHODS

Gastric biopsies from 50 patients suffering from dyspepsia were tested in this study. Part of each biopsy specimen was cultured and the remainder was fixed in liquid nitrogen. After mounting of frozen sections on microscopic slides, they were hybridized with oligonucleotide probes for detection of clarithromycin-resistant H.pylori. The slides were visualized under a fluorescent microscope. Susceptibility of cultured strains of H. pylori to clarithromycin was also determined by the E-test and the results were compared.

RESULTS

Twenty-five of 50 biopsy specimens examined by FISH were positive for H.pylori. FISH showed that 17 strains (68%) were susceptible to clarithromycin and 6 strains (24%) were resistant. Bacteria isolated following culture of 2 biopsy specimens had a mixture of both clarithromycin-susceptible and resistant strains (8%). There was no discrepancy between the E-test and FISH technique for detection of resistant strains of H.pylori.

CONCLUSION

FISH is a rapid technique for detection of H.pylori in clinical samples. Moreover, strains susceptible to clarithromycin can be detected quickly. Therefore, this method is suitable for determination of susceptibility of H.pylori to clarithromycin, especially when a quick decision is necessary for treating dyspeptic patients.

Helicobacter pylori: present status and future prospects in Japan

The discovery of Helicobacter pylori has already changed the natural history of peptic ulcer disease, with most patients being cured at their first presentation. Similarly, the incidence of gastric cancer and other diseases related to H. pylori are likely to be greatly reduced in the near future. Isolation of the spiral intragastric bacterium H. pylori totally reversed the false dogma that the stomach was sterile, and it taught us that chronic infectious disease can still exist in modern society. Helicobacter pylori's unique location, persistence, and evasion of the immune system offer important insights into the pathophysiology of the gut. Also, the fact that it was overlooked for so long encourages us to think "outside the box" when investigating other diseases with obscure etiologies. We should consider such provocative scientific ideas as bridges to the future disease control.