A systematic comparison of triple therapies for treatment of Helicobacter pylori infection with proton pump inhibitor/ ranitidine bismuth citrate plus clarithromycin and either amoxicillin or a nitroimidazole

Sequential versus Standard Triple Therapy for First-Line Helicobacter pylori Eradication: An Update

BACKGROUND

non-bismuth sequential therapy (SEQ) was suggested as a first-line anti-Helicobacter pylori treatment alternative to standard triple therapy (STT).

METHODS

We conducted a systematic review with a meta-analysis of randomized controlled trials (RCTs) comparing the efficacy of 10-day SEQ vs. STT (of at least 7 days) using bibliographical searches up to July 2021, including treatment-naïve adult or children. The intention-to-treat (ITT) eradication rate and the risk difference (RD) were calculated.

RESULTS

Overall, 69 RCTs were evaluated, including 19,657 patients (9486 in SEQ; 10,171 in STT). Overall, SEQ was significantly more effective than STT (82% vs. 75%; RD 0.08; p < 0.001). The results were highly heterogeneous (I2 = 68%), and 38 studies did not demonstrate differences between therapies. Subgroup analyses suggested that patients with clarithromycin resistance only and all geographical areas but South America could benefit more from SEQ. Both therapies have evolved over the years, showing similar results when STT lasted 14 days; however, a tendency toward lower SEQ efficacy was noted from 2010 onwards.

CONCLUSIONS

Prior to 2010, SEQ was significantly more effective than STT, notably when 7-day STT was prescribed. A tendency toward lower differences between SEQ and STT has been noted, especially when using 10-day STT. None of the therapies achieved an optimal efficacy and therefore cannot be recommended as a valid first-line H. pylori treatment.

Controversies regarding management of Helicobacter pylori infections

PURPOSE OF REVIEW

The recognition that Helicobacter pylori should be considered and treated as an infectious disease has yet to fundamentally change diagnostic and treatment practices and has resulted in many controversies.

RECENT FINDINGS

We discuss the following controversies: whether the current 'per-patient' approach to H. pylori testing based on symptoms should be expanded to include achieving population-level H. pylori eradication, whether H. pylori should be approached as an infectious gastrointestinal disease similar to that of other infectious diseases of similar severity and outcome, whether treatment of H. pylori should be primarily empiric or based on antibiotic susceptibility and locally proven successful therapies as are other infectious diseases, whether it is necessary to obtain confirmation of treatment success in every patient treated for H. pylori , and whether potassium-competitive acid blockers should replace proton pump inhibitors in H. pylori therapy.

SUMMARY

Available guidelines and meta-analyses do not yet address H. pylori as an infectious disease. The diagnosis and management and treatment success of H. pylori infections trails behind that of other important infectious diseases. We provide new insights and propose changes in the traditional understanding required to modernize the management of H. pylori infections.

Implications of the paradigm shift in management of Helicobacter pylori infections

The recent availability of susceptibility testing for Helicobacter pylori infections in the United Sates has resulted in paradigm shifts in the diagnosis, therapy, and follow-up of H. pylori infections. Here, we reviewed the English literature concerning changes in H. pylori diagnosis and therapy with an emphasis on the last 3 years. We focus on the new methods that offer rapid and convenient susceptibility testing using either invasive (endoscopic) or noninvasive (stool) methods of obtaining test material. We also discuss the implications of this availability on therapy and follow-up after therapy. The approach to therapy was categorized into four groups: (1) therapies that can be used empirically, (2) therapies that should be restricted to those that are susceptibility-based, (3) potentially effective therapies that have yet to be optimized for local use, and (4), therapies that contain unneeded antibiotics that should not be prescribed. The most convenient and efficient method of susceptibility testing is by using reflexive stool testing in which if the sample is positive, it is automatically also used for determination of susceptibility. Reflexive testing can also be done via reflexive ordering (e.g., for all positive urea breath tests). The post therapy test-of-cure has emerged as a critical component of therapy as it not only provides feedback regarding treatment success but when combined with susceptibility testing also provide evidence regarding the cause of failure (e.g., poor adherence versus emergence of resistance during therapy. Susceptibility testing has made even the most current H. pylori guidelines for diagnosis and therapy generally obsolete. Clarithromycin, metronidazole, and levofloxacin triple therapies should only be administered as susceptibility-based therapy. Regimens containing unneeded antibiotics should not be given. We provide recommendations regarding the details and indications for all current therapies.

How widespread and convenient H. pylori susceptibility testing will result in pharmacological opportunities

INTRODUCTION

Until recently, antimicrobial therapy for Helicobacter pylori infections was almost universally empirical and based on a combination of expert opinion and local effectiveness. However, the new requirement that all therapeutic regimens reliably achieve high cure rates, the introduction of potassium competitive acid blockers and the availability of susceptibility testing many pharmacological opportunities particularly since all current therapies will require optimization. The ability to rapidly and inexpensively obtain H. pylori susceptibility data using stool samples makes obtaining susceptibility data practical and allows using susceptibility-based therapy routinely for both treatment-naïve patient and treatment failures.

AREAS COVERED

We searched the literature from 1990 to current to identify studies reporting the effect of susceptibility testing on H. pylori treatment. This review examines how widespread and convenient H. pylori susceptibility testing will result in pharmacological opportunities. . Many pharmacological opportunities will emanate from a renewal of efforts to develop, propagate, confirm, and update best practices based on local and regional susceptibility/resistance patterns.

EXPERT OPINION

The ability to evaluate treatment decisions and outcomes in susceptible infections and reliably achieve high cure rates should foster precise tailoring of pharmacologic therapy and should achieve the goals of high cure rates while preventing antimicrobial misuse and extending the useful life of current antibiotics.

Cross-roads for meta-analysis and network meta-analysis of H. pylori therapy

Helicobacter pylori infections are responsible for tremendous morbidity and mortality worldwide, leading to efforts to eradicate the organism. However, the effectiveness of antimicrobial therapy has been undermined by the progressive development of antimicrobial resistance. Treatments and treatment guidelines have been based on traditional pairwise meta-analyses of randomised controlled trials. More recently, network meta-analyses have also been used in an attempt to provide useful information to the clinician regarding which therapies appear best and which to avoid as the least efficacious. However, both forms of meta-analysis have been undermined by the same problems including the poor quality of the clinical trials using unoptimised regimens and incomparable comparisons related to marked geographic and ethnic genotypic and phenotypic heterogeneity. In addition, the comparator regimens often consist of invalid strawman comparisons. New approaches concerning H. pylori treatment and analysis of therapies are needed. H. pylori therapies should be based on antimicrobial stewardship, as in other infectious diseases. This approach requires the use of only optimised therapies proven to be reliably highly effective in the local population (eg, a cure rate of >90%) for both the study and the comparator regimens. Meta-analyses should be restricted to regimens that meet these criteria and must take into account the presence of marked geographical and host genetic and phenotypic heterogeneity. In addition, to provide clinically relevant results, treatment outcomes should focus on, and present, actual cure rates in addition to odd ratios.

Helicobacter pylori diagnosis and therapy in the era of antimicrobial stewardship

The diagnosis and therapy of Helicobacter pylori infection have undergone major changes based on the use the principles of antimicrobial stewardship and increased availability of susceptibility profiling. H. pylori gastritis now recognized as an infectious disease, as such there is no placebo response allowing outcome to be assessed in relation to the theoretically obtainable cure rate of 100%. The recent recognition of H. pylori as an infectious disease has changed the focus to therapies optimized to reliably achieve high cure rates. Increasing antimicrobial resistance has also led to restriction of clarithromycin, levofloxacin, or metronidazole to susceptibility-based therapies. Covid-19 resulted in the almost universal availability of polymerase chain reaction testing in hospitals which can be repurposed to utilize readily available kits to provide rapid and inexpensive detection of clarithromycin resistance. In the United States, major diagnostic laboratories now offer H. pylori culture and susceptibility testing and American Molecular Laboratories offers next-generation sequencing susceptibility profiling of gastric biopsies or stools for the six commonly used antibiotics without need for endoscopy. Current treatment recommendations include (a) only use therapies that are reliably highly effective locally, (b) always perform a test-of-cure, and (c) use that data to confirm local effectiveness and share the results to inform the community regarding which therapies are effective and which are not. Empiric therapy should be restricted to those proven highly effective locally. The most common choices are 14-day bismuth quadruple therapy and rifabutin triple therapy. Prior guidelines and treatment recommendations should only be used if proven locally highly effective.

Transitioning of Helicobacter pylori Therapy from Trial and Error to Antimicrobial Stewardship

Helicobacter pylori is the only major infection for which antimicrobial therapy is not designed using the principles of antimicrobial stewardship. Traditionally, antimicrobial therapy is a susceptibility-based therapy, achieves high cure rates, and includes surveillance programs to regularly provide updated data regarding resistance, outcomes, and treatment guidelines. Current H. pylori therapies identified by trial-and-error, and treatment recommendations and guidelines are based on comparisons among regimens that rarely take into account the prevalence or effect of resistance. The majority of patients currently treated achieve suboptimal results. A paradigm shift is required to abandon current approaches and embrace antimicrobial stewardship, and therefore reliably achieve high cure rates; develop, propagate, and update best practice guidelines; and provide surveillance of local or regional susceptibility/resistance patterns. These also require timely updates to clinicians regarding the current status of resistance, antimicrobial effectiveness, and ways to prevent antimicrobial misuse to extend the useful life of currently available antibiotics. Here, we discuss the differences among current approaches to H. pylori therapy and antimicrobial stewardship and identify what is required to achieve the transition. Conceptually, the differences are significant, and the transition will likely need to be both abrupt and complete. Recommendations for therapy during the transition period are given.

Standard triple therapy in Helicobacter pylori eradication in Turkey: Systematic evaluation and meta-analysis of 10-year studies

BACKGROUND/AIMS

This study aims at evaluating the mean eradication rate by a systematic compilation of the studies which involved the standard triple therapy (STT) in first-line Helicobacter pylori (Hp) eradication in Turkey over a period of 10 years between 2004 and 2013 using the meta-analysis method.

MATERIALS AND METHODS

The systematic compilation and meta-analysis were carried out according to the PRISMA standards defined in the Cochrane handbook. The results of full-text studies published in national and international journals in English and Turkish languages on Turkish population in a period of 10 years, from 2004 to 2013, are included in this study. The studies include open-label trials, controlled trials, treatment arms, and case series that included a triple therapy regimen consisting of standard doses of a proton pump inhibitor (PPI; omeprazole 20 mg BID, lansoprazole 30 mg BID, pantoprazole 40 mg BID, esomeprazole 40 mg BID, or rabeprazole 20 mg BID) along with clarithromycin 500 mg BID and amoxicillin 1 g BID for 7-14 days. They were scanned electronically via the search engines Google Scholar, PubMed, and the Turkish Medicine Index using specific keywords. The related keywords used were Turkey, Helicobacter pylori, infection, standard triple treatment, first-line therapy, eradication, omeprazole, lansoprazole, pantoprazole, rabeprazole, esomeprazole, clarithromycin, and amoxicillin. Studies carried out with adults were included in the evaluation. The publication year of the studies and the included number of patients, their age, gender, treatment duration (7, 10, and 14 days), and PPIs used were evaluated by two separate gastroenterologists and biostatisticians. Studies that used at least one reliable method (histology, urea breath test (UBT), or Helicobacter pylori stool antigen (HpSA) test) four weeks after completing the treatment for the control of Hp eradication were included. Only naive patients were accepted, and patients who had previously received eradication treatment were excluded. The effectiveness of the Hp eradication was analyzed using an intention-to-treat (ITT) or per-protocol (PP) analysis.

RESULTS

The STT regime of 45 studies complying with the inclusion criteria was evaluated. A total of 3715 patients were included in the study. Of the 3010 patients whose gender information was available, 55% were women and 45% were men; the weighted age average given explicitly in the studies was 42.14±0.67. The treatment lasted for 14 days in 42 studies, for 7 days in six studies, and for 10 days in 1 study. The eradication rates evaluated according to the ITT and PP analyses were 60% (95% CI: 56%-63%) and 57% (95% CI: 51%-62%), respectively. The rates for 7 days of treatment were 57% (95% CI: 46%-68%) and 60% (95% CI: 51%-67%) and for 14 days of treatment were 60% (95% CI: 56%-63%) and 56% (95% CI: 50%-62%), respectively. The ITT eradication rate of the only 10-day study was 78% (95% CI: 66%-86%). In the meta-regression analysis, the treatment duration, PPI, age, and gender ratio (women/men) used for the ITT analysis had no effect. The gender ratio and age were not considered in this analysis because they were not clearly stated in studies using the PP analysis. The duration of treatment and the PPI used had no effect.

CONCLUSION

A systematic meta-analysis of studies conducted during the period 2004-2013 in Turkey revealed that the rate of first-line Hp eradication using STT was unacceptably low, and the duration of treatment and PPI used made no difference.

Initial Trials With Susceptibility-Based and Empiric Anti-H. pylori Therapies in Mongolia

Background: Mongolia has a high prevalence of Helicobacter pylori infection and gastric cancer. We conducted a prospective, randomized, single-blind study to evaluate the efficacy of common regimens in Mongolia and to obtain specimens for susceptibility testing. Methods: Empiric treatments: 270 patients with confirmed H. pylori infection were randomized to receive 10 days clarithromycin-triple therapy (Clari-TT) (n = 90), modified bismuth quadruple therapy (M-BQT) (n = 90), or sequential therapy (ST) (n = 90). A second group of 46 patients received susceptibility-based Clari-TT. H. pylori was cultured from 131 patients and susceptibility testing was performed. H. pylori eradication was confirmed by stool antigen 4 weeks after the therapy. Results: Intention-to-treat (ITT) analysis cure rates were 71.1% (95% CI = 61.7-80.5%) for Clari-TT, 87.8% (95% CI = 81-94.6%) for M-BQT, 67.8% (95% CI = 58.1-77.5%) for ST vs. 89.1% (95% CI = 86-98.2%) for susceptibility-based Clari-TT. Per-protocol (PP) analysis results for these therapies were 72.7% (63.4-82%), 89.8% (83.5-96.1%), 68.5% (58.8-78.2%), and 97.6% (89.5-99.8%), respectively. Among 131 cultured H. pylori, resistance rates to amoxicillin, clarithromycin, and metronidazole were 8.4, 37.4, and 74%, respectively. Conclusion: In Mongolia, the prevalence of H. pylori resistance is high requiring bismuth quadruple therapy or susceptibility-based therapy to obtain acceptable cure rates.

Sequential Therapy or Standard Triple Therapy for Helicobacter pylori Infection: An Updated Systematic Review

The effectiveness of standard triple therapy (STT) for the eradication of Helicobacter pylori has decreased recently. Sequential therapy (SQT) is a new regimen proposed to address this problem. The aim of this study was to compare the efficacy of SQT versus STT for H. pylori eradication. We searched The Cochrane Library, MEDLINE, Web of Science, and EMBASE databases up to July 2014. The risk ratios (RRs) of eradication rate were pooled, with a 95% confidence interval (CI). Thirty-six randomized clinical trials including a total of 10,316 patients met the inclusion criteria. The RR for eradication of H. pylori with SQT compared with STT was 1.14 (95% CI: 1.09-1.17), the eradication rates were 84.1% and 75.1%, respectively. There was significant heterogeneity between trial results (I = 73%; P < 0.00001). Subgroup analyses showed that SQT was superior to both 7- and 10-day STT, but not significantly better than 14-day STT. This superiority existed when patients were treated with either metronidazole or tinidazole. Patients with single clarithromycin-resistant strain showed a greater benefit of SQT over STT (eradication rates 80.9% vs. 40.7%), RR = 1.98 (95% CI: 1.33-2.94). There was no significant difference between groups in terms of the risk of adverse effects. In conclusion, SQT is more efficacious than STT (7 days and 10 days) in the eradication of HP, but the pooled rate seemed suboptimal. Further research is needed to develop more effective therapeutic approaches. Surveillance of resistance rates should be performed to guide treatment.

MOLECULAR DETECTION OF CLARITHROMYCIN AND FLUOROQUINOLONES RESISTANCE IN HELICOBACTER PYLORI INFECTION, DIRECTLY APPLIED TO GASTRIC BIOPSIES, IN AN URBAN BRAZILIAN POPULATION

BACKGROUND

- Antimicrobial resistance is the major factor leading to eradication failure in H. pylori treatment. Molecular tests are useful to detect genetic mutations predictive of clarithromycin and fluoroquinolones resistance. Knowledge of the local prevalence rate of resistance is important to define the best recommended treatment.

OBJECTIVE

- To assess the prevalence of primary resistance of H. pylori to clarithromycin and fluoroquinolones, using a molecular test, in a Southeastern urban Brazilian population.

METHODS

- A total of 72 H. pylori seropositive patients [65% female, mean age 39 (19-73) years] never treated before for this infection were studied. All patients underwent gastroscopy in addition to antrum and corpus biopsies and molecular test GenoType HelicoDR (Hain Life Science, Germany) to detect H. pylori and point mutations in genes responsible for clarithromycin and fluoroquinolone resistance. The molecular procedure was divided into three steps: DNA extraction from biopsy samples, a multiplex amplification with biotinylated primers and a reverse hybridization. The most frequent point mutations involved in resistance to the two antibiotics were evaluated.

RESULTS

- Resistance to clarithromycin was detected in nine (12.5%) patients and to fluoroquinolones in eight (11.1%) patients. The point mutation A2147G was the most common (77.8%) among resistant strains to clarithromycin. In 50% of the resistant strains to fluoroquinolones, the mutant codon couldn't be identified.

CONCLUSION

- The resistance rates to clarithromycin and fluorquinolones in a large urban population in the Southeast of Brazil were acceptable, suggesting that these drugs remain appropriate options to first and second-line of H. pylori treatment. The molecular test represents an adequate diagnostic tool for monitoring H. pylori resistance.

Sequential versus standard triple first-line therapy for Helicobacter pylori eradication

BACKGROUND

Non-bismuth quadruple sequential therapy (SEQ) comprising a first induction phase with a dual regimen of amoxicillin and a proton pump inhibitor (PPI) for five days followed by a triple regimen phase with a PPI, clarithromycin and metronidazole for another five days, has been suggested as a new first-line treatment option to replace the standard triple therapy (STT) comprising a proton pump inhibitor (PPI), clarithromycin and amoxicillin, in which eradication proportions have declined to disappointing levels.

OBJECTIVES

To conduct a meta-analysis of randomised controlled trials (RCTs) comparing the efficacy of a SEQ regimen with STT for the eradication of H. pylori infection, and to compare the incidence of adverse effects associated with both STT and SEQ H. pylori eradication therapies.

SEARCH METHODS

We conducted bibliographical searches in electronic databases, and handsearched abstracts from Congresses up to April 2015.

SELECTION CRITERIA

We sought randomised controlled trials (RCTs) comparing 10-day SEQ and STT (of at least seven days) for the eradication of H. pylori. Participants were adults and children diagnosed as positive for H. pylori infection and naïve to H. pylori treatment.

DATA COLLECTION AND ANALYSIS

We used a pre-piloted, tabular summary to collect demographic and medical information of included study participants as well as therapeutic data and information related to the diagnosis and confirmatory tests.We evaluated the difference in intention-to-treat eradication between SEQ and STT regimens across studies, and assessed sources of the heterogeneity of this risk difference (RD) using subgroup analyses.We evaluated the quality of the evidence following Cochrane standards, and summarised it using GRADE methodology.

MAIN RESULTS

We included 44 RCTs with a total of 12,284 participants (6042 in SEQ and 6242 in STT). The overall analysis showed that SEQ was significantly more effective than STT (82% vs 75% in the intention-to-treat analysis; RD 0.09, 95% confidence interval (CI) 0.06 to 0.11; P < 0.001, moderate-quality evidence). Results were highly heterogeneous (I² = 75%), and 20 studies did not demonstrate differences between therapies.Reporting by geographic region (RD 0.09, 95% CI 0.06 to 0.12; studies = 44; I² = 75%, based on low-quality evidence) showed that differences between SEQ and STT were greater in Europe (RD 0.16, 95% CI 0.14 to 0.19) when compared to Asia, Africa or South America. European studies also showed a tendency towards better efficacy with SEQ; however, this tendency was reversed in 33% of the Asian studies. Africa reported the closest risk difference (RD 0.14 , 95% 0.07 to 0.22) to Europe among studied regions, but confidence intervals were wider and therefore the quality of the evidence showing SEQ to be superior to STT was reduced for this region.Based on high-quality evidence, subgroup analyses showed that SEQ and STT therapies were equivalent when STT lasted for 14 days. Although, overall, the mean eradication proportion with SEQ was over 80%, we noted a tendency towards a lower average effect with this regimen in the more recent studies (2008 and after); weighted linear regression showed that the efficacies of both regimens evolved differently over the years, having a higher reduction in the efficacy of SEQ (-1.72% yearly) than in STT (-0.9% yearly). In these more recent studies (2008 and after) we were also unable to detect the superiority of SEQ over STT when STT was given for 10 days.Based on very low-quality evidence, subgroup analyses on antibiotic resistance showed that the widest difference in efficacy between SEQ and STT was in the subgroup analysis based on clarithromycin-resistant participants, in which SEQ reached a 75% average efficacy versus 43% with STT.Reporting on adverse events (AEs) (RD 0.00, 95% CI -0.02 to 0.02; participants = 8103; studies = 27; I² = 26%, based on high-quality evidence) showed no significant differences between SEQ and STT (20.4% vs 19.5%, respectively) and results were homogeneous.The quality of the studies was limited due to a lack of systematic reporting of the factors affecting risk of bias. Although randomisation was reported, its methodology (e.g. algorithms, number of blocks) was not specified in several studies. Additionally, the other 'Risk of bias' domains (such as allocation concealment of the sequence randomisation, or blinding during either performance or outcome assessment) were also unreported.However, subgroup analyses as well as sensitivity analyses or funnel plots indicated that treatment outcomes were not influenced by the quality of the included studies. On the other hand, we rated 'length of STT' and AEs for the main outcome as high-quality according to GRADE classification; but we downgraded 'publication date' quality to moderate, and 'geographic region' and 'antibiotic resistance' to low- and very low-quality, respectively.

AUTHORS' CONCLUSIONS

Our meta-analysis indicates that prior to 2008 SEQ was more effective than STT, especially when STT was given for only seven days. Nevertheless, the apparent advantage of sequential treatment has decreased over time, and more recent studies do not show SEQ to have a higher efficacy versus STT when STT is given for 10 days.Based on the results of this meta-analysis, although SEQ offers an advantage when compared with STT, it cannot be presented as a valid alternative, given that neither SEQ nor STT regimens achieved optimal efficacy ( ≥ 90% eradication rate).

Evidence-based assessment of proton-pump inhibitors in Helicobacter pylori eradication: A systematic review

Peptic ulcer disease continues to be issue especially due to its high prevalence in the developing world. Helicobacter pylori (H. pylori) infection associated duodenal ulcers should undergo eradication therapy. There are many regimens offered for H. pylori eradication which include triple, quadruple, or sequential therapy regimens. The central aim of this systematic review is to evaluate the evidence for H. pylori therapy from a meta-analytical outlook. The consequence of the dose, type of proton-pump inhibitor, and the length of the treatment will be debated. The most important risk factor for eradication failure is resistance to clarithromycin and metronidazole.

Role of dental plaque, saliva and periodontal disease in Helicobacter pylori infection

Helicobacter pylori (H. pylori) infection is one of the most common bacterial infections in humans. Although H. pylori may be detected in the stomach of approximately half of the world's population, the mechanisms of transmission of the microorganism from individual to individual are not yet clear. Transmission of H. pylori could occur through iatrogenic, fecal-oral, and oral-oral routes, and through food and water. The microorganism may be transmitted orally and has been detected in dental plaque and saliva. However, the role of the oral cavity in the transmission and recurrence of H. pylori infection has been the subject of debate. A large number of studies investigating the role of oral hygiene and periodontal disease in H. pylori infection have varied significantly in terms of their methodology and sample population, resulting in a wide variation in the reported results. Nevertheless, recent studies have not only shown that the microorganism can be detected fairly consistently from the oral cavity but also demonstrated that the chances of recurrence of H. pylori infection is more likely among patients who harbor the organism in the oral cavity. Furthermore, initial results from clinical trials have shown that H. pylori-positive dyspeptic patients may benefit from periodontal therapy. This paper attempts to review the current body of evidence regarding the role of dental plaque, saliva, and periodontal disease in H. pylori infection.

Comparison of Helicobacter pylori eradication rates of standard 14-day quadruple treatment and novel modified 10-day, 12-day and 14-day sequential treatments

BACKGROUND & AIM

This study aimed to compare the efficacy and safety of bismuth-included standard regimen and modified sequential treatments in Turkey, where the success rate of standard triple therapy is very low.

METHODS

One-hundred and sixty patients with dyspeptic complaints and naïve Helicobacter pylori infection were randomized into four groups: 41 patients received standard 14-day quadruple treatment (STD) (Rabeprazole 20mg-bid, bismuth subcitrate (120 mg-qid), Tetracycline 500 mg-qid, Metronidazole 500 mg-tid) for 2 weeks. The modified sequential therapy groups received 20 mg rabeprazole and 1g amoxicillin, twice daily for the first 5 days, followed by Rabeprazole 20mg-bid, bismuth subcitrate (120 mg-qid), Tetracycline 500 mg-qid, Metronidazole 500 mg-tid for the remaining 5 (10 day sequential therapy group-10S) (42 patients), 7 (12 day sequential therapy group-12S) (42 patients) and 9 (14 day sequential therapy group-14S) (41 patients) days.

RESULTS

The overall compliance and H. pylori eradication rate among the 160 patients who completed the H. pylori eradication regimens were 86.9% (139/160) and 78.1% (125/160), respectively. The results were not statistically different between groups in the eradication rates. Per-protocol eradication rates were 76.5% in STD, 71.4% in 10S, 82.4% in 12S and 83.3% in 14S groups (p=0.7). Intention-to-treatment rates were 77.5% in STD, 72.5% in 10S, 82.5% in 12S and 80.0% in 14S groups (p=0.5).

CONCLUSION

The eradication rates of standard 14-day and different sequential quadruple treatment regimens are comparable and much more higher than with standard 14-day triple H. pylori eradication treatment that has been reported previously in Turkey.

Helicobacter pylori Eradication Therapy: Current Availabilities

Background. Though Helicobacter pylori (HP) infections have progressively declined throughout most of the industrialized countries, a gradual increase in failure of HP eradication treatments is observed. Aim. To critically review evidence on the efficacy of the therapeutic availabilities for HP eradication, as yet. Methods. A selection of Clinical Trials, Systematic Reviews and Meta-analyses within the time period 2010–2012, was performed through a Medline search. Previous references were included when basically supporting the first selection. Results. An increasing rise in HP resistance rates for antimicrobial agents is currently observed. Further causes of HP treatment failure include polymorphisms of the CYP 2C19, an increased body mass index (BMI), smoking, poor compliance and re-infections. Alternative recent approaches to standard triple therapy have been attempted to increase the eradication rate, including bismuth-containing quadruple therapy, non-bismuth containing quadruple therapy, sequential therapy and levofloxacin-containing regimens. Conclusions. The main current aims should be the maintenance of a high eradication rate (>85%) of HP and the prevention of any increase in antimicrobial resistance. In the next future, the perspective of a tailored therapy could optimize eradication regimens within the different countries.

Helicobacter pylori Eradication Therapies in the Era of Increasing Antibiotic Resistance: A Paradigm Shift to Improved Efficacy

With the rising prevalence of antimicrobial resistance, the eradication rates of Helicobacter pylori (H. pylori) with standard treatments are decreasing to unacceptable levels (i.e., ≤80%) in most countries. After these disappointing results, several authorities have proposed that infection with H. pylori should be approached and treated as any other bacterial infectious disease. This implicates that clinicians should prescribe empirical treatments yielding a per protocol eradication of at least 90%. In recent years several treatments producing ≥90% cure rates have been proposed including sequential therapy, concomitant quadruple therapy, hybrid (dual-concomitant) therapy, and bismuth-containing quadruple therapy. These treatments are likely to represent the recommended first-line treatments in the near future. In the present paper, we are considering a series of critical issues regarding currently available means and approaches for the management of H. pylori infection. Clinical needs and realistic endpoints are taken into account. Furthermore, emerging strategies for the eradication of H. pylori and the existing evidence of their clinical validation and widespread applicability are discussed.

Helicobacter pylori Eradication Therapies in the Era of Increasing Antibiotic Resistance: A Paradigm Shift to Improved Efficacy

With the rising prevalence of antimicrobial resistance, the eradication rates of Helicobacter pylori (H. pylori) with standard treatments are decreasing to unacceptable levels (i.e., ≤80%) in most countries. After these disappointing results, several authorities have proposed that infection with H. pylori should be approached and treated as any other bacterial infectious disease. This implicates that clinicians should prescribe empirical treatments yielding a per protocol eradication of at least 90%. In recent years several treatments producing ≥90% cure rates have been proposed including sequential therapy, concomitant quadruple therapy, hybrid (dual-concomitant) therapy, and bismuth-containing quadruple therapy. These treatments are likely to represent the recommended first-line treatments in the near future. In the present paper, we are considering a series of critical issues regarding currently available means and approaches for the management of H. pylori infection. Clinical needs and realistic endpoints are taken into account. Furthermore, emerging strategies for the eradication of H. pylori and the existing evidence of their clinical validation and widespread applicability are discussed.

Update on non-bismuth quadruple (concomitant) therapy for eradication of Helicobacter pylori

BACKGROUND

Traditional standard triple therapy for Helicobacter pylori (H. pylori) infection (proton pump inhibitor-clarithromycin-amoxicillin) can easily be converted to non-bismuth quadruple (concomitant) therapy by the addition of a nitroimidazole twice daily.

AIM

To critically review evidence on the role of non-bismuth quadruple therapy (proton pump inhibitor-clarithromycin-amoxicillin-nitroimidazole) in the treatment of H. pylori infection.

METHODS

Bibliographical searches were performed in MEDLINE and relevant congresses up to December 2011. We performed a meta-analysis of the studies evaluating the concomitant therapy, and of the randomized controlled trials comparing the concomitant and the standard triple therapy.

RESULTS

A meta-analysis of 19 studies (2070 patients) revealed a mean H. pylori cure rate (intention-to-treat) of 88% (95% confidence interval from 85% to 91%) for non-bismuth quadruple therapy. We performed a meta-analysis of the randomized controlled studies comparing the concomitant (481 patients) and the standard triple therapy (503 patients). The former was more effective than the latter: 90% versus 78% (intention-to-treat analysis). Results were homogeneous (I(2) = 0%). The odds ratio for this comparison was 2.36 (95% confidence interval from 1.67 to 3.34). A tendency toward better results with longer treatments (7-10 days versus 3-5 days) has been observed, so it seems reasonable to recommend the length of treatment achieving the highest cure rates (10 days). Clarithromycin resistance may reduce the efficacy of non-bismuth quadruple therapy, although the decrease in eradication rates seems to be far lower than in standard triple therapy. Experience with the non-bismuth quadruple therapy in patients with metronidazole-resistant strains is still very limited.

CONCLUSION

Non-bismuth quadruple (concomitant) therapy appears to be an effective, safe, and well-tolerated alternative to triple therapy and is less complex than sequential therapy. Therefore, this regimen appears well suited for use in settings where the efficacy of triple therapy is unacceptably low.

Review article: rifabutin in the treatment of refractory Helicobacter pylori infection

BACKGROUND

Even with the current most effective treatment regimens, a relevant proportion of patients will fail to eradicate Helicobacter pylori infection.

AIM

To evaluate the role of rifabutin in the treatment of H. pylori infection.

METHODS

Bibliographical searches were performed in MEDLINE. Data on the efficacy of rifabutin-containing regimens on H. pylori eradication were combined and meta-analysed using the generic inverse variance method.

RESULTS

Rifabutin shows good in vitro activity against H. pylori. Mean H. pylori rifabutin resistance rate (calculated from 11 studies including 2982 patients) was 1.3% (95% confidence interval = 0.9-1.7%). When only studies including patients naïve to H. pylori eradication treatment were considered, this figure was even lower (0.6%). On the other hand, higher values of rifabutin resistance were calculated (1.59%) when only post-treatment patients were considered. Overall, mean H. pylori eradication rate (intention-to-treat analysis) with rifabutin-containing regimens (1008 patients) was 73% (67-79%). Respective cure rates for second-line (223 patients), third-line (342 patients) and fourth/fifth-line (95 patients) rifabutin therapies were 79% (67-92%), 66% (55-77%) and 70% (60-79%) respectively. For treating H. pylori infection, almost all studies have administered rifabutin 300 mg/day; this dose seems to be more effective than 150 mg/day. The ideal length of treatment remains unclear, but 10- to 12-day regimens are generally recommended. The mean rate of adverse effects was 22% (19-25%). Myelotoxicity is the most significant, although this complication was rare. Until now, all patients have recovered of leucopenia uneventfully in a few days, and there have been no reports of infection or other adverse outcomes related to it.

CONCLUSION

Rifabutin-containing rescue therapy constitutes an encouraging strategy after multiple (usually three) previous eradication failures with key antibiotics such as amoxicillin, clarithromycin, metronidazole, tetracycline and levofloxacin.

Review article: the effectiveness of standard triple therapy for Helicobacter pylori has not changed over the last decade, but it is not good enough

BACKGROUND  A decrease in the Helicobacter pylori eradication rate after standard triple therapy has been suggested in recent years. AIM  To assess the efficacy of standard triple therapy in the eradication of H. pylori through an epidemiological analysis of all published Spanish trials. A secondary aim was to review the prevalence of clarithromycin resistance in Spain. METHODS  Articles on H. pylori eradication in Spain published in peer-reviewed journals were identified through MEDLINE searches. Studies that included a triple therapy consisting of any proton pump inhibitor with clarithromycin (500 mg b.d.) and amoxicillin (1 g b.d.) for up to 14 days were selected. Spanish studies evaluating the prevalence of clarithromycin resistance were also reviewed. Meta-analysis was performed using the generic inverse variance method. RESULTS The pooled eradication rates by year from Spanish studies evaluating the efficacy of the standard triple regimen revealed a relatively constant rate over the years. Overall, the analysis of the 32 studies (4727 patients) showed a mean H. pylori cure rate of 80% (95% CI = 77-82%) by intention-to-treat and 83% (81-86%) by per-protocol. When only peptic ulcer disease or 7-day regimens were considered, results were similar. Based on 13 studies (3293 patients), mean clarithromycin resistance rate was 8% (5-10%). CONCLUSION Although a decrease in the H. pylori eradication rate after triple therapy has been suggested in recent years, cure rates with this regimen did not change in Spain between 1997 and 2008. However, this by no means indicates that the efficacy of standard triple therapy in Spain is acceptable, as it has been calculated to be around only 80%. Therefore, it is evident that new strategies to improve first-line treatment are urgently needed.

Modified Sequential Therapy Regimen versus Conventional Triple Therapy for Helicobacter Pylori Eradication in Duodenal Ulcer Patients in China: A Multicenter Clinical Comparative Study

Objective. Antimicrobial resistance has decreased eradication rates for Helicobacter pylori infection worldwide. To observe the effect of eradicating Helicobacter pylori (H. pylori) and the treatment of duodenal ulcer by 2 kinds of modified sequential therapy through comparing with that of 10-day standard triple therapy. Methods. A total of 210 patients who were confirmed in duodenal ulcer active or heal period by gastroscopy and H. pylori positive confirmed by rapid urease test, serum anti-H. pylori antibody (ELASE), or histological examination enrolled in the study. All the patients were randomly divided into three groups: group A (70 cases) and group B (70 cases) were provided 10-day modified sequential therapy; group C (70 cases) was provided 10-day standard triple therapy. Patients of group A received 20 mg of Esomeprazole, 500 mg of Clarithromycin for the first 5 days, followed by 20 mg of Esomeprazole, 500 mg of Clarithromycin, and 1000 mg of Amoxicillin for the remaining 5 days. Group B received 20 mg of Esomeprazole, 1000 mg of Amoxicillin for the first 5 days, followed by 20 mg of Esomeprazole, 500 mg of Clarithromycin, and 1000 mg of Amoxicillin for the remaining 5 days. Group C received 20 mg of Esomeprazole, 500 mg of Clarithromycin, and 1000 mg of Amoxicillin for standard 10-day therapy. All drugs were given twice daily. H. pylori eradication rate was checked four to eight weeks after taking the medicine by using a ¹³C urea breath test. In the first, second, third, seventh, twenty-first, thirty-fifth days respectively, the symptoms of patients such as epigastric gnawing, burning pain, and acidity were evaluated simultaneously. Results. Overall, 210 patients accomplished all therapy schemes, 9 case patients were excluded. The examination result indicated that the H. pylori eradication rate of each group was as follows: group A 92.5% (62/67), group B 86.8% (59/68), and group C 78.8% (52/66). The H. pylori eradication rate of group A was slightly higher than group B (P < 0.05) and both of them were obviously higher than group C (P < 0.05). Modified sequential therapy was significantly more effective in patients with clarithromycin-resistant strains (80%/67% versus 31%; P = 0.02). Symptoms improvement: all the three groups could improve the symptoms such as epigastric gnawing, burning pain, and acidity since the first day. There was no significant difference in total score descending of symptoms between each group (P > 0.05). Conclusions. All the three therapy schemes could alleviate symptoms of duodenal ulcer patients in China efficiently. But as far as eradicating H. pylori is concerned, the modified sequential therapy was better than standard triple therapy, especially the therapy scheme used in group A.

A randomized study comparing levofloxacin, omeprazole, nitazoxanide, and doxycycline versus triple therapy for the eradication of Helicobacter pylori

OBJECTIVES

Resistance to standard Helicobacter pylori (HP) treatment regimens has led to unsatisfactory cure rates in HP-infected patients. This study was designed to evaluate a novel four-drug regimen (three antibiotics and a proton pump inhibitor (PPI)) for eradication of HP infection in treatment-naive patients.

METHODS

Patients with a diagnosis of HP gastritis or peptic ulcer disease confirmed using endoscopy and stool antigen testing were eligible for inclusion in this study. All patients underwent a washout period of 6 weeks from any prior antibiotic or PPI usage. Patients were then randomized to either levofloxacin, omeprazole, nitazoxanide, and doxycycline (LOAD) therapy for 7 days (LOAD-7) or 10 days (LOAD-10), including levofloxacin 250 mg with breakfast, omeprazole 40 mg before breakfast, nitazoxanide (Alina) 500 mg twice daily with meals and doxycycline 100 mg at dinner, or lansoprozole, amoxicillin, and clarithromycin (LAC) therapy for 10 days, which included lansoprozole 30 mg, amoxicillin 1 g with breakfast and dinner, and clarithromycin 500 mg with breakfast and dinner. HP eradication was confirmed by stool antigen testing at least 4 weeks after cessation of therapy.

RESULTS

Intention-to-treat analysis revealed significant differences (P<0.05) in the respective eradication rates of the LOAD therapies (88.9% (80/90) LOAD-10, 90% (81/90) LOAD-7, 89.4% (161/180) for combined LOAD) compared with those receiving LAC, 73.3% (66/90). There were no differences in adverse effects between the groups.

CONCLUSIONS

This open-label, prospective trial demonstrates that LOAD is a highly active regimen for the treatment of HP in treatment-naive patients. A large randomized controlled trial is warranted to further evaluate the efficacy of this regimen.

Review article: non-bismuth quadruple (concomitant) therapy for eradication of Helicobater pylori

BACKGROUND

Traditional standard triple therapy for Helicobacter pylori infection (PPI-clarithromycin-amoxicillin) can easily be converted to non-bismuth quadruple (concomitant) therapy by the addition of a nitroimidazole twice daily.

AIM

To critically review evidence on the role of non-bismuth quadruple therapy (PPI-clarithromycin-amoxicillin-nitroimidazole) in the treatment of H. pylori infection.

METHODS

Bibliographical searches were performed in MEDLINE and relevant congresses.

RESULTS

The first randomised comparison of the non-bismuth quadruple therapy and the sequential (PPI-amoxicillin 5days plus PPI-clarithromycin-nitroimidazole 5days) regimens recently concluded that both were similar in terms of efficacy and safety and that the sequential administration protocol may be unnecessarily complex. Several randomised controlled trials (and one meta-analysis) have demonstrated that non-bismuth quadruple therapy is more effective than and is equally well tolerated as standard triple therapy. A meta-analysis of 15 studies (1723 patients) revealed a mean H. pylori cure rate (intention-to-treat) of 90% for non-bismuth quadruple therapy. A tendency towards better results with longer treatments (7-10days vs. 3-5days) has been observed, so it seems reasonable to recommend the length of treatment by achieving maximal cure rates (10days). Clarithromycin resistance may reduce the efficacy of non-bismuth quadruple therapy, although the decrease in eradication rates seems to be far lower than in standard triple therapy. Experience with the non-bismuth quadruple therapy in patients with metronidazole-resistant strains is still very limited.

CONCLUSIONS

Non-bismuth quadruple (concomitant) therapy appears to be an effective, safe, and well-tolerated alternative to triple therapy and is less complex than sequential therapy. Therefore, this regimen appears well suited for use in settings where the efficacy of triple therapy is unacceptably low.

Helicobacter pylori eradication therapy research: Ethical issues and description of results

As an infectious disease, the approach to anti-Helicobacter pylori therapy differs from other common gastrointestinal conditions because treatment success of more than 90% to 95% should be expected and the reasons for treatment failure can always be understood. Neither comparisons with another regimen nor randomization are required to identify a highly successful therapy. Treatment success should be judged first in relation to outcome (ie, ≥95% or grade A). Inclusion of a known inferior regimen in a clinical trial is generally unethical. If the use of a known inferior drug is required by a regulatory agency, subjects must be given full and accurate information regarding expectations with each regimen; there can be no deceptions. Comparative trials should be restricted to highly successful treatments (ie, comparisons of different doses, durations, compliance, cost, and so forth). Success should be judged as ordered categories such as <85%, 85%-89%, 90%-94%, or ≥95% and statistically equivalent regimens with the same grade success (ie, 90%-94% [Grade B]) are inferior to those higher category (ie, ≥95% [Grade A]) regimens. Only grade A or B regimens should be prescribed. Here we discuss anti-H pylori eradication studies from the perspective [corrected] of an infectious disease with the goal of providing recommendations regarding changes in approach and in reporting that should help resolve the ethical issues and make the results of clinical trials more useful to clinicians.

Standard triple, bismuth pectin quadruple and sequential therapies for Helicobacter pylori eradication

AIM: To compare the effectiveness of standard triple, bismuth pectin quadruple and sequential therapies for Helicobacter pylori (H. pylori) eradication in a randomized, double-blinded, comparative clinical trial in China.

METHODS: A total of 215 H. pylori-positive patients were enrolled in the study and randomly allocated into three groups: group A (n = 72) received a 10-d bismuth pectin quadruple therapy (20 mg rabeprazole bid, 1000 mg amoxicillin bid, 100 mg bismuth pectin qid, and 500 mg levofloxacin qd); group B (n = 72) received the sequential therapy (20 mg omeprazole bid, 1000 mg amoxicillin bid, in 5 d, followed by 20 mg omeprazole bid, 500 mg tinidazole bid, 500 mg clarithromycin bid, for another 5 d); group C (n = 71) received a standard 1-wk triple therapy (20 mg omeprazole bid, 1000 mg amoxicillin bid, 500 mg clarithromycin bid). After all these treatments, 20 mg omeprazole bid was administrated for 3 wk. H. pylori status was assessed by histology, 13C-urea breath test and rapid urease test at baseline and 4-6 wk after completion of treatment. Ulcer cicatrization was assessed by gastroscopy. χ² test (P < 0.05) was used to compare the eradication rates and ulcer cicatrisation rates among the three groups.

RESULTS: The eradication rate was 83.33% (60/72) in group A, 88.89% (64/72) in group B, and 80.56% (58/71) in group C. The ulcer cicatrisation rate was 86.44% (51/59) in group A, 90.16% (55/61) in group B, and 84.91% (45/53) in group C. The sequential therapy yielded a higher eradication rate and ulcer cicatrisation rate than the standard triple and bismuth pectin quadruple therapies. Statistically, the eradication rate of group B was significantly different from groups A and C (P < 0.05), but the difference of ulcer cicatrisation rate and side effects was not statistically significant among the three groups (P > 0.05). The three protocols were generally well tolerated.

CONCLUSION: The sequential therapy has achieved a significantly higher eradication rate, and is a more suitable first-line alternative protocol for anti-H. pylori infection compared with the standard triple and bismuth pectin quadruple therapies.

First-line eradication of Helicobacter pylori: Are the standard triple therapies obsolete? A different perspective

Studies concerning the eradication of Helicobacter pylori have resulted in a proliferation of meta-analyses. To date, there are 303 meta-analyses cited in PubMed, 113 dealing with the therapy of the infection. A chronological analysis of the results of meta-analyses performed between 1998 and 2010 shows that first-line standard triple therapies achieved eradication rates on an intention-to-treat basis of around 80%; prolonging treatment to 14, but not 10 d should improve the results. The proton pump inhibitors have a similar efficiency, and giving a double dose is more efficient than the standard doses of these drugs. Triple and quadruple therapies proved to be equivalent. Based on meta-analytical data, the decrease in efficiency over time cannot be substantiated: eradication rates < 80% followed from the introduction of triple therapies. As alternatives, ranitidine bismuth citrate-, levofloxacin- or furazolidone-based therapies were shown to obtain the same eradication rates as standard triple regimens. Sequential therapies and quadruple non-bismuth-based therapies were superior to standard triple therapies but their use is limited to certain countries. In the author’s opinion, and from a meta-analytical viewpoint, standard triple therapies cannot yet be considered obsolete. Furthermore, non-inferiority trials are proposed for the future, including assessment of local contemporary antimicrobial resistance profiles and the CagA and CYP2C19 status of the enrolled patients.

Sequential therapy for Helicobacter pylori eradication: a critical review

BACKGROUND

Alternative treatment regimens for standard triple therapy are urgently needed.

AIM

To critically review the evidence on the role of "sequential" regimen for the treatment of Helicobacter pylori infection.

METHODS

Bibliographical searches were performed in MEDLINE and international congresses.

RESULTS

Several pooled-data analyses and meta-analyses have demonstrated that sequential regimen is more effective than standard triple therapy. Sequential therapy is not affected by bacterial (CagA status, infection density) and host factors (underlying disease, smoking). Clarithromycin resistance seems to be the only factor reducing their efficacy. However, even in these patients, an acceptable >75% eradication rate can be achieved. Unfortunately, almost all the studies have been performed in Italy. Whether it is necessary to provide the drugs sequentially or if the 4 components of sequential therapy can be given concurrently is unclear. Nonbismuth quadruple therapy seems to be an effective and safe alternative to triple therapy and is less complex than sequential therapy.

CONCLUSIONS

Sequential therapy is a novel promising treatment approach that deserves consideration as a treatment strategy for H. pylori infection. However, further robust assessment across a much broader range of patients is required before sequential therapy could supplant existing treatment regimens and be generally recommended in clinical practice.

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.

Helicobacter pylori eradication therapy: indications, efficacy and safety

BACKGROUND

Helicobacter pylori infects up to half of the world's population. It remains the major cause of peptic ulcer disease and is recognised as a carcinogen for its role in gastric carcinogenesis. Successful eradication of the bacteria is associated with improved health outcomes including fewer dyspeptic symptoms, reduced peptic ulcer recurrence and rebleeding, reduced peptic ulcer risk with NSAIDs and as a cure for low-grade gastric MALT lymphoma. The risk of gastric cancer is reduced in those without premalignant mucosal abnormalities at the time of eradication.

OBJECTIVE

This review outlines the current indications and options for therapy of H. pylori with particular reference to drug-induced adverse events associated with treatment.

METHODS

The indications for H. pylori eradication are evidence-based and in accordance with recent consensus statements and recommendations. The eradication treatment is based on numerous clinical trials and meta-analyses.

RESULTS/CONCLUSION

Eradication therapy, in general, is safe and well tolerated. Antibiotic therapy may be associated with significant drug adverse reactions, especially gastrointestinal symptoms.

Levofloxacin-based triple therapy for Helicobacter pylori re-treatment: role of bacterial resistance

BACKGROUND

First-line Helicobacter pylori therapy fails in more than 20% of patients. Quadruple therapy is the suggested second-line therapy, but bismuth salts are not anymore available worldwide. This study aimed to assess the efficacy of a levofloxacin-amoxycillin triple therapy as a second-line treatment, and the role of primary levofloxacin resistance.

METHODS

Forty patients, in whom first treatment with either standard 10-day triple or sequential therapy had failed, received 10-day triple therapy with rabeprazole (20mg b.d.), levofloxacin (250mg b.d.), and amoxycillin (1g b.d.). Cure rates were evaluated by the (13)C-urea breath test. Primary levofloxacin resistance was detected by culture.

RESULTS

Bacterial culture was available in 33 (82.5%) out 40 patients, and primary levofloxacin resistance was detected in 10 (30.3%) patients. Overall, 33 of 40 patients accepted to participate in this study, and all returned for follow-up after therapy. Compliance to the therapy was safe except 1 patient only who stopped earlier the treatment due to side effects (oral candidiasis). H. pylori infection was eradicated in 24 patients, accounting for a 72.7% (95% CI: 57-88) eradication rate at both intention-to-treat and per protocol analyses. The eradication rate was higher in patients harbouring levofloxacin-susceptible than resistant strains (75% versus 33.3%; P=0.074).

CONCLUSIONS

The eradication rate achieved by a levofloxacin-based re-treatment seems to be decreasing, and its efficacy is reduced in presence of levofloxacin resistance.

Nitrofuran-based regimens for the eradication of Helicobacter pylori infection

Several aspects of Helicobacter pylori eradication have been meta-analyzed; however, nitrofuran-based therapies constitute an exception. The aim of this study was the systematic review and meta-analysis of the effect of furazolidone- and nitrofurantoin-based regimens in the eradication of infection. Studies evaluating the effects of nitrofurans on H. pylori were identified from Medline, EMBASE, the Cochrane Controlled Trials Register and congress abstracts. The studies were classified into groups based on first-, second- and third-line regimens. The pooled eradication rates and combined odd ratios of the individual studies were calculated and compared with the published meta-analysis. The factors influencing the efficiency of the regimens were also analyzed. Side-effects of nitrofuran-based regimens were also analyzed. The pooled eradication rate of primary proton pump inhibitor-based regimens containing furazolidone was 76.3% (CI 67.8-84.2). The odds ratio for furazolidone-based regimens versus standard triple therapies was 2.34 (CI 0.76-3.92). Ranitidine bismuth citrate + furazolidone-based triple regimens were equally efficient (83.5%, CI 74.0-93.0, P = 0.06 versus triple therapies). Schedules including a H(2) antagonist + furazolidone + one other antibiotic achieved pooled eradication rates of 79.9% (CI 67.8-89.9, P = 0.04). Bismuth-based triple therapies achieved 84.5% (CI 72.6-93.0, P = 0.002). Primary quadruple regimens containing furazolidone were superior to triple therapies (83.4%, CI 69.7-92.3, P = 0.01). Second-line schedules containing furazolidone obtained eradication rates of 76.1% (CI 66.4-85.0, P = 0.28 versus primary regimens). Third-line 'rescue' therapies were efficient in 65.5% of the cases (CI 56.3-75.5, P = 0.0001). Side-effects of the regimens containing furazolidone were more frequent than in standard therapies (P = 0.02). The combined odds ratio of side-effects for furazolidone-based versus standard therapies was 0.74 (CI 0.32-1.98). The duration of treatment, but not the furazolidone dose, influenced the treatment outcome. Primary triple regimens containing furazolidone are slightly less efficient than the standard primary combinations; primary quadruple regimens were more efficient than triple therapies. Furazolidone is also efficient as a component of second-line or rescue therapies.

Helicobacter pylori eradication with either quadruple regimen with lactoferrin or levofloxacin-based triple therapy: a multicentre study

BACKGROUND

Helicobacter pylori eradication rate following standard triple therapy is decreasing worldwide. A quadruple therapy with lactoferrin and a levofloxacin-based triple therapy has been found to achieve a very high (>90%) cure rate. This study aimed to confirm these encouraging results.

METHODS

This was a prospective, open-label, randomised, multicentre, Italian study enrolling consecutive H. pylori infected patients. The infection at entry was assessed by endoscopy and biopsies (histology plus rapid urease test) in all patients, whilst bacterial eradication was assessed by 13C-urea breath test 4-6 weeks after therapy ended. Patients were randomised to receive either a 7-day, triple therapy with rabeprazole 20mg o.d., levofloxacin 500 mg o.d., and amoxycillin 1g b.i.d. (4 tablets/day) or a 7-day quadruple therapy comprising of rabeprazole 20mg, clarithromycin 500 mg, tinidazole 500 mg plus bovine lactoferrin 200mg, all given twice daily (10 tablets/day).

RESULTS

Overall, 144 consecutive patients were enrolled in the study. Following the triple therapy, H. pylori infection was cured in 49 out of 72 (68.1%; 95% CI=57-79) patients and in 49 out of 71 (69.1%; 95% CI=58-80) at intention-to-treat and per protocol analyses, respectively. Following the quadruple regimen, the infection was cured in 52 out of 72 (72.2%; 95% CI=62-83) and in 52 out of 68 (76.5; 95% CI=66-87) patients at intention-to-treat and per protocol analyses, respectively. No statistically significant difference emerged between the two therapy regimens.

CONCLUSIONS

H. pylori eradication rate following both quadruple therapy with lactoferrin and a low-dose PPI, triple therapy with levofloxacin is disappointingly low.

Primary antibiotic resistance in Helicobacter pylori strains isolated in northern and central Italy

BACKGROUND

Helicobacter pylori resistance to antibiotics is increasing worldwide, and it reduces the efficacy of therapy.

AIM

To assess current primary antibiotic resistance in H. pylori strains isolated in Italy.

METHODS

Between June 2004 and June 2006, H. pylori strains were isolated consecutively in the two participating centres (Bologna, northern Italy; Rome, central Italy) from patients never previously treated for the infection. Isolated strains were tested for primary clarithromycin, metronidazole and levofloxacin resistance using as break point the minimal inhibitory concentration >/=1, >/=8 and >/=1 mg/L for the three antibiotics, respectively.

RESULTS

Overall, 255 H. pylori strains were evaluated. The resistance rate was 16.9% for clarithromycin, 29.4% for metronidazole and 19.1% for levofloxacin. Clarithromycin resistance was significantly higher in non-ulcer dyspepsia than in peptic ulcer patients (19.1% vs. 0%, P = 0.02), metronidazole resistance was higher in foreign than Italian patients (50% vs. 22.9%, P = 0.0004) and levofloxacin resistance was higher in old than younger patients (28.4% vs. 14.4%, P = 0.048). Levofloxacin resistance was also more frequent in those strains with either clarithromycin or metronidazole resistance.

CONCLUSION

A very high rate of primary resistance towards the tested antibiotics was detected in our study.

Effective regimens for the treatment of Helicobacter pylori infection

Successful Helicobacter pylori eradication therapy remains a challenge in medical practice. Currently, a proton pump inhibitor-based triple therapy containing clarithromycin, amoxicillin or nitroimidazole for 7 days is the recommended first-line treatment approach with an expected eradication success rate of approximately 80%. As a second-line treatment option in the case of failure, a ranitidine bismuth citrate-based quadruple therapy is currently recommended curing another 80% of patients, leaving a subset of patients with persistent H. pylori infection. For these patients, promising rescue options have been evaluated including regimens that contain rifabutin, quinolones, furazolidone or high-dose amoxicillin. The role of susceptibility testing is still under discussion. It is not generally recommended prior to first-line treatment but guidelines propose a role for culture and antibiotic sensitivity testing after failure of the second attempt. Meanwhile, data on the geographic distribution of resistance pattern are available and may guide therapeutic decisions with regard to the combination of antibiotics chosen for the individual patients aiming at 100% cure rate in each individual patient.

Helicobacter pylori eradication with either 7-day or 10-day triple therapies, and with a 10-day sequential regimen

BACKGROUND

Helicobacter pylori eradication rates achieved by standard seven-day triple therapies are decreasing in several countries, while a novel 10-day sequential regimen has achieved a very high success rate. A longer 10-day triple therapy, similar to the sequential regimen, was tested to see whether it could achieve a better infection cure rate.

METHODS

Patients with nonulcer dyspepsia and H pylori infection were randomly assigned to one of the following three therapies: esomeprazole 20 mg, clarithromycin 500 mg and amoxycillin 1 g for seven days or 10 days, or a 10-day sequential regimen including esomeprazole 20 mg plus amoxycillin 1 g for five days and esomeprazole 20 mg, clarithromycin 500 mg and tinidazole 500 mg for the remaining five days. All drugs were given twice daily. H pylori eradication was checked four to six weeks after treatment by using a 13C-urea breath test.

RESULTS

Overall, 213 patients were enrolled. H pylori eradication was achieved in 75.7% and 77.9%, in 81.7% and 84.1%, and in 94.4% and 97.1% of patients following seven-day or 10-day triple therapy and the 10-day sequential regimen, at intention-to-treat and per protocol analyses, respectively. The eradication rate following the sequential regimen was higher than either seven-day (P=0.002) or 10-day triple therapy (P=0.02), while no significant difference emerged between the latter two regimens (P=0.6).

CONCLUSIONS

The 10-day sequential regimen was significantly more effective than both triple regimens, while 10-day triple therapy failed to significantly increase the H pylori eradication rate achieved by the standard seven-day regimen.

Evaluation of triple and quadruple Helicobacter pylori eradication therapies in Iranian children: a randomized clinical trial

BACKGROUND

Clinical trials in children concerning Helicobacter pylori eradication treatments are scarce. The purpose of this study was to assess the efficacy of proton pump inhibitor (PPI)-based triple therapy using PPI, amoxicillin and clarithromycin in Iranian children. We also evaluated the efficacy of quadruple therapy with PPI, metronidazole, amoxicilin and bismuth citrate in Iranian children.

METHODS

This was a randomized clinical trial performed in Emam Khomeini Hospital between 2003 and 2004. Patients with confirmed H. pylori infection by histology were divided into two groups in a randomized 1:1 scheme: the triple regimen group (omeprazole, clarithromycin and amoxicillin for 10 days) and the quadruple regimen group (omeprazole, amoxicillin, metronidazole and bismuth citrate for 10 days). The eradication was assessed by the C-urea breath test 4 weeks after the end of treatment and analyzed by per-protocol and intention-to-treat approaches.

RESULTS

One hundred and twenty-two patients (mean age 12.36+/-3.06 years) were entered into the study. Only 100 patients completed the study (50 patients in each regimen group). The eradication rates by triple therapy were 92% and 75.5% for the "per-protocol" and "intention-to-treat" approaches, respectively. In the quadruple regimen group, the eradication rates were 84% by the per-protocol approach and 68.8% in the intention-to-treat approach. Symptom responses to therapy were reported in all patients with successful eradication (88% of all patients).

CONCLUSION

With regard to recent recommendations, we also suggest PPI, amoxicillin and clarithromycin triple therapy as a first-line eradication treatment, and quadruple therapies as a second-line option, in Iranian children.

Second-line treatment for Helicobacter pylori eradication after sequential therapy failure: a pilot study

A 64-year-old woman was admitted to the hospital for abdominal fullness and constipation. In the pelvic cavity, an abdominal CT scan revealed massive ascites showing malignancy on histological examination. Upper GI endoscopy revealed type 3 gastric cancer from the anglus to the cardia. A barium-enema showed a stenotic lesion at the sigmoid colon due to peritoneal dissemination. An abnormally high CA125(1,400 mg/ml) level was detected in serum. We performed systemic chemotherapy of TS-1, CDDP and peritoneal infusion of docetaxel on the nonresected gastric cancer with peritoneal dissemination. After 2 cycles, cytology of ascites revealed no malignancy, and the serum CA125 value regained its normal level. After 3 cycles, the killer cell effect was recognized by laparoscopic examination and the stenotic change of sigmoid colon had almost disappeared. The patient clinically achieved good QOL by this method, which was very effective for nonresected gastric cancer with peritoneal dissemination.

Eradication of Helicobacter pylori: recent advances in treatment

Helicobacter pylori plays a key role in dyspepsia, peptic ulcer disease, and gastric neoplasia and eradication of the infection has become an important treatment goal in clinical practice. Seven-day proton-pump inhibitor-amoxicillin-clarithromycin triple therapy is the current first-line therapy for H. pylori but eradication rates are compromised by poor compliance and antibiotic resistance. Ten-day sequential treatment may emerge as an alternative first-line therapy. Bismuth-based quadruple therapy is the second-line regimen of choice. Antimicrobial sensitivity testing is not recommended in the routine management of H. pylori infection. Novel triple-therapy regimens containing rifabutin, levofloxacin, or furazolidone may be useful alternatives as second- or third-line therapy.

Quadruple therapy with lactoferrin for Helicobacter pylori eradication: a randomised, multicentre study

BACKGROUND

Helicobacter pylori eradication rate with standard triple therapies is decreasing. Recently, lactoferrin administration has been shown to significantly increase the cure rate of 7-day rabeprazole, clarithromycin and tinidazole triple therapy. We assessed whether lactoferrin also increases the eradication rate of 7-day esomeprazole, clarithromycin and amoxycillin triple therapy as first-line treatment.

METHODS

Overall, 133 consecutive patients with non-ulcer dyspepsia and H. pylori infection were randomised to receive either a standard 7-day triple therapy with esomeprazole 20mg b.i.d., clarithromycin 500 mg b.i.d. and amoxycillin 1g b.i.d. (68 patients) or a quadruple therapy comprising of the same regimen plus lactoferrin 200mg b.i.d. (65 patients). H. pylori at entry was assessed by endoscopy, while bacterial eradication was checked by (13)C urea breath test 4-6 weeks after treatment.

RESULTS

H. pylori eradication following standard triple therapy was achieved in 53/68 (77.9%; 95% CI = 68-88) and in 53/66 (80.3%; 95% CI = 71-89) patients at ITT and PP analyses, respectively. Following the quadruple regimen, the infection was cured in 50/65 (76.9%; 95% CI = 67-87) and 50/64 (78.1%; 95% CI = 68-88) patients at ITT and PP analyses, respectively. No statistically significant difference emerged between the two therapeutic regimens, both at ITT (p = 0.9) and PP analyses (p = 0.9). Side effects were complained by seven (10.3%) patients and six (9.2%) patients following the triple and quadruple regimens, respectively (p = 0.9), with only one patient in the quadruple group interrupting the treatment due to side effects.

CONCLUSIONS

Quadruple therapy with lactoferrin did not significantly increase the H. pylori cure rate of standard 7-day clarithromycin-amoxycillin based triple therapy in non-ulcer dyspepsia patients.

A 10-day levofloxacin-based triple therapy in patients who have failed two eradication courses

BACKGROUND

A standard third-line treatment is lacking, and European guidelines recommend performing culture in these patients. However, the use of this procedure as 'routine practice' is definitively not feasible.

AIM

To evaluate the eradication rate of a 10-day levofloxacin-based triple therapy in patients who have failed two eradication courses for Helicobacter pylori.

METHODS

A total of 151 patients with persistent Helicobacter pylori infection after two treatments were studied. Patients were considered positive if two of three endoscopic tests were positive. Susceptibility testing was also performed. Patients received a standard dose of proton-pump inhibitors twice daily, levofloxacin 250 mg twice daily and amoxicillin 1 g twice daily, for 10 days. Endoscopic follow-up was carried out 4-6 weeks after the end of eradication therapy.

RESULTS

About 76% (95% CI: 68.8-82.3), and 85% (95% CI: 77.5-89.7) of patients were eradicated according to intention-to-treat and per-protocol analysis, respectively. Eradication rates of the strains showed as 92% (95% CI: 83.2-96.7) of those resistant to both metronidazole and clarithromycin but susceptible to levofloxacin.

CONCLUSIONS

In patients who failed previous regimens, the 10-day levofloxacin-based triple therapy is safe and effective, allowing eradication in almost 80% of the patients.

Effect of CYP2C19 and MDR1 polymorphisms on cure rate in patients with acid-related disorders with Helicobacter pylori infection

A proton pump inhibitor (PPI) plus two antibiotics (amoxicillin and either clarithromycin or metronidazole) are recommended for treatment of acid-related disorders with Helicobacter pylori (H. pylori) infection. The aim of this pharmacogenetic study was to evaluate the efficacy of triple therapy with PPIs on eradication of H. pylori infection in relation to cytochrome P450 2C19 (CYP2C19) and P-glycoprotein (MDR1) gene polymorphisms. The retrospective study involved 70 Polish Caucasian patients with H. pylori infection, diagnosed and treated with one of the two different triple therapy regimens [omeprazole, amoxicillin, and clarithromycin (OAC) or pantoprazole, amoxicillin, and metronidazole (PAM)]. Using genomic DNA, CYP2C19 (*2 and *3) and C3435T MDR1 alleles were determined by means of polymerase chain reaction-restriction fragment length polymorphism assays. A significantly higher prevalence (P<0.05) of heterozygous extensive metabolizers (hetEM) with CYP2C19*1/*2 genotype (32.4% versus 8.3%) and homozygous with 3435TT MDR1 genotype (38.2% versus 13.9%) was found in patients cured after the first cycle of triple therapy than in patients with failure of eradication after the first cycle. CYP2C19*1/*2 and 3435TT MDR1 genotypes as well as PAM regimen of treatment were also predictive of successful eradication of H. pylori infection after the first cycle of triple therapy at univariate/multivariate logistic regression analysis. This pharmacogenetic study on the influence of different CYP2C19 and C3435T MDR1 genotypes on H. pylori eradication suggests that CYP2C19 and MDR1 polymorphisms may be independent predictable determinants of the efficacy of triple therapy including PPI. The PAM regimen of treatment seems to be more effective after the first cycle of the therapy than the OAC regimen.

Systematic review and meta-analysis: proton pump inhibitor vs. ranitidine bismuth citrate plus two antibiotics in Helicobacter pylori eradication

OBJECTIVE

To systematically review the Helicobacter pylori eradication efficacy with ranitidine bismuth citrate (RBC) and two antibiotics, and to conduct a meta-analysis of randomized clinical trials comparing the efficacy of proton pump inhibitor (PPI) vs. RBC with two antibiotics for 1 week.

SELECTION OF STUDIES

Studies evaluating RBC plus two antibiotics were considered. For the meta-analysis, randomized controlled trials comparing PPI vs. RBC plus two antibiotics for 1 week were included.

SEARCH STRATEGY

Electronic and manual bibliographical searches. Assessment of study quality and data extraction: Independently done by two reviewers.

DATA SYNTHESIS

'Intention-to-treat' eradication rate. Meta-analysis was performed, combining the odds ratios (OR) of the individual studies. Subanalysis: Depending on the type of antibiotics and the quality of the studies.

RESULTS

Mean H. pylori eradication with 7-day RBC-clarithromycin-amoxicillin, RBC-clarithromycin-nitroimidazole, and RBC-amoxicillin-nitroimidazole was 83%, 86%, and 71%, respectively. The meta-analysis showed comparable efficacy with RBC and PPI when they were combined with clarithromycin and amoxicillin (OR = 1.11; 95% CI = 0.88-1.40), or with amoxicillin and metronidazole (OR = 0.92; 95%CI = 0.60-1.41). However, when comparing PPI vs. RBC plus clarithromycin and a nitroimidazole, higher cure rates with RBC than with PPI were demonstrated (OR = 1.65; 95% CI = 1.15-2.37).

CONCLUSION

The efficacy of RBC and PPI-based triple regimens were comparable when using the clarithromycin-amoxicillin or the amoxicillin-metronidazole combination. However, RBC seems to have a higher efficacy than PPI when clarithromycin and a nitroimidazole are the antibiotics prescribed. Therefore, if one prefers to use the clarithromycin-nitroimidazole regimen, RBC should be used instead of a PPI.

First-line eradication therapy for Helicobacter pylori in primary health care based on antibiotic resistance: results of three eradication regimens

AIM

To determine the efficacy of three Helicobacter pylori eradication regimens and factors affecting the eradication results in Finland.

METHODS

A total of 342 H. pylori-positive adult patients from primary health care referred for gastroscopy at 23 centres in different parts of Finland were randomized to receive either (i) lansoprazole 30 mg b.d., amoxicillin 1 g b.d. and metronidazole 400 mg t.d.s. (LAM), (ii) lansoprazole 30 mg b.d., amoxicillin 1 g b.d. and clarithromycin 500 mg b.d. (LAC), or (iii) ranitidine bismuth citrate 400 mg b.d., metronidazole 400 mg t.d.s. and tetracycline 500 mg q.d.s. (RMT). A (13)C-urea breath test was performed 4 weeks after therapy.

RESULTS

The eradication result could be assessed in 329 cases. Intention-to-treat cure rates of LAM, LAC, and RMT were 78, 91 and 81%. The difference was significant between LAM and LAC (P = 0.01) and between LAC and RMT (P = 0.04). The eradication rates in cases with metronidazole-susceptible vs. -resistant isolates were for LAM 93% vs. 53% (P = 0.00001), for LAC 95% vs. 84%, and for RMT 91% vs. 67% (P = 0.002). Previous antibiotic use, smoking, and coffee drinking reduced the efficacy of therapy.

CONCLUSIONS

In unselected patients in primary health care, LAC was the most effective first-line eradication.

Efficacy of a Low-Dose Omeprazole-Based Triple-Therapy Regimen for Helicobacter pylori Eradication Independent of Cytochrome P450 Genotype

OBJECTIVES

To investigate the efficacies of two different triple-therapy regimens (standard versus low doses), and the influence of cytochrome P450 enzyme (CYP) genetic polymorphism on these efficacies, in Japanese patients undergoing Helicobacter pylori eradication treatment.

METHODS

All patients received 1 week of triple therapy. Patients in group A (low-dose regimen) received omeprazole 40 mg/day + amoxicillin 1500 mg/day + clarithromycin 800 mg/day; patients in group B (standard-dose regimen) received omeprazole 40 mg/day + amoxicillin 2000 mg/day + clarithromycin 1000 mg/day.

RESULTS

A total of 225 patients (113 in group A and 112 in group B) were randomised to one of the two triple-therapy regimens. The eradication rates were 78.8% (89/113 patients; 95% CI 70.1, 85.9) in group A and 83.0% (93/112 patients; 95% CI 74.8, 89.5) in group B. Genetic polymorphism of CYP2C19, a major metabolic enzyme of omeprazole, did not affect eradication rates, while susceptibility to clarithromycin greatly affected the success of eradication. The cumulative ulcer relapse rate at 24 weeks after endoscopically documented ulcer healing (30 weeks after completion of the drug regimen) was 8.3% for group A and 12.5% for group B (log rank test: p = 0.6248). However, comparison of the cumulative relapse rate of 6.7% in patients after successful H. pylori eradication with the relapse rate of 27.3% in those who failed H. pylori eradication revealed a significant difference in the remission-time curve (log rank test: p = 0.0047). This finding suggested the existence of a relationship between H. pylori eradication failure and ulcer relapse. Both drug regimens were well tolerated. Endoscopically proven reflux esophagitis developed in about 10% of patients after eradication, but was not clinically significant.

CONCLUSIONS

One week of triple therapy with a low-dose regimen provides adequate H. pylori eradication in Japanese patients. CYP genetic polymorphism is of minimal clinical significance with both triple-therapy regimens.

Helicobacter pylori infection: anything new should we know?

Over the past year, 2003-4, there have been a number of studies consolidating previous work in relation to pathogenesis of disease, diagnosis and management of Helicobacter pylori. Studies into the pathogenesis of disease have identified the main adhesin of H. pylori as an important virulence marker and as a potential target for therapy. Molecular investigations of both the strain and host variations have identified the action of several of the virulence factors, e.g. cagA, vacA, on disrupting host cell signalling and the consequences in respect of the release of chemokines from the damaged gastric epithelium and the effect on apoptosis. Over the past year, there have been further diagnostic kits developed based on modifications of current technology. Two promising areas of research for diagnosis are the use of host/strain genome polymorphisms as a means of identifying high-risk patients who may develop severe disease and the use of proteomics to identify potential antigens of diagnostic (or therapeutic) use. The three main antibiotics that are used in first-line eradication regimens are clarithromycin, metronidazole and amoxycillin. Of these, metronidazole has the highest prevalence of resistance, followed by clarithromycin; amoxycillin resistance is only rarely reported. The decreasing success of current first-line therapy is the driving force for the development of new antibiotic combinations and a search for novel sources for chemotherapeutic agents and novel therapeutic targets.