Prevalence of resistance to clarithromycin and its clinical impact on the efficacy of Helicobacter pylori eradication

High-dose amoxicillin-proton pump inhibitor dual therapy as first-line treatment for Helicobacter pylori infection in Northwest China: A prospective, randomised controlled trial

AIMS

We aimed to assess the eradication efficacy and factors that influencing it of high-dose dual therapy (HDDT) in Gansu region, Northwest China.

METHODS

A total of 216 treatment-naive patients with Helicobacter pylori infection were randomly assigned to two groups for the 14-day eradication treatment: the HDDT group (amoxicillin 750 mg q.i.d. and esomeprazole 40 mg t.i.d.) and the amoxicillin and clarithromycin-containing bismuth quadruple therapy group (ACBQT: esomeprazole 20 mg, bismuth potassium citrate 2 g, amoxicillin 1 g, and clarithromycin 500 mg; b.i.d.). The eradication rates, adverse effects and patient compliance of these two groups were compared. Eradication efficacy was determined by ¹³ C urea breath test (¹³ C UBT) 4-8 weeks after finishing treatment. Antibiotic resistance was determined by the Epsilometer testing (E-test) method.

RESULTS

The eradication rates for the HDDT and ACBQT groups were 71.0% and 74.7% (P = .552) by per-protocol analysis, and 65.7% and 68.5% (P = .664) by intention-to-treat analysis. The overall adverse event rates in the HDDT and ACBQT groups were 2.0% and 43.4% (P < .001), respectively. The resistance rates to amoxicillin, clarithromycin, tetracycline, levofloxacin and metronidazole were 15.2%, 42.0%, 5.4%, 35.7% and 83.0%, respectively. Amoxicillin resistance and delta over baseline (DOB) of ¹³ C UBT ≥ 20 before treatment significantly reduced the eradication rate in 112 participants with H. pylori cultured.

CONCLUSION

The HDDT as first-line treatment for H. pylori was unsatisfactory in Gansu. Amoxicillin resistance and DOB of ¹³ C UBT ≥ 20 before treatment were significantly correlated with H. pylori eradication failure.

The high-dose amoxicillin-proton pump inhibitor dual therapy in eradication of Helicobacter pylori infection

INTRODUCTION

More attention has been paid to the eradication therapy of Helicobactor pylori with the enhancement of health awareness of patients. However, the increasing antibiotic resistance of H. pylori, due to the wide use and abuse of antibiotics, has become a critical factor affecting the efficacy of eradication. To effectively improve the eradication rate of H. pylori, high-dose amoxicillin-proton pump inhibitor (PPI) dual therapy has recently become one of the hot issues.

AREAS COVERED

The authors review the schemes and efficacy of high-dose amoxicillin-PPI dual therapies in eradication of H. pylori infection. The review indicates that the H. pylori eradication rate of the dual therapy is overall comparable to or better than that of bismuth-containing quadruple therapy or standard triple therapy. It is more effective to administer both amoxicillin and PPI 3-4 times daily for 14 days in the high-dose amoxicillin-PPI dual therapy, and esomeprazole seems to be superior to other PPIs.

EXPERT OPINION

The high-dose amoxicillin-PPI dual therapy is currently a promising H. pylori eradication regimen in clinical practice, deserving further verification and discussion. Much more attention should be paid to the influence of CYP2C19 polymorphisms and virulence genotyping on H. pylori eradication, and the homogeneity and objectivity of the comparison among different studies.

Comparison of azithromycin and clarithromycin triple therapy regimens for helicobacter pylori eradication in hemodialysis patients

Background

Helicobacter pylori eradication with clarithromycin is more expensive than with azithromycin.

Objectives

This study aimed to compare the effectiveness of these two antibiotics in eradicating H. pylori in hemodialysis (HD) patients.

Patients and Methods

This is a prospective, randomized, double-blinded clinical trial analysis of HD patients. Patients who had dyspepsia and showed positive results for two of three tests, anti-H. pylori serology, H. pylori stool antigen (HpSAg), or Urease Breath Test (UBT), were included in the study. The subjects consisted of 39 dialysis patients who were randomly divided into two groups that received medication twice daily. Group OAC received 20 mg omeprazol, 500 mg amoxycilin, and 250 mg clarithromycin, and Group OAAz received 20 mg omeprazol, 500 mg amoxicillin, and 250 mg azithromycin. Both regimens were administered for 14 days. Eradication was investigated by performing the UBT and the HpSAg test eight weeks later.

Results

This study began with 39 patients, 37 of which completed the treatment schedule (20 males and 17 females, mean age 59 years). Two patients died due to MI before beginning treatment. In the OAC group, negative results on the UBT and HpSAg tests were found in 82.4% and 88.2% of the participants, respectively. In the OAAz group, these values were 80% and 85%, respectively. The data showed that the difference between the two regimens was not significant (P = 1.0).

Conclusions

According to the data, no differences in eradication rates were apparent between the azitromycin and the claritromycin regimens. However, lower cost and fewer complaints could be considered as an advantage of the triple therapy with azithromycin.

Correlation between creatinine clearance and Helicobacter pylori infection eradication with sequential and triple therapeutic regimens: A randomised clinical trial

BACKGROUND AND STUDY AIMS

Uraemic patients show susceptibility to gastrointestinal mucosal lesions and colonisation by Helicobacter pylori (HP). Antibiotic resistance constitutes a problem in treatment and bismuth preparations are toxic in uraemic patients. This study aimed to assess the correlation between creatinine clearance (CrCl) and eradication of HP infection with new sequential and standard triple therapeutic regimens.

PATIENTS AND METHODS

A total of 120 HP-positive patients with renal function impairment and 60 control patients with HP infection were enrolled in this study. Patients were divided into four groups on the basis of CrCl and were randomly assigned to one of the two different regimens: A 14-day standard triple therapy with 20mg omeprazole bid, 1000mg amoxicillin bid and 500mg clarithromycin bid and a new sequential regimen with 20mg omeprazole bid and 1000mg amoxicillin bid both for 14 days, 500mg ciprofloxacin bid for the first 7 days and 200mg furazolidone bid for the last 7 days. Doses of amoxicillin, clarithromycin and ciprofloxacin were reduced to 50% in the cases of CrCl <30mgdl(-1).

RESULTS

One hundred and sixty two out of 180 HP-positive patients (54.3% male, 51.6±12.1 years) completed treatment in the four groups and were studied. According to renal function they were classified into group A (n=39), haemodialysis (HD) patients; group B (n=37), CrCl <30mgdl(-1) without HD; group C (n=36), CrCl between 30 and 60mgdl(-1); and group D (n=50), control subjects with CrCl >90mgdl(-1). HP was successfully eradicated in 77.7% of patients with standard triple therapy and in 81.4% of patients with the sequential therapy. There was no significant difference among the study groups in the rate of HP-infection eradication with both regimens.

CONCLUSION

HP eradication rates did not differ with both sequential and standard therapeutic regimens in uraemic and non-uraemic patients. We, therefore, prefer the standard triple therapy due to its simplicity and reported.

Meta-analysis: the effect of antibiotic resistance status on the efficacy of triple and quadruple first-line therapies for Helicobacter pylori

BACKGROUND

Information regarding the effects of drug resistance on therapies for Helicobacter pylori is limited.

AIMS

To determine the effect of drug resistance on the efficacy of first-line treatment regimens for H. pylori and identify the most efficacious treatments in the presence of drug resistance.

METHODS

We searched for studies using the keywords: 'Helicobacter pylori','resistance' and 'treatment' or 'therapy'. Multilevel meta-regression models were used to determine the effect of drug resistance on treatment efficacy.

RESULTS

We analysed data from 93 studies with 10,178 participants. For triple therapies, clarithromycin resistance had a greater effect on treatment efficacy than nitroimidazole resistance. Metronidazole resistance reduced efficacy by 26% in triple therapies containing a nitroimidazole, tetracycline and bismuth, while efficacy was reduced by only 14% when a gastric acid inhibitor was added to the regimen. Quadruple therapies containing both clarithromycin and metronidazole were the most efficacious; >80% of H. pylori infections were consistently eradicated with these regimens.

CONCLUSIONS

Drug resistance was a strong predictor of efficacy across triple therapies for the eradication of H. pylori in adults. Resistance to either clarithromycin or metronidazole, but not both simultaneously, may be overcome by using quadruple therapies, especially those containing both clarithromycin and metronidazole.

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.

Efficacy of two triple eradication regimens in children with Helicobacter pylori infection

Triple therapy with bismuth subsalicylate, amoxicillin, metronidazole (BAM) or with omeprazole, amoxicillin, clarithromycin (OAC) has been commonly used for the eradication of Helicobacter pylori infection. We compared the efficacy of these triple therapies in children with H. pylori infection. We retrospectively analyzed results in 233 children with H. pylori infection and treated with OAC (n=141) or BAM (n=92). Overall eradication rates of triple therapy with OAC and BAM were 74% and 85%, respectively, which showed no statistical difference. Our study showed that the triple therapy with BAM was more effective for the first-line eradication of H. pylori infection in Korean children, but has no statistical difference with OAC regimen.

Randomized trial of rifabutin-based triple therapy and high-dose dual therapy for rescue treatment of Helicobacter pylori resistant to both metronidazole and clarithromycin

BACKGROUND

The clinical management of Helicobacter pylori infected patients who failed standard eradication therapies remains a challenge.

AIM

To investigate the efficacy of rifabutin-based triple therapy and high-dose dual therapy for rescue treatment of H. pylori, and the correlation between cytochrome P450 2C19 (CYP2C19) polymorphisms and treatment outcome.

METHODS

Patients infected with H. pylori resistant to both metronidazole and clarithromycin (n = 145) were randomized to either esomeprazole 20 mg, rifabutin 150 mg and amoxicillin 1 g, each given b.d. for 7 days (ERA), or to omeprazole 40 mg and amoxicillin 1000 mg, each given t.d.s. for 14 days (OA). Crossover therapy was offered in cases of persistent infection. CYP2C19 polymorphisms were determined by polymerase chain reaction restriction fragment length polymorphism.

RESULTS

Intention-to-treat and per-protocol eradication rates were: ERA 74% (62.4-83.6) and 78% (66.7-87.3); high-dose OA 70% (57.5-79.7) and 75% (62.5-84.5). Crossover therapy was successful in seven of 10 patients with ERA and in eight of 10 patients with OA. Premature discontinuation of treatment occurred in 2% and 5% of patients, respectively. There was only a non-significant trend to lower eradication rates in homozygous extensive metabolizers.

CONCLUSIONS

Triple therapy with esomeprazole, rifabutin and amoxicillin and high-dose omeprazole/amoxicillin are comparable and effective and safe for rescue therapy of H. pylori regardless of the patient's CYP2C19 genotype.

Antibacterial activity of highly negative charged polyoxotungstates, K27[KAs4W40O140] and K18[KSb9W21O86], and Keggin-structural polyoxotungstates against Helicobacter pylori

The antibacterial activity of polyoxometalates (PMs) against Helicobacter pylori was investigated based on determinations of minimum inhibitory concentration (MIC) and fractional inhibitory concentration (FIC), time-killing of the bacteria, bacterial morphology and PM-uptake into the bacteria cell. The result of MIC values revealed that, of 13 PMs used in this study, highly negative-charged polyoxotungstates, such as K27[KAs4W40O140] and K18[KSb9W21O86], and Keggin-structural polyoxotungstates exhibited a potent antibacterial activity with the MIC values of less than 256 microg/ml. The former was the most active, and superior to metronidazole (MTZ) against MTZ-susceptible and resistant strains and also to clarithromycin (CLR) against CLR-resistant strains. In contrast, most of polyoxomolybdates showed little antibacterial activity with the MIC values of more than 256 microg/ml. The result of FIC index values indicated that the antibacterial polyoxotungstates had partially synergistic effect in combination with MTZ and CLR but indifferent effect in combination with amoxicillin (AMX). From the results of the time-killing and scanning electron microscope images, K27[KAs4W40O140] and K18[KSb9W21O86] proved the concentration-dependent bactericidal activity with the morphological change from bacillary form to coccoid form, while Keggin-structural K5[SiV(V)W11O40] showed the bacteriostatic activity with small change of morphology to coccoid form. The fluorescent X-ray analysis demonstrated that these polyoxotungstates were taken into the bacteria cell. It is pointed out that the Keggin-structure and/or high negativity polyoxotungstates are an important factor for the antibacterial activity against H. pylori.

One-year follow-up study of Helicobacter pylori eradication rate with 13C-urea breath test after 3-d and 7-d rabeprazole-based triple therapy

AIM: To investigate the long-term role of a 3-d rabeprazole-based triple therapy in patients with Helicobacter pylori(H pylori)-infected active peptic ulcers.

METHODS: We prospectively studied 115 consecutive patients with H pylori-infected active peptic ulcers. H pylori infection was confirmed if any two of H pylori DNA, histology, and rapid urease test were positive. Patients were assigned to either an open-labeled 3-d course of oral amoxicillin 1000 mg b.i.d., clarithromycin 500 mg b.i.d., and rabeprazole 20 mg b.i.d., or 7-d course of oral amoxicillin 1000 mg b.i.d., clarithromycin 500 mg b.i.d., and rabeprazole 20 mg b.i.d. Subsequently, all patients received oral rabeprazole 20 mg once daily until the 8^th wk. Three months after therapy, all patients were followed-up endoscopically for the peptic ulcer, H pylori DNA, histology, and rapid urease test. One year after therapy, H pylori infection was tested using the ¹³C-urea breath test.

RESULTS: The ulcer healing rates 3 mo after therapy were 81.0% vs 75.4% for the 3-d and 7-d groups [intention-to-treat (ITT) analysis, P = 0.47] respectively, and 90.4% vs 89.6% for the 3-d and 7-d groups [per-protocol (PP) analysis, P = 0.89] respectively. The eradication rates 3 mo after therapy were 75.9% vs 73.7% for the 3-d and 7-d groups (ITT, P = 0.79) respectively, and 84.6% vs 87.5% for the 3-d and 7-d groups (PP, P = 0.68) respectively. One year after therapy, seventy-five patients returned to receive the ¹³C-urea breath test, and the eradication rates were 78.4% vs 81.6% in 3-d and 7-d groups (PP, P = 0.73) respectively.

CONCLUSION: Our study showed the eradication rates against H pylori infection 3 and 12 mo after triple therapy were not different between the 3-d and 7-d rabeprazole-based groups. Therefore, the 3-d rabeprazole-based triple therapy may be an alternative treatment for peptic ulcers with H pylori infection.

Helicobacter pylori infection in hemodialysis patients: Susceptibility to amoxicillin and clarithromycin

AIM: To evaluate susceptibility of Helicobacter pylori to amoxicillin and clarithromycin in end-stage renal disease (ESRD) patients and non-uremic controls.

METHODS: The subjects with dyspeptic complaints were 33 ESRD patients and 46 age- and sex-matched non-uremic controls who exhibited H pylori on antral biopsy specimens. The two groups were age and sex matched. The H pylori strains’ pattern of susceptibility to amoxicillin and clarithromycin was investigated with the agar dilution technique.

RESULTS: None of the H pylori strains from either group showed resistance to amoxicillin with the agar dilution method. Twelve (36.4%) of the ESRD group strains and 7 (15.2%) of the control group strains showed resistance to clarithromycin, and this difference was statistically significant (P<0.05).

CONCLUSION: Resistance to amoxicillin does not appear to be an important problem in H pylori-infected ESRD and non-uremic patients in our region. In contrast, the rates of resistance to clarithromycin are high, particularly in the ESRD population.

Reliable detection of macrolide-resistant Helicobacter pylori via fluorescence in situ hybridization in formalin-fixed tissue

Macrolide-resistant Helicobacter (H.) pylori represent an increasing therapeutic problem. Macrolide resistance is usually determined phenotypically in vitro with methods such as E-test or agar dilution test. A prerequisite for those tests, however, is bacterial culture that is not routinely set up in the course of gastroscopy. In contrast, formalin-fixed, paraffin-embedded biopsies are regularly available from patients who have undergone gastroscopy. In such biopsies macrolide-resistant H. pylori can be detected by the genotype-based technique of fluorescence in situ hybridization (FISH). Experience gained by this new method, however, is still extremely limited, especially in formalin-fixed tissue. Therefore, we retrospectively investigated formalin-fixed, paraffin-embedded biopsy specimens by FISH in 104 patients suffering from therapy-resistant H. pylori gastritis. To test the accuracy of FISH, we initially examined specimens from 53 patients for whom results of the E-test were available. Next we analyzed biopsies from another 51 patients that had been selected since phenotypical resistance testing had failed despite documented culturing attempts. In all 104 patients, H. pylori was detected by FISH and could thus be investigated for macrolide resistance. Overall, macrolide-resistant bacteria were found in 71 patients (68.3%). In 49 of 53 patients (92.4%), FISH and E-test returned identical results (no significant discordance according to McNemar's chi(2)-test). Taken together, our study demonstrates that FISH is a highly sensitive and reliable method for detecting macrolide-resistant H. pylori in formalin-fixed, paraffin-embedded biopsy specimens, which represents the routine method of processing tissue obtained upon gastroscopy.

Pantoprazole based therapies in Helicobacter pylori eradication: a systematic review and meta-analysis

AIM

To perform a systematic review on the efficacy of pantoprazole based therapies in Helicobacter pylori eradication, and to conduct a meta-analysis comparing the efficacy of pantoprazole and other proton pump inhibitors (PPIs) when co-prescribed with antibiotics.

METHODS

Studies evaluating pantoprazole combined with antibiotics were considered. Only randomized clinical trials comparing pantoprazole and other PPIs when co-prescribed with antibiotics, and differing only in the PPI (pantoprazole vs other), were eligible for inclusion in the meta-analysis. Bibliographical searches in several electronic databases, and manual search of abstracts from congresses, were conducted. The percentage (weighted mean) of patients with eradication success was calculated. Meta-analysis was performed combining the odds ratios (ORs) of the individual studies in a global OR.

RESULTS

The mean eradication rate with pantoprazole plus clarithromycin for 14 days was 60%. Cure rates with 7 day pantoprazole based triple regimens were higher: pantoprazole, amoxicillin and clarithromycin (78%); pantoprazole, clarithromycin and nitroimidazole (84%); and pantoprazole, amoxicillin and nitroimidazole (74%). Twelve studies comparing pantoprazole and other PPIs were selected for the meta-analysis, including 534 and 603 patients, respectively. The mean eradication rate for H. pylori using pantoprazole plus antibiotics was 83%, and 81% when other PPIs were used (OR = 1; 95% confidence interval (CI) from 0.61 to 1.64). When sub-analysis was performed, including only studies comparing pantoprazole with omeprazole, or pantoprazole with lansoprazole, differences were also statistically non-significant. The meta-analysis of the six studies prescribing equivalent doses of all PPIs demonstrated similar results with pantoprazole and with other PPIs (OR = 1.07; 95% CI from 0.71 to 1.62), the results being statistically homogeneous.

CONCLUSIONS

Pantoprazole achieves similar cure rates to those of omeprazole and lansoprazole when co-prescribed with antibiotics for the eradication of H. pylori infection.

Eradication of Helicobacter pylori by 7-day triple-therapy regimens combining pantoprazole with clarithromycin, metronidazole, or amoxicillin in patients with peptic ulcer disease: results of two double-blind, randomized studies

AIM

To compare the short-term (7-day) safety and efficacy of two triple-therapy regimens using pantoprazole with those of two dual-therapy regimens (one with pantoprazole and one without), for Helicobacter pylori eradication in patients with peptic ulcer disease.

METHODS

H. pylori infection was identified by rapid urease (CLOtest), and confirmed by histology and culture. Patients were enrolled into one of two randomized, double-blind, multicenter, parallel-group studies. In study A, patients received oral pantoprazole 40 mg, clarithromycin 500 mg, and metronidazole 500 mg (PCM); pantoprazole, clarithromycin and amoxicillin 1000 mg (PCA); or pantoprazole and clarithromycin (PC). In study B, patients received PCM, PCA, PC, or clarithromycin and metronidazole without pantoprazole (CM). Treatments were given twice daily for 7 days. H. pylori status after therapy was assessed by histology and culture at 4 weeks after completing the course of study treatment. Modified intent-to-treat (MITT; each study: n = 424, n = 512) and per-protocol (PP; each study: n = 371, n = 454) populations were analyzed. The MITT population comprised all patients whose positive H. pylori status was confirmed by culture and histology; the PP population comprised patients who also complied with > or = 85% of study medication doses.

RESULTS

A total of 1016 patients were enrolled. Cure rates among patients with clarithromycin-susceptible H. pylori strains were 82 and 86% for PCM, and 72 and 71% for PCA, in studies A and B, respectively. Cure rates among patients with metronidazole-susceptible H. pylori strains were 82 and 87% for PCM, and 71 and 69% for PCA, in studies A and B, respectively. The combined eradication rates observed with the PCM regimen were superior to those of all other regimens tested. Side-effects were infrequent and mild.

CONCLUSIONS

PCM had the highest overall eradication rate in these two studies examining 7-day treatment regimens. All regimens were safe and well tolerated.

A prospective, randomized study of quadruple therapy and high-dose dual therapy for treatment of Helicobacter pylori resistant to both metronidazole and clarithromycin

BACKGROUND AND AIM

Failure of primary anti-H. pylori therapy results in a high rate of antimicrobial resistance. Here, we investigated the efficacy of high-dose dual therapy and quadruple therapy as salvage treatments for eradication of H. pylori resistant to both metronidazole and clarithromycin.

PATIENTS AND METHODS

Patients with at least one treatment failure and infected with H. pylori resistant to both metronidazole and clarithromycin, were randomized to receive either omeprazole 4 x 40 mg and amoxicillin 4 x 750 mg; or omeprazole 2 x 20 mg, bismuthcitrate 4 x 107 mg, metronidazole 4 x 500 mg and tetracycline 4 x 500 mg. Both regimens were given for 14 days. In cases of persistent infection, a cross-over therapy was performed.

RESULTS

Eighty-four patients were randomized. Cure of H. pylori infection was achieved in 31 patients after dual therapy and in 35 patients after quadruple therapy (per protocol: 83.8% (95% CI, 67.9-93.8) and 92.1% (95% CI, 78.6-98.3), respectively (p=0.71); intention to treat: 75.6% (95% CI: 59.7-87.6) and 81.4% (95% CI: 66.6-91.6), respectively (p=0.60)). Cross-over therapy was performed in six of nine patients, four of whom were cured of the infection.

CONCLUSION

Both high-dose dual therapy and quadruple therapy are effective in curing H. pylori infection resistant to both metronidazole and clarithromycin in patients who experienced previous treatment failures.

Recent use of proton pump inhibitor-based triple therapies for the eradication of H pylori: a broad data review

INTRODUCTION

For the eradication of Helicobacter pylori a 1-week triple therapy combining proton pump inhibitors with two antibiotics has been recommended as a gold standard therapy. However, a recent broad data review on the efficacy of the different regimens is missing. Therefore, the aim of this study was to systematically review the recent literature.

METHODS

We undertook a broad data review of the efficacy of nine different 7-day triple therapies consisting of a proton pump inhibitor (lansoprazole, pantoprazole, omeprazole) in its standard dosage and two antibiotics. Relevant original papers on H. pylori eradication in adults, published in English or German between 1995 and 2000, were identified from MEDLINE searches. Studies were reviewed and selected according to predefined criteria.

RESULTS

Our predefined criteria were fulfilled by 79 full paper articles including 112 study arms with 8383 patients on intention-to-treat, or 6787 patients on per-protocol basis, respectively. The mean eradication rates unweighted or weighted by the number of patients in the study arm vary from 71.9% to 83.8% for intention-to-treat analysis and from 78.5% to 91.2% for per-protocol analysis.

CONCLUSIONS

All nine PPI based triple therapy regimens are very effective in H. pylori eradication. The current literature review underlines that the use of either lansoprazole, omeprazole, or pantoprazole combined with two antibiotics yield similar high eradication rates.

The impact of Helicobacter pylori resistance on the efficacy of a short course pantoprazole based triple therapy

BACKGROUND: Many of the currently used Helicobacter pylori eradication regimens fail to cure the infection due to either antimicrobial resistance or poor patient compliance. Those patients will remain at risk of developing potentially severe complications of peptic ulcer disease. AIM: We studied the impact of the antimicrobial resistance on the efficacy of a short course pantoprazole based triple therapy in a single-center pilot study. METHODS: Forty previously untreated adult patients (age range 20 to 75 years, 14 males) infected with Helicobacter pylori and with inactive or healing duodenal ulcer disease were assigned in this open cohort study to 1 week twice daily treatment with pantoprazole 40 mg, plus clarithromycin 250 mg and metronidazole 400 mg. Helicobacter pylori was assessed at entry and 50 ± 3 days after the end of treatment by rapid urease test, culture and histology of gastric biopsies. The criteria for eradication was a negative result in the tests. Susceptibility of Helicobacter pylori to clarithromycin and metronidazole was determined before treatment with the disk diffusion test. RESULTS: One week treatment and follow up were complete in all patients. Eradication of Helicobacter pylori was achieved in 35/40 patients (87.5%) and was higher in patients with nitroimidazole-susceptible strains [susceptible: 20/20 (100%), resistant: 10/15 (67%)]. There were six (15%) mild adverse events reports. CONCLUSIONS: A short course of pantoprazole-based triple therapy is well tolerated and effective in eradicating Helicobacter pylori. The baseline metronidazole resistance may be a significant limiting factor in treatment success.

Fluorescence in situ hybridization vs. epsilometer test for detection of clarithromycin-susceptible and clarithromycin-resistant Helicobacter pylori strains in gastric biopsies from children

AIM

To compare the results of culture and epsilometer test with fluorescence in situ hybridization for the detection of Helicobacter pylori and the presence of clarithromycin-susceptible and clarithromycin-resistant strains in antral biopsies from children.

METHODS

Antral biopsies from 149 unselected children were investigated prospectively; 15 had previously received anti-H. pylori therapy. H. pylori status was defined by histology, rapid urease test and 13C-urea breath test. Fluorescence in situ hybridization was applied on fresh tissue with probes specific for the clarithromycin-susceptible wild type and three clarithromycin-resistant mutants. Susceptibility to clarithromycin was tested by epsilometer test in two laboratories.

RESULTS

Culture and fluorescence in situ hybridization gave negative results in all 66 H. pylori-negative children (specificity, 100%). Of 83 infected children, cultures were successful in 75 (90%), epsilometer test in 71 (86%) and fluorescence in situ hybridization in 77 (93%). Eleven children (13%) showed discrepant results between the applied methods, indicating mixed infection. Clarithromycin-resistant isolates were identified in 16 of 73 previously untreated children.

CONCLUSIONS

Primary resistance to clarithromycin is common (22%) in H. pylori isolates from children living in Germany. Fluorescence in situ hybridization is an excellent, fast method for the detection of H. pylori and clarithromycin-resistant mutants in gastric biopsies. Multiple biopsies identify mixed infections, indicating that clarithromycin-resistant and clarithromycin- susceptible strains are not evenly distributed within the stomach.

Levofloxacin based regimens for the eradication of Helicobacter pylori

BACKGROUND

A 7 day treatment scheme based on rabeprazole/levofloxacin/amoxycillin or tinidazole achieved an eradication rate over 90%. However, the combination of drugs and duration of treatment for the correct use of levofloxacin in the eradication of are still unclear.

OBJECTIVE

To compare the efficacy and tolerability of rabeprazole/levofloxacin based dual therapies given for 5, 7 or 10 days with rabeprazole/levofloxacin/amoxycillin triple therapy for 7 days.

METHODS

One hundred and sixty patients with infection documented by the C-urea breath test and histology were included in this prospective, open label study. Subjects were randomized in four groups: (1) levofloxacin (500 mg o.d.), amoxycillin (1 g b.d.) and rabeprazole (20 mg o.d.) for 7 days; (2) levofloxacin (500 mg o.d.) and rabeprazole (20 mg o.d.) for 5 days; (3) levofloxacin (500 mg o.d.) and rabeprazole (20 mg o.d.) for 7 days; and (4) levofloxacin (500 mg o.d.) and rabeprazole (20 mg o.d.) for 10 days. Six weeks after the end of therapy status was checked by using the C-urea breath test.

RESULTS

All patients completed the therapeutic regimens. The eradication rate was not significantly modified by treatment duration in the dual therapy schemes (5 days: 20/40, 50%; 7 days: 28/40, 70%; 10 days: 26/40, 65%). The eradication rate of the 1 week levofloxacin based triple therapy was significantly higher than that observed using any dual therapies (36/40). No major adverse effects were observed.

CONCLUSIONS

A rabeprazole/levofloxacin dual eradication regimen is simple and well tolerated but does not achieve an acceptable eradication rate when compared to a 1 week rabeprazole/levofloxacin/amoxycillin triple therapy. The eradication rate did not increase with a longer regimen.

Comparison of azithromycin and clarithromycin in triple therapy regimens for the eradication of Helicobacter pylori

OBJECTIVE

We sought to compare an azithromycin-based regimen with an already established clarithromycin-based regimen in the eradication of Helicobacter pylori infection.

METHODS

A prospective, randomized, blinded comparative analysis was performed on 56 patients with upper GI symptoms who presented to the Gastroenterology Department at the Naval Medical Center Portsmouth. All patients had documented H. pylori infection on endoscopy via rapid urease test and histopathology. Patients were randomized to a treatment arm, which consisted of bismuth, clarithromycin, amoxicillin, and lansoprazole (B-LAC) or one consisting of bismuth, azithromycin, amoxicillin, and lansoprazole (B-LAA). To assess eradication, patients then received repeat endoscopy at 8 wk from entrance into the study. Rapid urease test and histopathology were again used to evaluate infection. Patients recorded all side effects. Comparison between the two groups was made using the chi2 method.

RESULTS

Of the 56 patients included in the study, 27 went on to receive B-LAC, whereas 29 received B-LAA. The per protocol eradication rate was 84.6% with B-LAC and 55.5% with B-LAA (p = 0.021). Under intention to treat analysis, the eradication rates for B-LAC and B-LAA were 81% and 52%, respectively (p = 0.019). There was a significant difference between the two groups in number of subjects using nonsteroidal anti-inflammatory drugs (NSAIDs) (p = 0.013) and a trend toward a difference in histamine-2 (H2) blocker use (p = 0.066). Taking these two variables into account, a logistical regression was performed and continued to show a significant superiority in the B-LAC regimen (p = 0.03).

CONCLUSIONS

The results of our study suggest that B-LAC is superior to B-LAA in the eradication of Helicobacter pylori. Our results also suggest that B-LAA is not a suitable regimen in the treatment of H. pylori because of its substandard eradication rate.

Review article: treatment of Helicobacter pylori infection and factors influencing eradication

Currently available Helicobacter pylori eradication therapies are considered very effective and safe. The most recent eradication guidelines proposed in the Maastricht 2-2000 Consensus Report recommend the use of proton pump inhibitors (standard b.d.) along with clarithromycin (500 mg b.d.) and amoxycillin (1000 mg b.d.) or metronidazole (500 mg b.d.) for a minimum of 7 days. The combination of amoxycillin and clarithromycin is preferred because it may favour best results with a second-line proton pump inhibitor quadruple therapy. The recommended second-line therapy includes a combination of a proton pump inhibitor (standard b.d.) with bismuth salt (subsalicylate/subcitrate 120 mg q.d.s.), metronidazole (500 mg t.d.s.), and tetracycline (500 mg q.d.s.) for a minimum of 7 days. Extended proton pump inhibitor-based triple therapy can be used if bismuth is not available. Specialists should manage subsequent failures. Based on direct and indirect evidence from well-designed studies and clinical experience, eradication is recommended in gastric and duodenal ulcers, MALToma, atrophic gastritis, postgastric cancer resection, and in first-degree relatives of gastric cancer patients. The most common reason for treatment failure is poor compliance with eradication guidelines. Antibiotic resistance may be a significant factor in certain geographical areas. Proton pump inhibitors are an integral part of the eradication regimens as proved by meta-analyses of clinical trials. Novel agents used in secondary failure are few and depend on the use of new antibiotics. The role of H. pylori-specific antibiotics, probiotics, and vaccines is not established as yet. Widespread acceptance of the eradication guidelines should be regarded as the single most important factor in eradication success.

High rate of post-therapeutic resistance after failure of macrolide-nitroimidazole triple therapy to cure Helicobacter pylori infection: impact of two second-line therapies in a randomized study

BACKGROUND

The optimal second-line treatment after failed Helicobacter pylori therapy has not been established.

AIMS

To ascertain whether quadruple therapy or triple therapy with omeprazole, clarithromycin and amoxicillin is the superior re-treatment after triple therapy containing a macrolide and a nitroimidazole, and to determine the impact of microbial in vitro resistance.

METHODS

Patients after failed triple therapy were randomly allocated to one of two 1-week second-line treatments: omeprazole, 40 mg, clarithromycin, 500 mg, and amoxicillin, 1 g, all b.d.; or omeprazole, 20 mg b.d., bismuth subsalicylate, 600 mg q.d.s., metronidazole, 400 mg t.d.s., and tetracycline, 500 mg q.d.s. Post-therapeutic Helicobacter pylori status was assessed by 13C-urea breath test at least 4 weeks after treatment.

RESULTS

The study was terminated after including 84 patients. H. pylori cure rates differed significantly: omeprazole-clarithromycin-amoxicillin: intention-to-treat, 43%; per protocol, 50%; omeprazole-bismuth subsalicylate-metronidazole-tetracycline: intention-to-treat, 68%; per protocol, 69%. The frequencies of resistance after first-line therapy were: metronidazole, 90%; clarithromycin, 71%; both combined, 68%. For clarithromycin resistance, H. pylori cure with omeprazole-clarithromycin-amoxicillin was 30% vs. 83% for clarithromycin susceptibility.

CONCLUSIONS

Omeprazole-bismuth subsalicylate-metron- idazole-tetracycline was superior to omeprazole-clarithromycin-amoxicillin, but both therapies yielded unsatisfactory results. The high rate of post-therapeutic dual resistance has a negative impact on omepraz- ole-clarithromycin-amoxicillin, and probably also on omeprazole-bismuth subsalicylate-metronidazole-tetracycline, and limits the choice for second-line treatment.

Treatment of Helicobacter pylori infection. Indications and regimens: an update

The management of Helicobacter pylori infection is still surrounded by controversy and uncertainties. Indications and correct application of current regimens for Helicobacter pylori infection are still considered a matter of debate. Regarding indications, only peptic ulcer and mucosa associated lymphoid tissue lymphoma are considered clear indications for treatment. In other conditions, such as atrophic gastritis, post gastric cancer resection, first-degree relatives of gastric cancer patients, dyspeptic patients, patients with gastro-oesophageal reflux disease and non-steroidal anti-inflammatory drug users, the value of Helicobacter pylori eradication is still controversial. The regimens for first-line and second-line treatment of Helicobacter pylori infection have been recommended by the Maastricht 2 Consensus Report. Although all the treatments are considered to be effective, physicians still do not agree on what first-line regimen should be used. Furthermore, a consensus on the duration of the antibiotic treatment is still lacking, although Maastricht guidelines for treatment of Helicobacter pylori infection recommend a one-week therapy. Also regimens, as a third-line treatment, and methods to improve compliance and clinical outcome are still a matter of debate. All these points will be considered in the present review

Pooled analysis on the efficacy of the second-line treatment regimens for Helicobacter pylori infection

BACKGROUND

Although many of the currently available Helicobacter pylori eradication regimens fail to cure 5%-12% of patients, an optimal re-treatment therapy for eradication-failure patients has still not been established. The aim of this study was to examine all reports concerning the efficacy of re-eradication regimens for H. pylori infection, and to establish optimal re-eradication regimens.

METHODS

Studies concerning re-eradication regimens were retrieved from the MEDLINE database, reference lists and major congress abstract lists up through December 1999. Data from all selected reports were pooled into several groups depending on second-line or initial therapies. Pooled eradication rates of re-treatment regimens were compared using Fisher's exact test (P < 0.05).

RESULTS

Sixteen articles and 24 abstracts with 75 total treatment arms were included in this study. Pooled re-eradication rates by proton-pump inhibitor (PPI)-based dual therapy, PPI-based triple therapy, ranitidine bismuth-based triple therapy and quadruple therapy were 45.8%, 69.8%, 80.2% and 75.8%, respectively. Eradication rates from studies with two new antimicobials added were higher than rates from studies with only one new antimicrobial added (P = 0.0064).

CONCLUSION

Ranitidine bismuth-based triple therapies, as well as quadruple therapies, seem to be the most effective re-treatment therapies in all currently undertaken therapies. The strategy of adding two new antimicrobials to previous regimens was also effective in re-eradication therapy.

Twelve year observation of primary and secondary antibiotic-resistant Helicobacter pylori strains in children

BACKGROUND

The effectiveness of Helicobacter pylori eradication regimens is influenced by antibiotic susceptibility of infecting strains. Data concerning antibiotic resistance in children are limited. We report the evolution of primary and secondary resistance in a series of Belgian children during the last 12 years.

PATIENTS AND METHODS

From 1989 through 2000, H. pylori gastritis was diagnosed in 569 children, and antibiotic susceptibility tests were performed in 555. Eradication, using different schemes, failed in 128 of 457 treated children. After eradication failure antibiotic susceptibility determination was performed in 87 of 128. Comparison of antibiotic susceptibility of strains isolated from the gastric body and from the antrum was performed in 238 samples.

RESULTS

Resistance to amoxicillin was not observed. The rate of primary resistance to nitroimidazole derivatives was 18.0% (101 of 555) and remained constant throughout this period, whereas primary resistance to macrolides increased from an average of 6.0% (range, 0 to 10%) before 1995 to 16.6% (range, 10 to 25%, P < 0.001) thereafter. Antibiotic consumption in Belgium, especially macrolides, did not show important fluctuations during the study period. Secondary resistance developed in 39 of 87 patients (46%). Strains isolated from different gastric locations show identical susceptibility testing in all but 5 of 238.

CONCLUSIONS

Resistance of H. pylori to macrolides increased in our pediatric population which did not appear to correlate with macrolides prescription habits in our country. After eradication failure acquired secondary resistance was observed in one-half of the patients.

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

BACKGROUND

Triple therapies with proton pump inhibitor/ranitidine bismuth citrate (RBC), clarithromycin (C) and either amoxicillin (A) or a nitroimidazole (I) are widely accepted as treatment for Helicobacter pylori infection. However, it is not clear which of these antibiotic combinations should be preferred.

AIM

To evaluate whether there is a difference in efficacy between triple therapies with proton pump inhibitor/RBC, clarithromycin and either amoxicillin or a nitroimidazole.

METHODS

The literature was examined for randomized trials comparing proton pump inhibitor/RBC-C-A and proton pump inhibitor/RBC-C-I. Studies were grouped according to the type of acid inhibitor used (proton pump inhibitor or RBC) and differences between pooled cure rates were calculated.

RESULTS

Forty-seven studies were identified: seven using RBC, 39 using proton pump inhibitor, one using both. RBC-C-I was somewhat superior to RBC-C-A, although this difference only reached statistical significance in intention-to-treat analysis. Overall, proton pump inhibitor-C-I and proton pump inhibitor-C-A were equally effective, but in nitroimidazole-susceptible strains, proton pump inhibitor-C-I performed better, in nitroimidazole-resistant strains, proton pump inhibitor-C-A performed better. No serious side-effects were reported and pooled drop-out rates were equal.

CONCLUSIONS

In general, proton pump inhibitor-C-I and proton pump inhibitor-C-A are equally effective and therefore other factors such as local prevalence of resistant strains, cost of therapy and options for second-line treatment should determine which regimen should be preferred. When using RBC, the RBC-C-I combination is somewhat superior to RBC-C-A.

Prevalence of Helicobacter pylori resistance to antibiotics in Northeast Italy: a multicentre study. GISU. Interdisciplinary Group for the Study of Ulcer

AIMS

To evaluate prevalence of primary Helicobacter pylori antibiotic resistances in Northeast Italy and to identify risk factors associated with this resistance.

MATERIALS AND METHODS

A total of 248 patients undergoing upper gastrointestinal endoscopy were enrolled from 19 Endoscopy Units over a 6-month period. From each patient, 4 gastric biopsies were taken for histology and 2 were sent to the Central Referral Microbiological Laboratory for culture and determination of antibiotic activity against Helicobacter pylori by means of E-test. Strains were considered resistant when minimum inhibitory concentration was >8 microg/ml for metronidazole and >1 microg/ml for clarithromycin. No cut-off value was predefined for amoxycillin.

RESULTS

Culture of Helicobacter pylori was successfully performed in 167 patients. Primary resistance to metronidazole, clarithromycin or amoxycillin was 14.9%, 1.8% and 0%, respectively Patients infected with Helicobacter pylori strains resistant to antibiotics were more frequently females than males (70.3% vs 41.4%), had a significantly lower coffee intake (66.6% vs 86.6%) and lower body mass index (23.7+/-2.6 vs 25.3+/-3.6) than patients with susceptible Helicobacter pylori strains. Age, smoking, alcohol use, family history of Helicobacter pylori infection, concomitant diseases and treatments, endoscopic diagnoses, Helicobacter pylori density and histological activity of chronic gastritis were not associated with antibiotic resistance. Multivariate analysis confirmed that female gender (odds ratio = 2.74, 95% confidence interval = 1.03-7.27) was the only significant risk factor associated with antibiotic resistance.

CONCLUSIONS

In this population, primary Helicobacter pylori resistance to metronidazole was higher than resistance to clarithromycin, and female gender was significantly associated with this resistance. The low prevalence of resistance to metronidazole, clarithromycin and amoxycillin identified in this geographical area suggests that proton pump inhibitor-based triple regimens including these antibiotics may still be used as first line therapies against Helicobacter pylori infection.

Incidence of secondary Helicobacter pylori resistance to antibiotics in treatment failures after 1-week proton pump inhibitor-based triple therapies: a prospective study

BACKGROUND

Antibiotic-resistant Helicobacter pylori strains are becoming increasingly prevalent, although it is not clear to what extent the new resistant organisms will spread.

AIM

To evaluate the incidence of secondary Helicobacter pylori resistance to metronidazole, clarithromycin and/or amoxycillin after one-week proton pump inhibitor based triple therapy failure in patients who were, before therapy infected with Helicobacter pylori strains susceptible to these antibiotics.

PATIENTS AND METHODS

Enrolled in the study were 97 consecutive Helicobacter pylori-positive subjects infected by Helicobacter pylori strains susceptible to metronidazole, clarithromycin and amoxycillin. Activity of tested antibiotics was determined by means of the E-test. Patients were treated for seven days with a proton pump inhibitor, omeprazole 20 mg twice daily or pantoprazole 40 mg once daily, plus clarithromycin 250 mg twice daily and metronidazole 250 mg four times daily; or with a proton pump inhibitor plus amoxycillin 1 g twice daily and clarithromycin 500 mg twice daily. Two months after completion of therapy, endoscopy and gastric biopsies for histology, rapid urease test and culture were repeated.

RESULTS

Four patients were dropped from the study Overall Helicobacter pylori cure rates expressed as both intention-to-treat and per-protocol analyses, were, respectively 80% (40/50) and 81.6% (40/49) with proton pump inhibitor, clarithromycin and metronidazole and 76.6% (36/47) and 81.8% (36/44) with proton pump inhibitor amoxycillin and clarithromycin. No significant differences were observed between the two treatments. Subjects in whom treatment failed were significantly younger and had less active ulcer than cured patients. Of treatment failures, 70.6% (12 out of 17 subjects) de veloped a secondary resistance to metronidazole (35.33% and/or clarithromycin (64.7%). Secondary antibiotic resistance occurred in 77. 8% of treatment failures treated with proton pump inhibitor, clarithromycin and metronidazole and in 62.5% of those treated with proton pump inhibitor, amoxycillin and clarithromycin. Considering all patients treated, the overall incidence of secondary metronidazole and/or clarithromycin resistance after therapy was reported in 12.9% of subjects (12 out of 93 treated patients).

CONCLUSIONS

Secondary Helicobacter pylori resistances to metronidazole and/or clarithromycin occurred in large percentages in patients with treatment failure after the one-week proton pump inhibitor-based triple therapies, proton pump inhibitor, clarithromycin and metronidazole and proton pump inhibitor, amoxycillin and clarithromycin. It is likely that new antibiotics or treatment strategies will be needed in the near future to successfully treat Helicobacter pylori infection.