Moxifloxacin-containing triple therapy as second-line treatment for Helicobacter pylori infection: effect of treatment duration and antibiotic resistance on the eradication rate

Study of Zuojin Pill in Treating Chronic Atrophic Gastritis by UPLC-Q-TOF/MS Based on Serum and Urine Metabolomics Combined with Network Pharmacology

Zuojin Pill (ZJP) is widely used for the treatment of gastrointestinal diseases, while its specific mechanism has not been systematically investigated. The aim of this study was to explore the therapeutic effects and potential mechanism of ZJP in chronic atrophic gastritis (CAG) through UPLC-Q-TOF/MS-based metabolomics combined with network pharmacology. ZJP and omeprazole significantly reduce contents of IL-1β, IL-6, IL-10, and iNOS and improve pathological characteristics. Metabolomic results indicated that the therapeutic effects of ZJP were mainly related to ten metabolites, namely, choline, L-threonine, hydroxypyruvic acid, creatine, taurine, succinic acid, cis-aconitic acid, citric acid, succinic acid semialdehyde, and uric acid. Pathway analysis showed that the treatment of CAG by ZJP was associated with taurine and hypotaurine metabolism; glyoxylate and dicarboxylate metabolism; glycine, serine, and threonine metabolism; glycerophospholipid metabolism; citrate cycle (TCA cycle), alanine, aspartate, and glutamate metabolism; butanoate metabolism; and purine metabolism. Validation of metabolic markers and key targets of network pharmacology through RT-PCR analysis showed that ZJP significantly downregulated a series of inflammatory markers, such as MAPK1, PKIA, RB1, SCN5A, RXRA, E2F1, PTGS1, IGF2, ADRB1, ADRA1B, PTGS2, and GABRA1. This study was the first to use a combination of metabolomics and network pharmacology to clarify the therapeutic effects of ZJP on CAG and the regulation of multiple metabolic pathways.

Update on quinolone-containing rescue therapies for Helicobacter pylori infection

Third generation of quinolones, such as levofloxacin and moxifloxacin, -containing regimens are often used in second-line or rescue treatment of Helicobacter pylori infection. However, the increasing antibiotic resistance to quinolones affects the efficacies of quinolones-containing therapies in recent years. Therefore, there is a need to enhance the effectiveness of quinolones-containing therapies. Sitafloxacin, a fourth-generation quinolone, and vonoprazan, a novel potassium-competitive acid blocker, are now available as more effective treatment options. The aim of this paper is to summarize the current evidence of quinolone-containing therapies in rescue treatments, and to discuss the importance of drug sensitivity tests or analysis of gyrA mutation before treatments.

Primary and secondary antibiotic resistance of Helicobacter pylori in Korea from 2003 to 2018

BACKGROUND

Antimicrobial resistance of Helicobacter pylori (H pylori) affects the efficacy of eradication therapy. The aim of this study was to estimate the prevalence of primary and secondary resistance of H pylori isolates to antibiotics in Korea.

METHODS

The present study was performed from 2003 to 2018. Primary resistance was evaluated in 591 patients without any history of eradication and secondary resistance in 149 patients from whom Helicobacter pylori was cultured after failure of eradication. A minimal inhibitory concentration test was performed for amoxicillin, clarithromycin, metronidazole, tetracycline, levofloxacin, and rifabutin using the agar dilution method.

RESULTS

An increase in the primary resistance rate was found in clarithromycin (P < .001), metronidazole (P < .001), and both levofloxacin (P < .001) during the study period. The primary resistance rates of amoxicillin and tetracycline were low and stable during the study period. The secondary resistance rate significantly increased in metronidazole and levofloxacin (P = .022 and .039, respectively).

CONCLUSIONS

The primary and secondary resistance rates of clarithromycin, metronidazole, and levofloxacin for Helicobacter pylori in Korea were high and increased over time. However, the primary and secondary resistance rates of amoxicillin and tetracycline were low and stable over time. These results will help in selecting effective eradication regimens of H pylori in Korea in the future.

Impact of Helicobacter pylori eradication on refractory thrombocytopenia in patients with chronic HCV awaiting antiviral therapy

The possibility of delaying treatment of HCV due to severe thrombocytopenia is challenging. This study aimed to detect the prevalence of active helicobacter infection as a claimed cause of thrombocytopenia in a cohort of Egyptian patients with chronic active HCV awaiting combined anti-viral therapy. The study included 400 chronic HCV patients with thrombocytopenia. Laboratory investigations included liver function tests, real time quantitative PCR, reticulocytic count, ESR, ANA, bone marrow aspiration, measurement of anti-helicobacter antibodies, and helicobacter stool antigen. Positive cases for active H. pylori were given the standard triple therapy for 2 weeks. Helicobacter stool antigen was detected 4 weeks after termination of therapy and the change in platelet count was detected 1 month after eradication. A total of 248 out of 281 seropositive patients for H. pylori (88.3 %) showed positive stool antigen (p = 0.01). Eradication was achieved in 169 (68.1 %) patients with platelet mean count 114.9 ± 18.8 × 10(3)/μl with highly significant statistical difference from pretreatment value (49.7 ± 9.2 × 10(3)/μl, p = 0.000). Seventy-nine patients were resistant to conventional triple therapy and given a 7-day course of moxifloxacin-based therapy; 61 patients responded (77.1 %) with mean platelet improvement from 76.4 ± 17.4 × 10(3)/μl to 104.2 ± 15.2 × 10(3)/μl (p = 0.000). The non-responders showed no improvement in their platelet count (74.6 ± 20.5 vs. 73.6 ± 15.3 × 10(3)/ul, P = 0.5). Eradication of active H. pylori in HCV augments platelet count and enhances the early start of antiviral therapy.

Efficacy of 7-Day and 14-Day Bismuth-Containing Quadruple Therapy and 7-Day and 14-Day Moxifloxacin-Based Triple Therapy as Second-Line Eradication for Helicobacter pylori Infection

BACKGROUND/AIMS

Bismuth-containing quadruple and moxifloxacin-based triple regimens are recommended as second-line therapy for Helicobacter pylori infection. The aim of this study was to compare the efficacy of each regimen.

METHODS

From August 2004 to October 2012, a total of 949 patients (mean age, 54.32±12.08 years; male, 49.4%) who failed H. pylori eradication with a standard triple regimen were included. Patients treated with a bismuth-containing quadruple regimen for 7 and 14 days were designated as 7-BMT and 14-BMT, respectively, and those treated with a moxifloxacin-based triple regimen for 7 and 14 days were designated as 7-MA and 14-MA, respectively. H. pylori eradication was confirmed using the (13)C-urea breath test, rapid urease test or histology.

RESULTS

The eradication rates by 7-BMT, 14-BMT, 7-MA, and 14-MA were 66.4% (290/437), 71.1% (113/159), 53.1% (51/96), and 73.5% (189/257), respectively, by intention-to-treat analysis (ITT) and 76.5% (284/371), 83.8% (109/130), 55.6% (50/90), and 80.6% (187/232), respectively, by per-protocol analysis (PP). The eradication rates were higher in 14-BMT than 7-BMT by the ITT and PP analyses (p=0.277 and p=0.082, respectively). The 14-BMT and 14-MA treatments showed similar efficacies by ITT and PP (p=0.583 and p=0.443, respectively).

CONCLUSIONS

The 7-BMT, 14-BMT, and 14-MA treatments showed similar and suboptimal efficacies. In both regimens, extending the duration of treatment may be reasonable considering the high level of antibiotic resistance in Korea.

Comparison of the efficacy of culture-based tailored therapy for Helicobacter pylori eradication with that of the traditional second-line rescue therapy in Korean patients: a prospective single tertiary center study

OBJECTIVE

The effectiveness of Helicobacter pylori therapies has declined with an increase in antibiotic resistance. To overcome this problem, the efficacy of tailored H. pylori eradication therapy based on antimicrobial susceptibility testing was compared with that of empirical second-line rescue regimens.

MATERIAL AND METHODS

Patients who had persistent H. pylori infection after the first eradication were recommended to undergo culture for determining the minimal inhibitory concentration (MIC) via gastroscopy, which increased the cost by 300%. Fourteen-day esomeprazole, tripotassium dicitrate bismuthate, metronidazole and tetracycline (EBMT) therapy or esomeprazole, moxifloxacin and amoxicillin (MEA) therapy was performed according to the results of antibiotic susceptibility testing. In case of refusal to undergo culture, the participants were treated with either 14-day empirical EBMT or MEA regimen for second eradication after explaining the complexity, side effects and costs associated with each regimen. This trial was registered at ClinicalTrials.Gov (NCT 02349685).

RESULTS

In the 219 patients included, the intention to treat (ITT) and per protocol (PP) eradication rates was 75.3% and 79.8% in the 14-day EBMT group (n = 89), 70.8% and 72.4% in the 14-day MEA group (n = 89) and 87.8% and 100.0% in the 14-day tailored therapy group (n = 41), respectively. Based on the PP analysis, the 14-day tailored therapy group showed a significantly higher eradication rate than the 14-day EBMT or MEA group (both p ≤ 0.001).

CONCLUSIONS

Tailored therapy based on H. pylori culture and MIC test could be an option as a second-line eradication regimen in the presence of high level of antimicrobial resistance.

Comparison of levofloxacin- and moxifloxacin-based triple therapies with standard treatment in eradication of Helicobacter pylori as first-line therapy

AIM

It is recommended that treatments that include clarithromycin should be avoided in eradication of Helicobacter pylori (HP) in cases where clarithromycin resistance is higher than 20%. We aimed to compare levofloxacin- and moxifloxacin-based triple therapies with standard treatment and with each other in eradication of helicobacter pylori as first-line therapy.

MATERIALS AND METHODS

Patients were randomized prospectively as three groups. There were 102 patients in the levofloxacin group, 101 patients in the moxifloxacin group, and 103 patients in the standard treatment group. The patients received levofloxacin 500 mg daily, amoxicillin 1 g b.i.d. and lansoprazole 30 mg b.i.d. for ten days (LAL) in the levofloxacin group; moxifloxacin 400 mg daily, amoxicillin 1 g b.i.d. and lansoprazole 30 mg b.i.d. (MAL) in the moxifloxacin group; and clarithromycin 500 mg b.i.d., amoxicillin 1 g b.i.d. and lansoprazole 30 mg b.i.d. (CAL) in the standard treatment group. At post-treatment week 6, HP was checked by using stool antigen test.

RESULTS

In the eradication of Helicobacter pylori, the success rate as determined by per protocol (PP) analysis was 92% in the LAL group, 91.8% in the MAL group, and 82.4% in the CAL group. A statistically significant difference was found in the LAL and MAL groups compared to the CAL group (p < 0.05). There was no difference between the LAL and MAL groups.

CONCLUSIONS

It was determined that levofloxacin- and moxifloxacin-based triple therapies were more effective than the standard treatment in first-line setting in the eradication of Helicobacter pylori. In addition, no difference was found between levofloxacin- and moxifloxacin-based triple therapies. Currently observed high efficacy may be evaluated in treatment. Although quinolon resistance is not considered a major problem, it appears to be a factor that may reduce treatment success over a period of time.

High Efficacy of Finafloxacin on Helicobacter pylori Isolates at pH 5.0 Compared with That of Other Fluoroquinolones

Finafloxacin is a novel fluoroquinolone with improved antimicrobial efficacy, especially in an acidic environment. The efficacy of finafloxacin for the inhibition of Helicobacter pylori infection was compared with the efficacies of levofloxacin and moxifloxacin at neutral and acidic pH. The impacts of gyrA point mutation on the efficacy of those three fluoroquinolones were also investigated. A total of 128 clinical H. pylori strains were utilized. MICs of levofloxacin, moxifloxacin, and finafloxacin were determined at pH 5.0 and pH 7.0 by the agar dilution method. The impact of gyrA point mutations that are responsible for fluoroquinolone resistance was analyzed; the results showed 50 strains with an Asn-87 point mutation, 48 strains with an Asp-91 point mutation, and the remaining 30 strains with no gyrA mutations. The use of finafloxacin led to MIC values at pH 5.0 that were lower than the values seen at pH 7.0 for 112 strains (112/128, 87.5%), and this proportion was higher than that seen with moxifloxacin (21/128, 16.4%, P < 0.001). Finafloxacin also demonstrated a rate of susceptibility (MIC, <1 μg/ml) (37.5%, 48/128) at pH 5.0 that was higher than that seen with moxifloxacin (2.3%, 3/128) (P < 0.001). The trends were similar regardless of which of the Asn-87, Asp-91, and A2143 point mutations were present. In conclusion, the superior antimicrobial efficacy of finafloxacin against H. pylori in an acidic environment suggests the possible use of finafloxacin for treatment of H. pylori infection, as has been proposed by its developer, Merlion Pharma.

Treatment of Helicobacter pylori Infection in Korea: A Systematic Review and Meta-analysis

The efficacy of seven-day clarithromycin-based standard triple therapy (STT) for Helicobacter pylori has decreased in Korea over the past decade. The aim of this meta-analysis was to clarify the efficacy of first-line and second-line therapies in Korea. This systematic review will provide an overview of H. pylori eradication and present new therapeutic strategies used in Korea. An extensive search of the literature concerning STT, sequential therapy (SET), concomitant therapy (CT), bismuth-containing quadruple therapy (BCQT) and various other therapies used in Korea was performed. All selected studies were randomized controlled trials (RCTs). Eighteen RCTs were eligible for systematic review. The alternative regimens comparing seven-day STT as a first-line therapy include SET, CT, levofloxacin-based therapy (LBT), BCQT, and STT with prolonged duration. The results of the meta-analysis suggest that SET is superior to seven-day STT. The overall eradication rate by intention to treat (ITT) analysis was 69.8% for STT and 79.7% for SET. The overall eradication rate by per-protocol (PP) analysis was 77.0% for STT and 85.0% for SET. The odds ratios for the ITT and PP eradication rate were 0.57 (95% confidence interval [CI], 0.43 to 0.74) and 0.52 (95% CI, 0.35 to 0.76), respectively. In the subgroup analysis, however, there were no significant differences between SET and STT with prolonged durations. Alternative regimens to seven-day BCQT as second-line therapy include LBT, moxifloxacin-based therapy and 14-day BCQT. The eradication rates of these alternative regimens were not superior to that of the conventional treatment. SET is superior to seven-day STT but not to STT with prolonged duration.

The Diagnostic Validity of Citric Acid-Free, High Dose (13)C-Urea Breath Test After Helicobacter pylori Eradication in Korea

BACKGROUND

The (13)C-urea breath test ((13)C-UBT) is a noninvasive method for diagnosing Helicobacter pylori (H. pylori) infection. The aims of this study were to evaluate the diagnostic validity of the (13)C-UBT cutoff value and to identify influencing clinical factors responsible for aberrant results.

METHODS

(13)C-UBT (UBiTkit; Otsuka Pharmaceutical, cutoff value: 2.5‰) results in the range 2.0‰ to 10.0‰ after H. pylori eradication therapy were compared with the results of endoscopic biopsy results of the antrum and body. Factors considered to affect test results adversely were analyzed.

RESULTS

Among patients with a positive (13)C-UBT result (2.5‰ to 10.0‰, n = 223) or a negative (13)C-UBT result (2.0‰ to < 2.5‰, n = 66) after H. pylori eradication, 73 patients (34.0%) were false positive, and one (1.5%) was false negative as determined by endoscopic biopsy. The sensitivity, specificity, false-positive rate, and false-negative rate for a cutoff value of 2.5‰ were 99.3%, 47.1%, 52.9%, and 0.7%, respectively, and positive and negative predictive values of the (13)C-UBT were 67.3% and 98.5%, respectively. Multivariate analysis showed that a history of two or more previous H. pylori eradication therapies (OR = 2.455, 95%CI = 1.299-4.641) and moderate to severe gastric intestinal metaplasia (OR = 3.359, 95%CI = 1.572-7.178) were associated with a false-positive (13)C-UBT result.

CONCLUSION

The (13)C-UBT cutoff value currently used has poor specificity for confirming H. pylori status after eradication, and this lack of specificity is exacerbated in patients that have undergone multiple prior eradication therapies and in patients with moderate to severe gastric intestinal metaplasia. In addition, the citric-free (13)C-UBT would increase a false-positive (13)C-UBT result.

Two-week, high-dose proton pump inhibitor, moxifloxacin triple Helicobacter pylori therapy after failure of standard triple or non-bismuth quadruple treatments

BACKGROUND

Aim was to evaluate the efficacy and tolerability of a moxifloxacin-containing second-line triple regimen in patients whose previous Helicobacter pylori eradication treatment failed.

METHODS

Prospective multicentre study including patients in whom a triple therapy or a non-bismuth-quadruple-therapy failed. Moxifloxacin (400mg qd), amoxicillin (1g bid), and esomeprazole (40 mg bid) were prescribed for 14 days. Eradication was confirmed by (13)C-urea-breath-test. Compliance was determined through questioning and recovery of empty medication envelopes.

RESULTS

250 patients were consecutively included (mean age 48 ± 15 years, 11% with ulcer). Previous (failed) therapy included: standard triple (n = 179), sequential (n = 27), and concomitant (n = 44); 97% of patients took all medications, 4 were lost to follow-up. Intention-to-treat and per-protocol eradication rates were 82.4% (95% CI, 77-87%) and 85.7% (95% CI, 81-90%). Cure rates were similar independently of diagnosis (ulcer, 77%; dyspepsia, 82%) and previous treatment (standard triple, 83%; sequential, 89%; concomitant, 77%). At multivariate analysis, only age was associated with eradication (OR = 0.957; 95% CI, 0.933-0.981). Adverse events were reported in 25.2% of patients: diarrhoea (9.6%), abdominal pain (9.6%), and nausea (9.2%).

CONCLUSION

14-day moxifloxacin-containing triple therapy is an effective and safe second-line strategy in patients whose previous standard triple therapy or non-bismuth quadruple (sequential or concomitant) therapy has failed, providing a simple alternative to bismuth quadruple regimen.

The diagnostic validity of the (13)c-urea breath test in the gastrectomized patients: single tertiary center retrospective cohort study

BACKGROUND

This study was conducted to evaluate the diagnostic validity of the (13)C-urea breath test ((13)C-UBT) in the remnant stomach after partial gastrectomy for gastric cancer.

METHODS

The (13)C-UBT results after Helicobacter pylori eradication therapy was compared with the results of endoscopic biopsy-based methods in the patients who have received partial gastrectomy for the gastric cancer.

RESULTS

Among the gastrectomized patients who showed the positive (13)C-UBT results (≥ 2.5‰, n = 47) and negative (13)C-UBT results (< 2.5‰, n = 114) after H. pylori eradication, 26 patients (16.1%) and 4 patients (2.5%) were found to show false positive and false negative results based on biopsy-based methods, respectively. The sensitivity, specificity, false positive rate, and false negative rate for the cut-off value of 2.5‰ were 84.0%, 80.9%, 19.1%, and 16.0%, respectively. The positive and negative predictive values were 44.7% and 96.5%, respectively. In the multivariate analysis, two or more H. pylori eradication therapies (odds ratio = 3.248, 95% confidence interval= 1.088-9.695, P = 0.035) was associated with a false positive result of the (13)C-UBT.

CONCLUSIONS

After partial gastrectomy, a discordant result was shown in the positive (13)C-UBT results compared to the endoscopic biopsy methods for confirming the H. pylori status after eradication. Additional endoscopic biopsy-based H. pylori tests would be helpful to avoid unnecessary treatment for H. pylori eradication in these cases.

The efficacy of moxifloxacin-containing triple therapy after standard triple, sequential, or concomitant therapy failure for Helicobacter pylori eradication in Korea

Background/Aims

Retreatment after initial treatment failure for Helicobacter pylori is very challenging. The purpose of this study was to evaluate the efficacies of moxifloxacin-containing triple and bismuth-containing quadruple therapy.

Methods

A total of 151 patients, who failed initial H. pylori treatment, were included in this retrospective cohort study. The initial regimens were standard triple, sequential, or concomitant therapy, and the efficacies of the two following second-line treatments were evaluated: 7-day moxifloxacin-containing triple therapy (rabeprazole 20 mg twice a day, amoxicillin 1,000 mg twice a day, and moxifloxacin 400 mg once daily) and 7-day bismuth-containing quadruple therapy (rabeprazole 20 mg twice a day, tetracycline 500 mg 4 times a day, metronidazole 500 mg 3 times a day, and tripotassium dicitrate bismuthate 300 mg 4 times a day).

Results

The overall eradication rates after moxifloxacin-containing triple therapy and bismuth-containing quadruple therapy were 69/110 (62.7%) and 32/41 (78%), respectively. Comparison of the two regimens was performed in the patients who failed standard triple therapy, and the results revealed eradication rates of 14/28 (50%) and 32/41 (78%), respectively (p=0.015). The frequency of noncompliance was not different between the two groups, and there were fewer adverse effects in the moxifloxacin-containing triple therapy group (2.8% vs 7.3%, p=0.204 and 25.7% vs 43.9%, p=0.031, respectively).

Conclusions

Moxifloxacin-containing triple therapy, a recommended second-line treatment for initial concomitant or sequential therapy failure, had insufficient efficacy.

Prevalence of multiple drug-resistant Helicobacter pylori strains among patients with different gastric disorders in Iran

Emergence of multidrug-resistant (MDR) strains of Helicobacter pylori is a global health concern. This study was aimed to determine the frequency of MDR H. pylori strains in Iran. H. pylori isolates were obtained from cultured gastric biopsy samples on selective culture media after their characterization by PCR and conventional biochemical methods. The minimal inhibitory concentrations of rifampicin, ciprofloxacin, levofloxacin, ampicillin, clarithromycin, erythromycin, metronidazole, and tetracycline were determined for 111 strains that were isolated from 197 dyspeptic patients by the agar dilution method. The primary resistance rates were 61.3% (68/111) for metronidazole, 15.3% (17/111) for ampicillin, and 14.4% (16/111) for rifampicin. Resistance rates for other antimicrobials were as follows: macrolides (erythromycin or clarithromycin) 32.4% (36/111) and quinolones (levofloxacin or ciprofloxacin) 30.6% (34/111). Among the resistant strains, the rates of double and multiple drug resistance phenotypes were 22.6% (19/84) and 34.5% (29/84), respectively. The quadruple drug resistance phenotype encompasses 37.9% of the MDR strains, of which 90% of them was resistant to metronidazole. In conclusion, these results showed a high frequency of MDR phenotypes among the studied H. pylori strains in Iran. The eradication of the H. pylori strains presenting high resistance rates to macrolides, fluoroquinolones, or metronidazole could be achieved by approved tetracycline- or amoxicillin-containing regimens as alternative regimens to standard triple therapy.

GenoType HelicoDR test in the determination of antimicrobial resistance of Helicobacter pylori in Korea

OBJECTIVE

Antimicrobial resistance of Helicobacter pylori is most important factor in eradication success. GenoType HelicoDR test has been developed for rapid detection of antimicrobial resistance. The present study evaluated the clinical usefulness of GenoType HelicoDR test in Korea.

MATERIALS AND METHODS

To detect 23S rRNA for clarithromycin resistance and gyrA mutations for fluoroquinolone resistance, both DNA sequencing after minimal inhibitory test (MIC) and GenoType HelicoDR test were performed in H. pylori isolates from the gastric mucosa of 101 patients. The eradication results of clarithromycin and moxifloxacin-containing triple therapy were evaluated by the 23S rRNA and gyrA mutations.

RESULTS

For 42 isolates with A2143G mutation by GenoType HelicoDR, 83.3% (35/42) of concordance rate was estimated with DNA sequencing method and 85.7% (36/42) for MIC test. For 43 isolates with N87K mutation by GenoType HelicoDR, 71.1% (31/43) of concordance rate was estimated with DNA sequencing and 88.4% (38/43) for MIC test. The sensitivity and specificity of GenoType HelicoDR test in determination of 23S rRNA mutation were 94.9% and 87.1%, and those of gyrA 98.2% and 80.0%. The sensitivity and specificity of GenoType HelicoDR test in determination of clarithromycin resistance based on MIC test were 55.0% and 80.0%, for fluoroquinolone 74.4% and 70.0%.

CONCLUSION

GenoType HelicoDR test is useful to determine mutations responsible for clarithromycin or fluoroquinolone-containing eradication failure but has a limitation for the clinical applicability in determination of resistance.

Comparison of standard triple therapy, sequential therapy and moxifloxacin-based triple therapy for Helicobacter pylori infection: Patients' compliance and bacterial eradication rates

OBJECTIVE

To compare the patients' compliance with and the efficacy of existing treatments for Helicobacter pylori eradication, including moxifloxacin-based triple therapy, sequential treatment and the standard treatment.

METHODS

Patients with H. pylori infection were randomly assigned to three therapy groups. The triple therapy (MML) group was given moxifloxacin 400 mg/day, metronidazole 500 mg b.i.d. and lansoprazole 30 mg b.i.d. for 10 days. The sequential treatment (AL-CML) group was administrated amoxicillin 1 g b.i.d. and lansoprazole 30 mg b.i.d. for the first 5 days, followed by clarithromycin 500 mg b.i.d., metronidazole 500 mg b.i.d. and lansoprazole 30 mg b.i.d. for the second 5 days. The standard treatment (CAL) group received amoxicillin 1 g b.i.d., clarithromycin 500 mg b.i.d. and lansoprazole 30 mg b.i.d. for 14 days. The eradication rates were evaluated by per-protocol (PP) analysis and intention-to-treat (ITT) analysis.

RESULTS

The eradication rates were 87.1, 85.9 and 85.2% by PP analysis and 87.1, 84.9 and 84.2% by ITT analysis in the MML, AL-CML and CAL group, respectively, and patients' compliance rates were 98.2, 96.5 and 97.1%, respectively. There were no significant differences in treatment efficacy and compliance rates in the MML, AL-CML and CAL groups (P > 0.05).

CONCLUSIONS

The present study revealed that standard triple therapy, sequential therapy and moxifloxacin-based triple therapy are all effective treatment regimens in terms of H. pylori eradication rates and compliance with therapy in Turkey.

A comparison between 15-day sequential, 10-day sequential and proton pump inhibitor-based triple therapy for Helicobacter pylori infection in Korea

OBJECTIVE

The eradication rate of 10-day sequential therapy for Helicobacter pylori (H. pylori) infection was not satisfactory in Korea, probably due to antibiotic resistance. To compare the treatment efficacy of 15-day and 10-day sequential therapy of conventional 7-day proton pump inhibitor (PPI) triple therapy for the treatment of H. pylori infection.

METHODS

A total of 332 patients with H. pylori infection were randomly assigned to receive either 7-day PPI triple therapy, 10-day sequential therapy or 15-day sequential therapy. Eradication rate, drug compliance, and adverse events were compared among the three regimens.

RESULTS

The eradication rates by intention-to-treat analysis were 64.3% (95% CI: 55.5-73.2; 74 of 115 patients), 72.1% (95% CI: 63.6-80.5; 80 of 111 patients), and 80.2% (95% CI: 72.5-87.9; 85 of 106 patients) in the 7-day PPI triple, 10-day and 15-day sequential therapy groups, respectively (p = 0.032). The eradication rates by per-protocol analysis were 68.5% (95% CI: 59.6-77.4; 74 of 108 patients), 78.4% (95% CI: 70.3-86.5; 80 of 102 patients), and 89.5% (95% CI: 83.2-95.8; 85 of 95 patients) in the 7-day PPI triple, 10-day and 15-day sequential therapy groups, respectively (p = 0.001). There were no statistically significant differences between the three eradication therapy groups in regard to drug compliance and adverse events.

CONCLUSION

The 15-day sequential therapy demonstrated improved eradication efficacy compared with 7-day PPI triple and 10-day sequential therapy in Korea.

Helicobacter pylori eradication with moxifloxacin-containing therapy following failed first-line therapies in South Korea

AIM: To investigate moxifloxacin-containing triple therapy as second-line treatment for Helicobacter pylori (H. pylori) infection following failed first-line treatment.

METHODS: The sample included 312 patients for whom first-line treatment failed between January 2008 and May 2013; 27 patients were excluded, and a total of 285 patients received 7- or 14-d moxifloxacin-containing triple therapy as second-line treatment for H. pylori infection. First line regimens included 7-d standard triple (n = 172), 10-d bismuth-containing quadruple (n = 28), 14-d concomitant (n = 37), or 14-d sequential (n = 48) therapy. H. pylori status was evaluated using ¹³C-urea breath testing 4 wk later, after completion of the treatment. The primary outcome was the H. pylori eradication rate analyzed using intention-to-treat (ITT) and per protocol (PP) analyses. The secondary outcome was the occurrence of serious adverse events. Demographic and clinical factors were analyzed using Student’s t-tests and Pearson’s χ² tests according to first- and second-line regimens. A P value of less than 0.05 was considered statistically significant.

RESULTS: The eradication rate of moxifloxacin-containing triple therapy was 68.4% (ITT; 95%CI: 62.8-73.5) and 73.9% (PP; 95%CI: 68.3-78.8). The eradication rate was significantly higher with 14 d compared to 7 d of treatment (77.5% vs 62.5%, P = 0.017). Peptic ulcer patients had a higher eradication rate than the patients without ulcers (82.9% vs 70.6%, P = 0.046). The demographic and clinical characteristics were not significantly different between the groups according to first-line therapies. ITT and PP analyses of the moxifloxacin-containing triple therapy indicated the following eradication rates: 70.9% (95%CI: 63.8-77.2) and 77.2% (95%CI: 70.1-83.1) for standard triple; 67.9% (95%CI: 51.5-84.2) and 67.9% (95%CI: 51.5-84.2) for bismuth-containing quadruple; 60.4% (95%CI: 46.3-73.0) and 70.7% (95%CI: 54.0-80.9) for sequential; and 67.6% (95%CI: 51.5-80.4) and 67.6%(95%CI: 51.5-80.4) for concomitant therapy. There were no statistically significant differences in the efficacy of the first-line regimens (P = 0.492). The most common adverse event was diarrhea. There were no serious adverse events and no significant differences in the frequency of side effects between the first- and second-line regimens (28.7% vs 26.1%, respectively).

CONCLUSION: Moxifloxacin-containing triple therapy as second-line treatment resulted in low eradication rates. There were no differences in the efficacy between the first-line regimens in South Korea.

Advances in research of Helicobacter pylori resistance to levofloxacin

Helicobacter pylori (H. pylori) has been identified as the most important risk factor for chronic active gastritis and peptic ulcer disease. Resistance to antibiotics is increasing in H. pylori and is the main reason for failure of H. pylori eradication therapy. It is now widely accepted that resistance to fluoroquinolones (levofloxacin) is related with mutations of H. pylori gyrA gene. Molecular mechanisms of and detection methods for H. pylori resistance to levofloxacin have become the focus of current research. Therefore, study on H. pylori resistance to antibiotics is of great significance for eradication therapy of H. pylori infection.

Gender analysis of moxifloxacin clinical trials

PURPOSE

To determine the inclusion of women and the sex-stratification of results in moxifloxacin Clinical Trials (CTs), and to establish whether these CTs considered issues that specifically affect women, such as pregnancy and use of hormonal therapies. Previous publications about women's inclusion in CTs have not specifically studied therapeutic drugs. Although this type of drug is taken by men and women at a similar rate, adverse effects occur more frequently in the latter.

METHODS

We reviewed 158 published moxifloxacin trials on humans, retrieved from MedLine and the Cochrane Library (1998-2010), to determine whether they complied with the gender recommendations published by U.S. Food and Drug Administration Guideline.

RESULTS

Of a total of 80,417 subjects included in the moxifloxacin CTs, only 33.7% were women in phase I, in contrast to phase II, where women accounted for 45%, phase III, where they represented 38.3% and phase IV, where 51.3% were women. About 40.9% (n=52) of trials were stratified by sex and 15.3% (n=13) and 9% (n=7) provided data by sex on efficacy and adverse effects, respectively. We found little information about the influence of issues that specifically affect women. Only 3 of the 59 journals that published the moxifloxacin CTs stated that authors should stratify their results by sex.

CONCLUSIONS

Women are under-represented in the published moxifloxacin trials, and this trend is more marked in phase I, as they comprise a higher proportion in the other phases. Data by sex on efficacy and adverse effects are scarce in moxifloxacin trials. These facts, together with the lack of data on women-specific issues, suggest that the therapeutic drug moxifloxacin is only a partially evidence-based medicine.

Long-term follow up Helicobacter Pylori reinfection rate after second-line treatment: bismuth-containing quadruple therapy versus moxifloxacin-based triple therapy

BACKGROUND

The increasing trend of antibiotic resistance requires effective second-line Helicobacter pylori (H. pylori) treatment in high prevalence area of H. pylori. The aim of our study was to evaluate the reinfection rate of H. pylori after second-line treatment that would determine the long-term follow up effect of the rescue therapy.

METHODS

A total of 648 patients who had failed previous H. pylori eradication on standard triple therapy were randomized into two regimens: 1, esomeprazole (20 mg b.i.d), tripotassium dicitrate bismuthate (300 mg q.i.d), metronidazole (500 mg t.i.d), and tetracycline (500 mg q.i.d) (EBMT) or 2, moxifloxacin (400 mg q.d.), esomeprazole (20 mg b.i.d), and amoxicillin (1000 mg b.i.d.) (MEA). At four weeks after completion of eradication therapy, H. pylori tests were performed with 13C urea breath test or invasive tests. In patients who maintained continuous H. pylori negativity for the first year after eradication therapy, H. pylori status was assessed every year. For the evaluation of risk factors of reinfection, gender, age, clinical diagnosis, histological atrophic gastritis or intestinal metaplasia were analyzed.

RESULTS

The recrudescence rate of the EBMT was 1.7% and of the MEA group 3.3% (p = 0.67). The annual reinfection rate of H. pylori of EBMT was found to be 4.45% and the MEA group 6.46%. Univariate analysis (Log-rank test) showed no association with any clinical risk factor for reinfection.

CONCLUSIONS

The long-term reinfection rate of H. pylori stayed low in both of bismuth-containing quadruple therapy and moxifloxacin-based triple therapy; thus reinfection cannot affect the choice of second-line treatment.

TRIAL REGISTRATION

Clinical Trial Registration Number NCT01792700.

Guidelines for treatment of Helicobacter pylori in the East and West

Infection with Helicobacter pylori remains a major healthcare burden, with persistently high prevalence rates, especially in less-developed countries. H. pylori infection is causally related to non-malignant and malignant gastroduodenal diseases, such as peptic ulcer diseases, gastric cancer and gastric mucosa-associated lymphoid tissue lymphoma. Current international guidelines recommend a standard triple therapy as first-line therapy, including a proton pump inhibitor and a combination of amoxicillin and clarithromycin. Standard triple therapy has shown a decreasing efficacy over the years. The main reason is the increasing antibiotic resistance, particular to clarithromycin of H. pylori strains. Several new treatment options or modifications of already established regimens have been introduced to overcome treatment failure. In this article, we intend to report the reasons for treatment failure, and furthermore we give an overview of new treatment options as alternatives to the current treatment regimens. Finally, the strategy for the future is considered.

Prevalence of primary and secondary antimicrobial resistance of Helicobacter pylori in Korea from 2003 through 2012

BACKGROUND

Antimicrobial resistance of Helicobacter pylori (H. pylori) affects the efficacy of eradication therapy. The aim of this study was to estimate the prevalence of primary and secondary resistance of H. pylori isolates to antibiotics and to characterize the risk factors associated with antimicrobial resistance in Korea.

MATERIALS AND METHODS

This study was performed during the period of 2003-2012. Primary resistance was evaluated from 347 patients without any history of eradication, and secondary resistance was evaluated in 86 patients from whom H. pylori was cultured after failure of eradication. Minimal inhibitory concentration test was performed for amoxicillin, clarithromycin, metronidazole, tetracycline, azithromycin, levofloxacin, and moxifloxacin using agar dilution method. Primary and secondary resistance rates of H. pylori to 7 antibiotics were evaluated and risk factors for the antibiotic resistance were analyzed.

RESULTS

Increase in the primary resistance rate was found in amoxicillin (6.3-14.9%, p = .051), clarithromycin (17.2-23.7%, p = .323), and both of levofloxacin and moxifloxacin (4.7-28.1%, p = .002) during the study period. Secondary resistance rate significantly increased in metronidazole, levofloxacin, and moxifloxacin. Increase of resistance occurred after initial failure of eradication therapy in case of clarithromycin (p < .001), azithromycin (p < .001), levofloxacin (p = .011), and moxifloxacin (p = .020). Multivariable analyses showed that clarithromycin, azithromycin, levofloxacin, and moxifloxacin resistance was associated with previous eradication treatment history.

CONCLUSIONS

The increased primary and secondary antibiotic resistance of H. pylori in Korea is ongoing, and it will become a significant limitation for effective eradication of H. pylori in the future.

[Comparison of rifabutin- and levofloxacin-based third-line rescue therapies for Helicobacter pylori]

BACKGROUND/AIMS

There is increasing need for third-line therapy of Helicobacter pylori due to increasing level of antibiotics resistance. The aim of this study was to compare rifabutin and levofloxacin rescue regimens in patients with first- and second-line Helicobacter pylori eradication failures.

METHODS

Patients, in whom a first treatment with proton pump inhibitor-clarithromycin-amoxicillin and a second trial with proton pump inhibitor-bismuth-tetracycline-metronidazole had failed, received treatment with either rifabutin or levofloxacin, plus amoxicillin (1 g twice daily) and standard dose proton pump inhibitor. Eradication rates were confirmed with 13C-urea breath test or rapid urease test 4 weeks after the cessation of therapy.

RESULTS

Eradication rates were 71.4% in the rifabutin group, and 57.1% in the levofloxacin group, respectively. Although there was no significant difference in Helicobacter pylori eradication rates between two groups (p=0.656), rifabutin based regimen showed relatively higher eradication rate.

CONCLUSIONS

Helicobacter pylori eradication rates of rifabutin- or levofloxacin-based triple therapy could not achieve enough eradication rate. Further studies would be needed on combination of levofloxacin and rifabutin-based regimen or culture based treatment.

Salvage Options for Eradication of Helicobacter pylori During Tetracycline Backorder

Objective:

To review salvage options for Helicobacter pylori eradication regimens during a tetracycline backorder for patients with triple-therapy failure.

Data Sources:

A search of PubMed (1980-June 2012) was conducted using a combination of the terms H. pylori or Helicobacter pylori, salvage therapy, and eradication or treatment as text word searches.

Study Selection and Data Extraction:

Clinical trials and meta-analyses published in English were included. A manual review of the bibliographies of available literature was conducted and relevant articles were reviewed for inclusion.

Data Synthesis:

Treatment of H. pylori consists of a triple-drug regimen that includes a proton pump inhibitor (PPI), amoxicillin or metronidazole, and clarithromycin. Failure with this therapy is becoming increasingly common due to macrolide resistance. Upon failure with this regimen, it is recommended that a quadruple regimen with bismuth subsalicylate, metronidazole, tetracycline, and a histamine2 receptor antagonist or a PPI be used. Recent backorders by the 2 manufacturers for tetracycline restrict the use of this regimen. Options that can be considered include minocycline or doxycycline in place of tetracycline, levofloxacin- or moxifloxacin-based regimens, a tinidazole-based regimen, or a rifabutin-based regimen. This article includes a review of 1 study each of minocycline and doxycycline, 5 levofloxacin studies (including meta-analyses), 2 moxifloxacin studies, 1 rifabutin study, and 1 tinidazole study. There are limited data with other tetracyclines; however, given the resistance to quinolones in some areas and possible drug interactions and adverse effects from rifabutin, minocycline or doxycycline regimens may be a better second-line regimen option.

Conclusions:

Given the current tetracycline shortage, minocycline and doxycycline are options to be considered in patients with a macrolide-based treatment failure. Fluoroquinolones may be an option for patients who have not received these drugs for other indications in the recent past or in areas where resistance is low.

Quadruple therapy with moxifloxacin and bismuth for first-line treatment of Helicobacter pylori

AIM: To compare triple therapy vs quadruple therapy for 10 d as first-line treatment of Helicobacter pylori (H. pylori) infection.

METHODS: Consecutive H. pylori positive patients never treated in the past for this infection were randomly treated with triple therapy of pantoprazole (PAN) 20 mg bid, amoxicillin (AMO) 1 g bid and moxifloxacin (MOX) 400 mg bid for 10 d (PAM) or with quadruple therapy of PAN 20 mg bid, AMO 1 g bid, MOX 400 mg bid and bismuth subcitrate 240 mg bid for 10 d (PAMB). All patients were found positive at 13 C-Urea breath test (UBT) performed within ten days prior to the start of the study. A successful outcome was confirmed with an UBT performed 8 wk after the end of treatment. χ² analysis was used for statistical comparison. Per protocol (PP) and intention-to-treat (ITT) values were also calculated.

RESULTS: Fifty-seven patients were enrolled in the PAM group and 50 in the PAMB group. One patient in each group did not return for further assessment. Eradication was higher in the PAMB group (negative: 46 and positive: 3) vs the PAM group (negative: 44 and positive: 12). The H. pylori eradication rate was statistically significantly higher in the PAMB group vs the PAM group, both with the PP and ITT analyses (PP: PAMB 93.8%, PAM 78.5%, P < 0.02; ITT: PAMB 92%, PAM 77.1 %, P <0.03).

CONCLUSION: The addition of bismuth subcitrate can be considered a valuable adjuvant to triple therapy in those areas where H. pylori shows a high resistance to fluoroquinolones.

Resistance of Helicobacter pylori strains to antibiotics in Korea with a focus on fluoroquinolone resistance

BACKGROUND AND AIM

New regimens, including those with new fluoroquinolones, have been developed to overcome the antibiotic resistance of Helicobacter pylori. We aimed to assess the antibiotic resistance rates, as well as the molecular mechanisms of fluoroquinolone resistance, of the clinical isolates obtained in Korea.

METHODS

The minimal inhibitory concentration (MIC) values of ciprofloxacin, amoxicillin, clarithromycin, metronidazole and tetracycline were determined by the agar dilution method for 185 treatment-naïve Helicobacter pylori isolates. The resistant strains were evaluated for the presence of point mutations in the quinolone resistance-determining region (QRDR) of the gyrA and gyrB genes by direct nucleotide sequencing.

RESULTS

Twenty-nine (29/185, 15.7%) of the strains were found to be resistant to ciprofloxacin. The resistance rates to amoxicillin, clarithromycin, metronidazole and tetracycline were 2.2% (four of 185), 10.8% (20 of 185), 30.3% (56 of 185) and 0.5% (one of 185), respectively. The most common mutations in the H. pylori gyrA gene were found at codons corresponding to Asp87 (16/29, 55.2%) and Asn91 (10/29, 34.5%).

CONCLUSIONS

Primary H. pylori resistance to ciprofloxacin occurred at a high frequency. The fluoroquinolone resistance is most likely mediated through amino acid point mutation in the gyrA gene at Asn87 and Asp91.

[Primary antibiotic resistance of Helicobacter pylori strains and eradication rate according to gastroduodenal disease in Korea]

BACKGROUND/AIMS

This study was performed to evaluate whether the prevalence rates of primary antibiotic resistance in Helicobacter pylori (H. pylori) isolates and the eradication rate of H. pylori could be different between cancer and non-cancer patients.

METHODS

H. pylori were isolated from gastric mucosal biopsy specimens obtained from 269 Koreans, who did not have any eradication therapy history and were diagnosed as one of the following diseases; chronic gastritis, benign gastric ulcer, duodenal ulcer or gastric cancer. The susceptibilities of the H. pylori isolates to amoxicillin, clarithromycin, metronidazole, tetracycline, azithromycin, ciprofloxacin, levofloxacin and moxifloxacin were examined with the agar dilution method. In addition, eradication rate of H. pylori was evaluated.

RESULTS

There was no significant difference in the primary antibiotic resistance to above eight antibiotics among chronic gastritis, peptic ulcer disease and gastric cancer. Furthermore there was no difference of antibiotic resistance between cancer and non-cancer patients, and there was no difference of eradication rate of H. pylori according to disease.

CONCLUSIONS

Primary antibiotic resistance and H. pylori eradication rate were not different between cancer and non-cancer patients.

Randomized trial on 14 versus 7 days of esomeprazole, moxifloxacin, and amoxicillin for second-line or rescue treatment of Helicobacter pylori infection

BACKGROUND

Triple therapy with a proton pump inhibitor, moxifloxacin, and amoxicillin has been proven effective in first-line treatment of Helicobacter pylori infection.

AIM

To explore 1, the value of triple therapy with esomeprazole, moxifloxacin, and amoxicillin in second-line or rescue treatment of Caucasian patients and 2, the impact of treatment duration on eradication success.

METHODS

H. pylori-infected patients with at least one previous treatment failure were randomized to oral esomeprazole 20 mg b.i.d., moxifloxacin 400 mg o.d., and amoxicillin 1000 mg b.i.d. for either 7 (EMA-7) or 14 days (EMA-14). Eradication was confirmed by 13C urea breath test. Antimicrobial susceptibility testing was performed in all patients at baseline and in patients who failed treatment.

RESULTS

Eighty patients were randomized, and 60% had ≥ 2 previous treatment failures. Pretreatment resistance against clarithromycin and metronidazole was found in 70.5 and 61.5% of cases, respectively. The intention-to-treat eradication rate was significantly higher after EMA-14 compared with EMA-7 (95.0 vs 78.9%, p = .036). No independent risk factor for treatment failure could be identified. There were no serious adverse events. Five of the EMA-14 patients (12.5%) compared with none of the EMA-7 patients discontinued prematurely because of adverse events (p = .031). Post-treatment resistance against moxifloxacin was found in one of seven patients with isolated organisms (14.3%).

CONCLUSION

Second-line/rescue H. pylori eradication therapy with esomeprazole, moxifloxacin, and amoxicillin is very effective and well tolerated. Fourteen days of treatment significantly increase the eradication rate but also the rate of adverse events.

Treatment of Helicobacter pylori

PURPOSE OF REVIEW

The article will give an overview on reasons for treatment failure and tries to show new concepts for Helicobacter pylori treatment.

RECENT FINDINGS

Several new treatment options or modifications of already established regimens have been introduced to overcome treatment failure. Antibiotic resistance to H. pylori is the key factor for treatment failure. At the moment, standard triple therapy remains the primary choice in regions with proven low clarithromycin resistance rates. In areas with high clarithromycin resistance, four drug treatment regimens, including quadruple and sequential therapy, have proven the best results as first-line regimens. The options for second-line treatment regimens are manifold. Second-line treatment regimens need to be adapted accurately to local resistance rates.

SUMMARY

Treatment of H. pylori infection is challenged by a dramatic fall in eradication rates all over the world. Newer regimens have been introduced including sequential, quadruple therapies and those regimens provide promising results, but the knowledge about local resistance rates remains the key to an effective therapy.

Dual therapy trial using esomeprazole and amoxicillin as third-line rescue therapy for Helicobacter pylori infection

BACKGROUND/AIMS

The purpose of this study was to evaluate the efficacy and tolerability of dual therapy consisting of esomeprazole and amoxicillin as a rescue therapy for Helicobacter pylori infection.

METHODS

From December 2009 to August 2010, 21 patients who experienced two consecutive eradication failures were included. They received esomeprazole (40 mg, b.i.d.) and amoxicillin (1,000 mg, b.i.d.) for 14 days as a third eradication regimen. Compliance and side effects were determined from an interview. H. pylori status was evaluated using the (13)C urea breath test at least 6 weeks after treatment.

RESULTS

The mean age of the patients was 59 years and included 52% males. Indications for treatment were functional dyspepsia (61.9%), peptic ulcer disease (28.6%), and gastric adenoma (9.5%). H. pylori was eradicated in 14 of 21 (66.7%) patients. Minor side effects were reported in three of the 21 patients (14.3%). These side effects consisted mainly of nausea and epigastric discomfort.

CONCLUSIONS

A 2-week course of dual therapy failed to show satisfactory results in third-line H. pylori eradication, but it was very safe and tolerable. Therefore, dual therapy constitutes an encouraging empirical strategy for the elderly and infirm patients with multiple previous eradication failures.

[Regional difference of antibiotic resistance of helicobacter pylori strains in Korea]

BACKGROUND/AIMS

This study was performed to compare the prevalence rates of primary antibiotic resistance in Helicobacter pylori (H. pylori) isolates among different regions of Korea.

METHODS

H. pylori were isolated from gastric mucosal biopsy specimens of 99 Koreans who lived in Gyeonggi (n=40), Kangwon province (n=40) and Busan (n=19) from April to August in 2008. All the patients had no history of H. pylori eradication therapy. The susceptibilities of the H. pylori isolates to amoxicillin, clarithromycin, metronidazole, tetracycline, azithromycin, ciprofloxacin, levofloxacin, and moxifloxacin were tested according to the agar dilution method.

RESULTS

There was a difference in resistance to clarithromycin in three institutes located among Gyeonggi (32.5%), Kangwon province (12.5%) and Busan (42.1%) by One way ANOVA test (p=0.027) and nonparametric Kruskal Wallis test (p=0.027). However, by post-hoc analysis, there was no statistically significant difference among three regions. Similarly, the other 7 antibiotics (amoxicillin, metronidazole, tetracycline, azithromycin, ciprofloxacin, levofloxacin and moxifloxacin) did not show any significant difference.

CONCLUSIONS

There was no significant regional difference of the primary antibiotic resistance of H. pylori. However, the included patient number might not be enough for this conclusion demanding further evaluations.

Mutations of Helicobacter pylori associated with fluoroquinolone resistance in Korea

BACKGROUND AND AIM

Fluoroquinolone resistance of Helicobacter pylori is known to be dependent on mutations in the QRDR of gyrA. This study was performed to investigate the distribution of gyrA point mutations and to evaluate the impact of the mutations on second-line H. pylori eradication therapy.

METHODS

After H. pylori isolation from gastric mucosal specimens, fluoroquinolone resistance was examined using the agar dilution method. DNA sequencing of the QRDR of gyrA was performed in 89 fluoroquinolone-resistant and 27 fluoroquinolone-susceptible isolates. Transformation experiments were performed to confirm mutations in the resistant strains. The eradication rates of moxifloxacin-containing triple therapy were evaluated depending on the resistance of fluoroquinolone.

RESULTS

The gyrA mutations were detected in 75.3% (55 of 73 strains) of the primary resistant strains and 100% (16 strains) of the secondary resistant strains. The most common mutations were Asp-91 (36.0%) and Asn-87 (33.7%). The MIC values in the transformed strains differed depending on the gyrA mutations, N87, and D91. Six patients with fluoroquinolone-resistant strains received moxifloxacin-containing triple therapy as the second-line therapy, and two of three patients with Asn-87 mutations (66.7%) failed in the eradication. By contrast, three patients with Asp-91 mutations had successful eradication treatment.

CONCLUSIONS

Fluoroquinolone resistance of H. pylori was caused by gyrA Asn-87 and Asp-91 point mutations. The Asn-87 mutation seems to be an important determinant of failure of fluoroquinolone-containing triple eradication therapy based on eradication results.

Second-line Helicobacter pylori eradication: a randomized comparison of 1-week or 2-week bismuth-containing quadruple therapy

OBJECTIVES

The increasing levels of bacterial antibiotic resistance have increased the need to evaluate the second-line treatments for Helicobacter pylori. Bismuth-based quadruple therapy is recommended as a second-line treatment, but the optimal duration of this treatment is still debatable. We prospectively analyzed the eradication rate of H. pylori according to the duration of the second-line bismuth-based quadruple therapy.

METHODS

One hundred and ninety-nine patients who failed at H. pylori eradication were prospectively randomized to receive pantoprazole 40 mg twice daily, metronidazole 500 mg thrice daily, and bismuth subcitrate 300 mg and tetracycline 500 mg four times daily for 7 days (PBMT7) or for 14 days (PBMT14). The post-treatment H. pylori status was determined by the (13) C-urea breath test. The eradication rates, drug compliance, and side effects of each group were evaluated.

RESULTS

The intention-to-treat (ITT) eradication rates were 81.6% (95% CI 73.9-89.3%, 80/98) in the PBMT7 arm and 85.1% (95% CI 78.2-92.0%, 86/101) in the PBMT14 arm (p=.028, noninferiority test), while the per-protocol (PP) eradication rates were 89.6% (95% CI 83.2-96.0%, 78/87) and 96.2% (95% CI 92.0-100.0% 77/80) (p=.015, noninferiority test), respectively. The compliance was 88.8% (87/98) and 79.2% (80/101) in the PBMT7 and PBMT14 groups, respectively. (p=.066) The number of patients having severe side effects was 15.3% (15/98) and 21.8% (22/101) in the PBMT7 and PBMT14 groups, respectively, which was similar between both groups. (p=.243).

CONCLUSIONS

Although PBMT7 was not inferior to PBMT14 statistically, PBMT could not demonstrate enough ITT/PP eradication rate. Therefore, it could be better to extend the duration of treatment for 2 weeks for the second-line treatment of H. pylori in Korea.

Should quinolones come first in Helicobacter pylori therapy?

New generations of fluoroquinolones, like levofloxacin and moxifloxacin, exhibit a broad-spectrum activity against Gram-positive and Gram-negative bacteria, and have been successfully introduced into the treatment of Helicobacter pylori infection. Based on a large body of evidence, current guidelines recommend the use of levofloxacin- or moxifloxacin-containing proton-pump inhibitor (PPI) triple therapies in second-line or rescue treatment of H. pylori infection. The efficacy of standard PPI triple therapies has substantially declined during the last decade, mainly due to increasing resistance against the key antibiotics clarithromycin and metronidazole. Therefore, alternative strategies for first-line therapy of H. pylori infection have been evaluated in a considerable number of clinical trials including sequential regimens, nonbismuth quadruple regimens, and quinolone-containing PPI triple therapy regimens. The aim of this paper is to summarize the current body of evidence of levofloxacin- and moxifloxacin-containing regimens in first-line treatment of H. pylori infection, and to discuss the risks and benefits of these strategies in the light of increasing resistance of H. pylori to quinolones.

Effects of multistrain probiotic-containing yogurt on second-line triple therapy for Helicobacter pylori infection

BACKGROUND AND AIMS

The adjuvant effects of probiotic-containing yogurt on second-line triple therapy for Helicobacter pylori (H. pylori) infection have not been evaluated.

METHODS

A total of 337 patients with persistent H. pylori infection, after first-line triple therapy, were randomly assigned to receive either triple therapy with (yogurt group, n=151) or without (control group, n=186) Will yogurt. Triple therapy consisted of 400 mg moxifloxacin q.d., 1000 mg amoxicillin b.i.d., and 20 mg esomeprazole b.i.d. for 14 days. Will yogurt contains Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium longum, and Streptococcus thermophilus. H. pylori eradication was evaluated by the (13)C-urea breath test, histology, or the rapid urease test.

RESULTS

The eradication rates by intention-to-treat analysis were 66.7% and 68.9% in the control and yogurt groups, respectively (P=0.667). The eradication rates by per-protocol analysis were 78.5% and 86% in the control and the yogurt groups, respectively (P=0.110). The adverse event rates were 25.3% and 28.5% in the control group and yogurt group, respectively (P=0.508).

CONCLUSIONS

The addition of yogurt containing probiotics to moxifloxacin-containing second-line treatment neither improved H. pylori eradication rates nor reduced the adverse events of treatment.

In vitro activity of nemonoxacin, tigecycline, and other antimicrobial agents against Helicobacter pylori isolates in Taiwan, 1998-2007

The minimum inhibitory concentrations (MICs) of 330 nonduplicate Helicobacter pylori isolates to nemonoxacin, tigecycline, and eight other antimicrobial agents were determined by using the agar dilution method. Sequencing the quinolone resistance-determining regions (QRDRs) in the gyrA gene of these isolates was also performed. Resistance to clarithromycin showed an increasing trend during the ten-year study period and was highest (38%) in 2005. Tigecycline had potent in vitro activities against all isolates, with an MIC(90) of 0.06 μg/ml. Among the quinolones tested, nemonoxacin (MIC(50) of 0.12 μg/ml and MIC(90) of 0.25 μg/ml) and gemifloxacin had one to two-fold better in vitro activities than ciprofloxacin, levofloxacin, and moxifloxacin. Among the nine isolates (2.7%) with levofloxacin resistance, four (44.4%) were also resistant to metronidazole, three (33.3%) to clarithromycin, and two (22.2%) to amoxicillin. Isolates with levofloxacin resistance exhibited one or two of three amino acid alterations (Ser-70, Asn-87, and Asp-91) involved in QRDRs in the gyrA gene. A double mutation at Ser70Cys and Asn87Ile had a higher level of resistance. The results of this study suggest a potentially useful role of nemonoxacin and tigecycline in the treatment of infections caused by H. pylori. The gyrA mutation at Ser-70 is a novel finding and has an impact on levofloxacin resistance.

Distribution of gyrA mutations in fluoroquinolone-resistant Helicobacter pylori strains

AIM: To investigate the resistance of Helicobacter pylori (H. pylori) to ciprofloxacin (CIP), levofloxacin (LVX) and moxifloxacin (MOX) in the Beijing area and to elucidate the resistance mechanisms.

METHODS: Seventy-nine H. pylori clinical strains, isolated from patients who had undergone upper gastrointestinal endoscopy in Peking University First Hospital from 2007 to 2009, were tested for their susceptibility to CIP, LVX and MOX using the E-test method. H. pylori strain 26695 was included in the susceptibility testing as a control strain. According to the minimal inhibitory concentration (MIC) values, a strain was classified as resistant to CIP, LVX or MOX when the MIC was > 1 μg/mL. We amplified by polymerase chain reaction (PCR) and sequenced the quinolone resistance-determining regions of the gyrA and gyrB genes from 29 quinolone-resistant and 16 quinolone-susceptible H. pylori strains selected at random.

RESULTS: In this study, the resistance rates of H. pylori to CIP, LVX or MOX were 55.7% (44/79), and the primary resistance rates were 26.6% (21/79). Patients with secondary resistance had received LVX in previous eradication treatments, but not MOX or CIP. Forty-five strains, including 29 CIP, LVX or MOX-resistant strains (MIC: 1.5-32 μg/mL) and 16 susceptible strains, were selected randomly from the 79 strains and used in PCR analysis. Among these 45 strains, 27 resistant strains had mutations in the gyrA gene, including 11 strains with mutations corresponding to Asp-91 (MIC: 2-32 μg/mL), one of which also had a mutation corresponding to Val-150, and 16 strains had mutations at Asn-87 (MIC: 4-32 μg/mL), three of which also had mutations corresponding to Arg-140 or Val-150. In addition, Arg-140, Val-150 or Ala-97 mutations were separately detected in three susceptible strains. Analysis of the gyrB gene showed that one strain of low resistance had a mutation corresponding to Ser-457 that coexisted with an Asp-91 mutation. There was a significant difference in the occurrence of mutations in the gyrA gene between CIP, LVX and MOX-resistant and -susceptible strains (P < 0.05), but 2 resistant strains were found to possess no quinolone resistance-determining region mutations.

CONCLUSION: Resistance is primarily mediated through point mutations in gyrA. Whether other mechanisms are responsible for resistance in strains without mutations in the QRDR should be detected.

Bismuth-containing quadruple therapy as second-line treatment for Helicobacter pylori infection: effect of treatment duration and antibiotic resistance on the eradication rate in Korea

BACKGROUND

The eradication rate of first-line Helicobacter pylori treatment is only 70-85% and has been decreasing due to the increase in antibiotic resistance. The aim of this study was to evaluate the efficacy of bismuth-containing quadruple therapy as second-line treatment for H. pylori infection based on treatment duration.

METHODS

We prospectively enrolled 227 patients that were found to have persistent H. pylori infection after first-line proton-pump inhibitor-clarithromycin-amoxicillin triple therapy. Patients were randomized to 1-week (112 patients) and 2-week (115 patients) quadruple therapy with tripotassium dicitrate bismuthate 300 mg q.i.d., metronidazole 500 mg t.i.d., and tetracycline 500 mg q.i.d. and esomeprazole 20 mg b.i.d. The eradication rate, drug compliance, and adverse events were compared based on treatment duration.

RESULTS

The eradication rates were 72/112 (64.3%, 95% CI: 0.504-0.830) and 71/92 (77.2%, 0.440-0.749) with 1-week group, and 95/115 (82.6%, 1.165-2.449) an 88/94 (93.6%, 1.213-5.113) with 2-week group by intention-to-treat therapy (p = .002) and per-protocol analysis (p = .001), respectively. The adverse events increased as the treatment durations increased from 7 to 14 days (20.0 and 42.5%, respectively, p < .001). However, there was no significant difference in the patient compliance or the rate of major adverse events between the 1- and 2-week groups (6.3 and 12.5%, respectively, p = .133).

CONCLUSION

Two-week bismuth-containing quadruple therapy was more effective than the 1-week treatment, and should be considered for second-line treatment in Korea.

[Diagnosis and treatment guidelines for Helicobacter pylori infection in Korea]

Eleven years has passed since the guideline of the Korean College of Helicobacter and Upper Gastrointestinal Research group for H. pylori infection was produced in 1998. During this period the research for H. pylori has much progressed that H. pylori is now regarded as the major cause of gastric cancer. The seroprevalence of H. pylori in Korea was found to be decreased especially below the age of 40s and in the area of Seoul-Gyeonggi province, and annual reinfection rate of H. pylori has decreased up to 2.94%. In the aspect of diagnostic tests of H. pylori the biopsy is recommended in the body instead of antrum in the subjects with atrophic gastritis and/or intestinal metaplasia for the modified Giemsa staining or Warthin Starry silver staining. The urea breath test is the test of choice to confirm eradication when follow-up endoscopy is not necessary. Definite indication for H. pylori eradication is early gastric cancer in addition to the previous indications of peptic ulcer including scar and Marginal zone B cell lymphoma (MALT type). Treatment is also recommended for the relatives of gastric cancer patient, unexplained iron deficiency anemia, and chronic idiopathic thrombocytopenic purpura. One or two week treatment of proton pump inhibitor (PPI) based triple therapy consisting of one PPI and two antibiotics, clarithromycin and amoxicillin, is recommended as the first line treatment regimen. In the case of treatment failure, one or two weeks of quadruple therapy (PPI+metronidazole+tetracycline+bismuth) is recommended. Herein, Korean College of Helicobacter and Upper Gastrointestinal Research proposes a diagnostic and treatment guideline based on currently available evidence.