Lansoprazole and secnidazole with clarithromycin, amoxycillin or pefloxacin in the eradication of Helicobacter pylori in a developing country

A systematic review of the literature on mechanisms of 5-nitroimidazole resistance in Trichomonas vaginalis

BACKGROUND

Trichomonas vaginalis is the most common non-viral sexually transmitted infection. 5-Nitroimidazoles [metronidazole (MTZ) and tinidazole (TDZ)] are FDA-approved treatments. To better understand treatment failure, we conducted a systematic review on mechanisms of 5-nitroimidazole resistance.

METHODS

PubMed, ScienceDirect and EMBASE databases were searched using keywords Trichomonas vaginalis, trichomoniasis, 5-nitroimidazole, metronidazole, tinidazole and drug resistance. Non-English language articles and articles on other treatments were excluded.

RESULTS

The search yielded 606 articles, of which 550 were excluded, leaving 58 articles. Trichomonas vaginalis resistance varies and is higher with MTZ (2.2-9.6%) than TDZ (0-2%). Resistance can be aerobic or anaerobic and is relative rather than absolute. Differential expression of enzymes involved in trichomonad energy production and antioxidant defenses affects 5-nitroimidazole drug activation; reduced expression of pyruvate:ferredoxin oxidoreductase, ferredoxin, nitroreductase, hydrogenase, thioredoxin reductase and flavin reductase are implicated in drug resistance. Trichomonas vaginalis infection with Mycoplasma hominis or T. vaginalis virus has also been associated with resistance. Trichomonas vaginalis has two genotypes, with greater resistance seen in type 2 (vs type 1) populations.

DISCUSSION

5-Nitroimidazole resistance results from differential expression of enzymes involved in energy production or antioxidant defenses, along with genetic mutations in the T. vaginalis genome. Alternative treatments outside of the 5-nitroimidazole class are needed.

Secnidazole: next-generation antimicrobial agent for bacterial vaginosis treatment

Secnidazole is a next-generation 5-nitroimidazole approved for more than three decades in Europe, Asia, South America and Africa and recently in the USA as a single-dose (2 g) treatment of bacterial vaginosis (BV). Secnidazole is characterized by potent in vitro antimicrobial activity against BV-associated pathogens, as well as prolonged terminal elimination half-life and systemic exposure. These characteristics form the basis of effective and safe treatment of BV with a 2-g single-dose secnidazole regimen, which was recently confirmed in double-blind, placebo-controlled clinical trials conducted in the USA. The option to treat BV with single-dose secnidazole not only cures the primary infection but also may diminish risks of serious sequelae of untreated or undertreated infection.

In Vitro Study of the Susceptibility of Clinical Isolates of Trichomonas vaginalis to Metronidazole and Secnidazole

Nitroimidazoles (metronidazole [MTZ] and tinidazole [TNZ]) are the only drugs recommended for treatment of Trichomonas vaginalis infections. MTZ resistance occurs in 4% to 10% of cases of vaginal trichomoniasis (R. D. Kirkcaldy et al., Emerg Infect Dis 18:939-943, 2012; J. R. Schwebke and F. J. Barrientes, Antimicrob Agents Chemother 50:4209-4210, 2006) and TNZ resistance in 1% of cases (J. R. Schwebke and F. J. Barrientes, Antimicrob Agents Chemother 50:4209-4210, 2006). Emerging nitroimidazole-resistant trichomoniasis is concerning, because few alternatives to standard therapy exist. We assessed the prevalence of in vitro aerobic MTZ and secnidazole resistance among T. vaginalis isolates collected in 2015 to 2016 from 100 women in Birmingham, Alabama, with positive cultures. Archived specimens were treated with secnidazole or MTZ (0.2 to 400 μg/ml) for 48 h, according to U.S. Centers for Disease Control and Prevention protocols. Ninety-six (96%) of the 100 clinical Trichomonas isolates tested demonstrated lower minimum lethal concentrations for secnidazole than for MTZ, suggesting that secnidazole has better in vitro activity than MTZ.

Comparison of efficacy and pharmacoeconomics of two Helicobacter pylori eradication regimens in peptic ulcer disease

Background

Helicobacter pylori, the cause of most peptic ulcer diseases, infects approximately 50% of the population worldwide. Indian data on cost and effectiveness of the standard first-line therapies for H. pylori eradication are scarce. Thus, the present study was aimed at comparing the cost and efficacy of two standard first-line therapies: Regimen I comprising pantoprazole (40 mg) plus amoxicillin (750 mg) plus clarithromycin (500 mg) (PAC) and Regimen II comprising rabeprazole (20 mg) plus amoxicillin (625 mg) plus metronidazole (200 mg) (RAM).

Methodology

This prospective, observational, bottom-up study collected demographic, economic, diagnostic, and therapeutic data from 60 H. pylori-positive patients. The study was carried out for 6 months in the Gastroenterology Department of a Tertiary Care Hospital in Hyderabad, Telangana, India.

Results

Health-care system perspective was used to account for direct costs. Average cost per patient for complete H. pylori eradication was Rs. 10,221 and Rs. 8568 for Regimen I and Regimen II, respectively. Inpatient cost was considerably higher than the outpatient cost. Diagnostic costs ranked first in direct costs, followed by hospitalization costs, medication costs, and finally, physician's office visit cost. Individual patient's costs difference between two regimens was found to be statistically significant. Overall, Regimen I proved to be more efficacious than Regimen II, but Regimen II proved to be more cost-effective than Regimen I. Furthermore, incremental cost-effectiveness analysis revealed additional cost of Rs. 127 per patient if the patient was treated with Regimen I instead of Regimen II.

Conclusion

Our study showed that Regimen II (RAM) was more cost-effective than Regimen I (PAC), but PAC achieved faster H. pylori eradication than RAM. We assume that this study provides local clinical data as to which regimen may be useful in a particular patient. National Level Clinical Trials are required to further ascertain this conclusion.

Safety and efficacy of 1-week levofloxacin-based triple therapy in first-line treatment for Helicobacter pylori-related peptic ulcer disease in Kashmir, India

BACKGROUND AND OBJECTIVES

There is no ideal therapy for eradication of Helicobacter pylori infection. We evaluated the efficacy and safety of 1-week triple therapy with rabeprazole, levofloxacin, and tinidazole in a metronidazole resistance prevalent region for eradicating H. pylori infection in patients with gastroduodenal ulcers.

METHODS

This was an open-label, prospective study. Consecutive patients with endoscopy-proven duodenal or gastric ulcer and who were H. pylori-positive were treated with levofloxacin 500 mg once a day, rabeprazole 20 mg twice a day, and tinidazole 500 mg twice daily for 7 days followed by rabeprazole 20 mg OD for 8 weeks. Endoscopy was repeated 8 weeks after the end of therapy to check for ulcer healing and H. pylori status.

RESULTS

One hundred and thirty-one patients with gastroduodenal ulcers (duodenal 118, and gastric 13) were included. Drug compliance was 97.7 %. The eradication rate of H. pylori by intention-to-treat analysis was 85.5 % (95 % confidence interval 79.5-91.5) (112 of 131 patients) and by per-protocol analysis was 91.8 % (95 % confidence interval 86.9-96.7) (112 of 122 patients). Adverse effects were reported in 17 %: abdominal pain in 3.05 %, metallic taste in 6.87 %, and nausea and vomiting in 4.58 %.

CONCLUSIONS

Levofloxacin-tinidazole-based triple therapy was highly effective and safe as a first-line regimen in Indian patients with gastroduodenal ulcer disease associated with H. pylori infection. The regimen was well tolerated.

Moxifloxacin-containing triple therapy versus bismuth-containing quadruple therapy for second-line treatment of Helicobacter pylori infection: a meta-analysis

BACKGROUND

Moxifloxacin-containing triple therapy has been suggested as an alternative second-line therapy for Helicobacter pylori infection.

AIMS

To systematically review the efficacy and tolerance of moxifloxacin-containing triple therapy in second-line H. pylori eradication, and to conduct a meta-analysis of studies comparing this regimen with bismuth-containing quadruple therapy.

MATERIALS AND METHODS

 Electronic databases including Medline, Embase, Cochrane controlled trials register, Web of Science, PubMed, Chinese Biomedical Literature Database (updated to December 2010), and manual searches were conducted. A meta-analysis of all randomized controlled trials (RCTs) comparing moxifloxacin-containing triple therapy to bismuth-containing quadruple therapy in the second-line treatment of H. pylori infection was performed.

RESULTS

Seven RCTs including 787 patients were assessed. The meta-analysis showed that the eradication rate in the moxifloxacin group was significantly higher than that in the quadruple therapy group (74.9 vs 61.4%, OR 1.89, 95% CI: 1.38-2.58, p < .0001); besides, the rates of side effects and discontinuing therapy because of side effects in the moxifloxacin group were significantly lower than those in the quadruple therapy group (side effects: 10.1 vs 27.8%, OR 0.27, 95% CI: 0.18-0.41, p < .00001; discontinuing therapy because of side effects: 1.4 vs 8.2%, OR 0.18, 95% CI: 0.08-0.40, p < .0001). These results were constant in the sensitivity analyses.

CONCLUSION

Moxifloxacin-containing triple regimen is more effective and better tolerated than the bismuth-containing quadruple therapy in the second-line treatment of H. pylori infection.

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.

Second-line treatment for Helicobacter pylori infection based on moxifloxacin triple therapy: a randomized controlled trial

BACKGROUND

In eradication of Helicobacter pylori infection, standard quadruple second-line therapy consisting of proton pump inhibitor (PPI), bismuth, metronidazole and tetracycline often fails and shows poor patient compliance. The aim of our study was to evaluate the efficacy and tolerability of moxifloxacin-based triple therapy as an alternative second-line protocol.

METHODS

A total of 160 patients, in whom the initial standard PPI triple therapy had failed to eradicate H. pylori infection, were included in the study. The initial H. pylori status was assessed using the (13)C-urea breath test. Patients were randomized to one of the following 7-day treatment regimens: (1) OMM: omeprazole 20 mg twice a day, moxifloxacin 400 mg/day, metronidazole 500 mg three times a day; and (2) OBMT: omeprazole 20 mg twice a day, colloidal bismuth subcitrate 120 mg four times a day, metronidazole 500 mg three times a day, tetracycline 500 mg four times a day. Patient compliance and adverse events were evaluated one week after completion of therapy. H. pylori status was re-assessed with the (13)C-urea breath test six weeks after the end of therapy.

RESULTS

The eradication rates were 73.2% (60/82) and 78.9% (60/76) with moxifloxacin-based triple therapy, and 53.8% (42/78) and 64.6% (42/65) with bismuth-based quadruple therapy, by intention-to-treat (p = 0.018) and per-protocol (p = 0.088) analyses, respectively. Adverse events/intolerability were described in 12/82 patients in the OMM group and 18/78 patients in the OBMT group. Compliance with treatment was 92.7% in the OMM group and 83.3% in the OBMT group.

CONCLUSION

Moxifloxacin-based triple therapy is a highly effective second-line eradication treatment in H. pylori infection. Because of its high levels of safety and tolerability, this protocol represents an adequate alternative to the standard bismuth-based quadruple therapy.

Moxifloxacin-based triple therapy versus clarithromycin-based triple therapy for first-line treatment of Helicobacter pylori infection: a meta-analysis of randomized controlled trials

BACKGROUND

Moxifloxacin-based triple therapy has been suggested as an alternative first line therapy to clarithromycin-based triple therapy for Helicobacter pylori infection.

AIMS

To systematically review the efficacy and tolerance of moxifloxacin-based triple therapy, and to conduct a meta-analysis of studies comparing this regimen with clarithromycin-based triple therapy.

METHODS

A search of The Cochrane Library, PUBMED, EMBASE, EBM Review databases, Science Citation Index Expanded, and CMB (Chinese Biomedical Literature Database) was performed. Randomized controlled trials comparing moxifloxacin-based triple therapy to gold standard triple therapy in the first-line treatment of Helicobacter pylori infection were selected for meta-analysis. Relative risk was used as a measure of the effect of the two above-mentioned regimens with a fixed-effects model using the methods of DerSimonian and Laird.

RESULTS

Four randomized controlled trials totaling 772 patients were included. The meta-analysis showed that the mean eradication rate was 84.1 (318/378) in the moxifloxacin-based triple therapy group and 73.6 (290/394) in the clarithromycin-based triple therapy group; there was statistical significance between the two groups (RR, 1.13; 95% CI, 1.01, 1.27; P=0.04). There were no statistically significant difference in the overall side effects (RR, 0.61; 95% CI, 0.25, 1.48; P<0.28).

CONCLUSIONS

Moxifloxacin-based triple therapy is more effective and does not increase the incidence of overall side effects compared to clarithromycin-based triple therapy in the treatment of H. pylori infection.

High eradication rate of H. pylori with moxifloxacin-based treatment: a randomized controlled trial

INTRODUCTION

Eradication of Helicobacter pylori remains a problematic treatment issue in clinical practice. The intention is to find a treatment that achieves a high rate of eradication at a low price and treatment options that are now used give us the opportunity to achieve this goal. Recently published results showing a low rate of resistance and better compliance with moxifloxacin-based treatment regimens indicate the need to investigate its efficacy in H. pylori eradication. This study is based on proving the efficacy of moxifloxacin in H. pylori eradication within the triple therapy.

AIMS AND METHODS

The aim of the study was to compare the efficacy of one week of moxifloxacin-based treatment with the standard treatment for H. pylori eradication. Patients with H. pylori infection and non-ulcer dyspepsia (n = 277) were randomly divided into four groups to receive: moxifloxacin 400 mg/d, metronidazole 400 mg twice daily, lansoprazole 30 mg twice daily (MML group); moxifloxacin 400 mg/d, amoxicillin 1 g twice daily, lansoprazole 30 mg twice daily (MAL group); clarithromycin 500 mg twice daily, metronidazole 400 mg twice daily, lansoprazole 30 mg twice daily (CML group); clarithromycin 500 mg twice daily, amoxicillin 1 g twice daily, lansoprazole 30 mg twice daily (CAL group). The patients were assessed for prevalence of H. pylori using the CLO test, histology and culture on gastric biopsy samples obtained during upper gastrointestinal endoscopy before randomization and 4-6 weeks after completion of treatment. Bacterial sensitivity to clarithromycin and moxifloxacin was determined with the E-test.

RESULTS

265 (95.6%) patients completed the study forming the basis for PP analysis. Eradication rates of H. pylori in ITT and in PP analyses were: in the MML group 93.5% (58/62) and 96.7% (58/60), respectively; in the MAL group 86.4% (57/66) and 90.5% (57/63); in the CML group 70.4% (50/71) and 75.8% (50/66); and in the CAL group 78.2% (61/78) and 80.2% (61/76). Moxifloxacin treatment protocols were significantly more effective on both ITT and PP analyses than the clarithromycin based protocols with only one exception (MAL vs. CAL on ITT analysis). Among 238 patients (86% of the entire study group), strains showing primary resistance to clarithromycin were found in 10.8% and to moxifloxacin in 5.9%. Eradication of moxifloxacin sensitive/resistant strains was 98.1%/75% for MML (p < 0.01) and 91.1%/66.7% for MAL (p = n.s.); comparison of eradication of sensitive strains in MML and MAL regimens was 98.1%/91.1% (p < 0.05), and for resistant strains 75%/66.7% (p = n.s.). CML and CAL protocols did not differ in efficacy of eradication of clarithromycin sensitive or resistant strains.

CONCLUSION

Moxifloxacin-based triple therapies showed higher eradication rates with few side effects and good drug compliance when compared with standard H. pylori treatments. Moreover, the increased prevalence of clarithromycin resistance suggests that moxifloxacin-based regimens could be safe and effective options in treatment of H. pylori infection.

Levofloxacin-based triple therapy in first-line treatment for Helicobacter pylori eradication

BACKGROUND

The standard first-line therapies for Helicobacter pylori eradication are based on clarithromycin and amoxicillin or metronidazole. Recent studies suggested levofloxacin as an alternative option for both first-and second-line H. pylori eradication treatment.

AIMS

To compare efficacy and tolerability of two different 7-day standard triple therapies versus 7-day levofloxacin-based triple therapy in first-line treatment for H. pylori infection.

METHODS

Three hundred consecutive H. pylori positive patients were randomized to receive: clarithromycin, amoxicillin, esomeprazole (Group A: N = 100); clarithromycin, metronidazole, esomeprazole (Group B: N = 100); or clarithromycin, levofloxacin, esomeprazole (Group C: N = 100). H. pylori status was rechecked by (13)C urea breath test 6 wk after the end of therapy.

RESULTS

Sixteen out of 300 patients discontinued treatment because of the occurrence of side effects (Group A, 5; Group B, 7; Group C, 4). The eradication rates in intention to treat (ITT) and per protocol (PP) analyses were: Group A, 75% and 79%; Group B, 72% and 77.4%; and Group C, 87% and 90.6%. The eradication rate achieved with levofloxacin-based triple therapy was significantly higher than that with standard therapies in either ITT (87%vs 75%, p <0.05; 87%vs 72%, p <0.01;) or PP analysis (90.6%vs 79%, p <0.05; 90.6 vs 77.4, p <0.05). No difference was found between standard triple therapies. The incidence of side effects was similar among groups.

CONCLUSIONS

A 7-day levofloxacin-based triple therapy can achieve higher H. pylori eradication rates than standard regimens. These data suggest levofloxacin-based regimens can be the most effective in first-line anti-H. pylori therapy, at least in the Italian population.

Novel therapeutic targets in Helicobacter pylori

The failure of current regimens to treat the gastric pathogen Helicobacter pylori is a growing problem. Responsible for gastritis and peptic ulcer disease, and designated as a Class 1 carcinogen, its presence in up to 90% of the population of the developing world makes its treatment a primary concern. The use of genomic, proteomic and transcriptomic data to determine essential gene products as targets for novel therapeutic agents is of key interest in this research. This review describes how such data can be obtained, evaluated and eventually used as a basis for the development of both vaccine and novel anti-helicobacter agents. It indicates both past successes and possible new avenues to exploit the increased availability of such data, whilst also examining the limitations of such approaches.

Moxifloxacin-based strategies for first-line treatment of Helicobacter pylori infection

BACKGROUND

Standard anti-Helicobacter pylori therapy may not achieve a satisfactory eradication rate. Fluoroquinolones, such as moxifloxacin, are safe and promising agents for H. pylori eradication.

AIM

To compare the efficacy of two 1-week moxifloxacin-based H. pylori eradication regimens with two standard treatments.

METHODS

Three hundred and twenty H. pylori-positive subjects were randomized into four groups to receive: moxifloxacin, amoxicillin, esomeprazole (Group MAE); moxifloxacin, tinidazole and esomeprazole (Group MTE); standard triple therapies with clarithromycin, amoxicillin and esomeprazole (Group CAE) or tinidazole (Group CTE) for 7 days. H. pylori status was re-assessed 6 weeks after the end of therapy by 13C urea breath test.

RESULTS

Three hundred and twenty patients completed the efficacy analysis per protocol; H. pylori eradication rate in group MTE was 90% (72 of 80) and 92% (72 of 78), in group MAE was 88% (70 of 80) and 89%, (70 of 79) in Group CAE was 73% (58 of 80) and 78% (58 of 74), and in Group CTE was 75% (60 of 80) and 79% (60 of 76), respectively, in intention-to-treat and in per protocol analyses. Eradication rates of moxifloxacin-based triple therapies were significantly higher than that observed using standard triple schemes. The incidence of side effects was significantly lower in moxifloxacin groups than in control groups.

CONCLUSIONS

Seven-day moxifloxacin-based triple therapies provide optimal eradication rates with a good compliance when compared with the standard triple therapy schemes.

Efficacy and tolerability of rifampicin-based rescue therapy for Helicobacter pylori eradication failure in peptic ulcer disease

In vitro activity of rifampicin has been shown against H. pylori. It has also been reported that the prevalence of H. pylori is low in patients with tuberculosis treated with rifampicin. Clinical trials are required to establish the efficacy of rifampicin as a salvage therapy for eradication of H. pylori. We aimed to evaluate the efficacy of rifampicin-based salvage therapy for eradication of H. pylori in patients with peptic ulcer disease. Twenty-eight patients with peptic ulcer disease who either had failed eradication of H. pylori or had a recurrence of H. pylori following successful eradication were included in the prospective study. The inclusion criteria included one or more failed attempts at eradication and presence of H. pylori infection as evidenced by positivity of at least two of three tests: rapid urease test (RUT), 14C urea breath test (UBT), and histology. The subjects were treated with a 10-day regimen consisting of rifampicin, 450 mg od, tetracycline, 1 g bd, and esomeprazole, 40 mg bd. Four weeks after completion of therapy, H. pylori status was assessed by RUT, 14C, UBT, and histology. Liver function tests were done before and at the end of therapy. The study subjects included 25 males and 3 females with a mean age of 33.7+/-8.92 years (range: 22-65 years). The median duration of symptoms was 42 months, with a range of 1-180 months. The median number of eradication attempts was two, with one prior attempt in 6 (21.4%), two attempts in 19 (67.9%), and three attempts in 3 (10.7%) patients. Successful H. pylori eradication as defined by concomitant negativity of RUT, UBT, and histology with special stains was achieved in 32.1% (9/28) of patients by intention-to-treat and 33.3% (9/27) of patients by per-protocol analysis. This pilot study suggests that rifampicin-based regimes have no role as salvage eradication therapy in refractory cases of H. pylori infection with peptic ulcer disease.

Use of imidazole-based eradication regimens for Helicobacter pylori should be abandoned in North India regardless of in vitro antibiotic sensitivity

BACKGROUND AND AIM

The purpose of this study was to compare the efficacy of tinidazole- versus clarithromycin-based triple regimens for eradication of Helicobacter pylori in North Indian patients of peptic ulcer disease, and to correlate the outcome with in vitro antibiotic susceptibility.

METHODS

One hundred and forty-six H. pylori-infected patients with active ulcer were included in the prospective, randomized study. A total of 70 patients received lansoprazole 30 mg b.d., amoxycillin 1000 mg b.d. and tinidazole 500 mg b.d. (LAT), and 76 patients received lansoprazole 30 mg b.d., amoxycillin 1000 mg b.d. and clarithromycin 500 mg b.d. (LAC) for 14 days. The H. pylori status was assessed by urea breath test, rapid urease test, and histology and antibiotic sensitivity pattern by Epsilometer test.

RESULTS

In per-protocol analysis of 112 patients the H. pylori eradication rate was 42.3% (95% confidence interval (CI): 0.29-0.56) in LAT, and 64.8% (95%CI: 0.52-0.78) in LAC (95%CI of difference of proportions: 0.13-0.33, P = 0.01). Ulcer healed in 69.2% in the LAT group (95%CI: 0.57-0.82) and 81.7% in the LAC group (95%CI: 0.72-0.92; P = 0.02). Antibiotic susceptibility testing was done in 31 patients. Metronidazole resistance was present in 41.9% isolates but was unrelated to the outcome of the LAT regimen.

CONCLUSION

Imidazole-based eradication regimens should be abandoned in North India regardless of in vitro susceptibility results.

Rank order of success favors longer duration of imidazole-based therapy for Helicobacter pylori in duodenal ulcer disease: a randomized pilot study

BACKGROUND

Studies on eradication therapy in developing countries have shown a success rate of 70-85%, which is suboptimal. Duration of therapy may be an important factor dictating eradication success in such regions.

AIMS

The study was undertaken to evaluate the effect of increasing the treatment period on eradication of Helicobacter pylori in duodenal ulcer disease.

METHODS

A randomized trial was carried out in which 64 consecutive H. pylori-infected patients with duodenal ulcer disease were enrolled. The patients were randomized to one of the three trial arms. Therapy consisted of lansoprazole 30 mg twice a day (b.i.d.), amoxycillin 1 g b.i.d. and tinidazole 500 mg b.i.d. The treatment period was 1 week in group I, 2 weeks in group II and 3 weeks in group III. At inclusion, patients underwent endoscopy and the presence of H. pylori was documented by a positive urease test and C14 urea breath test. Four weeks after completion of eradication therapy, the patients were subjected to repeat endoscopy to assess ulcer healing and tests for H. pylori infection.

RESULTS

Sixty-four patients (55 male and nine female; mean age 35.5 years) were enrolled in each group. The H. pylori eradication rate for group I (1 week of therapy) was 47.6%, that for group II (2 weeks of therapy) was 80%, and that for group III (3 weeks of therapy) was 91.3% (p =.003). The ulcer healing rates were 71.4, 80 and 95.6% in groups I, II and III, respectively (p =.09).

CONCLUSIONS

The 3-week regimen significantly improved the eradication rate as compared with the 1-week regime. Increasing the duration of therapy significantly improved the chances of eradication of H. pylori in duodenal ulcer disease.

Anti-Helicobacter pylori therapy in India: differences in eradication efficiency associated with particular alleles of vacuolating cytotoxin (vacA) gene

BACKGROUND AND AIMS

The efficiency of Helicobacter pylori eradication varies geographically, as do many parameters that might affect therapeutic efficiency, including bacterial genotype. The aim of the present study was to determine the efficiency of H. pylori eradication using a 10-day proton pump inhibitor-based triple-therapy regimen (omeprazole, clarithromycin and amoxycillin) in an eastern Indian patient population, and to find out the relationship, if any, of the success or failure of the therapy to known features of bacterial genotype.

METHODS

Helicobacter pylori infections were analyzed in 66 duodenal ulcer patients by upper gastrointestinal endoscopy, rapid urease tests, histology and culture. The cytotoxin-associated gene (cagA) and vacuolating cytotoxin (vacA) gene status of cultured strains were studied by polymerase chain reaction. Treatment was given for 10 days and endoscopy was repeated at 4 and 12 weeks post therapy to monitor ulcer healing and H. pylori eradication.

RESULTS

Ulcer healing was observed in 60 patients (96.77%). Helicobacter pylori was eradicated in 41 (62.12% intention to treat, 66.13% per protocol) of the 66 duodenal ulcer patients, but not in the other 25. The bacteria from 47 patients were genotyped. The only significant disease-associated difference in patterns observed was that the vacA m1 allele was represented more disproportionately among patients with eradication failures (68%) than in those with successful eradication (39%) (P < 0.05) No significant association of vacAs1 (signal sequence allele) or cag pathogenicity island status with persistence was detected.

CONCLUSIONS

This study highlights the public health need for cheaper, more cost-effective anti-H. pylori therapies for developing countries, and suggests that subtle features of bacterial genotype can influence therapeutic efficiency. The possibility that particular vacA mid region alleles affect persistence, perhaps through toxin action on particular gastric cell types, merits further study.

Review article: alternative antibacterial agents for Helicobacter pylori eradication

Standard eradication therapies against Helicobacter pylori appear to be effective in most cases, but in clinical practice a failure rate higher than the 5-10% reported in clinical trials is often observed. Among the various reasons responsible for therapeutic failure, antibiotic resistance is becoming a major issue in some countries. A range of different antibacterial agents is currently under investigation: several macrolides, new fluoroquinolones, furazolidone and rifabutin. Although not formally tested in refractory cases, azithromycin, spiromycin, levofloxacin and furazolidone represent the most promising antibacterial agents for possible inclusion in eradication regimens. Rifabutin has been evaluated in H. pylori infections resistant to standard therapies. Although very effective, the drug is expensive and its use should be restricted to the most difficult cases to avoid the development of rifabutin resistance in Mycobacterium spp.

[Treatment of Helicobacter pylori infections]

The treatment of Helicobacter pylori (H.p.) infection is based on the recommendations of the Maastricht consensus conference 1996. The main indications for eradication of H.p. are peptic ulcer disease, gastritis with severe histological abnormalities, low grade gastric MALT lymphoma and a history of resection for gastric cancer. The results of recent studies demonstrate that the symptoms of non-ulcer dyspepsia are not improved by H.p. eradication. A family history of gastric cancer and an earlier operation for peptic ulcer are considered advisable indications for the treatment of H.p. infection. Triple therapies consisting of a proton pump inhibitor (PPI) or ranitidine bismuth citrate plus 2 antibiotics are established as effective and well-tolerated first line regimens. The most important antibiotics are clarithromycin and amoxicillin. The efficacy of metronidazole is impaired by an increasing rate of resistant strains. Only few new antibiotics are currently tested in clinical trials. After the failure of a first anti-H.p. treatment it is advisable to change antibiotics according to the probability of resistance, to increase dosage and duration of treatment and to include bismuth compounds in the second line regimen. An alternative option after failed triple therapies may be a high dosage and prolonged dual regimen with a PPI and amoxicillin or quadruple therapy consisting of a PPI, bismuth subcitrate, tetracycline and metronidazole.

Efficacy of two one-week rabeprazole/levofloxacin-based triple therapies for Helicobacter pylori infection

BACKGROUND

One-week low-dose proton pump inhibitor-based triple therapies have usually proved to be effective treatments for Helicobacter pylori infection.

AIM

To investigate the eradication efficacy, safety profile and patient compliance of two triple therapies containing a standard dose of rabeprazole and a new fluoroquinolone, levofloxacin.

METHODS

One hundred patients referred to us for gastroscopy, who were H. pylori-positive, were consecutively recruited in a prospective, open-label study. The enrolled patients were randomised to receive a seven-day course of rabeprazole 20 mg o.d. plus levofloxacin 500 mg o.d. and either amoxycillin 1 g b.d. (RLA group) or tinidazole 500 mg b.d. (RLT group). Their H. pylori status was assessed by means of histology and rapid urease test at entry, and by 13C-urea breath test 8 weeks after the end of treatment.

RESULTS

All 100 enrolled patients completed the study. Forty-six of 50 patients treated with RLA (both PP and ITT analysis: 92%; 95% CI: 81-98%) and 45 of 50 with RLT (both PP and ITT analysis: 90%: 95% CI: 78-97%), became H. pylori-negative. Slight or mild side-effects occurred in 4 (8%) patients of the RLA group and in 5 (10%) of the RLT group.

CONCLUSIONS

This study demonstrates the efficacy of two 1-week rabeprazole-based triple therapies including levofloxacin to eradicate H. pylori. These regimens prove to be safe, well-tolerated, and achieved good eradication rates. Levofloxacin may be an effective alternative to clarithromycin in triple therapy regimens.

Pooled analysis of Helicobacter pylori eradication regimes in Asia

BACKGROUND AND AIMS

Differences in Helicobacter pylori strains and their resistance to antimicrobials between Asian and Western countries may affect the success in eradicating this bacterium. Our objective was to systematically review the regimens that have been tested in Asia.

METHODS

Data on anti-H. pylori therapies reported from Asia in a large number of publications identified up to December 1998 were pooled into a few groups based on the combination of drugs used. A comparison of different groups was made by calculating the pooled eradication rates.

RESULTS

Seventy-three studies with 134 treatment arms were reviewed. Pooled eradication rates of dual, triple and quadruple therapies were 61.0, 86.5 and 93.4%, respectively. Proton pump inhibitor (PPI)-based combinations were more widely used and effective, with overall eradication rates of 90.7% in triple therapy and 93.4% in quadruple therapy. Bismuth combined with tetracycline and metronidazole also showed a high eradication rate of 92.0%.

CONCLUSIONS

Proton pump inhibitor-based triple therapy with either clarithromycin, amoxycillin or metronidazole was one of the most commonly used and effective anti-H. pylori triple therapy regimens in Asia. The classical triple therapy with a bismuth, tetracycline and metronidazole combination has a similar efficacy. The results of anti-H. pylori treatment in Asia are not different from those in Western countries.

Challenges to therapy in the future

Quadruple therapy (with a proton pump inhibitor (PPI), metronidazole, tetracycline and bismuth) is generally reserved for second-line treatment; however, studies using this regimen for 7 days have found it to be effective even in metronidazole-resistant strains. Resistance is an ongoing problem with antimicrobial therapy but considerable progress has now been made into understanding the underlying genetic mechanisms of this process. Metronidazole resistance in Europe is usually in the range of 20-30% of strains but may be as high as 70% in some countries. One genetic mechanism involved is thought to be a mutation of the rdxA gene. Macrolide resistance appears to be on the increase in Europe, varying from 1% in some countries to 13% in others. The genetic mechanism involved has been shown to be a point mutation of a ribosomal RNA. Amoxicillin resistance is an emerging problem that has an adverse effect on eradication rates in clinical practice. Resistance has been shown to be caused by the absence of one of the four binding proteins in the cell wall. Few novel antibiotics have been developed for use in eradication therapy, although rifabutin, secnidazole and furazolidone have shown some success as part of combination therapy. Alternative therapies that have been tested include mucosal protective agents which have been used in place of a PPI in some eradication regimens with some success, and the somatostatin analog, octreotide, that has been used as part of quadruple therapy in place of a PPI and produced eradication rates of approximately 88%. The ultimate challenge is still to develop a safe and effective vaccine against Helicobacter pylori. Current and future research will also focus on identifying genetic targets for therapy, adhesion molecule analogs to prevent binding of the bacterium, and urease inhibitors. The current triple therapy treatment options available for the eradication of Helicobacter pylori infection are over 90% effective in susceptible organisms and there are very few medical conditions to which we can offer such efficacious treatment. Unfortunately, the recommendations made at consensus conferences are not always put into practice and physicians in primary care may be unaware of the true efficacy of eradication therapy. Treatment is very simple: three drugs, twice a day for 1 week. The main focus for both primary care physicians and gastroenterologists should be to reinforce the need for patient compliance, otherwise we will see an increase in antibiotic resistance. Patients should be prewarned that they may experience some mild side effects and should be encouraged to complete the course of treatment. The real challenge for the future will be the management of patients who do not respond to first-line treatment. This paper will focus on potential problems with therapy, such as antibiotic resistance, and possible future solutions, such as novel antibiotics and vaccines.

A practical approach to patients with refractory Helicobacter pylori infection, or who are re-infected after standard therapy

The vast majority of recurrences of Helicobacter pylori infection after apparent eradication are observed during the first year. Almost all of these early recurrences are due to recrudescence rather than reinfection by a new strain. After the first year, the recurrence rates approximate to the rate of natural acquisition of H. pylori infection. By contrast, in developing countries, higher rates of recurrence suggest a major role of real reinfection. Important predictive factors of H. pylori treatment success are compliance and bacterial susceptibility to antibiotics. The new 1-week triple therapies, based on a proton pump inhibitor (PPI) and 2 antibiotics, lead to treatment discontinuation but rarely. If containing a nitroimidazole, their efficacy is reduced to 60 to 80% by pretreatment in vitro resistance. The prevalence of nitroimidazole resistance varies dependent on the geographical area, with rates over 50% in tropical regions. Resistance against macrolides hinders treatment success in 50 to 80% of patients. In the US, south-western Europe and Japan the prevalence of macrolide resistance amounts to about 10%, in other countries about 3%. After failed treatment, acquired resistance is frequent. Testing for resistance is recommended to facilitate the decision for an alternative triple therapy or for quadruple therapy comprising bismuth, metronidazole, tetracycline and a PPI. It seems reasonable to increase the dose of PPI in a retreatment regimen containing amoxicillin. Post-treatment double resistance against nitroimidazoles and macrolides reduces the success of most of the currently evaluated retreatment regimens. To overcome double resistance, high dose PPI plus amoxicillin is one approach, beside other experimental multidrug treatments.