Efficacy of one-day quadruple therapy for H pylori infection in Chinese patients

Bismuth-containing quadruple therapy for Helicobacter pylori: lessons from China

Antimicrobial resistance has continued to undermine many popular anti-Helicobacter pylori therapies. Antibiotic resistance to commonly used anti-H. pylori drugs in China has increased markedly, making China an ideal site to identify regimens that remain effective despite widespread antimicrobial resistance. Bismuth is one of the few antimicrobials to which resistance does not develop. Factors contributing to H. pylori treatment success include host factors (e.g., genetic differences in the metabolism of the drugs used), bacterial factors (e.g., susceptibility), and details of the regimen (e.g., doses, dosing interval, dosing in relation to meals, formulation, etc.). We reviewed the recent experience in China with bismuth-containing quadruple therapies. The experience consists of 16 studies with 25 arms involving 1971 patients to identify successful regimens (defined as reliably obtaining 90% or greater eradication per protocol) deserving further study. Despite high rates of resistance to commonly used antimicrobials, several regimens could achieve high success. These were characteristically 14-day regimens containing a proton pump inhibitor and either tetracycline and metronidazole or furazolidone and amoxicillin. We propose approaches for further development including for optimization and simplification related to convenience and side effects (e.g., twice rather than three or four times daily or administration at the noon and evening meal instead of at breakfast and evening) while maintaining effectiveness of at least 90%. Studies in China identified regimens that were highly effective despite the high prevalence of resistance to metronidazole, fluoroquinolones, and macrolides. Multicenter randomized studies will be required to confirm which is the best.

Furazolidone-based therapies for Helicobacter pylori infection: a pooled-data analysis

BACKGROUND/AIM

Furazolidone-based therapies are used in developing countries to cure Helicobacter pylori infection due to its low cost. The low bacterial resistance toward furazolidone may render appealing the use of this drug even in developed countries. However, some relevant safety concerns do exist in using furazolidone.

PATIENTS AND METHODS

This was a systematic review with pooled-data analysis of data regarding both eradication rate and safety of furazolidone-based therapies for H. pylori infection. Intention-to-treat (ITT) and per-protocol (PP) eradication rates were calculated.

RESULTS

Following furazolidone-based first-line therapy, H. pylori eradication rates were 75.7% and 79.6% at ITT and PP analysis, respectively (P<0.001). The overall incidence of side effects and severe side effects were 33.2% and 3.8%, respectively. At multivariate analysis, only high-dose furazolidone was associated with increased therapeutic success (OR: 1.5, 95% CI: 1.3-2.7; P<0.001), while occurrence of side effects was relevant following treatment for a long duration (OR: 2.9, 95% CI: 2.2-4.1; P<0.001), high-dose furazolidone (OR: 2.3, 95% CI: 1.7-3.2; P<0.001) and bismuth-containing regimens (OR: 2.1, 95% CI: 1.5-2.8; P<0.001).

CONCLUSIONS

Furazolidone-based regimens usually achieve low eradication rates. Only a high-dose regimen improves the cure rate, but simultaneously increases the incidence of severe side effects. Therefore, we suggest that patients have to be clearly informed about the possible genotoxic and carcinogenetic effects for which furazolidone use is not approved in developed countries.

Is short-term therapy really sufficient to eradicate Helicobacter pylori infection?

OBJECTIVE

The aim of our study was to perform a systematic review and meta-analysis of the efficacy of short-term protocols for Helicobacter pylori eradication and to review the safety and adverse profiles of these eradication protocols.

METHODS

Literatures were located through electronic searches by PubMed, Medline, ISI Web of Knowledge, and Cochrane Library using the relevant terms. Abstracts of important meetings were searched manually in some journal supplements. Additional bibliographies were identified from the reference lists of identified studies. Three independent reviewers systemically identified randomized controlled trials (RCTs) comparing short-duration protocols vs. 7-d proton pump inhibitor (PPI)-based triple protocols, as well as studies reporting eradication rates of short-duration protocols for H. pylori. Summary effect size was calculated as relative risk (RR) and 95% confidence intervals (CI) using Review Manager 4.2, and P<0.05 was defined as statistically significant in all analyses.

RESULTS

Among 90 abstracts retrieved, 15 studies were analyzed, including a total of 30 treatment regimens with 1856 subjects. Mean intention-to-treat (ITT) cure rates of 63.2% and 81.3% were achieved with short-term protocols and 7-d PPI-containing protocols, respectively. Per-protocol (PP)-based overall cure rates were 66.6% and 86.1%, respectively. Short-term therapy was inferior to 7-d triple regimen (P<0.00001). After sub-analysis, however, comparing the effects of > or = 3-d protocols and 7-d triple protocols, the cumulative ITT RR was 0.95 (P=0.26), and PP RR was 0.95 (P=0.10), without significant heterogeneity. Moreover, slightly fewer adverse-effects were found in short-term protocols.

CONCLUSIONS

Although more economical, short-duration protocols are inferior to 7-d PPI-based triple protocols with regarding to eradication rate of H. pylori. Protocols of more than 3 d, however, may be equivalent to 7-d protocols.

Catalytic features and eradication ability of antibody light-chain UA15-L against Helicobacter pylori

We have successfully developed a catalytic antibody capable of degrading the active site of the urease of Helicobacter pylori and eradicating the bacterial infection in a mouse stomach. This monoclonal antibody UA15 was generated using a designed recombinant protein UreB, which contained the crucial region of the H. pylori urease beta-subunit active site, for immunization. The light chain of this antibody (UA15-L) by itself showed a proteolytic activity to substantially degrade both UreB and the intact urease. Oral administration of UA15-L also significantly reduced the number of H. pylori in a mouse stomach. This is the first example of a monoclonal catalytic antibody capable of functioning in vivo, and such an antibody may have a therapeutic utility in the future.

Nitrofuran-based regimens for the eradication of Helicobacter pylori infection

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