First-line eradication of H pylori infection in Europe: A meta-analysis based on congress abstracts, 1997-2004

Current status of Helicobacter pylori resistance to Clarithromycin and Levofloxacin in Malaysia-findings from a molecular based study

Background

Resistance to clarithromycin and levofloxacin in Helicobacter pylori which resulted in treatment failures has become a major challenge for physicians worldwide. The resistance is mainly mediated by mutations in a specific domain of the 23S rRNA, gyrA and gyrB genes for clarithromycin and levofloxacin respectively. Hence in this study, we aimed to investigate the current status of H. pylori resistance in our hospital to these two antibiotics based on the molecular approach.

Materials and Methods

Gastric biopsy samples were obtained from treatment-naïve patients. Bacterial genomic DNA was extracted using a commercial kit and continued with DNA amplification using polymerase chain reaction (PCR) with specific primers. The PCR amplicons were subjected to sequencing on 23S rRNA gene targeting nucleotide positions at 2,146, 2,147, 2,186 and amino acids at gyrA positions 87 and 91 and gyrB positions 436, 438, 481, 484 to investigate the possible mutations or polymorphisms of genes that lead to clarithromycin and levofloxacin resistance respectively.

Results

Sixty-one urease-positive gastric biopsy samples were studied. The findings revealed the primary resistance rates to clarithromycin was 14.8% and to levofloxacin was 3.3% in our current scenario based on detection of reported resistance-related mutations of A2147G and D91N in 23S rRNA and gyrA genes, respectively. Interestingly, we found a high rate of silent mutations of the gyrA codon 87Asn (32.8%, 20/61) and two polymorphisms of the gyrB D481E (16.4%, 10/61) and R484K (21.3%, 13/61). The role of these polymorphisms in gyrB remained to be elucidated whether the levels of levofloxacin resistance are related to the position/amino acid.

Conclusion

The primary resistance rate of H. pylori to clarithromycin has increased compared to the previous report in Malaysia. Therefore, molecular screening could aid and is important for the selection of antibiotics for H. pylori eradication therapies.

Helicobacter pylori therapy: a paradigm shift

Helicobacter pylori (H. Pylori) is a leading cause of gastroduodenal disease, including gastric cancer. H. pylori eradication therapies and their efficacy are summarized. A number of current treatment regimens will reliably yield >90% or 95% cure rates with susceptible strains. None has proven to be superior. We show how to predict the efficacy of a regimen in any population provided one knows the prevalence of antibiotic resistance. As with other infectious diseases, therapy should always be susceptibility-based. Susceptibility testing should be demanded. We provide recommendations for empiric therapies when that is the only option and describe how to distinguish studies providing misinformation from those providing reliable and interpretable data. When treated as an infectious disease, high H. pylori cure rates are relatively simple to reliably achieve.

Update on the Diagnosis and Management of Helicobacter pylori Infection in Adults

Treatment of Helicobacter pylori infection is becoming increasingly challenging due largely to the rising rates of antimicrobial resistance and to the relative complexity of treatment regimens. If a reliable test to assess the antimicrobial sensitivity/resistance of H. pylori was readily available, treatment would be more focused and-presumably-more effective. However, antimicrobial sensitivity testing is difficult to obtain in most parts of the United States. Therefore, physicians have to rely on clinical judgment in selecting treatment regimens for their infected patients. The aims of this review are to summarize recent treatment recommendations and to examine available evidence for how we might improve on our current treatment selections. Information on this review is directed primarily toward physicians practicing in the United States.

Optimum duration of regimens for Helicobacter pylori eradication

BACKGROUND

The optimal duration for Helicobacter pylori (H. pylori) eradication therapy is controversial, with recommendations ranging from 7 to 14 days. Several systematic reviews have attempted to address this issue but have given conflicting results and limited their analysis to proton pump inhibitor (PPI), two antibiotics (PPI triple) therapy. We performed a systematic review and meta-analysis to investigate the optimal duration of multiple H. pylori eradication regimens.

OBJECTIVES

The primary objective was to assess the relative effectiveness of different durations (7, 10 or 14 days) of a variety of regimens for eradicating H. pylori. The primary outcome was H. pylori persistence. The secondary outcome was adverse events.

SEARCH METHODS

The Cochrane Library, MEDLINE, EMBASE, and CINAHL were searched up to December 2011 to identify eligible randomised controlled trials (RCTs). We also searched the proceedings of six conferences from 1995 to 2011, dissertations and theses, and grey literature. There were no language restrictions applied to any search.

SELECTION CRITERIA

Only parallel group RCTs assessing the efficacy of one to two weeks duration of first line H. pylori eradication regimens in adults were eligible. Within each regimen, the same combinations of drugs at the same dose were compared over different durations. Studies with at least two arms comparing 7, 10, or 14 days were eligible. Enrolled participants needed to be diagnosed with at least one positive test for H. pylori on the basis of a rapid urease test (RUT), histology, culture, urea breath test (UBT), or a stool antigen test (HpSA) before treatment. Eligible trials needed to confirm eradication of H. pylori as their primary outcome at least 28 days after completion of eradication treatment. Trials using only serology or a polymerase chain reaction (PCR) to determine H. pylori infection or eradication were excluded.

DATA COLLECTION AND ANALYSIS

Study eligibility and data extraction were performed by two independent review authors. Data analyses were performed within each type of intervention, for both primary and secondary outcomes. The relative risk (RR) and number needed to treat (NNT)/number needed to harm (NNTH) according to duration of therapy were calculated using the outcomes of H. pylori persistence and adverse events. A random-effects model was used. Subgroup analyses and sensitivity analyses were planned a priori.

MAIN RESULTS

In total, 75 studies met the inclusion criteria. Eight types of regimens were reported with at least two comparative eligible durations. They included: PPI + two antibiotics triple therapy (n = 59), PPI bismuth-based quadruple therapy (n = 6), PPI + three antibiotics quadruple therapy (n = 1), PPI dual therapy (n = 2), histamine H2-receptor antagonist (H₂RA) bismuth quadruple therapy (n = 3), H₂RA bismuth-based triple therapy (n = 2), H₂RA + two antibiotics triple therapy (n = 3), and bismuth + two antibiotics triple therapy (n = 2). Some studies provided data for more than one regimen or more than two durations.For the PPI triple therapy, 59 studies with five regimens were reported: PPI + clarithromycin + amoxicillin (PCA); PPI + clarithromycin + a nitroimidazole (PCN); PPI + amoxicillin + nitroimidazole (PAN); PPI + amoxicillin + a quinolone (PAQ); and PPI + amoxicillin + a nitrofuran (PANi). Regardless of type and dose of antibiotics, increased duration of PPI triple therapy from 7 to 14 days significantly increased the H. pylori eradication rate (45 studies, 72.9% versus 81.9%), the RR for H. pylori persistence was 0.66 (95% CI 0.60 to 0.74), NNT was 11 (95% CI 9 to 14). Significant effects were seen in the subgroup of PCA (34 studies, RR 0.65, 95% CI 0.57 to 0.75; NNT 12, 95% CI 9 to 16); PAN (10 studies, RR 0.67, 95% CI 0.52 to 0.86; NNT = 11, 95% CI 8 to 25); and in PAQ (2 studies, RR 0.37, 95% CI 0.16 to 0.83; NNT 3, 95% CI 2 to 10); but not in PCN triple therapy (4 studies, RR 0.87, 95% CI 0.71 to 1.07). Significantly increased eradication rates were also seen for PPI triple therapy with 10 versus 7 days (24 studies, 79.9% versus 75.7%; RR 0.80, 95% CI 0.72 to 0.89; NNT 21, 95% CI 15 to 38) and 14 versus 10 days (12 studies, 84.4% versus 78.5%; RR 0.72, 95% CI 0.58 to 0.90; NNT 17, 95% CI 11 to 46); especially in the subgroup of PAC for 10 versus 7 days (17 studies, RR 0.80, 95% CI 0.70 to 0.91) and for 14 versus 10 days (10 studies, RR 0.69, 95% CI 0.52 to 0.91). A trend towards increased H. pylori eradication rates was seen with increased duration of PCN for 10 versus 7 days, and of PAN for 10 versus 7 days and 14 versus 10 days, though this was not statistical significant. The proportion of patients with adverse events, defined by authors, was marginally significantly increased only between 7 days and 14 days (15.5% versus 19.4%; RR 1.21, 95% CI 1.06 to 1.37; NNTH 31, 95% CI 18 to 104) but not for other duration comparisons. The proportion of patients discontinuing treatment due to adverse events was not significantly different between treatment durations.Only limited data were reported for different durations of regimens other than PPI triple therapy. No significant difference of the eradication rate was seen for all regimens according to different durations except for H₂RA bismuth quadruple therapy, where a significantly higher eradication rate was seen for 14 days versus 7 days, however only one study reported outcome data.

AUTHORS' CONCLUSIONS

Increasing the duration of PPI-based triple therapy increases H. pylori eradication rates. For PCA, prolonging treatment duration from 7 to 10 or from 10 to 14 days is associated with a significantly higher eradication rate. The optimal duration of therapy for PCA and PAN is at least 14 days. More data are needed to confirm if there is any benefit of increasing the duration of therapy for PCN therapy. Information is limited for regimens other than PPI triple therapy; more studies are needed to draw meaningful conclusions for optimal duration of other H. pylori eradication regimens.

Optimum duration of regimens for Helicobacter pylori eradication

BACKGROUND

The optimal duration for Helicobacter pylori (H. pylori) eradication therapy is controversial, with recommendations ranging from 7 to 14 days. Several systematic reviews have attempted to address this issue but have given conflicting results and limited their analysis to proton pump inhibitor (PPI), two antibiotics (PPI triple) therapy. We performed a systematic review and meta-analysis to investigate the optimal duration of multiple H. pylori eradication regimens.

OBJECTIVES

The primary objective was to assess the relative effectiveness of different durations (7, 10 or 14 days) of a variety of regimens for eradicating H. pylori. The primary outcome was H. pylori persistence. The secondary outcome was adverse events.

SEARCH METHODS

The Cochrane Library, MEDLINE, EMBASE, and CINAHL were searched up to December 2011 to identify eligible randomised controlled trials (RCTs). We also searched the proceedings of six conferences from 1995 to 2011, dissertations and theses, and grey literature. There were no language restrictions applied to any search.

SELECTION CRITERIA

Only parallel group RCTs assessing the efficacy of one to two weeks duration of first line H. pylori eradication regimens in adults were eligible. Within each regimen, the same combinations of drugs at the same dose were compared over different durations. Studies with at least two arms comparing 7, 10, or 14 days were eligible. Enrolled participants needed to be diagnosed with at least one positive test for H. pylori on the basis of a rapid urease test (RUT), histology, culture, urea breath test (UBT), or a stool antigen test (HpSA) before treatment. Eligible trials needed to confirm eradication of H. pylori as their primary outcome at least 28 days after completion of eradication treatment. Trials using only serology or a polymerase chain reaction (PCR) to determine H. pylori infection or eradication were excluded.

DATA COLLECTION AND ANALYSIS

Study eligibility and data extraction were performed by two independent review authors. Data analyses were performed within each type of intervention, for both primary and secondary outcomes. The relative risk (RR) and number needed to treat (NNT)/number needed to harm (NNTH) according to duration of therapy were calculated using the outcomes of H. pylori persistence and adverse events. A random-effects model was used. Subgroup analyses and sensitivity analyses were planned a priori.

MAIN RESULTS

In total, 75 studies met the inclusion criteria. Eight types of regimens were reported with at least two comparative eligible durations. They included: PPI + two antibiotics triple therapy (n = 59), PPI bismuth-based quadruple therapy (n = 6), PPI + three antibiotics quadruple therapy (n = 1), PPI dual therapy (n = 2), histamine H2-receptor antagonist (H₂RA) bismuth quadruple therapy (n = 3), H₂RA bismuth-based triple therapy (n = 2), H₂RA + two antibiotics triple therapy (n = 3), and bismuth + two antibiotics triple therapy (n = 2). Some studies provided data for more than one regimen or more than two durations.For the PPI triple therapy, 59 studies with five regimens were reported: PPI + clarithromycin + amoxicillin (PCA); PPI + clarithromycin + a nitroimidazole (PCN); PPI + amoxicillin + nitroimidazole (PAN); PPI + amoxicillin + a quinolone (PAQ); and PPI + amoxicillin + a nitrofuran (PANi). Regardless of type and dose of antibiotics, increased duration of PPI triple therapy from 7 to 14 days significantly increased the H. pylori eradication rate (45 studies, 72.9% versus 81.9%), the RR for H. pylori persistence was 0.66 (95% CI 0.60 to 0.74), NNT was 11 (95% CI 9 to 14). Significant effects were seen in the subgroup of PCA (34 studies, RR 0.65, 95% CI 0.57 to 0.75; NNT 12, 95% CI 9 to 16); PAN (10 studies, RR 0.67, 95% CI 0.52 to 0.86; NNT = 11, 95% CI 8 to 25); and in PAQ (2 studies, RR 0.37, 95% CI 0.16 to 0.83; NNT 3, 95% CI 2 to 10); but not in PCN triple therapy (4 studies, RR 0.87, 95% CI 0.71 to 1.07). Significantly increased eradication rates were also seen for PPI triple therapy with 10 versus 7 days (24 studies, 79.9% versus 75.7%; RR 0.80, 95% CI 0.72 to 0.89; NNT 21, 95% CI 15 to 38) and 14 versus 10 days (12 studies, 84.4% versus 78.5%; RR 0.72, 95% CI 0.58 to 0.90; NNT 17, 95% CI 11 to 46); especially in the subgroup of PAC for 10 versus 7 days (17 studies, RR 0.80, 95% CI 0.70 to 0.91) and for 14 versus 10 days (10 studies, RR 0.69, 95% CI 0.52 to 0.91). A trend towards increased H. pylori eradication rates was seen with increased duration of PCN for 10 versus 7 days, and of PAN for 10 versus 7 days and 14 versus 10 days, though this was not statistical significant. The proportion of patients with adverse events, defined by authors, was marginally significantly increased only between 7 days and 14 days (15.5% versus 19.4%; RR 1.21, 95% CI 1.06 to 1.37; NNTH 31, 95% CI 18 to 104) but not for other duration comparisons. The proportion of patients discontinuing treatment due to adverse events was not significantly different between treatment durations.Only limited data were reported for different durations of regimens other than PPI triple therapy. No significant difference of the eradication rate was seen for all regimens according to different durations except for H₂RA bismuth quadruple therapy, where a significantly higher eradication rate was seen for 14 days versus 7 days, however only one study reported outcome data.

AUTHORS' CONCLUSIONS

Increasing the duration of PPI-based triple therapy increases H. pylori eradication rates. For PCA, prolonging treatment duration from 7 to 10 or from 10 to 14 days is associated with a significantly higher eradication rate. The optimal duration of therapy for PCA and PAN is at least 14 days. More data are needed to confirm if there is any benefit of increasing the duration of therapy for PCN therapy. Information is limited for regimens other than PPI triple therapy; more studies are needed to draw meaningful conclusions for optimal duration of other H. pylori eradication regimens.

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

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

[Helicobacter pylori -- 2010]

Helicobacter pylori, discovered 27 years ago, has remained the most prevalent infectious agent in the world. In the author's hypothesis, the increase of peptic ulcer prevalence in the 19-20th century could be attributable to the extended worldwide use of gastric tubes for secretory testing which led to the iatrogenic transmission of pathogenic strains. Helicobacter pylori outer membrane proteins (OMP), and duodenal ulcer promoting (dupA) proteins were identified as novel virulence factors, leading to the production of pro-inflammatory cytokines, which could be future targets of therapy. There is no ideal first-line eradication of the infection and according to expert's opinion, the efficiency of these regimens has fallen gradually in recent years to unacceptably low levels; however, in the author's opinion this is a multifactorial phenomenon which can not be generalized. As alternative drugs, the efficiency of levofloxacin, furazolidone and rifabutin has been proven by meta-analyses. Sequential and bismuth-free quadruple therapies, although highly efficient, are not yet used on a large scale. The recurrence of the infection is 2.27%/year in developed and of 13.0%/year in developing countries. Spontaneous eradication occurred in 8-20% of the children and 5-11% of adults. The prevalence of clarithromycin resistance is increasing worldwide. In Hungary, it has reached 10.9% in county cities, according to a national survey. In a district of Budapest called Ferencváros, the prevalence between 2005 and 2009 was 16-22%, with no increasing trend. The development of enzymatic inhibitors (urease, carbonic anhydrase and gamma-glutamyl transpeptidase), modified antibiotics and efflux pump inhibitors seem promising ways because these compounds do not lead to resistance; however, none have yet been used in humans.

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

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

Drug utilization of clarithromycin for gastrointestinal disease treatment

AIM: To evaluate the patterns of use of clarithromycin for gastrointestinal disease treatment and promote its rational use.

METHODS: Using a structured pro forma, we conducted a two-month survey of the electronic prescriptions containing immediate-release (IR) or sustained-release (SR) product of clarithromycin for outpatients with gastrointestinal diseases in a 2200-bed general hospital. Suitability of the prescription was audited retrospectively.

RESULTS: One hundred and sixty-four prescriptions of SR product and 110 prescriptions of IR product were prescribed for gastrointestinal disease treatment. Among prescriptions for anti-Helicobacter pylori (H pylori) therapy, triple therapy take the dominant position (91.8%), followed by quadruple therapy (4.3%) and dual therapy (3.9%). Amoxicillin was the most frequently co-prescribed antibiotic. Furazolidone and levofloxacin are used more widely than metronidazole or tinidazole. Clarithromycin SR was administered at inappropriate time points in all prescriptions. Fifty percent of all prescriptions of clarithromycin SR, and 6.4% of prescriptions of clarithromycin IR, were prescribed at inappropriate dosing intervals. Surprisingly, disconcordance between diagnoses and indications was observed in all prescriptions of clarithromycin SR which has not been approved for treating H pylori infection although off-label use for this purpose was reported in literature. On the contrary, only one prescription (0.9%) of clarithromycin IR was prescribed for unapproved indication (i.e. gastro-oesophageal reflux disease). 1.4% of prescriptions for chronic gastritis or peptic ulcer treatment were irrational in that clarithromycin was not co-prescribed with gastric acid inhibitors. Clinical significant CYP3A based drug interactions with clarithromycin were identified.

CONCLUSION: There is a great scope to improve the quality of clarithromycin prescribing in patients with gastrointestinal disease, especially with regard to administration schedule, concordance between indications and diagnoses and management of drug interactions.

Clinical application progress of Rifaximin in the treatment of digestive diseases

Rifaximin, a derivative of rifamycin, has high antibacterial activity on various kinds of Gram-positive and -negative aerobes and anaerobes, and it is a new drug in the treatment of giardiasis. Rifaximin is not easy to be absorbed after oral administration, and mild systemic adverse reaction is the main characteristic. Recently, Rifaximin has been widely and effectively used in the therapy of many diseases related to intestinal bacterial infection such as hepatic encephalopathy, diverticular disease, overgrowth of intestinal bacteria, inflammatory bowel disease (IBD) and H. pylori infection. The above advances were reviewed in the present article.