Low Clarithromycin Resistance Research Articles

Current trends in <i>Helicobacter pylori</i> eradication therapy

According to the Maastricht VI consensus, the triple therapy (PPI + clarithromycin + amoxicillin) and bismuth-based quadruple therapy (PPI + bismuth + tetracycline + metronidazole) are considered and may be proscribed empirically as first-line regimens in the regions with low clarithromycin resistance rates (<15%). In the regions with high clarithromycin resistance rates (> 15%), as well as in the regions with unknown resistance to this antibacterial agent, it is recommended to use classical quadruple therapy with bismuth drugs as the main choice and quadruple therapy without bismuth drugs (“simultaneous” or “concomitant”) as an alternative. The second-line regimens of empiric choice (when antimicrobial susceptibility testing is not available) include fluoroquinolone-based quadruple therapy (PPI + levofloxacin + amoxicillin + bismuth) or fluoroquinolone-based triple therapy (PPI + levofloxacin + amoxicillin) and bismuth-based quadruple therapy. The Maastricht VI consensus regulates the use of rifabutin-based triple therapy (PPI + amoxicillin + rifabutin) as a “rescue” therapy, if the above ET schemes are ineffective and there is no possibility to conduct an antimicrobial susceptibility test. In its latest clinical guidelines, the Russian Gastroenterological Association (RGA) recommends with a view to achieving maximum treatment efficiency during classic triple ET and levelling the risk of further progression of clarithromycin resistance in Russia to take additional measures to increase its effectiveness (detailed instruction of a patient and control over strict adherence to the prescribed regimen, prolonging the course up to 14 days; prescribing PPI at increased dose twice a day; the latest generation PPIs (rabeprazole and esomeprazole); adding bismuth tripotassium dicitrate (240 mg 2 times a day) to the standard triple therapy; adding cytoprotector rebamipide (100 mg 3 times a day) to the standard triple therapy; adding a probiotic with proven efficacy to the standard triple therapy within controlled studies).

Antibiotic Susceptibility and Clarithromycin Resistance Determinants in Helicobacter pylori in the Northeast of Spain: A One-Year Prospective Study.

Helicobacter pylori is one of the most widespread infections, and it is reaching alarming resistance levels worldwide. The recommended first-line empirical treatment differs according to the local rate of clarithromycin resistance. Macrolide resistance is mainly associated with three point mutations in the 23S rRNA gene. The aim of this study was to describe the antibiotic susceptibility of H. pylori in our healthcare area and the main mechanisms involved in clarithromycin resistance. Gastric biopsies (n = 641) were collected and cultured in a one-year prospective study. Antibiotic susceptibility testing was performed by gradient diffusion. A multiplex real-time PCR test (AllplexTMH.pylori & ClariR Assay, Seegene) was used to detect the most frequent mutations associated with clarithromycin resistance. Overall, 141 isolates were available for antibiotic susceptibility testing. The highest resistance rates were detected in metronidazole and levofloxacin. The rate of clarithromycin resistance was 12.1%, and the associated mutations were A2143G and A2142G. More than half of the clarithromycin-resistant isolates presented high MIC values (>256 mg/L). Tetracycline resistance was not detected, suggesting that therapies that contain tetracycline could be a suitable option. The low clarithromycin resistance rate coupled with the high rates of metronidazole resistance may support the recovery of the classical triple therapy in our healthcare area.

Management of Helicobacter pylori infection.

Helicobacter pylori infection exhibits a wide disease spectrum ranging from asymptomatic gastritis, peptic ulcer disease, to gastric cancer. H. pylori can induce dysbiosis of gastric microbiota in the pathway of carcinogenesis and successful eradication can restore gastric homeostasis. Diagnostic testing and treatment for H. pylori infection is recommended in patients with active or past history of peptic ulcer, chronic dyspepsia, chronic non-steroidal anti-inflammatory drugs (NSAID) or aspirin use, precancerous gastric lesions, gastric cancer, mucosa-associated lymphoid tissue (MALT) lymphoma, family history of gastric cancer, family history of peptic ulcers, household family member having active H. pylori infection, iron deficiency anemia, idiopathic thrombocytopenic purpura, or vitamin B12 deficiency. Recommended first-line regimens for H. pylori eradication are classified according to clarithromycin resistance. In areas of high clarithromycin resistance (≥15%), we recommend 14-day concomitant therapy or 14-day bismuth quadruple therapy (BQT) as first-line regimen. In areas of low clarithromycin resistance (<15%), we recommend 14-day triple therapy or 14-day BQT as first-line treatment. Second-line regimens are 14-day levofloxacin triple therapy or 14-day BQT if BQT is not previously used. For patients with multiple treatment failure, antimicrobial susceptibility testing (AST) should be performed. If AST is not available, we recommend using antibiotics not previously used or for which resistance is unlikely, such as amoxicillin, tetracycline, bismuth, or furazolidone. High-dose potent proton pump inhibitor or vonoprazan is recommended to achieve adequate acid suppression. Probiotics can be used as an adjuvant treatment to reduce the side effects of antibiotics and enhance eradication rate.

Low clarithromycin resistance in virulent Helicobacter pylori from dyspeptic patients at a tertiary care centre in Odisha

PurposeUniversal eradication or use of failing antibiotic can add fuel to the antimicrobial resistance pandemic. Outcome of Helicobacter pylori (HP) infection depends at least partly virulence factors and its eradication as preventive measure against gastric cancer is advocated by some guidelines. There is need to identify candidates at risk for gastric cancer and antimicrobial resistance in HP for rational management. Such candidates could be identified by studying the association of virulence factors with clinical outcome. As this data is lacking from Odisha this study was undertaken. Methods113 consecutive dyspeptic patients who underwent endoscopy at our hospital were recruited to obtain gastric biopsies for culture and antibiotic susceptibility, histological examination, molecular detection of HP, virulence typing (cagA, EPIYA typing, vacA, vacAs1/s2, vacAm1/m2 and babA2) by conventional PCR and identification of clarithromycin resistance by real-time PCR. Cultured isolates were subjected to antibiotic sensitivity using e strips as per EUCAST guidelines. Results93 (82.3%) dyspeptic patients were infected by HP by histology & PCR, while 90 (79.6%) were rapid urea test positive, and HP was cultured from 32 (28.3%) of these patients. Eleven (11.8%) of the 93 samples with HP were resistant to clarithromycin by real-time PCR. Of the 93 patients with HP infection by histopathology and PCR, 62 (66.7%), 87(93.5%) and 43 (46.2%) harboured cagA, vacA and babA2 genes. The western cagA found in 33 (35.5%) samples and vacAs1m1 in 50 (53.8%) samples were the commonest virulence subtypes. No association was found between virulence factors and outcome except vacAs2m2 and vac s1/m1m2, which were significantly associated with peptic ulcers. Phenotypically 11(34.4%), 1(3.1%), 21(65.6%) and 26 (81.2%) isolates were resistant to clarithromycin, amoxicillin, levofloxacin, and metronidazole. ConclusionsThis is the first study that explored the antibiotic resistance of HP, and its virulence factors in dyspeptic patients from this region of India.

Update on the first-line treatment of Helicobacter pylori infection in areas with high and low clarithromycin resistances.

Current international consensuses on Helicobacter pylori eradication therapy recommend that only regimens that reliably produce eradication rates of ⩾90% should be used for empirical treatment. The Real-world Practice & Expectation of Asia-Pacific Physicians and Patients in Helicobacter Pylori Eradication Survey also showed that the accepted minimal eradication rate in H. pylori-infected patients was 91%. According to efficacy prediction model, the per-protocol eradication rates of 7-day and 14-day standard triple therapies fall below 90% when clarithromycin resistance rate ⩾5%. Several strategies including bismuth-containing, non-bismuth-containing quadruple therapies (including sequential, concomitant, hybrid and reverse hybrid therapies), high-dose dual therapy and vonoprazan-based triple therapy have been proposed to increase the eradication rate of H. pylori infection. According to efficacy prediction model, the eradication rate of 14-day concomitant therapy, 14-day hybrid therapy and 7-day vonoprazan-based triple therapy is less than 90% if the frequency of clarithromycin-resistant strains is higher than 90%, 58% and 23%, respectively. To meet the recommendation of the consensus report and patients' expectation, local surveillance networks for resistance of H. pylori to clarithromycin are required to select appropriate eradication regimens in each geographic region. In areas with low (<5%) clarithromycin resistance (e.g. Sweden, Philippine, Myanmar and Bhutan), 7-day and 14-day standard triple therapies can be adopted for the first-line treatment of H. pylori infection with eradication rates of ⩾90%. In areas with high (⩾5%) clarithromycin resistance (most other countries worldwide) or unknown clarithromycin resistance, 14-day hybrid, 14-day reverse hybrid, 14-day concomitant and 10- to 14-day bismuth quadruple therapy can be used to treat H. pylori infection.

Prevalence of Helicobacter pylori infection and antibiotic resistance profile in Armenia

BackgroundThe prevalence of Helicobacter pylori infection was never assessed in Armenia, nor was the prevalence of H. pylori resistance against the main antibiotics concerned, despite the fact that these data are fundamental to establish evidence-based recommendations for management of this infection. We aimed to fill this gap by assessing prevalence of H. pylori among adult population in Armenia and resistance of H. pylori strains to clarithromycin and levofloxacin.MethodsHelicobacter pylori seroprevalence was determined in 217 asymptomatic adult subjects submitted to a health checkup using an ELISA. Molecular methods were used to detect H. pylori in gastric biopsies from 91 adult dyspeptic patients [55 (60.4%) were positive] as well as the mutations associated with clarithromycin resistance by real-time PCR and with levofloxacin by sequencing the gyrA QRDR.ResultsHelicobacter pylori seropositivity was found to be 41.5% globally and increased with age from 13.6% (age 18–25 years) to 83.3% (age > 65 years). Only two cases were found with a A2142/43G mutation causing clarithromycin resistance, and 6 cases showed mutations associated with levofloxacin resistance.ConclusionsHelicobacter pylori infection is estimated to be about 42% among adults in Armenia and the low clarithromycin resistance allows the use of the standard triple therapy as a first line therapy.

Treatment of Helicobacter pylori infection in 2018

Treatment options for the eradication of Helicobacter pylori continue to evolve. There have been many guidelines for H.pylori treatment published, which may lead to some confusion. However, most are in agreement with the most recent iteration of the Maastricht treatment guidelines. Triple therapy is still the most frequently used treatment, especially in areas of low clarithromycin resistance. Its best results are achieved when taken for a minimum of 10days and with high-dose acid suppression. Quadruple therapy is gaining in popularity particularly in areas with increasing resistance to standard triple therapy. Whether three antibiotics, or bismuth and two antibiotics are used, excellent eradication rates are achieved, albeit with increased side effects. Levofloxacin second-line therapy is widely used; however bismuth, when available, is an increasingly successful option. Sequential therapy is challenging in terms of compliance and is no longer recommended. This past year witnessed a notable increase in the number of studies based on antimicrobial susceptibility testing and tailored eradication therapy, reflecting the role of culture-guided treatment, which may well represent the future of H.pylori treatment and prevent the inappropriate use of antibiotics.

Pharmacological considerations and step-by-step proposal for the treatment of Helicobacter pylori infection in the year 2018.

Over the past 30 years, multidrug regimens consisting of a proton pump inhibitor (PPI) and two or three antibiotics have been used in treating Helicobacter pylori (H. pylori) infection. In clinical practice, the optimal regimen to cure H. pylori infection should be decided regionally. Considering the first treatment, the Maastricht V/Florence Consensus Report and the American College of Gastroenterology Clinical Management Guideline highlight that in countries with low clarithromycin resistance rates (<15%), an empiric clarithromycin-based regimen can be used. In countries with high clarithromycin resistance rates or, in the American Guideline, with a previous exposure to clarithromycin, a bismuth-containing quadruple therapy (with metronidazole and tetracycline) is the first choice. In case of persistent infection, after a previous clarithromycin-containing regimen, this drug should be avoided in second line therapy. Options after initial eradication failure include tailored therapy (choosing antibiotic combinations based on antibiotic susceptibility testing), empiric bismuth-containing quadruple therapy or triple levofloxacin-based therapy. Encouraging data are reported, both for the first-line and for rescue treatments, with the use of a formulation of bismuth subcitrate potassium, metronidazole, and tetracycline contained in a single capsule, together with a PPI. Rifabutin- and furazolidone-based regimens should also be considered in rescue regimens. Vonoprazan, a new type of potassium-competitive acid blocker that produces more potent acid inhibition than PPIs, provides improved H. pylori eradication rates in combination with antibiotics. In this review, the authors provide an overview on the current knowledge on the treatment of H. pylori infection, with focus on therapeutic challenges in this field.

Role of Bismuth in the Eradication of Helicobacter pylori.

Bismuth salts exert their activity within the upper gastrointestinal tract through action of luminal bismuth. Bismuth exerts direct bactericidal effect on Helicobacter pylori by different ways: forms complexes in the bacterial wall and periplasmic space, inhibits different enzymes, ATP synthesis, and adherence of the bacteria to the gastric mucosa. Bismuth also helps ulcer healing by acting as a barrier to the aggressive factors and increasing mucosal protective factors such as prostaglandin, epidermal growth factor, and bicarbonate secretion. To date, no resistance to bismuth has been reported. Also synergism between bismuth salts and antibiotics was present. It was shown that metronidazole and clarithromycin resistant H. pylori strains become susceptible if they are administered together with bismuth. Bismuth-containing quadruple therapy was recommended both by the Second Asia-Pacific Consensus Guidelines and by the Maastricht IV/Florence Consensus Report as an alternative first choice regimen to standard triple therapy, in areas with low clarithromycin resistance, and it is recommended as the first-line therapeutic option in areas with a high prevalence of clarithromycin resistance. Greater than 90% eradication success can be obtained by bismuth-containing quadruple therapy. Choosing bismuth as an indispensable part of first-line therapy is logical as both metronidazole and clarithromycin resistances can be overcome by adding bismuth to the regimen.

Luminal Clinical

<b>Luminal Clinical</b>

Treatment of Helicobacter pylori infection: Where are we now?

Gastric cancer and Helicobacter pylori infection remain a burden in many Asian countries. In the face of rising antibiotic resistance, the eradication rate of standard triple therapy is declining in many Asian countries. We reviewed the updated epidemiology of gastric cancer, prevalence of H. pylori infection, and antibiotic resistance in Asia. We also reviewed the strategies to improve the efficacy of H. pylori eradication therapies, including the use of high dose proton pump inhibitor, four drug therapies (including bismuth quadruple, concomitant, and sequential therapy), susceptibility guided therapy, extending the treatment duration to 14 days, and development of effective rescue therapy. Four drug therapies are usually more effective than triple therapy when given in the same duration, except in areas with concomitantly high metronidazole resistance and low clarithromycin resistance. The efficacies of different four drug regimens appeared to be similar. However, trials from different geographic areas showed contradictory results, indicating that the optimal therapy should be decided according to the local prevalence of antibiotic resistance. We proposed a prediction model to calculate the efficacy of different regimens according to the prevalence of antibiotic resistance. More large randomized trials which provide information on the antibiotic resistance are urgently needed to build a more accurate and reliable model. It is hoped that we will be able to decide the optimal regimens by routine surveillance of antibiotic resistance.

Optimal H. pylori Therapy in Areas of High and Low Clarithromycin Resistance

Increasing antimicrobial resistance decreases the success of clarithromycin-containing therapies for Helicobacter pylori eradication. Researchers performed both a standard meta-analysis and a Bayesian network meta-analysis of 117 studies evaluating eradication rates of 17 first-line regimens for H. pylori in 32,852 treatment-naive patients. Subgroup analyses were conducted for countries with high (>15%) and low (<15%) clarithromycin resistance …

First-line Helicobacter pylori eradication therapies in countries with high and low clarithromycin resistance: a systematic review and network meta-analysis

ObjectiveTo determine the optimal regimen of different first-line Helicobacter pylori eradication therapies according to the clarithromycin resistance rate.DesignElectronic search for articles published between January 2005 and April 2016. Randomised, controlled...

The Toronto Consensus for the Treatment of Helicobacter pylori Infection in Adults

Helicobacter pylori infection is increasingly difficult to treat. The purpose of these consensus statements is to provide a review of the literature and specific, updated recommendations for eradication therapy in adults. A systematic literature search identified studies on H pylori treatment. The quality of evidence and strength of recommendations were rated according to the Grading of Recommendation Assessment, Development and Evaluation (GRADE) approach. Statements were developed through an online platform, finalized, and voted on by an international working group of specialists chosen by the Canadian Association of Gastroenterology. Because of increasing failure of therapy, the consensus group strongly recommends that all H pylori eradication regimens now be given for 14 days. Recommended first-line strategies include concomitant nonbismuth quadruple therapy (proton pump inhibitor [PPI]+ amoxicillin+ metronidazole+ clarithromycin [PAMC]) and traditional bismuth quadruple therapy (PPI+ bismuth+ metronidazole+ tetracycline [PBMT]). PPI triple therapy (PPI+ clarithromycin+ either amoxicillin or metronidazole) is restricted to areas with known low clarithromycin resistance or high eradication success with these regimens. Recommended rescue therapies include PBMT and levofloxacin-containing therapy (PPI+ amoxicillin+ levofloxacin). Rifabutin regimens should be restricted to patients who have failed to respond to at least 3 prior options. Optimal treatment of H pylori infection requires careful attention to local antibiotic resistance and eradication patterns. The quadruple therapies PAMC or PBMT should play a more prominent role in eradication of H pylori infection, and all treatments should be given for 14 days.

Improved eradication rate of standard triple therapy by adding bismuth and probiotic supplement for Helicobacter pylori treatment in Thailand.

Helicobacter pylori (H. pylori) remains an important cause of gastric cancer and peptic ulcer disease worldwide. Treatment of H. pylori infection is one of the effective ways to prevent gastric cancer. However, standard triple therapy for H. pylori eradication is no longer effective in many countries, including Thailand. This study was designed to evaluate the efficacy of adding bismuth and probiotic to standard triple therapy for H. pylori eradication. In this prospective single center study, H. pylori infected gastritis patients were randomized to receive 7- or 14-day standard triple therapy plus bismuth with probiotic or placebo. Treatment regimen consisted of 30 mg lansoprazole twice daily, 1 g amoxicillin twice daily, 1 g clarithromycin MR once daily and 1,048 mg bismuth subsalicylate twice daily. Probiotic bacteria composed of Bifidobacterium lactis, Lactobacillus acidophilus and Lactobacillus paracasei. Placebo was conventional drinking yogurt without probiotic. CYP2C19 genotyping and antibiotic susceptibility tests were also done. H pylori eradication was defined as a negative 13C-urea breath test at least 2 weeks after completion of treatment. One hundred subjects were enrolled (25 each to 7- and 14-day regimens with probiotic or placebo). Antibiotic susceptibility tests showed 36.7% metronidazole and 1.1% clarithromycin resistance. CYP2C19 genotyping revealed 40.8%, 49% and 10.2% were rapid, intermediate and poor metabolizers, respectively. The eradication rates of 7- or 14 regimens with probiotics were 100%. Regarding adverse events, the incidence of bitter taste was significantly lower in the 7- day regimen with the probiotic group compared with 7- day regimen with placebo (40% vs. 64%; p=0.04). The 7-day standard triple therapy plus bismuth and probiotic can provide an excellent cure rate of H. pylori (100%) in areas with low clarithromycin resistance such as Thailand, regardless of CYP2C19 genotype. Adding a probiotic also reduced treatment-related adverse events.

Su1159 High Efficacy of 14-Day Standard Triple Therapy Plus Bismuth With Probiotic Supplement for H. pylori Eradication in Low Clarithromycin Resistance Areas

Su1159 High Efficacy of 14-Day Standard Triple Therapy Plus Bismuth With Probiotic Supplement for H. pylori Eradication in Low Clarithromycin Resistance Areas

Letter: curing Helicobacter pylori infection in a clinical setting

Tay et al. proposed recently a new quadruple therapy after the failure of a first-line therapy for eradicating Helicobacter pylori.1 They reported an impressive eradication rate of >95%.1 However, they prescribed this regimen according to preantibiotic sensitivity testing based on bacterial culture. Although this approach seems to achieve a higher eradication rate, it may not be suitable for use in primary care. Current Maastricht IV guidelines still advise clarithromycin-based 7-day triple therapy in areas of low clarithromycin resistance,2 although clarithromycin resistance is very high worldwide, ranging from <10% in Northern Europe to 18.9% in Asia and 29.3% in America.3 However, this does not reflect the current eradication rate worldwide using this therapeutic regimen. In fact, its success rate has remained stable in the Far East as, for example, occurred from 2000 to 2010 in South Korea (86.7% vs. 88.3%, P = 0.06).4 On the contrary, in our experience, its effectiveness decreased significantly during the last decade or so. From January 1996 to December 2006, we treated 1497 dyspeptic patients with standard 7-day triple therapy (PPI-amoxycillin-clarithromycin). The overall H. pylori eradication rate was 70.4% (on intention-to-treat analysis). However, looking at the trend during the observation period, we found that it decreased significantly from 90.0% (95% CI: 87.1–93.9) in 1996 to 51.1% (95% CI: 48.1–55.9) in 2006 on intention-to-treat analysis (P = 0.001). It was well tolerated, with adverse events occurring in 7.9% (95% CI: 4.7–10.1) of the overall population, and only 1.4% of the overall population (95% CI: 0.33–3.6) had to discontinue treatment and withdraw from the study. After multivariate analysis, only smoking habit influenced eradication rates. Several other factors, ranging from adherence to therapy to age at the time of treatment, were assessed, but none were significant (see Table 1). Why this difference between Italy and other countries has occurred remains unclear, but it needs more in-depth analysis. In terms of using culture in managing resistant H. pylori infection, performing culture systematically in primary care has some limitations. Culture is not always available on a routine basis, it is expensive and time-consuming, especially when a low bacterial load is present,5 the sensitivity is not 100%, and therefore the antimicrobial susceptibility cannot be obtained in all cases6; and antibiotic susceptibility testing in clinical practice yields useful information only with respect to a few antibiotics. In our experience, levofloxacin-containing sequential therapy can be used as an alternative strategy.7 In conclusion, the optimal first-line H. pylori eradication therapy has yet to be discovered. Preantibiotic sensitivity testing should be used with caution, due to several limitations that affect the test yet. Declaration of personal and funding interests: None.

Improved Efficacy of Proton Pump Inhibitor – Amoxicillin – Clarithromycin Triple Therapy for Helicobacter pylori Eradication in Low Clarithromycin Resistance Areas or for Tailored Therapy

Standard triple therapy for Helicobacter pylori eradication is no longer effective as an empiric choice in most areas. Even in low clarithromycin resistance areas, results ≥95% are infrequently achieved. This study was designed to search for a version of standard triple therapy for use low prevalence areas or as tailored therapy that is highly effective irrespective of CYP2C19 genotype. Two prospective pilot single center studies were performed in Thailand. H.pylori-infected subjects were randomized to 7- or 14-day regimens using a high-dose proton pump inhibitor (PPI) triple therapy consisting of lansoprazole (60mg) twice daily, amoxicillin 1g twice daily, and long-acting clarithromycin MR 1g once daily. H.pylori was defined as positive H.pylori culture; or two positive tests (rapid urease test and histology); CYP2C19 genotyping was performed. H.pylori eradication was evaluated by (13) C-UBT 4 or more weeks after treatment. Hundred and ten subjects were enrolled (55 each to the 7- and 14-day regimens). Antibiotic susceptibility testing (25 strains) showed 40% metronidazole resistance but no clarithromycin resistance. CYP2C19 genotyping (64 subjects) revealed 56.3% rapid metabolizer, 29.7% intermediate metabolizer, and 14% poor metabolizer. The eradication rate with the 14-day regimen was 100% (95% CI=93.5-100%) and 92.7% (95% CI=82-97%) with the 7-day regimen. The difference was related to improved eradication at 14days in rapid metabolizers (i.e. 100 vs 88.2%). Triple therapy using a 14-day high-dose PPI and long-acting clarithromycin provided an excellent cure rate (100%) regardless of the CYP2C19 genotype.

Pseudomembranous colitis associated with a triple therapy forHelicobacter pylorieradication

Helicobacter pylori (H. pylori) is one of the most common chronic bacterial infections in humans, affecting half of world's population. Therapy for H. pylori infection has proven to be both effective and safe. The one-week triple therapy including proton pump inhibitor, clarithromycin, and amoxicillin or metronidazole is still recommended as a first-line treatment to eradicate H. pylori infection in countries with low clarithromycin resistance. Generally, this therapy is well-tolerated, with only a few and usually minor side effects. However, rare but severe adverse effects such as pseudomembranous colitis have been reported, Clostridium difficile (C. difficile) infection being the main causative factor in all cases. We report the cases of two women who developed pseudomembranous colitis after a 1-wk triple therapy consisting of pantoprazole 20 mg bid, clarithromycin 500 mg bid, and amoxicillin 1 g bid to eradicate H. pylori infection. A limited colonoscopy showed typical appearance of pseudomembranous colitis, and the stool test for C. difficile toxins was positive. Rapid resolution of symptoms and negative C. difficile toxins were obtained in both patients with oral vancomycin. No relapse occurred during a four and eleven-month, respectively, follow up. These cases suggest that physicians should have a high index of suspicion for pseudomembranous colitis when evaluate patients with diarrhea following H. pylori eradication therapy.

Treatment of Helicobacter pylori

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