Additive effect of pronase on the efficacy of eradication therapy against Helicobacter pylori

The impact of oral ciprofloxacin on the structure and functions of rat gastric mucosa

Ciprofloxacin (CPX), is a fluoroquinolone antibiotic used to treat a number of gram-negative and gram-positive bacterial infections. Ciprofloxacin can cause severe side effects, ranging from tendon problems, nerve damage, to serious mood or behavior changes.

The purpose of this study was to investigate how ciprofloxacin affects gastric cell lines in rats with a distinctive emphasis on physiological, histopathological, and bacteriological changes. Male albino rats (n = 21) were distributed into three groups; control, CPX, and CPX-withdrawal groups. The treated rats were given CPX tablets (12.5 mg/kg) dissolved in carboxymethyl cellulose (CMC) 0.5% orally once daily via gavage for sixty consecutive days. Control rats received only the vehicle. The withdrawal group was treated for 60 days and the drug was withdrawn for another sixty days. After completion of the experiment, all rats were sacrificed and gastric tissues were treated for light, immunohistochemical, and scanning electron microscopic examination. Image J software was used to measure immune-labeled gastric epithelial cells. Blood samples were also collected for H. Pylori immunoglobulins IgM, IgA, and IgG. Results showed that treated rats acquired significantly strongly positive tumor necrosis factor (TNFα) and significant reduction of serum level of H. pylori IgM, IgA, and IgG in all the study groups. It could be concluded that prolonged oral CPX administration to albino rats changes the gastric mucosal architecture and bacteriology.

Chemical modification of drug molecules as strategy to reduce interactions with mucus

Many drug molecules possess inadequate physical-chemical characteristics that prevent to surpass the viscous mucus layer present in the surface of mucosal tissues. Due to mucus protective role and its fast turnover, these drug molecules end up being removed from the body before being absorbed and, thus, before exerting any physiologic affect. Envisaging a better pharmacokinetics profile, chemical modifications, to render drug a more mucopenetrating character, have been introduced to drug molecules backbone towards more effective therapies. Mucus penetration increases when drug molecules are provided with net-neutral charge, when they are conjugated with mucolytic agents and through modifications that makes them resistant to enzymes present in mucus, with the overall increase of their hydrophilicity and the decrease of their molecular weight. All of these characteristics act as a whole and influence each other so they must be well thought when drug molecules are being designed for mucosal delivery.

High Dose Ilaprazole/Amoxicillin as First-Line Regimen for Helicobacter pylori Infection in Korea

Objective. The eradication rate of Helicobacter pylori (H. pylori) following standard triple therapy has declined over the past few decades. This study has determined whether high dose dual therapy (PPI and amoxicillin) is adequate for eradicating H. pylori in Korea. Methods. This was an open-labeled study of H. pylori infected treatment-naive patients. Subjects received dual therapy for 14 days: ilaprazole 40 mg tablets given twice a day and amoxicillin 750 mg tablets given 4 times a day. At the end of the therapy, the subjects visited the clinic to confirm compliance and monitor for any side effects. Subjects visited again after 4–6 weeks to confirm H. pylori status through a urea breath test. Results. The cure rate of H. pylori was 79.3% (23 of 29) (95% confidence interval: 61.6–90.2) in the intention-to-treat analysis and 82.1% (23 of 28) in the per-protocol analysis. Compliance rates were high (96.6%) and side effects were minimal and tolerable. Conclusion. A high dose of ilaprazole + amoxicillin was ineffective as the first-line therapy for eradicating H. pylori in Korea. Future studies should focus on intragastric pH measurements and assess amoxicillin resistance.

Additive Effect of Pronase on the Eradication Rate of First-Line Therapy for Helicobacter pylori Infection

Background/Aims

Helicobacter pylori colonizes on the apical surface of gastric surface mucosal cells and the surface mucous gel layer. Pronase is a premedication enzyme for endoscopy that can disrupt the gastric mucus layer. We evaluated the additive effects of pronase combined with standard triple therapy for H. pylori eradication.

Methods

This prospective, single-blinded, randomized, controlled study was conducted between June and October 2012. A total of 116 patients with H. pylori infection were enrolled in the study (n=112 patients, excluding four patients who failed to meet the inclusion criteria) and were assigned to receive either the standard triple therapy, which consists of a proton pump inhibitor with amoxicillin and clarithromycin twice a day for 7 days (PAC), or pronase (20,000 tyrosine units) combined with the standard triple therapy twice a day for 7 days (PACE).

Results

In the intention-to-treat analysis, the eradication rates of PAC versus PACE were 76.4% versus 56.1% (p=0.029). In the per-protocol analysis, the eradication rates were 87.5% versus 68.1% (p=0.027). There were no significant differences concerning adverse reactions between the two groups.

Conclusions

According to the interim analysis of the trial, pronase does not have an additive effect on the eradication of H. pylori infection (ClinicalTrial.gov: NCT01645761).

An Additive Effect of Oral N-Acetyl Cysteine on Eradication of Helicobacter pylori

Background. Helicobacter pylori is highly adapted to the gastric environment where it lives within or beneath the gastric mucous layer. The aim of this study was to evaluate whether the addition of N-acetyl cysteine to the treatment regimen of H. pylori infection would affect eradication rates of the disease. Methods. A total of 79 H. pylori positive patients were randomized to two therapeutic groups. Both groups received a 14-day course of three-drug regimen including amoxicillin/clarithromycin/omeprazole. Experimental group (38 subjects) received NAC, and control group (41 subjects) received placebo, besides three-drug regimen. H. pylori eradication was evaluated by urea breath test at least 4 weeks after the cessation of therapy. Results. The rate of H. pylori eradication was 72.9% and 60.9% in experimental and control groups, respectively (P = 0.005). By logistic regression modeling, female gender (OR 3.68, 95% CI: 1.06–5.79; P = 0.040) and treatment including NAC (OR 1.88, 95% CI: 0.68–3.15; P = 0.021) were independent factors associated with H. pylori eradication. Conclusion. The results of the present study show that NAC has an additive effect on the eradication rates of H. pylori obtained with three-drug regimen and appears to be a promising means of eradicating H. pylori infection.

Efficacy and pharmacological mechanism of pronase-enhanced low-dose antibiotics for Helicobacter pylori eradication

This study examined the efficacy and pharmacological mechanism of pronase-assisted low-dose antibiotics for eradication of Helicobacter pylori. Mongolian gerbils infected with H. pylori received 7-day treatment (omeprazole, different concentrations of pronase, amoxicillin, and clarithromycin), and the efficacy was assessed using the eradication rate and the colonization of H. pylori. In Mongolian gerbils orally administered pronase, the thickness of the gastric mucous layer (GML) was examined using immunohistochemical and alcian blue staining, and the concentrations of amoxicillin in gastric tissue and serum were detected using high-performance liquid chromatography (HPLC). The eradication rates were 80.0% (12/15) in the high-pronase quadruple group (HPQG) and 86.7% (13/15) in the high-antibiotic group (HAG) (P = 1.000). The antibiotic dose in the HPQG was only 1/20 that in the HAG. Thirty minutes after oral treatment with pronase, the sticky protein of the GML was hydrolyzed, and the GML became thinner. Higher amoxicillin concentrations in both the gastric tissue and serum were observed in the pronase group than in the Am10 group. The concentration of amoxicillin in the Am10-plus-Pr108 group in gastric tissue was 3.8 times higher than in the Am10 group in 5 min. Together, these data suggest that pronase significantly reduced the dose of antibiotics used in H. pylori eradication. The pharmacological mechanism is likely pronase removal of the mucus layer, promoting chemical factor (i.e., gastric acid and pepsinogen) distribution and increasing the antibiotic concentrations in the deep GML, which acted on H. pylori collectively. Thus, pronase may enhance the level of antibiotics for eradication of H. pylori in the clinic.

Dual proton pump inhibitor plus amoxicillin as an empiric anti-H. pylori therapy: studies from the United States

BACKGROUND

Studies with CYP2C19 slow metabolizers have shown that the combination of a proton pump inhibitor (PPI) plus amoxicillin (dual therapy) can reliably cure more than 90% of Helicobacter pylori infections. Theoretically, the use of a PPI dose that provides equivalent acid suppression with fast metabolizers and slow metabolizers would achieve high cure rates irrespective of the CYP2C19 genotype.

AIM

To evaluate high-dose PPI plus amoxicillin dual therapy for H. pylori eradication.

METHODS

H. pylori-infected individuals (positive by 2 tests) received esomeprazole 40 mg plus amoxicillin 750 mg every 8 h for 14 days. The protocol was planned based on the "efficient identification strategy" requiring more than 90% success, with stop criteria of 6 or more failures within 50 patients or a cure rate of less than 80%.

RESULTS

Thirty-six patients (5 women, 31 men), average age 58 years, were enrolled before achieving stop criteria. All were first H. pylori treatments. The intention-to-treat cure was achieved in 26/36 [72.2%; 95% confidence interval (CI) = 56-84%] and in 26/35 per protocol (74.2%; 95% CI = 56-87%). There were no significant side effects. Compliance was 85% or greater in all (100% in 91.6%).

CONCLUSIONS

If the hypothesis that consistently high intragastric pH is required to reliably achieve more than 90% H. pylori eradication, our regimen was not sufficient. Success may require more than every 8 h dosing, the concomitant administration of sodium bicarbonate, or the use of a long-acting PPI. However, the result was positive in that dual therapy with the doses tested here was at least as successful as empiric triple therapy.

Effect of the mucolytic erdosteine on the success rate of PPI-based first-line triple therapy for Helicobacter pylori eradication: a prospective, double-blind, randomized, placebo-controlled study

OBJECTIVE

Because Helicobacter pylori creates a well-sheltered microenvironment within the gastric mucus layer, it has been speculated that the disruption of this space by a mucolytic agent may enhance the eradication rate. The aim of the present study was to investigate the effect of erdosteine, a strong mucolytic agent, on the effectiveness of PPI-based, first-line triple therapy in the eradication of H. pylori.

MATERIAL AND METHODS

Initially, 196 patients were enrolled to the study. Of these, 79 H. pylori-positive patients were randomized to the erdosteine group (triple therapy consisting of pantoprazole, amoxicillin and clarithromycin plus erdosteine; n = 40) or the placebo group (triple therapy plus placebo; n = 39) for 14 days. Endoscopic biopsies and (13)C-urea breath tests were performed at entry and at 4-6 weeks after the completion of the treatment. Additionally, rapid urease tests were performed at entry.

RESULTS

The eradication of H. pylori was achieved in 30 (75%) of the 40 patients in the erdosteine group and in 20 (51.3%) of the 39 patients in the placebo group, according to the ITT analysis (p = 0.028). When the PP analysis was performed as well, H. pylori eradication was achieved in 30 (78.9%) of the 38 patients in the erdosteine group and in 20 (52.6%) of the 38 patients in the placebo group (p = 0.016).

CONCLUSIONS

Erdosteine is an efficient adjuvant therapy that could be used in conjunction with first-line triple therapy in the treatment of H. pylori.

New concepts of resistance in the treatment of Helicobacter pylori infections

The prevalence of antimicrobial drug resistance is now so high that all patients infected with Helicobacter pylori should be considered as having resistant infections. Ideally, therapy should be based on pretreatment antibiotic-susceptibility testing but this strategy is not currently practical. At present, clarithromycin-containing triple therapies do not reliably produce a > or =80% cure rate on an intention-to-treat basis and are, therefore, no longer acceptable as empiric therapy. In this Review, we discuss concepts of resistance that have become part of mainstream thinking for other infectious diseases but have not yet become so with regard to H. pylori. We also put data on the pharmacokinetics and pharmacodynamics of the drugs used in H. pylori therapy and the effect of host cytochrome P450 genotypes in context with treatment outcomes. Our primary focus is to address the problem of H. pylori resistance from a novel perspective, which also attempts to anticipate the direction that research will need to take to provide clinicians with reliable approaches to this serious infection. We also discuss current therapies that provide acceptable cure rates when used empirically (i.e. sequential therapy; four-drug, three-antibiotic, non-bismuth-containing 'concomitant' therapy; and bismuth-containing quadruple therapy) and how they might be further improved.

Helicobacter pylori: testing and treatment

Helicobacter pylori is an important pathogen worldwide. Accurate diagnosis and appropriate therapy is important in clinical practice. Invasive tests that accurately identify current infection include the biopsy urease test and histology. The best noninvasive tests for diagnosis include the urea breath test and stool antigen testing. Proton pump inhibitor therapy can lead to false-negative H. pylori test results, and treatment should be stopped for 1-2 weeks prior to testing if possible. In the setting of bleeding peptic ulcer disease, urea breath testing is recommended to rule out a false-negative biopsy test result if needed. The current recommendations for when to test for H. pylori vary around the world. Well-accepted indications include active and past ulcer disease, and gastric-mucosa associated lymphoid tissue lymphoma. There is no universal agreement regarding whether all patients with functional dyspepsia should be tested and treated, although this is an evidence-based recommendation. There is also evidence that H. pylori eradication prevents peptic ulcer disease in those starting NSAIDs long term. Primary treatment remains triple therapy with 10-14 days probably being superior to shorter courses of therapy. Quadruple therapy is recommended if standard triple therapy fails. Salvage therapies with levofloxacin, rifabutin or furazolidone have been identified. Novel approaches to treatment include sequential therapy and use of adjuvants.

In vitro bactericidal activities of Japanese rice-fluid against Helicobacter pylori strains

BACKGROUND

Helicobacter pylori has now been widely recognized as a causative agent of gastroduodenal diseases. The development of safer anti- H. pylori compounds is desirable due to the antibiotic-resistant strains emerged to date.

METHODS

We successfully developed the compounds of Rice-fluid derived from unpolished, polished, and usually cooked Japanese rice, and investigated their in vitro antibacterial activities by means of the Time-Kill-Curve methods against various species of bacteria including H. pylori strains.

RESULTS

All of the compounds revealed keen bactericidal activities against H. pylori, followed by Streptococcus pneumoniae and Campylobacter jejuni strains, but failed to affect the viability of other bacterial species investigated including staphylococci, enterococci, Pseudomonas aeruginosa, and other gram-negative rods belonging to the family Enterobacteraceae. The bactericidal activities were demonstrated to be time- and concentration-dependent.

CONCLUSIONS

The compounds of Rice-fluid are considered to be potentially new and safe therapeutic regimens against H. pylori infections. The mechanism of their bactericidal activities against H. pylori strains remains to be elucidated.

Helicobacter pylori diagnosis and management

H pylori is a global human pathogen and is the major cause of gastritis and the gastritis-associated diseases: gastric ulcer, duodenal ulcer, gastric cancer, and primary gastric B-cell lymphoma (MALToma). Although several reliable diagnostic tests are widely available, the ideal regimen for treating the infection re-mains to be established. The current first-line or legacy triple therapy regimens fail in 20% to 40% of patients. Causes of treatment failure include antibiotic resistance, poor compliance, short (7-10 days) duration of therapy, and drug-related side effects. Fourteen-day triple therapy has an approximately 12% better cure rate than does 7-day therapy; therefore, shorter durations can no longer be recommended. Recent studies confirmed older observations that the success rate of legacy triple regimens (PPI plus two antibiotics) can be improved if the duration is extended to 14 days or if a third antibiotic is given. Sequential therapy (PPI plus amoxicillin followed by a PPI plus clarithromycin plus metronidazole) requires further evaluation although the concept appears very promising and therapy should probably replace the legacy triple therapies. More studies are needed to examine doses, durations, and the need for sequential administration of the drugs, which extends the duration to 14 days. Nonetheless, sequential quadruple therapy probably should replace the legacy triple therapies. Classic quadruple therapy contains bismuth, a PPI, 1500 mg of metronidazole, and 1500 mg of tetracycline. It provides the highest average eradication rates and in many regions should be considered as the initial approach. Confirmation of eradication using noninvasive diagnostic tests, such as a urea breath test or stool antigen assay, is now the standard of care. The diagnosis of latent or symptomatic H pylori like the diagnosis of latent or symptomatic syphilis, always should prompt treatment. Because of decreasing cure rates, new and improved therapies are needed.

Comparison of localized gastric mucosa-associated lymphoid tissue (MALT) lymphoma with and without Helicobacter pylori infection

BACKGROUND

The clinical features and clinical course of Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue (MALT) lymphoma are unclear and a treatment strategy has not yet been established.

AIM

To clarify the clinical differences between H. pylori-positive and H. pylori-negative gastric MALT lymphoma, we compared these two types of gastric MALT lymphoma.

MATERIALS AND METHODS

Fifty-seven patients with localized gastric MALT lymphoma were studied. H. pylori infection was present in 41 and absent in 16. Treatment consisted of antibiotic therapy and/or 30 Gy radiation therapy. Response assessment was performed every 3-6 months by esophagogastroduodenoscopy including gathering biopsy samples, endoscopic ultrasonography, clinical examination, and various imaging procedures. The median follow-up period was 37 months.

RESULTS

There were no significant differences between H. pylori-positive and H. pylori-negative gastric MALT lymphoma patients in terms of sex, age, stage, gross phenotype, affected area of the stomach, or the presence of monoclonality. Complete regression was achieved with antibiotic therapy against H. pylori-negative gastric MALT lymphoma in one of nine patients (11.1%), compared to 28 of 38 patients (73.7%) with H. pylori-positive gastric MALT lymphoma (p < .001). Radiation therapy showed high effectiveness for the local control of H. pylori-negative or antibiotic-resistant gastric MALT lymphoma (92.9%), although distant recurrence was recognized in three of 14 patients (21.4%). Two of 16 patients (12.5%) with H. pylori-negative gastric MALT lymphoma died because of the transformation of the disease into diffuse large B-cell lymphoma. There was a significant difference in both the overall and cause-specific survival rate between the two groups (p = .038).

CONCLUSION

Radiation therapy is the effective treatment for H. pylori-negative or antibiotic-resistant localized gastric MALT lymphoma. However, careful systemic follow-up for distant involvement should be required. Transformation into diffuse large B-cell lymphoma is thought to be the important cause of death in patients with gastric MALT lymphoma.

Rifaximin-based regimens for eradication of Helicobacter pylori: a pilot study

BACKGROUND

Triple therapy is the treatment of choice for Helicobacter pylori-infected patients with an eradication rate ranging from 70 to 85%. Poor compliance and antibiotic resistance are the main causes of treatment failure. The aim of the present study was to assess the efficacy of rifaximin, a poorly absorbed antibiotic, for H. pylori eradication.

METHODS

We enrolled 48 consecutive H. pylori-positive patients affected. They were randomized to receive two 7-day rifaximin-based triple therapies: rifaximin tablets 400 mg t.i.d., esomeprazole 40 mg o.d. and clarithromycin 500 mg b.i.d. (CRE) or levofloxacin 500 mg o.d. (LRE). H. pylori eradication was assessed using a (13)C-urea breath test 4 weeks after the end of therapy. Treatment compliance and the incidence of side effects were also evaluated.

RESULTS

No dropouts were observed. The eradication rate both on intention-to-treat and per-protocol analysis did not show significant differences between groups: 58% (14/24 patients) in group 1 and 42% (10/24 patients) in group 2 (p = 0.24, OR 1.96, 95% CI 0.62-6.18). No significant differences in patients' compliance and incidence of side effects were found between groups.

CONCLUSIONS

Rifaximin-based therapy showed optimal compliance but a limited eradication rate compared to standard first-line treatment. Further investigations are needed to evaluate different dosages and combinations.

Effect of N-acetyl cysteine on Helicobacter pylori

BACKGROUND

Use of mucolytic agents that result in reduced mucous viscosity of the gastric mucous has been suggested to have an additive effect in curing Helicobacter pylori infection.

METHODS

Seventy Hpylori-positive patients were given either eradication treatment consisting of 500 mg clarithromycin bid and 30 mg lansoprazole bid for 10 days plus 10 mL (400 mg) N-acetyl cysteine (NAC) liquid tid (AC group) or eradication treatment only (control group). The results were compared 1 month after the completion of the treatment.

RESULTS

Fifty-eight patients were available for statistical analysis. Of the 28 patients in the AC group, 14 (50.0%) eradicated the infection after treatment, whereas only 7 of 30 (23.3%) patients in the control group had negative results. The difference between the AC group and the control group was statistically significant (P = 0.034). In both groups, there was no difference in the number of smokers and in the eradication rates between smokers and nonsmokers. Eradication treatment with or without NAC caused no significant side effects in either group.

CONCLUSIONS

Our findings suggest that NAC has an additive effect on the eradication rates of H pylori obtained with dual therapy with lansoprazole and clarithromycin. NAC does not have any known activity against H pylori, but it may improve the delivery of antibiotics at the site of infection due to its ability to reduce the thickness of the mucus.

N-acetylcysteine, a novel treatment for Helicobacter pylori infection

N-Acetylcysteine (NAC), being both a mucolytic agent and a thiol-containing antioxidant, may affect the establishment and maintenance of H. pylori infection within the gastric mucus layer and mucosa. Agar and broth dilution susceptibility tests determined the MIC of H. pylori strain SSI to NAC. H. pylori load in SSI strain-infected C57BL mice was determined as colony forming units per gram of gastric tissue. Gastritis assessment was scored and gastric surface hydrophobicity was determined by contact angle measurement. MICs of NAC were 5 to 10 and 10 to 15 mg/ml using the agar dilution and broth dilution methods, respectively. NAC (120 mg per day for 14 days) reduced the H. pylori load in mice by almost 1 log compared with sham treatment. Pretreatment with NAC (40 mg/day) also significantly reduced the H. pylori load but did not prevent H. pylori colonization. Both H. pylori infection and NAC reduced the surface hydrophobicity of murine gastric mucosa. No significant differences were observed in the gastritis scores of H. felis- or H. pylori-infected mice receiving either NAC or sham treatments. This study demonstrates that NAC inhibits the growth of H. pylori in both agar and broth susceptibility tests and in H. pylori-infected mice. NAC did not alter the severity of H. pylori- or H. felis-induced gastritis.

Treatment of Helicobacter pylori infection

Review of the recently published data on Helicobacter pylori management highlights various interesting aspects. Current H. pylori eradication guidelines generally suggest a noninvasive 'test and treat' strategy for all dyspeptic patients with certain age limits depending on the local gastric neoplasia risk. According to the 'Maastricht 2-2000 Consensus Report' treatment should be thought of as a 'package' considering first- and second-line eradication therapies together. Various centres have published their results using novel antimicrobial formulations and 'rescue' and 'sequential' therapies. Review suggests that care at the specialist level remains a challenge and guidelines are deficient particularly as regards the selection and duration of eradication therapies. Results indicate that differences for CYP2C19 genotype and the selection of proton pump inhibitors have no significant role in determining eradication rates whereas antibiotic resistance and socio-economic factors play a variable role according to different geographical areas. Compliance remains an important factor in determining clinical outcome at the primary and secondary levels worldwide.