Clarithromycin for Helicobacter pylori infection

Helicobacter pylori, a Gram-negative organism that survives in the deep mucus layer and attaches to the gastric surface cells, is estimated to be present in up to one-half of the US population. Chronic H. pylori infection causes chronic gastritis, peptic ulcer diseases and even gastric cancer. Cure of the infection leads to healing of gastric inflammation, prevention of development of peptic ulcer, as well as accelerated healing of peptic ulcers, and prevention of ulcer recurrence. Treatment of H. pylori has undergone substantial evolution over the past decade. Despite the in vitro susceptibility, results from single or even dual drug therapy is typically unsatisfactory and the best therapy is yet to be defined. The best current therapies for H. pylori infection consist of a proton pump inhibitor (PPI) or ranitidine bismuth citrate and two antibiotics (triple therapies), or bismuth, tetracycline, metronidazole and a PPI (quadruple therapy). Clarithromycin is one of the most useful antimicrobials against H. pylori. It is an acid-stable macrolide with a broad spectrum of antibacterial activity, well absorbed with a wide tissue distribution and with mild side effects. Clarithromycin has a low minimum inhibitory concentration (MIC50) for H. pylori and its effect is potentiated by acid inhibition. When combined with a PPI or ranitidine bismuth citrate and amoxicillin or metronidazole, eradication rates of more than 95% can be achieved with susceptible organisms. However, the prevalence of primary and acquired clarithromycin resistance, which is due to mutations within a conserved loop of 23S rRNA of H. pylori, is increasing. In practice, the presence of clarithromycin resistance usually implies reduced success when clarithromycin-containing regimes are used. There is a need for improved therapies for H. pylori where antibiotic resistance is less of a problem.     

Helicobacter pylori infection--current treatment practice

Helicobacter pylori infection, which is present in 30 - 60% of the population in developed countries and in more than 60% in developing countries, is established to be a major cause of gastritis, peptic ulcer disease and gastric cancer. Eradication therapy has been incorporated into clinical practice over the past 15 years. Treatment regimens include a 2 week bismuth-based triple therapy (a bismuth compound plus metronidazole, tetracycline or amoxycillin), a 1 week proton-pump inhibitor (PPI)-based triple therapy and a 1 week ranitidine bismuth citrate (RBC)-based triple therapy (a PPI or RBC plus any two of the three antibiotics, metronidazole, amoxycillin and clarithromycin). These regimens achieve eradication rates of > 80%. H. pylori resistance to metronidazole and clarithromycin decreases the clinical efficacy of most regimens, despite the high eradication rates for resistant strains achieved by the RBC-triple therapy in some recent trials. The dose of antibiotics (especially clarithromycin) and the duration of treatment may also influence the eradication rate. Doctors' beliefs impact on clinical practice and, thus, influence the clinical application of eradication therapy. Whereas peptic ulcer disease and primary gastric low-grade B-cell mucosa-associated lymphoid tissue lymphoma (MALToma) have become established as definite indications for eradication therapy, there remain controversies surrounding non-ulcer dyspepsia, gastro-oesophageal reflux disease, atrophic gastritis, intestinal metaplasia, use of non-steroidal anti-inflammatory drugs (NSAIDs) and H. pylori-related extradigestive diseases.     

Helicobacter pylori infection - current treatment practice

Helicobacter pylori infection, which is present in 30 - 60% of the population in developed countries and in more than 60% in developing countries, is established to be a major cause of gastritis, peptic ulcer disease and gastric cancer. Eradication therapy has been incorporated into clinical practice over the past 15 years. Treatment regimens include a 2 week bismuth-based triple therapy (a bismuth compound plus metronidazole, tetracycline or amoxycillin), a 1 week proton-pump inhibitor (PPI)-based triple therapy and a 1 week ranitidine bismuth citrate (RBC)-based triple therapy (a PPI or RBC plus any two of the three antibiotics, metronidazole, amoxycillin and clarithromycin). These regimens achieve eradication rates of >> 80%. H. pylori resistance to metronidazole and clarithromycin decreases the clinical efficacy of most regimens, despite the high eradication rates for resistant strains achieved by the RBC-triple therapy in some recent trials. The dose of antibiotics (especially clarithromycin) and the duration of treatment may also influence the eradication rate. Doctors’ beliefs impact on clinical practice and, thus, influence the clinical application of eradication therapy. Whereas peptic ulcer disease and primary gastric low-grade B-cell mucosa-associated lymphoid tissue lymphoma (MALToma) have become established as definite indications for eradication therapy, there remain controversies surrounding non-ulcer dyspepsia, gastro-oesophageal reflux disease, atrophic gastritis, intestinal metaplasia, use of non-steroidal anti-inflammatory drugs (NSAIDs) and H. pylori-related extradigestive diseases.     

幽门螺杆菌根除方法新进展

幽门螺杆菌(Helicobacter pylori,HP)感染是慢性胃炎、消化性溃疡及胃癌的主要致病原因,根除HP感染可以有效降低胃癌发病率.推荐一线根除方案为PPI或雷尼替丁枸椽酸铋+克拉霉素、甲硝唑及阿莫西林中的两种抗生素,疗程7～14天,但其根除失败率高达20％.二线治疗方案包括标准四联方案(铋剂+四环素+甲硝唑+PPI)或三联方案(PPI+左氧氟沙星+阿莫西林).对于二线治疗失败的病人,应采取个体化治疗措施,根据药敏结果选用药物,或使用新的抗生素.可供选择的三线治疗药物有喹喏酮类药物、四环素、利福布汀以及呋喃唑酮等,大剂量PPI+阿莫西林也显示出了良好疗效.     

Ranitidine bismuth citrate plus clarithromycin is effective for healing duodenal ulcers, eradicating H. pylori and reducing ulcer recurrence. RBC H. pylori Study Group [see comments]

AIM: To compare the efficacy of the coadministration of ranitidine bismuth citrate plus the antibiotic clarithromycin, with ranitidine bismuth citrate alone or clarithromycin alone for the healing of duodenal ulcers, eradication of H. pylori and the reduction of ulcer recurrence. METHODS: This two-phase, randomized, double-blind, placebo- controlled, multicentre study consisted of a 4-week treatment phase followed by a 24-week post-treatment observation phase. Patients with an active duodenal ulcer were treated with either ranitidine bismuth citrate 400 mg b.d. for 4 weeks plus clarithromycin 500 mg t.d.s. for the first 2 weeks; ranitidine bismuth citrate 400 mg b.d. for 4 weeks plus placebo t.d.s. for first 2 weeks; placebo b.d. for 4 weeks plus clarithromycin 500 mg t.d.s. for the first 2 weeks; or placebo b.d. for 4 weeks plus placebo t.d.s. for the first 2 weeks. RESULTS: Ulcer healing rates after 4 weeks of treatment were highest with ranitidine bismuth citrate plus clarithromycin (82%) followed by ranitidine bismuth citrate alone (74%; P = 0.373), clarithromycin alone (73%; P = 0.33) and placebo (52%; P = 0.007). Ranitidine bismuth citrate plus clarithromycin provided significantly better ulcer symptom relief compared with clarithromycin alone or placebo (P < 0.05). The coadministration of ranitidine bismuth citrate plus clarithromycin resulted in significantly higher H. pylori eradication rates 4 weeks post-treatment (82%) than did treatment with either ranitidine bismuth citrate alone (0%; P < 0.001), clarithromycin alone (36%; P = 0.008) or placebo (0%; P < 0.001). Ulcer recurrence rates 24 weeks post-treatment were lower following treatment with ranitidine bismuth citrate plus clarithromycin (21%) compared with ranitidine bismuth citrate alone (86%; P < 0.001), clarithromycin alone (40%; P = 0.062) or placebo (88%; P = 0.006). All treatments were well tolerated. CONCLUSIONS: The coadministration of ranitidine bismuth citrate plus clarithromycin is a simple, well-tolerated and effective treatment for active H. pylori- associated duodenal ulcer disease. This treatment regimen effectively heals duodenal ulcers, provides effective symptom relief, eradicates H. pylori infection and reduces the rate of ulcer recurrence. The eradication of H. pylori infection in patients with recently healed duodenal ulcers is associated with a significant reduction in the rate of ulcer recurrence.     

雷尼替丁枸橼酸铋联合克拉霉素根除幽门螺杆菌疗效观察

目的 比较雷尼替丁枸橼酸铋联合克拉霉素与奥美拉唑、甲硝唑、克拉霉素两种疗法对幽门螺杆菌（Hp）的根除效果。方法 123例Hp阳性的消化性溃疡患者分为2组：A组62例，以雷尼替丁枸橼酸铋1片（含：雷尼替丁100mg，枸橼酸铋钾110mg）、克拉霉素250mg口服，2次／d，疗程7d；B组61例，以奥美拉唑20mg、克拉霉素250mg加甲硝唑400mg口服，2次／d，疗程7d。结果 A、B两组的Hp根除率分别为86．9％和85．2％，活动期溃疡愈合率分别为97．6％和100％，副反应发生率分别为6．6％和8．2％，两组间Hp根除率、活动期溃疡愈合率和副反应发生率差异均无显著性（均P〉0．05）。结论 雷尼替丁枸橼酸铋联合克拉霉素与奥美拉唑、甲硝唑、克拉霉素两种疗法疗效相当，而雷尼替丁枸橼酸铋联合克拉霉素因价廉、安全在临床上更为实用。     

Antibiotic-resistant H. pylori infection and its treatment

Helicobacter pylori infection causes progressive damage to gastric mucosa and results in serious disease such as peptic ulcer disease, MALT lymphoma, or gastric adenocarcinoma in 20% to 30% of patients. The current approach is to make a firm diagnosis, give combination antibiotic and antisecretory therapy, and confirm that the infection has been cured 4 to 6 weeks later. Antimicrobial resistance is largely responsible for treatment failures. Resistance to metronidazole can frequently be overcome by increasing the dose and duration of treatment with acid suppression. Clarithromycin is the most effective antibiotic against H. pylori but, unfortunately, resistance to it is increasing and can not be overcome by increasing the dose or duration of therapy with clarithromycin. The choice of therapy should be based on local susceptibility patterns. Re-treatment regimens for treatment failure should exclude antibiotics where acquired resistance is expected (i.e., clarithromycin and possibly metronidazole). Where available, treatment failure should prompt endoscopy and culture and susceptibility testing. Overall, higher doses and longer durations of treatment result in the best cure rates. When multiple treatment regimens fail, salvage therapy regimens such as bismuth or furazolidone quadruple therapy (a bismuth and tetracycline HCl 4 times a day along with a proton pump inhibitor twice a day, and either metronidazole 400 or 500 mg three times daily or furazolidone 100 mg three times daily for 14 days) can be used. Newer agents are needed to cope with the increasing prevalence of antibiotic resistance among H. pylori.     

Basis for the management of drug-resistant Helicobacter pylori infection

The discovery that most stomach diseases are a consequence of an Helicobacter pylori infection has completely changed the management of stomach diseases. Antibacterials are the treatment of choice in addition to proton pump inhibitors (PPIs) or ranitidine bismuth. We are now faced with the problem of antimicrobial resistance, which is the main cause of treatment failure. H. pylori acquires resistance essentially via point mutations, and today this phenomenon is found with most antibacterials. The most important resistance to consider is that to clarithromycin, since it is the first-choice antibacterial and clarithromycin resistance is highly clinically significant. Quadruple therapy or triple therapies with amoxicillin-metronidazole or tetracycline-metronidazole and a PPI or ranitidine bismuth can then be used despite a possible resistance to metronidazole if the strain is resistant to clarithromycin. Resistance to both clarithromycin and metronidazole may lead to the use of other combinations, i.e. amoxicillin-rifabutin, amoxicillin-levofloxacin or amoxicillin-furazolidone. Resistance to any of these drugs means their use must be avoided. In some instances, it may also be advisable to prescribe amoxicillin as the sole antibacterial, or to use a quadruple therapy with furazolidone instead of metronidazole. Although it is theoretically possible to cure a drug-resistant H. pylori infection, a practical limitation is the availability of the drugs in certain countries. Furthermore, the progressive increase in drug resistance warrants the need for new antibacterials in the near future.     

Strategy for treatment of Helicobacter pylori infection in adults. II. Practical policy in 2000

The approach to the patient with suspected H. pylori infection consists of an adequate indication to test for the presence of the infection, choice of an appropriate antimicrobial regimen, and education about its use and side effects, followed by post-therapy testing to confirm cure. We review the drugs and regimens for H. pylori eradication and present a strategy for treating the infection. The major factor in choosing an antibiotic regimen is the pattern of antibiotic resistance in the community. Triple therapy with a proton pump inhibitor (PPI) or ranitidine bismuth citrate (RBC) and two antimicrobials is recommended as the first choice regimen. In regions where metronidazole and clarithromycin resistance are common, initial therapy with quadruple therapy consisting of bismuth, metronidazole, tetracycline, and a PPI is recommended. In general, higher doses and longer durations are associated with better outcomes. For this reason we recommend that the minimum duration of 10 days and we prefer 14 days. The actual choice of the antimicrobial combination will also be influenced by the drugs approved by the local regulatory bodies. Side effects, eradication failure and current as well as future designs of eradication therapies are also discussed.     

Helicobacter pylori-positive duodenal ulcer: three-day antibiotic eradication regimen

BACKGROUND: The most widely used treatments for ulcer healing and Helicobacter pylori eradication consist of a 1-2 week regimen of a proton pump inhibitor plus two or three antimicrobials. AIMS: To evaluate the efficacy, safety, cost, and tolerance of a three-day regimen with three antibiotics vs. a 10-day treatment with a proton pump inhibitor or vs. a ranitidine bismuth citrate triple therapy. METHODS: Two hundred and twenty-one patients with endoscopically-proven H. pylori-positive duodenal ulcers were recruited to the study. Recruited patients were assigned to one of the following four regimens: (I) omeprazole 40 mg o.m. plus amoxycillin 1 g b.d. and clarithromycin 500 mg b.d. for 10 days (OAC: 55 patients); (ii) omeprazole 40 mg o.m. on days 1-5, plus amoxycillin 1 g b.d., clarithromycin 500 mg b.d. and metronidazole 500 mg b.d. on days 3-5 (OACM: 56 patients); (iii) ranitidine bismuth citrate 400 mg b.d. plus amoxycillin 1 g b.d. and clarithromycin 500 mg b.d. for 10 days (RAC: 54 patients); (iv) ranitidine bismuth citrate 400 mg b.d. on days 1-5, plus amoxycillin 1 g b.d., clarithromycin 500 mg b.d. and metronidazole 500 mg b.d. on days 3-5 (RACM: 56 patients). Fisher's exact test was used to compare data regarding healing and eradication in the four groups. RESULTS: The intention-to-treat eradication and ulcer healing rates for the RACM regimen were 95% and 98%, respectively. Statistically significant differences were observed, relating to the eradication and healing of ulcers, between RACM and either the RAC or OAC regimens. CONCLUSION: The three-day antibiotic therapy with amoxycillin, clarithromycin and metronidazole in addition to ranitidine bismuth citrate is a very effective anti-H. pylori regimen.     

One-week ranitidine bismuth citrate-based triple therapy for the eradication of Helicobacter pylori in Hong Kong with high prevalence of metronidazole resistance

AIM: To compare 1-week ranitidine bismuth citrate-based (RBC) triple therapy vs. omeprazole-based (O) triple therapy for the eradication of Helicobacter pylori infection in Hong Kong with high prevalence of metronidazole resistance. METHODS: Patients with non-ulcer dyspepsia and H. pylori infection were randomized to receive either: (i) RBCCM: ranitidine bismuth citrate (pylorid) 400 mg, clarithromycin 250 mg and metronidazole 400 mg; or (ii) OCM: omeprazole 20 mg, clarithromycin 250 mg and metronidazole 400 mg, each given twice daily for 1 week. Endoscopy (CLO test, histology and culture) and 13C-urea breath test were performed before randomization and 6 weeks after drug treatment. RESULTS: A total of 180 patients were randomized. H. pylori eradication rates (intention-to-treat, n=180/per protocol, n=166) were 83%/92% for RBCCM and 66%/70% for OCM (P=0.01, intention-to-treat and P=0.001, per protocol, respectively). RBCCM treatment was unaffected by metronidazole susceptibility and achieved a significantly higher eradication rate in metronidazole-resistant cases (89%) than the OCM group (45%, P=0.0064). CONCLUSION: One-week ranitidine bismuth citrate-based triple therapy is significantly better than omeprazole-based triple therapy for the eradication of H. pylori infection, especially in metronidazole-resistant cases. It is an effective regimen for the eradication of H. pylori infection in regions with a high prevalence of metronidazole resistance.     

Current concepts in the management of Helicobacter pylori infection--the Maastricht 2-2000 Consensus Report

Significant progress and new insights have been gained in the 4 years since the first Maastricht Consensus Report, necessitating an update of the original guidelines. To achieve this, the European Helicobacter Pylori Study Group organized a meeting of specialists and experts from around the world, representatives from National Gastroenterology Societies and general practitioners from Europe to establish updated guidelines on the current management of Helicobacter pylori infection. The meeting took place on 21-22 September 2000. A "test and treat" approach is recommended in adult patients under the age of 45 years (the age cut-off may vary locally) presenting in primary care with persistent dyspepsia, having excluded those with predominantly gastro-oesophageal reflux disease symptoms, non-steroidal anti-inflammatory drug users and those with alarm symptoms. Diagnosis of infection should be by urea breath test or stool antigen test. As in the previous guidelines, the eradication of H. pylori is strongly recommended in all patients with peptic ulcer, including those with complications, in those with low-grade gastric mucosa-associated lymphoid tissue lymphoma, in those with atrophic gastritis and following gastric cancer resection. It is also strongly recommended in patients who are first-degree relatives of gastric cancer patients and according to patients' wishes after full consultation. It is advised that H. pylori eradication is considered to be an appropriate option in infected patients with functional dyspepsia, as it leads to long-term symptom improvement in a subset of patients. There was consensus that the eradication of H. pylori is not associated with the development of gastro-oesophageal reflux disease in most cases, and does not exacerbate existing gastro-oesophageal reflux disease. It was agreed that the eradication of H. pylori prior to the use of non-steroidal anti-inflammatory drugs reduces the incidence of peptic ulcer, but does not enhance the healing of gastric or duodenal ulcer in patients receiving antisecretory therapy who continue to take non-steroidal anti-inflammatory drugs. Treatment should be thought of as a package which considers first- and second-line eradication therapies together. First-line therapy should be with triple therapy using a proton pump inhibitor or ranitidine bismuth citrate, combined with clarithromycin and amoxicillin or metronidazole. Second-line therapy should use quadruple therapy with a proton pump inhibitor, bismuth, metronidazole and tetracycline. Where bismuth is not available, second-line therapy should be with proton pump inhibitor-based triple therapy. If second-line quadruple therapy fails in primary care, patients should be referred to a specialist. Subsequent failures should be handled on a case-by-case basis by the specialist. In patients with uncomplicated duodenal ulcer, eradication therapy does not need to be followed by further antisecretory treatment. Successful eradication should always be confirmed by urea breath test or an endoscopy-based test if endoscopy is clinically indicated. Stool antigen test is the alternative if urea breath test is not available.     

Comparison of 1-week vs. 2- or 4-week therapy regimens with ranitidine bismuth citrate plus two antibiotics for Helicobacter pylori eradication

BACKGROUND: Helicobacter pylori eradication therapies based on ranitidine bismuth citrate have recently been introduced in clinical practice. AIM: To compare the efficacy of three regimens containing ranitidine bismuth citrate given for 1, 2 and 4 weeks, combined with two antibiotics for the first week, in the eradication of H. pylori. METHODS: Eighty-six consecutive patients (50 duodenal ulcer disease, 36 non-ulcer dyspepsia) with H. pylori infection were offered three eradication regimens: (a) 1-week group (n=28), ranitidine bismuth citrate 400 mg b.d. for 7 days; (b) 2-week group (n=29), ranitidine bismuth citrate 400 mg b.d. for 14 days; and (c) 4-week group (n=29), ranitidine bismuth citrate 400 mg b.d. for 28 days. In all patients, clarithromycin 500 mg b.d. and metronidazole 500 mg b.d. were given for the first week. Endoscopy was repeated 1 month after the end of treatment and eradication was considered to be successful if both rapid urease test and histology were negative. RESULTS: Overall, H. pylori was eradicated in 84% (72/86) patients on intention-to-treat analysis, whereas the per protocol cure rate was 89% (72/81). Eradication rates were 23/27 (85%) (95% confidence interval (CI): 66-96%), 25/27 (92%) (95% CI: 76-99%) and 24/27 (89%) (95% CI: 71-98%) in the 1-, 2- and 4-week groups, respectively, on per protocol analysis, and 25/28 (82%) (95% CI: 63-94%), 25/29 (86%) (95% CI: 68-96%) and 24/29 (83%) (95% CI: 64-94%), respectively, on intention-to-treat analysis (P > 0.05, N.S.). No significant differences were observed between groups concerning duodenal ulcer healing, resolution of symptoms and adverse effects. CONCLUSIONS: The 1-week regimen with ranitidine bismuth citrate, clarithromycin and metronidazole is effective in H. pylori eradication. Prolongation of treatment with ranitidine bismuth citrate for 2 or 4 weeks does not achieve a statistically significant more favourable outcome.     

Pharmacokinetic considerations in the eradication of Helicobacter pylori

As Helicobacter pylori plays an important role in the aetiopathogenesis of peptic ulcer, therapeutic strategies aimed at maintaining long term remission have shifted from the control of intragastric pH to targeting H. pylori. According to recent international guidelines the clinical goals--rapid ulcer healing and prevention of relapse--can be best accomplished by combination therapy consisting of an antisecretory drug (proton pump inhibitor or ranitidine) and 2 antimicrobial agents (preferable amoxicillin, clarithromycin or metronidazole). When applying such multidrug regimens, possible synergy between the agents suggests that pharmacokinetic considerations might help to improve H. pylori eradication rates, which should be above 85 to 90% on an intention-to-treat basis. The present review summarises the pharmacokinetic properties and interaction potential of all drugs presently used in the various H. pylori eradication regimens, with emphasis on particular patient populations such as the elderly and those with renal impairment. The drugs considered are omeprazole, lansoprazole, pantoprazole, rabeprazole, ranitidine and ranitidine bismutrex, bismuth salts, amoxicillin, clarithromycin, azithromycin, roxithromycin, metronidazole, tinidazole and tetracycline. When addressing the clinically important questions of the efficacy, safety and costs of the recommended regimens, the impact of drug disposition on H. pylori eradication should not be neglected.     

Ranitidine bismuth citrate with clarithromycin alone or with metronidazole for the eradication of Helicobacter pylori

BACKGROUND: Both triple therapy with ranitidine bismuth citrate (RBC) plus two antibiotics for 7 days and dual therapy of RBC with clarithromycin for 14 days have been extensively studied; both regimens effectively eradicate Helicobacter pylori. However, few studies have assessed the efficacy of dual therapy given for 7 days. AIM: To compare the efficacy and safety of RBC 400 mg with clarithromycin 500 mg, alone or with metronidazole 400 mg, given twice daily for 7 days for the eradication of H. pylori. METHODS: This single centre, randomized, double-blind study involved 118 patients with dyspepsia or a history of peptic ulcer disease. H. pylori infection was detected initially by CLO test, and confirmed in 109 patients by urea breath test and/or microbiology culture. H. pylori eradication was assessed 4 and 12 weeks after the end of treatment by urea breath test. H. pylori antibiotic susceptibility was assessed pre-study in all patients, and post-treatment in patients with a positive post-treatment urea breath test. Adverse events were recorded throughout the study. RESULTS: H. pylori was eradicated in 93% of patients who received RBC with clarithromycin and metronidazole and in 84% of patients who received RBC with clarithromycin (intention-to-treat rates). Per protocol eradication rates were 98% and 90% for triple therapy and dual therapy, respectively. The eradication of metronidazole-resistant H. pylori was achieved in 100% and 88% of patients following dual therapy and triple therapy, respectively, and acquired resistance to clarithromycin occurred in only one patient following treatment failure. Both treatments were well-tolerated; only one patient (2%) was withdrawn from each treatment group due to adverse events. CONCLUSIONS: RBC with clarithromycin and metronidazole is a highly effective and well-tolerated triple therapy regimen for the eradication of H. pylori. RBC with clarithromycin dual therapy has a similar efficacy, and offers an alternative to triple therapy when there are concerns about treatment with metronidazole or the use of multiple antibiotics. Both regimens are effective against antibiotic-resistant strains of H. pylori.     

One-week regimens containing ranitidine bismuth citrate, furazolidone and either amoxicillin or tetracycline effectively eradicate Helicobacter pylori: a multicentre, randomized, double-blind study

BACKGROUND: The metronidazole resistance of Helicobacter pylori strains has increased rapidly. AIM: To evaluate the efficacy and safety of new 1-week regimens containing ranitidine bismuth citrate, furazolidone and either amoxicillin or tetracycline. METHODS: One hundred and twenty patients with H. pylori-positive inactive duodenal ulcer or non-ulcer dyspepsia diagnosed by endoscopy were recruited randomly to receive one of two regimens for 7 days: ranitidine bismuth citrate, 350 mg b.d., furazolidone, 100 mg b.d., and either amoxicillin, 1000 mg b.d. (n=60), or tetracycline, 500 mg b.d. (n=60). H. pylori infection was identified by rapid urease testing and histology. 13C-Urea breath test was performed to evaluate the cure of H. pylori infection at least 4 weeks after completion of triple therapy. RESULTS: The eradication rates of H. pylori by ranitidine bismuth citrate-furazolidone-amoxicillin and ranitidine bismuth citrate-furazolidone-tetracycline regimens were 82% and 85% (P > 0.05), respectively, by intention-to-treat analysis, and 85% and 91% (P > 0.05), respectively, by per protocol analysis. Adverse effects were mild in both ranitidine bismuth citrate-furazolidone-amoxicillin and ranitidine bismuth citrate-furazolidone-tetracycline groups. CONCLUSIONS: One-week regimens containing ranitidine bismuth citrate, furazolidone and amoxicillin or tetracycline are well tolerated and effective for the eradication of H. pylori.     

Effect of ornidazole and clarithromycin resistance on eradication of Helicobacter pylori in peptic ulcer disease

BACKGROUND: Clarithromycin and nitroimidazoles such as metronidazole and ornidazole are among the most frequently used antibiotics for curing Helicobacter pylori infection. However, controversial data exist on whether their in vitro resistance has a negative impact on treatment outcome. METHODS: Patients with H. pylori positive active peptic ulcer disease were randomly assigned to receive lansoprazole 30 mg o.d., amoxycillin 1 g b.d. and ornidazole 500 mg b.d. (LAO) or lansoprazole 30 mg o.d., amoxycillin 1 g b.d. and clarithromycin 500 mg b.d. (LAC) for 2 weeks. Pre-treatment resistance to ornidazole and clarithromycin was assessed by Epsilometer (E-) test. Four weeks after completion of treatment, patients underwent a 13C urea breath test to assess H. pylori status. RESULTS: Data from 80 patients with active peptic ulcer disease and positive H. pylori status were analysed. The prevalence of primary drug resistance was 25% for metronidazole and 7.5% for clarithromycin. In patients treated with LAO, effective treatment was achieved in 87% of metronidazole-susceptible, but only 30% of metronidazole-resistant strains (P < 0.01). In the LAC group, therapy was successful in 81% of clarithromycin-susceptible strains, whereas treatment failed in all patients with primary clarithromycin resistance (n = 3). CONCLUSION: Resistance against nitroimidazoles significantly affects treatment outcome in H. pylori eradication therapy.     

Seven-day triple therapy with ranitidine bismuth citrate or omeprazole and two antibiotics for eradication of Helicobacter pylori in duodenal ulcer: a multicentre, randomized, single-blind study

AIM: To investigate the efficacy of a 1-week triple therapy with amoxycillin, clarithromycin, and omeprazole or ranitidine bismuth citrate (RBC) in curing Helicobacter pylori infection and healing duodenal ulcers. METHODS: One hundred and ninety-two consecutive out-patients with duodenal ulcer, in whom H. pylori infection was confirmed by histology and a urease biopsy test, were randomly assigned to a 1-week treatment with either 400 mg b.d. ranitidine bismuth citrate (RAC group) or 20 mg omeprazole b.d. (OAC group) in combination with 1 g amoxycillin b.d. and 500 mg clarithromycin b.d. RESULTS: Eradication of H. pylori was successful in 77% (per protocol) and 61% (intention-to-treat) of the patients in the RAC group and in 79% (per protocol) and 70% (intention-to-treat) of those in the OAC group. The difference was not significant. Per protocol analysis showed ulcers were healed in 97% of patients in the RAC group and 96% in the OAC group. Adverse effects were seen in four patients in each group: they caused discontinuation of the therapy in one patient of the OAC group. CONCLUSIONS: Eradication rates obtained in this study were lower than those expected on the basis of previously reported studies. The two 1-week treatment regimens were equally effective in healing H. pylori associated duodenal ulcer disease.     

Antibiotic resistance problems with Helicobacter pylori.

Helicobacter pylori is very susceptible in vitro to most antibiotics, but when they are used in the clinical setting, eradication of the bacteria from the gastric mucosa is not obtained. Dual or triple therapy including two of the following antibiotics: amoxicillin, tetracycline, metronidazole or clarithromycin, plus a proton pump inhibitor, bismuth salt or ranitidine bismuth citrate is the most frequently used. Various in vitro susceptibility methods have been used: disk diffusion, agar dilution and Epsilometer test (E-test). Metronidazole resistance among H. pylori strains is now found worldwide, and resistance rates vary according to the population studied. It is higher in developing than in developed countries and it could reach 80-90% in Africa. The prevalence on clarithromycin resistance is much lower, usually below 10%, although very high values are reported in Peru. Infection with metronidazole- or clarithromycin-resistant H. pylori strains is correlated with treatment failure when using regimens including these antibiotics.