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.     

A new quadruple therapy for Helicobacter pylori: influence of resistant strains on treatment outcome

BACKGROUND: There have been no reports concerning the efficacy and safety of a 1-week quadruple therapy regimen of omeprazole, amoxycillin, roxithromycin and metronidazole for Helicobacter pylori infections and the impact of primary resistance on the eradication rate. METHODS: One hundred and sixty-nine consecutive patients with peptic ulcer disease as well as gastritis with biopsy-proven H. pylori infection were entered into an open study of omeprazole 20 mg o.m., amoxycillin 500 mg t.d.s., roxithromycin 150 mg b.d., and metronidazole 250 mg t.d.s. Helicobacter pylori status was determined by urease test, histology and culture. Susceptibility to amoxycillin, metronidazole and roxithromycin was determined by the E-test. RESULTS: H. pylori was eradicated in 155 out of 169 (92%; 95% CI 88-96%) by intention-to-treat analysis, and in 155 out of 163 (95%; 95% CI 92-98%) by per protocol analysis. The prevalence of primary resistance against amoxycillin, roxithromycin and metronidazole was 2 out of 166 (1%), 16 out of 166 (10%) and 27 out of 166 (16%), respectively. H. pylori was eradicated in 25 out of 27 (93%) patients with metronidazole-resistant strains compared with 130 out of 136 (96%) in patients with metronidazole-sensitive strains of H. pylori. It was eradicated in 15 out of 16 (94%) patients with roxithromycin-resistant strains while in 140 out of 147 (95%) patients with roxithromycin-sensitive strains of H. pylori, and in two out of two (100%) patients with amoxycillin-resistant stains compared with 153 out of 161 (95%) in patients with amoxycillin-sensitive strains. H. pylori was eradicated in three out of four (75%) patients with double resistance against metronidazole and roxithromycin compared with 152 out of 159 (96%) patients with sensitive strains to metronidazole and or roxithromycin. None of these differences were statistically significant. Severe side-effects were found in only one out of 169 patients-anaphylaxis due to penicillin. CONCLUSIONS: The 1-week quadruple therapy with omeprazole, amoxycillin, metronidazole and roxithromycin was found to eradicate H. pylori in over 90% of all patients. This regimen was also found to be beneficial for patients with pre-treatment resistant strains to metronidazole, roxithromycin or amoxycillin, and was observed to be safe and well-tolerated.     

Randomized trial of omeprazole and clarithromycin combined with either metronidazole or amoxycillin in patients with metronidazole-resistant or -susceptible Helicobacter pylori strains

BACKGROUND: The impact of metronidazole resistance on the efficacy of proton pump inhibitor based triple therapies remains unclear. AIM: To study whether metronidazole resistance affects Helicobacter pylori eradication rates in patients treated for 1 week with either omeprazole 20 mg b.d., metronidazole 400 mg b.d. and clarithromycin 250 mg b.d. (OMC), or omeprazole 20 mg b.d., amoxycillin 1000 mg b.d. and clarithromycin 500 mg b.d. (OAC). METHODS: A randomized, single blind, single centre study with parallel groups was conducted. H. pylori positive patients were enrolled in a metronidazole-resistant (MR; MIC > 8 microgram/mL) or a metronidazole-susceptible group (MS; MIC < 4 microgram/mL), as determined by E-test. Within the strata patients were randomized to either OAC or OMC. RESULTS: One hundred and twenty-two patients were included. The per protocol cure rate for OAC was 52 out of 57 (91%) (MS 23 out of 26 (89%); MR 29 out of 31 (94%)) and for OMC 46 out of 55 (84%) (MS 19 out of 22 (86%); MR 27 out of 33 (82%)). CONCLUSIONS: One-week OAC and OMC are effective therapies. OAC and OMC were equally effective in patients with metronidazole-susceptible strains of H. pylori. Using the OMC regimen, neither equality nor significant differences in treatment outcome could be shown between patients with metronidazole-resistant or -susceptible strains of H. pylori.     

Efficacy of triple therapy comprising rabeprazole,amoxicillin and metronidazole for second-line Helicobacter pylori eradication in Japan,and the influence of metronidazole resistance

BACKGROUND: The widespread use of eradication therapy for Helicobacter pylori in Japan has led to an increase in antibiotic-resistant strains and the problem of re-treatment in cases of eradication failure. AIM: To perform drug sensitivity testing for metronidazole in 92 H. pylori-positive patients who had failed eradication treatment with first-line triple therapy, consisting of a proton pump inhibitor, amoxicillin and clarithromycin, and were administered metronidazole-containing second-line therapy. METHODS: Second-line eradication therapy, consisting of rabeprazole (20 mg b.d.), amoxicillin (750 mg b.d.) and metronidazole (250 mg b.d.), was administered for 1 week and the eradication rates and influence of metronidazole resistance were determined. RESULTS: The eradication rates for rabeprazole-amoxicillin-metronidazole were 88% (81/92) using intention-to-treat analysis and 91% (81/89) using per protocol analysis. The eradication rates were 97% (61/63) for metronidazole-sensitive strains and 82% (18/22) for metronidazole-resistant strains. CONCLUSIONS: As second-line H. pylori eradication treatment in Japan, rabeprazole-amoxicillin-metronidazole triple therapy is effective, even with metronidazole-resistant strains.     

Comparison of two low-dose one-week triple therapy regimens with and without metronidazole for cure of H. pylori infection.

BACKGROUND: One-week triple therapy consisting of omeprazole 20 mg b.d., clarithromycin 250 mg b.d. and tinidazole 500 mg b.d. is an effective therapy for H. pylori infection with a cure rate of 93%. We therefore compared two similar 1-week regimens consisting of a lansoprazole, clarithromycin and either metronidazole or tetracycline in a prospective study. METHODS: Two cohorts, each of 60 patients suffering from H. pylori infection associated with peptic ulcer disease or ulcer-like dyspepsia, were treated for 1 week with either lansoprazole 30 mg b.d., clarithromycin 250 mg b.d. and either metronidazole 400 mg b.d. (cohort A, n = 60) or tetracycline 300 mg b.d. (cohort B, n = 60). Four weeks after treatment, cure of H. pylori infection was evaluated by endoscopy using rapid urease testing together with histology. RESULTS: In cohort A, 55 patients out of 60 showed cure of H. pylori infection (92%); the treatment was well tolerated, but three patients suffered from side-effects. In cohort B, which was free of metronidazole, 50 out of 60 patients showed cure of H. pylori infection (83%); two patients reported side-effects. The differences between the two cohorts were not statistically significant. CONCLUSION: Triple therapy for 1 week with lansoprazole as the antisecretory agent seems to be as effective as is reported for omeprazole-based regimens.     

Failure of a 1-day high-dose quadruple therapy for cure of Helicobacter pylori infection

BACKGROUND: The optimal duration of treatment for eradication of Helicobacter pylori has still to be defined. A 1-day high-dose quadruple therapy with a combination of amoxycillin (or tetracycline), metronidazole, a bismuth salt and a proton pump inhibitor has led to eradication rates of 57-77%. In view of the high frequency of metronidazole-resistant strains of H. pylori in Europe, we hypothesized that by using clarithromycin in place of metronidazole and by increasing the dose of proton pump inhibitor, the efficacy of a 1-day high-dose quadruple therapy could be improved. METHODS: Patients were randomized to receive either amoxycillin 1000 mg b.d., clarithromycin 500 mg b.d. and lansoprazole 30 mg b.d. for 7 days, or amoxycillin 2000 mg q.d.s., clarithromycin 500 mg q.d.s., lansoprazole 30 mg t.d.s. and bismuth subcitrate 240 mg q.d.s. for 1 day. RESULTS: It was originally intended to include 100 patients. The first planned interim analysis performed after follow-up was completed for 30 patients revealed H. pylori eradication rates of 80% (12/15) in the 7-day triple therapy group and 20% (3/15) in the 1-day quadruple therapy group, the difference being highly significant (P = 0.003). Because the efficacy of the 1-day treatment was so low, the study was stopped for ethical reasons. Eleven patients who failed with the 1-day treatment were re-treated with the 7-day triple therapy: the eradication rate was 91% (10/11). CONCLUSIONS: One-day high-dose quadruple therapy with amoxycillin, clarithromycin, lansoprazole and bismuth subcitrate is dramatically less effective than the classic 7-day triple therapy with the same antibiotics.     

Furazolidone-containing short-term triple therapies are effective in the treatment of Helicobacter pylori infection

BACKGROUND: A furazolidone-containing therapeutic regimen for Helicobacter pylori infection has attracted special interest in the face of a rising world-wide metronidazole resistant H. pylori, and the expense of currently used antimicrobial regimens. AIM: To evaluate the efficacy of furazolidone-containing regimens in eradicating H. pylori. METHODS: One-hundred and forty H. pylori positive patients with endoscopically confirmed duodenal ulcer or functional dyspepsia received one of four different regimens to eradicate H. pylori. In the first trial, the patients were randomly assigned to receive a 1-week course of furazolidone 100 mg b.d. and clarithromycin 250 mg b.d., with either tripotassium dicitrato bismuthate (TDB) 240 mg b.d. (FCB group) or lansoprazole 30 mg daily (FCL group). In the second trial, the patients were randomly assigned to receive a 1-week course of clarithromycin 250 mg b.d. and omeprazole 20 mg daily, with either furazolidone 100 mg b.d. (FCO group) or metronidazole 400 mg b.d. (MCO group). Endoscopy was repeated 4 weeks following completion of therapy with re-assessment of H. pylori status on gastric biopsies by histology and culture. RESULTS: Four patients (1 in FCB, 1 in FCO and 2 in MCO groups) dropped out because they refused a follow-up endoscopy. Eradication rates of H. pylori on an intention-to-treat basis in the FCB, FCL, FCO and MCO groups were 91% (32/35, 95% CI: 82-99%), 91% (32/35, CI: 82-99%), 86% (30/35, CI: 74-97%) and 74% (26/35, CI: 60-89%) (all P > 0.05), respectively. Mild side-effects occurred in 15% of the 140 patients. In MCO group, the eradication rate in the patients infected with metronidazole-sensitive isolates of H. pylori was 86%, but dropped to 67% in those with metronidazole-resistance strains (P = 0.198). CONCLUSION: One-week regimens containing furazolidone and clarithromycin in combination with TDB or a proton pump inhibitor fulfil the criteria for successful H. pylori therapy.     

One-week triple therapy with omeprazole, amoxycillin and either clarithromycin or metronidazole for cure of Helicobacter pylori infection

Aim: The present study was designed to evaluate the efficacy and tolerability of 1-week triple therapy regimens for Helicobacter pylori .
Methods: In two consecutive series, 120 patients with proven H. pylori infection and peptic ulcer disease or functional dyspepsia were treated with either omeprazole 20 mg b.d., amoxycillin 1 g b.d. and clarithromycin 250 mg b.d. (OAC; n=60) or with omeprazole 20 mg b.d., amoxycillin 1 g b.d. and metronidazole 400 mg b.d. over 1 week (OAM; n=60). H. pylori infection was assessed by rapid urease test, culture and histology before and 4 weeks after cessation of the eradication therapy.
Results: H. pylori eradication succeeded in 53 out of 60 patients by omeprazole–amoxycillin–clarithromycin (OAC) (88%; 95% CI 77–95%) and in 47 out of 60 patients by omeprazole–amoxycillin–metronidazole (OAM) (78%; 95% CI 66–88%) (P=0.22). Nine patients of each group available for follow-up reported adverse events (15.0 and 15.5%, respectively) without necessity of discontinuation of the study medications. Serious adverse events were not observed.
Conclusions: Simple and convenient 1-week triple therapies consisting of omeprazole, amoxycillin and either clarithromycin or metronidazole are sufficiently effective in eradicating H. pylori infection.     

Furazolidone combination therapies for Helicobacter pylori infection in the United States

BACKGROUND: Antibiotic resistance has begun to impair the ability to cure Helicobacter pylori infection. AIM: To evaluate furazolidone as a component of combination therapies for treatment of H. pylori infection in the United States. METHODS: Patients with active H. pylori infection received furazolidone combination therapy for 14 days (furazolidone 100 mg and tetracycline 500 mg t.d.s.; omeprazole 20 mg o.d. in the morning and, depending on the pre-treatment antimicrobial susceptibility pattern, 500 mg of metronidazole or clarithromycin t.d.s.). RESULTS: A total of 27 patients received the metronidazole containing combination (cure rate 100%) and seven received the clarithromycin combination (cure rate 86%). Overall the cure rates for intention-to-treat was 97% (95% CI: 85% to 100%). The single failure took the clarithromycin containing combination for only 2 days (per protocol cure rate = 100%). Side-effects were common and led to discontinuation of therapy in 26% of patients. An attempt to eliminate metronidazole and clarithromycin and use furazolidone, tetracycline, and lansoprazole b.d. produced an unsatisfactory cure rate of 72%. CONCLUSION: Furazolidone combination therapy appears to be effective. Additional studies with different antimicrobial combinations and duration of therapy are warranted.     

Helicobacter pylori eradication using one-week low-dose lansoprazole plus amoxycillin and either clarithromycin or azithromycin

Aim : To evaluate and compare two 1-week low-dose triple therapies based on lansoprazole, amoxycillin and a macrolide in eradicating Helicobacter pylori .
Methods : Seventy consecutive patients, suffering from dyspeptic symptoms with H. pylori infection, were randomly allocated to one of two treatment groups: (A) (LAC; n =35) lansoprazole 30 mg once daily, amoxycillin 1000 mg b.d., clarithromycin 250 mg b.d., all for 7 days; and (B) (LAA; n =35) lansoprazole 30 mg once daily and amoxycillin 1000 mg b.d., both for 7 days, plus azithromycin 500 mg once daily for only 3 days. The H. pylori status was evaluated by means of histology and rapid urease test at entry and 8 weeks after treatment.
Results : Three patients did not complete the treatment: one in the LAC group was withdrawn owing to severe side-effects; two patients in the LAA group stopped the treatment prematurely. H. pylori eradication was obtained in 28 of 34 (82%; 95% CI=66–93%) patients in the LAC group and in 20 of 33 (61%; 95% CI=42–77%) patients in the LAA group. The difference is significant ( P <0.029). On intention-to-treat analysis, the rates of eradication were (28 of 35 patients, 80% in the LAC group and 20 of 35 patients, 57% in the LAA group. Side-effects occurred in nine (26%) and six (18%) patients in the LAC and LAA groups, respectively.
Conclusions : Low-dose lansoprazole plus amoxycillin and clarithromycin is more effective than low-dose lansoprazole plus amoxycillin and azithromycin, but it gave a greater incidence of side-effects.     

The effect of antibiotic resistance on the outcome of three 1-week triple therapies against Helicobacter pylori

BACKGROUND: Resistance of Helicobacter pylori to antibiotics may be a major reason for treatment failure. AIM: To evaluate the effect of primary H. pylori resistance to antibiotics on the cure rates of three anti-H. pylori 1-week triple therapies. METHODS: One hundred and sixteen consecutive patients diagnosed H. pylori-positive by gastric histology, rapid urease test and culture were enrolled. Activity of tested antibiotics was determined by means of the E-test. Patients were treated for 7 days with: (i) pantoprazole 40 mg o.d. plus amoxycillin 1 g b.d. and metronidazole 250 mg q.d.s. (PAM); (ii) pantoprazole 40 mg o.d. plus clarithromycin 250 mg b.d. and metronidazole 250 mg q.d.s. (PCM); or (iii) pantoprazole 40 mg o.d. plus amoxycillin 1 g b.d. and clarithromycin 250 mg b.d. (PAC). Two months after completion of therapy, endoscopy and gastric biopsies were repeated. RESULTS: Primary resistance rates to metronidazole, clarithromycin and amoxycillin were 17.2, 6.9 and 0%, respectively. Overall H. pylori cure rates expressed as intention-to-treat and per protocol analyses were, respectively, 79% and 86% with PAM, 82% and 89% with PCM, and 85% and 85% with PAC. Significantly lower cure rates were observed in metronidazole-resistant patients treated with PAM (56% vs. 96%, P = 0.01) or PCM (50% vs. 97%, P = 0.01). A trend towards lower H. pylori cure rates was observed in clarithromycin-resistant patients treated with PCM (67% vs. 91%, P = 0.74) or PAC (50% vs. 87%, P = 0.68). CONCLUSION: Primary resistance to metronidazole influences the H. pylori cure rate of anti-H. pylori proton pump inhibitor-based triple therapies which include this antibiotic. A similar trend exists for primary clarithromycin resistance.     

Impact of clarithromycin resistance on the effectiveness of a regimen for Helicobacter pylori: a prospective study of 1-week lansoprazole, amoxycillin and clarithromycin in active peptic ulcer

BACKGROUND: Clarithromycin is a key antimicrobial in the combinations used to cure Helicobacter pylori infections, so there is a need to define the impact of in vitro resistance on in vivo results. METHODS: A prospective trial was designed to study the effectiveness of the 1-week combination of lansoprazole, clarithromycin and amoxycillin in 102 consecutive patients with active peptic ulcer. The pre-treatment and post-treatment sensitivity to amoxycillin, metronidazole and clarithromycin were studied by E-test, and H. pylori status was defined by histology, culture and urease test at diagnosis and one month after treatment, and by urea-breath test 2 months after treatment. RESULTS: The eradication rate (intention-to-treat analysis) was 77% (95% CI: 69-86). No clinical factor was found to be different between eradicated and non-eradicated patients. Clarithromycin-resistant strains were found in 10 (10%; CI: 5-17) patients. The eradication rate was 20% (CI: 3-56) in these patients vs. 83% (CI: 75-91) in patients harbouring clarithromycin-sensitive strains (P < 0.001). A logistic-regression analysis confirmed clarithromycin resistance as the only factor associated with treatment failure. CONCLUSIONS: Clarithromycin resistance significatively impairs the effectiveness of the combination of lansoprazole, amoxycillin, and clarithromycin. The 80% efficacy goal will be difficult to reach in areas with high (>10%) primary clarithromyicin resistance, if currently recommended proton pump inhibitor-triple therapies are used.     

Helicobacter pylori infection treated with a tripotassium dicitrato bismuthate and metronidazole combination

Seventy-two patients with H. pylori infection in their antral mucosa took part in the study. Forty-three received metronidazole 400 mg t.d.s. for two weeks, plus De-Nol tabs 2 b.d. for four weeks, and the remaining 29 patients received metronidazole 400 mg t.d.s. for two weeks plus De-Nol liquid 5 ml q.d.s. for four weeks. Seven of 57 H. pylori isolates were found to have pre-treatment metronidazole resistance. Success, in terms of eradication of H. pylori, was assessed using a one-month post-treatment 14C urea breath test. Successful eradication of H. pylori was achieved in 72% and 79%, respectively, of the metronidazole/De-Nol tablet and metronidazole/De-Nol liquid groups. These figures increased to 87% and 84%, respectively, if the patients whose organisms were known to be metronidazole-sensitive were considered in isolation. H. pylori was successfully eradicated in only one of seven patients with a metronidazole-resistant organism.     

Primary resistance to antibiotics and its clinical impact on the efficacy of Helicobacter pylori lansoprazole-based triple therapies

AIM: To evaluate Helicobacter pylori primary resistance and its clinical impact on the efficacy of two lansoprazole-based eradication triple therapies. METHODS: H. pylori-positive patients (n=228) were randomized to receive one of the 1-week regimens: lansoprazole 30 mg, clarithromycin 500 mg and amoxicillin 1 g (LAC), or lansoprazole 30 mg, clarithromycin 500 mg and metronidazole 500 mg (LMC), each given twice daily. H. pylori status was assessed by 13C-urea breath test and culture at diagnosis and by 13C-urea breath test 6 weeks after therapy. Antibiotic susceptibility was determined by E-test (n=98). RESULTS: The eradication rates with per protocol/ intention-to-treat analyses were: LAC (n=95/114) 83%/69% and LMC (n=96/114) 85%/72%. Primary resistance was 11% for clarithromycin, 41% for metronidazole and 0% for amoxicillin. Eradication in metronidazole-susceptible/-resistant strains was 85%/82% in LAC and 83%/63% in LMC. Significantly lower cure rates were observed in clarithromycin-resistant patients treated with LAC (95% vs. 0%, P < 0.001) and LMC (86% vs. 0%, P < 0.001). CONCLUSIONS: One-week LAC and LMC are similarly effective therapies. Clarithromycin resistance significantly affected H. pylori eradication in both regimens.     

Comparison of lansoprazole-based triple and dual therapy for treatment of Helicobacter pylori-related duodenal ulcer: an Asian multicentre double-blind randomized placebo controlled study

BAKCGROUND: In Asian countries with limited resources, clarithromycin-based triple therapy may not be readily available. There are also few direct comparisons of different regimens in Asia. AIM: To compare two lansoprazole-based non-clarithromycin triple therapies and one dual therapy in a prospective double-blind placebo-controlled study of Helicobacter pylori eradication and duodenal ulcer healing. METHODS: Fourteen centres in Asia participated in this study. Patients with acute duodenal ulcer who were H. pylori-positive were recruited. They were randomized to receive: (a) lansoprazole 30 mg b.d., amoxycillin 1 g b.d. and metronidazole 500 mg b.d. for 2 weeks (LAM-2 W), or (b) LAM for 1 week and placebo (LAM-1 W), or (c) lansoprazole 30 mg b.d., amoxycillin 1 g b.d. and placebo for 2 weeks (LA-2 W). Upper endoscopy was repeated at week 6 to check for duodenal ulcer healing. Symptoms and side-effects were recorded. RESULTS: A total of 228 patients were recruited, and two patients took less than 50% of the drugs. H. pylori eradication rates (intention-to-treat) were 68 out of 82 (83%) with LAM-2 W, 55 out of 71 (78%) with LAM-1 W and 43 out of 75 (57%) with LA-2 W. There were significant differences (P=0. 001) in eradication rates when comparing either LAM-2 W or LAM-1 W with LA-2 W. The eradication rate in patients with metronidazole resistant H. pylori strains were significantly lower than those with metronidazole sensitive strains (P=0.0001). The duodenal ulcer healing rates at week 6 were 85%, 85% and 72% in LAM-2 W, LAM-1 W and LA-2 W, respectively (P=0.065). Side-effects occurred in 13%, 11% and 9% in LAM-2 W, LAM-1 W and LA-2 W, respectively. H. pylori eradication and initial ulcer size were factors affecting duodenal ulcer healing. CONCLUSIONS: This Asian multicentre study showed that 1-week lansoprazole-based triple therapy without clarithromycin has similar efficacy in H. pylori eradication and ulcer healing compared with a 2-week regimen. Both triple therapies were significantly better than dual therapy in H. pylori eradication. Therefore, 1-week lansoprazole-based triple therapy is as safe and effective as 2-week therapy in eradication of H. pylori infection and healing of duodenal ulcer in these Asian centres.     

The impact of antibiotic resistance on the efficacy of three 7-day regimens against Helicobacter pylori

BACKGROUND: Antibiotic resistance affects the success of anti-Helicobacter pylori therapies and varies greatly from country to country. AIM: To compare the efficacy of three short-term triple regimens in relation to H. pylori primary resistance in our region. METHODS: We enrolled 210 H. pylori-positive dyspeptic patients for this randomized, open, parallel-group study. Three arms of 70 patients each received the following 1-week regimens: (1) ranitidine bismuth citrate 400 mg b.d. + clarithromycin 250 mg b.d. + metronidazole 500 mg b.d. (RCM); (2) bismuth subcitrate 240 mg b.d. + amoxycillin 1000 mg b.d. + metronidazole 500 mg b.d. (BAM); (3) omeprazole 20 mg o.d. + clarithromycin 250 mg b.d. + metronidazole 500 mg b.d. (OCM). H. pylori was assessed by CLO-test and histology before and 4 weeks after therapy. Antibiotic resistance was assessed by E-test. RESULTS: On intention-to-treat analysis RCM was more effective than OCM (84% vs. 69%; P < 0.03) and BAM (84% vs. 63%; P < 0.004). MIC determination was successful in 117 out of 210 patients (55%); metronidazole resistance was present in 52 out of 117 patients (44%) and clarithromycin resistance was present in 17 out of 117 patients (14%). Excellent cure rates were achieved when strains were sensitive to both antibiotics (100% with RCM and BAM and 90% with OCM), whereas RCM was superior to OCM (P=0.009) and BAM (P=0.001) with respect to overall resistant strains (94% vs. 57% and 38%, respectively). CONCLUSIONS: One-week RCM is the best regimen to eradicate H. pylori in our geographical area. This seems to be linked to the better ability of RCM compared to OCM and BAM in overcoming the high prevalence of H. pylori resistance to both metronidazole and clarithromycin in our region.     

Low-dose lansoprazole and clarithromycin plus metronidazole vs. full-dose lansoprazole and clarithromycin plus amoxicillin for eradication of Helicobacter pylori infection

AIM: To compare, in a randomized controlled trial, the efficacy and tolerability of two 1-week triple therapies for Helicobacter pylori eradication. METHODS: One hundred and thirty-four consecutive patients with non-ulcer dyspepsia and H. pylori infection were randomized to receive lansoprazole 30 mg once daily, clarithromycin 250 mg twice daily, and metronidazole 500 mg twice daily (LCM group), or lansoprazole 30 mg twice daily, clarithromycin 500 mg twice daily, and amoxicillin 1000 mg twice daily (LCA group). H. pylori status was assessed by rapid urease test, histology and 13C-urea breath test before and after therapy. RESULTS: At 3 months, H. pylori eradication (intention- to-treat/per protocol analysis) was 92.4%/93.8% in the LCM group and 83.1%/85.7% in the LCA group (P=N.S.). Side-effects were more frequently reported in the LCA group (37.9%) than in the LCM group (19.7%) (P < 0.05). CONCLUSIONS: In this open, randomized controlled trial, eradication of H. pylori by low-dose lansoprazole and clarithromycin plus metronidazole was higher with significantly less side-effects than by full-dose lansoprazole and clarithromycin plus amoxicillin. This finding may be related to the stronger synergism of clarithromycin plus metronidazole, even at lower doses, than of clarithromycin plus amoxicillin. Considering the lower cost as well, LCM should be preferred to LCA in the eradication of H. pylori.     

Famotidine versus omeprazole in combination with clarithromycin and metronidazole for eradication of Helicobacter pylori—a randomized, controlled trial

BACKGROUND: One-week low-dose triple therapy is currently considered the gold standard regimen for treatment of Helicobacter pylori infection. However, the mechanisms involved in the synergy between antibiotics and proton pump inhibitors are controversial. AIMS: To test the hypothesis that acid suppression represents the crucial mechanism by which the antibacterial activity of antibiotics can be enhanced, and to assess the impact of primary resistance on treatment outcome. METHODS: One hundred and twenty patients with H. pylori infection and duodenal ulcer, gastric ulcer or non-ulcer dyspepsia were randomly assigned to a 1 week course of either famotidine 80 mg b.d., clarithromycin 250 mg b.d. and metronidazole 500 mg b.d. (FCM group; n = 60) or omeprazole 20 mg o.d., clarithromycin 250 mg b.d. and metronidazole 500 mg b.d. (OCM group; n = 60). Gastroscopy was performed at baseline and 5 weeks after completion of treatment. H. pylori status was assessed by biopsy urease test, histology and culture. RESULTS: In the intention-to-treat analysis, eradication of H. pylori was achieved in 47 of 60 patients (78%; 95% CI: 66-88%) in the FCM group, compared to 44 of 60 patients (73%; 95% CI: 60-84%) in the OCM group (N.S.). Using per protocol analysis, eradication therapy was successful in 47 of 52 patients (90%; 95% CI: 79-97%) treated with FCM and 44 of 57 patients (77%; 95% CI: 64-87%) treated with OCM (N.S.). Primary metronidazole resistance was present in 27% and primary clarithromycin resistance in 8% of strains. Overall per protocol eradication rates in strains susceptible to both antibiotics and strains with isolated metronidazole resistance were 93% and 84%, respectively. No patient with clarithromycin resistance responded to treatment. CONCLUSIONS: High-dose famotidine and omeprazole, combined with clarithromycin and metronidazole, are equally effective for eradication of H. pylori. In 1-week low-dose triple therapy, metronidazole resistance has no major impact on eradication rates whereas clarithromycin resistance is associated with a poor treatment outcome.     

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.     

High cure rate of Helicobacter pylori infection using tripotassium dicitrato bismuthate, furazolidone and clarithromycin triple therapy for 1 week

BACKGROUND: When metronidazole is used in bismuth-based or proton pump inhibitor-based triple therapy, the cure rate of Helicobacter pylori is usually high. However, metronidazole-resistant H. pylori strains, which are increasing in frequency, are a major cause of failed H. pylori eradication. AIM: To evaluate the efficacy of non-metronidazole containing bismuth-based triple therapy for H. pylori infection. METHODS: One-hundred and eighty H. pylori-positive patients with endoscopically documented peptic ulcer disease or functional dyspepsia were randomly assigned to one of three 1-week regimens containing tripotassium dicitrato bismuthate (also called colloidal bismuth subcitrate) 240 mg b.d. and two antibiotics: furazolidone 100 mg b.d. plus clarithromycin 250 mg b.d. (Group A); or clarithromycin 250 mg b.d. plus amoxycillin 1000 mg b.d. (Group B); or furazolidone 100 mg b.d. plus josamycin 1000 mg b.d. (Group C). H. pylori status was assessed by rapid urease test, histology and culture of gastric biopsy specimens taken from both the antrum and corpus, both before and at least 4 weeks after completion of therapy. RESULTS: Thirteen patients dropped out (3 in group A, 5 in group B and 5 in group C). Based on an intention-to-treat analysis, the eradication rates achieved in groups A, B and C were 88% (53/60), 58% (35/60) and 77% (46/60), respectively. These differences were significant between groups A and B (P < 0.001), as well as between groups B and C (P < 0.05). Side-effects occurred in 7 (12%) patients in group A, 3 (5%) in group B and 8 (13%) in group C, and were mild, with the exception of vomiting in one patient (group C) that resulted in withdrawal from the study. CONCLUSION: One-week triple therapy, consisting of tripotassium dicitrato bismuthate, low-dose furazolidone and low-dose clarithromycin, achieves a high cure rate of H. pylori.