Supplementing vitamins C and E to standard triple therapy for the eradication of Helicobacter pylori

What is known and Objective: Helicobacter pylori eradication rates of currently accepted triple therapy regimens vary between geographic locations and do not exceed 70–80%. Eradication rates are much lower in locations where uncontrolled antibiotic use is common such as Turkey. In the present study, we aimed to test whether supplementing vitamins C and E to standard triple therapy, including a proton pump inhibitor plus amoxicillin plus clarithromycin, increased the H. pylori eradication rate. Methods: Two hundred patients infected with H. pylori were randomized into two groups in an open‐label trial. In group A, patients (n = 160) were given standard triple therapy, including lansoprazole 30 mg BID plus amoxicillin 1000 mg BID plus clarithromycin 500 mg BID for 14 days, plus vitamin C 500 mg BID plus vitamin E 200 IU BID for 30 days. In group B, patients (n = 40) were given standard triple therapy for 14 days. The success of H. pylori eradication was defined as a negative ¹⁴C‐urea breath test result, 4–6 weeks after the completion of therapy. Comaprisons were by both intention‐to‐treat (ITT) and per‐protocol (PP) analysis. Results and Discussion: Two hundred patients (137 women, 63 men) were analysed using ITT analysis and 195 patients completed the study. In group A, H. pylori eradication was achieved in 132 of the 160 patients (82·5%) included in ITT analysis and 132 of the 157 patients (84%) included in PP analysis. In group B, H. pylori eradication was achieved in 18 of the 40 patients (45%) included in ITT analysis and 18 of the 38 patients (47·4%) included in PP analysis. Eradication rates were significantly higher in group A than in group B (P < 0·005). Eradication rates were not statistically significant between men and women in both groups. What is new and Conclusion: Adding vitamins C and E to standard triple therapy increases the eradication rate of H. pylori. Vitamins C and E may increase the eradication rate via increasing the effectiveness of the antibiotics by decreasing oxidative stress in the gastric mucosa and strengthening the immune system.     

Incidence ofHelicobacter pylori infections and therapy for anastomotic ulcers and residual gastritis in patients with residual stomachs

Seventy-seven patients with the vestibular portion of their stomachs resected (residual stomach) due to ulcers or stomach cancers were included in this study. Fifty-five (71.4%) of these patients hadHelicobacter pylori infections.H. pylori was found in all patients with stomach cancer, esophageal cancer, or esophageal venous varicosity, and in 86.7% of patients with esophagitis, 78.6% with residual gastritis, 70.0% with anastomotic ulcers, and in 51.6% of patients with normal mucosa in their resected stomachs. The in vitro antibacterial activities of amoxicillin, erythromycin, clarithromycin, minocycline, nalidixic acid, ofloxacin, lansoprazole, and omeprazole were determined against 10 clinical isolates ofH. pylori. All agents except ofloxacin, nalidixic acid and omeprazole showed satisfactory bactericidal activities. The clinical and bacteriological efficacies of a combined treatment regimen with lansoprazole and clarithromycin were evaluated in 10 patients with anastomotic ulcers and 6 patients with residual stomach inflammation after informed consent. The clinical efficacy of this treatment in these 16 patients was excellent for 3 patients, good for 12 patients, and fair for the other patient. Collectively, the treatment was effective in 15/16 (93.8%) of patients. The bacteriological efficacy of this treatment regimen was evaluated in 14 patients, with no evidence ofH. pylori 13 (92.9%) patients.     

Dose-dependent inhibition of CYP3A activity by clarithromycin during Helicobacter pylori eradication therapy assessed by changes in plasma lansoprazole levels and partial cortisol clearance to 6beta-hydroxycortisol

OBJECTIVE: A 7-day triple therapy with lansoprazole, amoxicillin (INN, amoxicilline), and clarithromycin is widely used for eradication of Helicobacter pylori. Because clarithromycin is a potent inhibitor of cytochrome P450 (CYP) 3A, we investigated whether the standard triple therapy with clarithromycin would elicit clinically relevant CYP3A inhibition and alter CYP3A-mediated lansoprazole disposition in H pylori-positive patients. METHODS: Twenty H pylori-positive patients with peptic ulcer disease were randomly assigned to 2 groups: One group received 200 mg clarithromycin, 30 mg lansoprazole, and 750 mg amoxicillin at 8 am and 8 pm for 7 days; the other group received 400 mg clarithromycin, 30 mg lansoprazole, and 750 mg amoxicillin at 8 am and 8 pm for 7 days. Ten healthy control subjects received 30 mg lansoprazole and 750 mg amoxicillin at 8 am and 8 pm for 7 days but did not receive clarithromycin. Urine samples were collected for 3 hours (from 8 am to 11 am) for urinary 6beta-hydroxycortisol and cortisol assay, and midpoint (at 9:30 am) plasma samples for cortisol assay were obtained from all participants before the drug therapy (day 0) and on day 7. In vivo CYP3A activity was assessed by the partial cortisol clearance by means of the formation of 6beta-hydroxycortisol (CL(cortisol-->6beta-hydroxycortisol)) and the urinary 6beta-hydroxycortisol/cortisol ratio. Additional plasma samples for lansoprazole, 5-hydroxylansoprazole, and lansoprazole sulfone assay were obtained at 11 am on day 7. RESULTS: The groups of patients given 400 and 800 mg/day clarithromycin for H pylori eradication therapy showed 39% (from 2.20 +/- 1.29 to 1.35 +/- 0.88 mL/min [day 0 versus 7, mean +/- SD]; P <.05) and 68% (2.40 +/- 1.22 to 0.76 +/- 0.51 mL/min; P <.05) reductions in CL(cortisol-->6beta-hydroxycortisol), respectively. In contrast, the control subjects given lansoprazole and amoxicillin without clarithromycin showed no significant changes in CL(cortisol-->6beta-hydroxycortisol). The urinary 6beta-hydroxycortisol/cortisol ratio also decreased significantly (P <.05) in the patient groups but not in the control subjects. The mean 3-hour plasma lansoprazole levels elevated in proportion to the doses of clarithromycin: 385 +/- 338 ng/mL for the control subjects, 696 +/- 797 ng/mL for the H pylori-positive patients given 400 mg/day clarithromycin, and 947 +/- 806 ng/mL for the H pylori-positive patients given 800 mg/day clarithromycin (P <.05 versus the control subjects). No significant differences were observed among the groups in the mean plasma ratios of 5-hydroxylansoprazole or lansoprazole sulfone to lansoprazole. CONCLUSIONS: The 7-day H pylori eradication therapy with clarithromycin, amoxicillin, and lansoprazole may elicit substantial inhibition of in vivo CYP3A activity. Although resultant elevations in plasma lansoprazole concentrations may be beneficial for H pylori eradication, caution must be exercised for possible drug interaction with a concomitantly administered CYP3A substrate (s) in patients undergoing H pylori eradication therapy with clarithromycin, amoxicillin, and lansoprazole.     

Comparison of the efficacy of 250 mg and 500 mg clarithromycin used with lansoprazole and amoxicillin in eradication regimens for<Emphasis Type="Italic">Helicobacter pylori</Emphasis> infection

AIMS AND METHODS: The aim of this study was to compare the efficacy of 250 mg and 500 mg clarithromycin used with lansoprazole and amoxicillin in eradication of H. pylori infection. 235 patients with H. pylori infections and non-ulcer dyspepsia were randomly assigned to one of the following regimens: lansoprazole 30 mg, amoxicillin 1000 mg, clarithromycin 250 mg (LAC250) and lansoprazole 30 mg, amoxicillin 1000 mg, clarithromycin 500 mg (LAC500). All drugs were given twice daily for 7 days. The patients were assessed for prevalence of H. pylori with the CLO test. Gastric biopsy samples obtained during upper gastrointestinal endoscopy before randomization and 4-6 weeks after completion of therapy were used for histology and culture. Bacterial sensitivity to clarithromycin and amoxicillin was determined with the E-test. RESULTS: 101 patients in the LAC250 mg group and 102 in the LAC500 group completed the study. On intention-to-treat analysis, eradication rates were 81% with LAC250 and 82% with LAC500 (p=0.88). On per-protocol analysis, eradication rates were 92% with LAC250 and 96% with LAC500 (p=0.23). Among the 203 patients (86% of the entire study group) for whom H. pylori antibiotic-sensitivity testing was technically feasible, primary resistance to clarithromycin was found in 9% and to amoxicillin in 0%. Eradication of clarithromycin sensitive/resistant strains was 94%/38% for LAC250 (p < 0.001) and 93%/40% for LAC500 (p < 0.001). CONCLUSIONS: The cure rates for the two regimens were similar, although adverse effects were more frequent with the LAC500 regimen, suggesting that 250 mg of clarithromycin b.d. may be sufficient in our patient population.     

Helicobacter pylori infection rate in patients with nontuberculous mycobacteriosis who are on longterm combination chemotherapy of clarithromycin and rifampicin

Clarithromycin resistance in Helicobacter pylori has increased the incidence of eradication failure. Clarithromycin is a key drug in the current treatment regimens for H. pylori infection, and it is also used for nontuberculous mycobacteriosis (NTM). The rate of H. pylori infection in 15 patients with NTM who were on longterm clarithromycin, rifampicin, and other drug therapy wasexamined, using the [¹³C] urea breath test. H. pylori was detected in 5 of the 15 patients (33.3%), whichwas significantly lower than the prevalence of H. pyloriin subjects who had routine upper gastrointestinal endoscopy in Japan (P = 0.0006). Thus, H. pylori resistance to clarithromycin is suggested to be low in patients with longterm administration, and the possibility exists of a combination of clarithromycin and rifampicin as a second-line therapy for the eradiation of H. pylori.     

Pharmacogenetics of esomeprazole or rabeprazole‐based triple therapy in Helicobacter pylori eradication in Hong Kong non‐ulcer dyspepsia Chinese subjects

Objective: Our study aimed to assess the effectiveness of esomeprazole or rabeprazole in combination with amoxicillin and clarithromycin for the eradication of Helicobacter pylori in Hong Kong non‐ulcer dyspepsia (NUD) patients. Methods: A prospective clinical trial was conducted at the Alice Ho Miu ling Nethersole Hospital outpatient endoscopy center from June 2004 to December 2005. Participants received amoxicillin 1 g, clarithromycin 500 mg, and, esomeprazole 20 mg (EAC) or rabeprazole 20 mg (RAC), all given twice daily for 1 week. The H. pylori status was determined by the [¹³C] urea breath test at least 4 weeks after completion of the treatment. Mutation status of CYP2C19 in exon 4 and exon 5 associated with the poor metabolizer phenotype was determined. Results: The intention‐to‐treat eradication rates in patients treated with RAC and EAC were 77% and 84·6% respectively, and per protocol‐based eradication rates were 83·7% and 88·9% respectively. The eradication rates did not vary with CYP2C19 phenotype found. For clarithromycin‐sensitive strains, the cure rates were statistically significant regardless of CYP2C19 polymorphism (P < 0·0001). Conclusion: Triple therapy with either EAC or RAC is effective for Hong Kong Chinese NUD patients with H. pylori infection. Success eradication was related to clarithromycin resistance and not CYP2C19 genotype.     

Comparison of the once‐daily levofloxacin‐containing triple therapy with the twice‐daily standard triple therapy for first‐line Helicobacter pylori eradication: a prospective randomised study

Background/Aims: Simple compound of Helicobacter pylori eradication therapy may improve drug compliance of patients. The aims of this study were to compare the efficacy and tolerability of a simple combination containing levofloxacin 7‐day once‐daily with standard twice‐daily triple therapy. Patients and Methods: This was a prospective, randomised, open‐label trial. A total of 189 consecutive patients diagnosed with peptic ulcer and H. pylori infection were enrolled. Patients were randomly divided into two groups: LEC group – levofloxacin 500 mg, esomeprazole 40 mg and clarithromycin 500 mg once daily for 7 days; AEC group – amoxicillin 1 g, esomeprazole 40mg and clarithromycin 500 mg twice daily for 7 days. Results: There were 90 patients in the LEC group and 99 patients in the AEC group. By intention‐to‐treat and per‐protocol analysis, the H. pylori eradication rate was 78.9% [71/90; 95% confidence interval (CI), 70.3–87.5%] and 83.5% (71/85; 95% CI, 75.5–91.6%) respectively, in the LEC group; and 74.8% (74/99; 95% CI, 66.0–83.5%) and 86.0% (74/86; 95% CI, 78.6–93.5%) respectively, in the AEC group. The incidence and tolerability of side effects were similar between these two groups. Conclusion: The efficacy and tolerability of once‐daily levofloxacin‐containing triple therapy are equal to those of the standard twice‐daily triple therapy in this study. However, none of the treatment regimens evaluated achieved enough eradication efficacies to be considered as a recommendable first‐line treatment.     

In vitro exposure to macrolide antibiotics in <Emphasis Type="Italic">Helicobacter pylori</Emphasis> strains isolated from children

Clarithromycin resistance of Helicobacter pylori is a serious problem in eradication therapy. We investigated whether the use of maclorides (clarithromycin, erythromycin, and azithromycin) induces clarithromycin resistance in the organism. Twenty H. pylori strains were isolated from pediatric patients with gastrointestinal symptoms. The minimum inhibitory concentrations (MICs) of each macrolide antibiotic were determined by the Etest. Among these, 17 strains susceptible to macrolide antibiotics were used for the in vitro induction of drug resistance. In each of these 17 strains of H. pylori, 30-day exposure to clarithromycin in experiments for in vitro induction did not change the MIC of any antibiotic, nor did it induce either the A2143G or the A2144G mutation in the 23S rRNA gene. These results suggest that the use of macrolide antibiotics does not induce clarithromycin resistance in H. pylori by 23S rRNA gene mutation.     

High eradication rate of H. pylori with moxifloxacin-based treatment: a randomized controlled trial

INTRODUCTION: Eradication of Helicobacter pylori remains a problematic treatment issue in clinical practice. The intention is to find a treatment that achieves a high rate of eradication at a low price and treatment options that are now used give us the opportunity to achieve this goal. Recently published results showing a low rate of resistance and better compliance with moxifloxacin-based treatment regimens indicate the need to investigate its efficacy in H. pylori eradication. This study is based on proving the efficacy of moxifloxacin in H. pylori eradication within the triple therapy. AIMS AND METHODS: The aim of the study was to compare the efficacy of one week of moxifloxacin-based treatment with the standard treatment for H. pylori eradication. Patients with H. pylori infection and non-ulcer dyspepsia (n = 277) were randomly divided into four groups to receive: moxifloxacin 400 mg/d, metronidazole 400 mg twice daily, lansoprazole 30 mg twice daily (MML group); moxifloxacin 400 mg/d, amoxicillin 1 g twice daily, lansoprazole 30 mg twice daily (MAL group); clarithromycin 500 mg twice daily, metronidazole 400 mg twice daily, lansoprazole 30 mg twice daily (CML group); clarithromycin 500 mg twice daily, amoxicillin 1 g twice daily, lansoprazole 30 mg twice daily (CAL group). The patients were assessed for prevalence of H. pylori using the CLO test, histology and culture on gastric biopsy samples obtained during upper gastrointestinal endoscopy before randomization and 4-6 weeks after completion of treatment. Bacterial sensitivity to clarithromycin and moxifloxacin was determined with the E-test. RESULTS: 265 (95.6%) patients completed the study forming the basis for PP analysis. Eradication rates of H. pylori in ITT and in PP analyses were: in the MML group 93.5% (58/62) and 96.7% (58/60), respectively; in the MAL group 86.4% (57/66) and 90.5% (57/63); in the CML group 70.4% (50/71) and 75.8% (50/66); and in the CAL group 78.2% (61/78) and 80.2% (61/76). Moxifloxacin treatment protocols were significantly more effective on both ITT and PP analyses than the clarithromycin based protocols with only one exception (MAL vs. CAL on ITT analysis). Among 238 patients (86% of the entire study group), strains showing primary resistance to clarithromycin were found in 10.8% and to moxifloxacin in 5.9%. Eradication of moxifloxacin sensitive/resistant strains was 98.1%/75% for MML (p < 0.01) and 91.1%/66.7% for MAL (p = n.s.); comparison of eradication of sensitive strains in MML and MAL regimens was 98.1%/91.1% (p < 0.05), and for resistant strains 75%/66.7% (p = n.s.). CML and CAL protocols did not differ in efficacy of eradication of clarithromycin sensitive or resistant strains. CONCLUSION: Moxifloxacin-based triple therapies showed higher eradication rates with few side effects and good drug compliance when compared with standard H. pylori treatments. Moreover, the increased prevalence of clarithromycin resistance suggests that moxifloxacin-based regimens could be safe and effective options in treatment of H. pylori infection.     

Quadruple therapy with ecabet sodium,omeprazole, amoxicillin and metronidazole is effective for eradication of Helicobacter pylori after failure of first‐line therapy (KDOG0201 Study)

Background and object: An antiulcer agent, ecabet sodium, is active against Helicobacter pylori. The aim of the present study was to clinically examine whether eradication therapy, which includes ecabet sodium, is effective in eradication of H. pylori after failure of first‐line therapy. Methods: Patients with peptic ulcer who failed with first‐line triple eradication therapy containing clarithromycin received quadruple therapy with omeprazole (20 mg, twice daily), amoxicillin (750 mg, twice daily), metronidazole (500 mg, twice daily) and ecabet sodium (1000 mg, twice daily) for 14 days. Eradication of H. pylori was judged by ¹³C‐urea breath test 8 weeks later. Results: Fifty‐two patients (36 men and 16 women) were included. Their mean age was 51·4 years (range 28–73). One patient dropped out because of diarrhoea. The eradication rate was 98·0% (50/51) according to the per‐protocol analysis and 96·2% (50/52) according to the intention‐to‐treat analysis. Side effects occurred in seven patients, but none were serious. Conclusions: Quadruple therapy including ecabet sodium is useful as second‐line eradication treatment for H. pylori.     

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.     

Vonoprazan vs lansoprazole for the treatment of artificial gastric ulcer after endoscopic submucosal dissection: a prospective randomized comparative study

Vonoprazan is a potent inhibitor of gastric acid secretion and may have better response than proton pump inhibitors (PPIs) in the treatment of endoscopic submucosal dissection induced artificial ulcers. However, reported outcomes remain controversial. In this study, we conducted a prospective, randomized comparative trial to evaluate healing effects of vonoprazan and lansoprazole on endoscopic submucosal dissection (ESD)-induced ulcers. We enrolled 216 patients who underwent endoscopic submucosal dissection for early gastric neoplasms. They were randomly divided into vonoprazan (20 mg/day) and lansoprazole (30 mg/day) groups. The primary endpoint was the reduction rate of ulcer and complete healing (scar) ratio of ESD-induced ulcers at 4 and 8 weeks. Finally, 101 patients of the vonoprazan group and 95 patients of the lansoprazole group were included in the analysis. There were no significant differences in the reduction rate between the vonoprazan and lansoprazole groups at either timepoint (4 weeks, 94.0 vs 93.4%; 8 weeks, 99.8 vs 99.9%, respectively). The complete healing ratio at 4 and 8 weeks did not differ significantly between the vonoprazan and lansoprazole groups (4 weeks, 11.9 vs 12.6%; 8 weeks, 87.1 vs 86.3%, respectively). In the anti-H. pylori-antibody negative or positive patients, there were no significant differences in the reduction rate and complete healing ratio between the vonoprazan and lansoprazole groups. Regardless of treatment choice, the overall complete healing ratio at 8 weeks was significantly higher in the anti-H. pylori-antibody negative patients than the positive patients (p = 0.006). The healing effects of vonoprazan on ESD-induced ulcers were comparative to those of lansoprazole.     

Ten days of levofloxacin-containing concomitant therapy can achieve effective Helicobacter pylori eradication in patients with type 2 diabetes

Background: This study investigated whether levofloxacin-containing concomitant therapy can effectively eradicate Helicobacter pylori infection in patients with type 2 diabetes mellitus (T2DM).

Methods: A total of 797 T2DM patients were screened for anti-H. pylori IgG antibodies, and the presence of H. pylori infection was confirmed by ¹³C-urea breath test. We prospectively randomized 114 of these patients to receive either 10 d of levofloxacin-concomitant therapy (n?=?55) or sequential therapy (n?=?59). Antimicrobial resistance of H. pylori isolates collected from the patients with T2DM (n?=?109) and dyspeptic controls without DM (n?=?110) was determined using the E-test. This study was approved by our Institutional Review Board (A-BR-103-021).

Results: The H. pylori eradication rates with concomitant therapy were higher than sequential therapy in both intention-to-treat (96.4% versus 81.4%, p?=?0.012) and per-protocol (100% versus 85.4%, p?=?0.006) analysis. The adverse effects in both groups were similarly mild. In the patients who received sequential therapy, clarithromycin resistance was significantly associated with eradication failure (p?=?0.02). There were no significant differences in the antibiotic-resistant rates to amoxicillin, clarithromycin, metronidazole, tetracycline, and levofloxacin between the patients with and without T2DM.

Conclusions: Ten days of levofloxacin-containing concomitant therapy is an effective and well-tolerated treatment to eradicate H. pylori infection for T2DM patients.

• Key messages

• Ten days of levofloxacin-containing concomitant therapy is well tolerated and superior to clarithromycin-containing sequential therapy for first-line H. pylori eradication in patients with type 2 diabetes.

• Clarithromycin resistance to H. pylori is the main factor associated with eradication failure in clarithromycin-containing sequential therapy in diabetic patients.

     

Triple therapy regimens involving H2 blockaders for therapy of Helicobacter pylori infections

Comparison of ranitidine and lansoprazole in short-term low-dose triple therapy for Helicobacter pylori infection. To evaluate the efficacy and safety of two 1-week low-dose triple-therapy drug regimens involving antisecretory drugs for Helicobacter pylori infection, 99 patients with H. pylori infection were treated with either lansoprazole (LPZ) or ranitidine (RNT) used together with clarithromycin (CAM) and metrinidazole (MTZ). The drug combination and administration periods in the PPI group were LPZ 30 mg, CAM 400 mg, MTZ 500 mg (LCM group). The ranitidine group received RNT 300 mg, CAM 400 mg, MTZ 500 mg (RCM group). The cure rate of H. pylori infection was 88% in the LCM group; 95% CI 79-97 and 92% in the RCM group; 95% CI 84-99.     

β-Lactamase inhibitors have antibacterial activities against Helicobacter pylori

Recently, it was reported that amoxicillin-clavulanate has slightly higher activity than amoxicillin against Helicobacter pylori. In this study, we evaluated the in-vitro antibacterial activity of β-lactamase inhibitors against H. pylori. We investigated the susceptibility of 30 H. pylori strains to β-lactamase inhibitors, including clavulanate, sulbactam, and tazobactam. In short-term bactericidal studies, a clinical isolate of H. pylori NU27 was exposed to 1 × minimum inhibitory concentration (MIC) of the β-lactamase inhibitors, amoxicillin, clarithromycin, and amoxicillin-clavulanate for 3 and 6 h. The MICs₉₀ for these β-lactamase inhibitors were 2, 4, and 2 mg/l, respectively. The short-term bactericidal studies showed that these β-lactamase inhibitors decreased viable counts of H. pylori during 6-h exposure at 1 × MIC. Our results suggest that β-lactamase inhibitors have in-vitro antibacterial activity against H. pylori. Amoxicillin and clavulanate used in combination resulted in increased antibacterial activity. Received: July 1, 1999 / Accepted: September 13, 1999     

Pharmacokinetics of lansoprazole,amoxicillin and clarithromycin after simultaneous and single administration

In a randomized, double-blind, placebo-controlled, four-way crossover study, possible influences of the triple therapy with amoxicillin, clarithromycin and the proton pump inhibitor lansoprazole on the pharmacokinetics of each of the drugs and the active 14-OH-clarithromycin metabolite were assessed. Twelve Helicobacter pylori-negative healthy male volunteers (age 27 +/- 4.3 years; creatinine clearance 7.0 +/- 2.0 L/h) were given lansoprazole 30 mg, amoxicillin 1 g and clarithromycin 500 mg, alone and in triple combination. Drug elimination intervals were at least 9 days between the dosing periods. The study medication was administered twice daily for 4 days. On the fifth day of each period, drugs were only given once in the morning, and blood and urine samples were collected for 12 h. The concentrations of the three substances administered, and 14-OH-clarithromycin, were determined by validated HPLC methods. Alterations in the serum kinetics were found for lansoprazole and the active 14-OH-clarithromycin metabolite (all data expressed as mean +/- S.D.). For lansoprazole, the elimination half-life (t(1/2)) was significantly prolonged (1.46 versus 1.7 h, P < 0.05) and the area under the concentration-time curve from 0 to 8 h (AUC(0-8)) was significantly increased (3.65 versus 4.59 mg.h/L, P < 0.05) by combination of the drugs. For 14-OH-clarithromycin, the peak concentration (C(max)) was 0.95 versus 1.18 mg/L and the AUC from 0 to 12 h (AUC(0-12)) was 8.3 versus 10.5 mg.h/L (augmented significantly, P < 0.05). The amoxicillin concentrations were slightly elevated by concomitant administration of lansoprazole and clarithromycin but without statistical significance (11.1 versus 12.6 mg/L). For clarithromycin, the time to maximum concentration of drug in serum (T(max)) was increased (2.73 versus 3.31 h, P < 0.05), whereas AUC and C(max) remained unchanged. Simultaneous administration of lansoprazole, amoxicillin and clarithromycin increases the serum concentrations of lansoprazole and the active 14-OH-clarithromycin metabolite significantly. These effects were not so pronounced as to have any therapeutic influence, making dosage adjustment unnecessary.     

Pharmacogenomics-based tailored versus standard therapeutic regimen for eradication of H. pylori

Helicobacter pylori eradication rates by triple therapy with a proton pump inhibitor, amoxicillin, and clarithromycin at standard doses depend on bacterial susceptibility to clarithromycin and patient CYP2C19 genotypes. We examined the usefulness of a personalized therapy for H. pylori infection based on these factors as determined by genetic testing. First, optimal lansoprazole dosing schedules that would achieve sufficient acid inhibition to allow H. pylori eradication therapy in each of different CYP2C19 genotype groups were determined by a 24-h intragastric pH monitoring. Next, 300 H. pylori-positive patients were randomly assigned to the standard regimen group (lansoprazole 30 mg twice daily (b.i.d.)), clarithromycin 400 mg b.i.d., and amoxicillin 750 mg b.i.d. for 1 week) or the tailored regimen group based on CYP2C19 status and bacterial susceptibility to clarithromycin assessed by genetic testing. Patients with failure of eradication underwent the second-line regimen. The per-patient cost required for successful eradication was calculated for each of the groups. In the first-line therapy, the intention-to-treat eradication rate in the tailored regimen group was 96.0% (95% CI=91.5-98.2%, 144/150), significantly higher than that in the standard regimen group (70.0%: 95% CI=62.2-77.2%, 105/150) (P<0.001). Final costs per successful eradication in the tailored and standard regimen groups were $669 and $657, respectively. In conclusion, the pharmacogenomics-based tailored treatment for H. pylori infection allowed a higher eradication rate by the initial treatment without an increase of the final per-patient cost for successful eradication. However, the precise cost-effectiveness of this strategy remains to be determined.     

Prevalence of Helicobacter pylori in symptomatic patients and detection of clarithromycin resistance using melting curve analysis

Abstract

Background:

Clarithromycin is often a component of combination therapies for Helicobacter pylori eradication; however, increases in resistance rates have decreased the success of the treatment.

Objective:

This study was designed to determine the prevalence of H pylori infection in symptomatic patients and to detect clarithromycin resistance rates using melting curve analysis.

Methods:

Patients scheduled for upper endoscopy at the Endoscopy Unit of the Department of Gastroenterology, Duzce University, Medical Faculty Hospital, Konuralp/Duzce, Turkey, were assessed for enrollment in the study. Two pairs of gastric biopsy specimens (antrum and corpus) were obtained from each study patient. Histopathologic examination, rapid urease test, culture, and polymerase chain reaction (PCR) of the specimens were used to identify H pylori infection. Clarithromycin resistance was detected using melting curve analysis.

Results:

Seventy-five patients (41 women, 34 men; mean [SD]age, 42.6 [14.5] years [range, 17–70 years]) were included in the study. Using histopathology and rapid urease test, H pylori was detected in 40 (53.3%) of the 75 specimens. H pylori was detected using PCR in 40 (53.3%) specimens and by culture in 10 (13.3%) specimens. The specificity and sensitivity of PCR and culture were interpreted by comparing them with the results of histopathologic examination and urease tests. The specificity and sensitivity of PCR were 68.6% and 72.5%, respectively, and the specificity and sensitivity of culture were 97.1% and 22.5%, respectively. Of the 40 isolates, 21 (52.5%) were susceptible to clarithromycin, 12 (30.0%) were resistant, and a mixed susceptibility pattern was detected in 7 (17.5%) specimens. H pylori isolates from 19 (79.2%) of the 24 patients who had formerly used clarithromycin showed clarithromycin resistance.

Conclusions:

The prevalence of H pylori infection was 53.3% for the symptomatic patients in this study, and 47.5% of the isolates showed clarithromycin resistance using melting curve analysis. The PCR-based system used in this study was accurate for the detection of H pylori infection as well as clarithromycin susceptibility testing directly in biopsy specimens.Key Words: Helicobacter pylori, clarithromycin resistance, melting curve analysis, PCR     

The status of antimicrobial resistance of Helicobacter pylori in Eastern Azerbaijan, Iran: comparative study according to demographics

Helicobacter pylori-associated infections are extremely common in Iran, but few data about antibiotic sensitivity of H. pylori are available for this region. The purpose of this study was to investigate the prevalence of resistance in isolates against commonly used antibiotics in Eastern Azerbaijan, Iran, and the dependence of prevalence on the sex and age of patients. H. pylori isolates were collected by culture from gastric biopsies. Antibiotic susceptibility of isolates was determined by use of the disk agar diffusion test, and the minimum inhibitory concentration of clarithromycin was established by use of the Etest. A total 395 of biopsy specimens were studied; 112 samples of H. pylori were isolated (28.3 %), 55 (49 %) from males and 57 (51 %) from females. The prevalence of resistance to clarithromycin, metronidazole, erythromycin, amoxicillin, ciprofloxacin, rifampin, nitrofurantoin, and tetracycline were 16 (14.3 %), 86 (76.8 %), 29 (26.0 %), 32 (28.6 %), 37 (33.0 %), 32 (28.6 %), 13 (11.6 %), and 21 (18.7 %), respectively. Antimicrobial resistance was not statistically significantly associated with sex or age. Furthermore, the prevalence of resistance to metronidazole was high and that to clarithromycin was reasonable, consistent with reported low success in H. pylori treatment in this area. Therefore, continuous surveillance of antibiotic resistance of H. pylori is essential.     

Potent antibacterial activity of Y-754, a novel benzimidazole compound with selective action against <Emphasis Type="Italic">Helicobacter pylori</Emphasis>

Y-754, a novel benzimidazole compound, was investigated for in vitro and in vivo antibacterial activity. Unlike amoxicillin, clarithromycin, and metronidazole, the compound had no activity against common aerobic and anaerobic bacteria other than Helicobacter pylori. The minimum inhibitory concentration of Y-754 against H. pylori, at 0.025µg/ml, was nearly equal to that of amoxicillin and clarithromycin. The respective concentrations of Y-754, amoxicillin, clarithromycin, and metronidazole required to inhibit 90% of 39 isolates of H. pylori were 0.05, 0.39, 6.25, and 25µg/ml, indicating the potent activity of Y-754, including activity against clarithromycin- and metronidazole-resistant strains. The anti-H. pylori activity of Y-754 was potent even at pH 5.5 and was bactericidal at concentrations of 0.1µg/ml and above. Exposure of H. pylori to Y-754 did not result in the induction of drug-resistant mutation. Oral administration (10mg/kg twice a day for 7 days) to Mongolian gerbils infected with strain ATCC 43504 demonstrated that Y-754 was effective in H. pylori eradication and that its eradication efficacy increased in line with the progress of damage to the gastric mucosa caused by H. pylori infection. Y-754 was also efficacious in the treatment of infection by the clarithromycin-resistant strain OIT-36. The results obtained lead to the expectation that the new benzimidazole Y-754 will, in the near future, be used for H. pylori eradication therapy in peptic ulcer patients.