Second-line levofloxacin-based quadruple therapy versus bismuth-based quadruple therapy for Helicobacter pylori eradication and long-term changes to the gut microbiota and antibiotic resistome: a multicentre, open-label, randomised controlled trial.

BACKGROUND: Levofloxacin-based therapy or bismuth-based quadruple therapy are the recommended second-line regimens for Helicobacter pylori eradication after failure of clarithromycin-based therapy. However, resistance to levofloxacin has increased in the past decade. Furthermore, little is known about the long-term effects of H pylori eradication on the antibiotic resistome. In this study, we compared these second-line eradication therapies for efficacy, tolerability, and short-term and long-term effects on the gut microbiota, antibiotic resistome, and metabolic parameters. METHODS: We did a multicentre, open-label, parallel group, randomised controlled trial at eight hospitals in Taiwan. Adult patients (age ≥20 years) with persistent H pylori infection after first-line clarithromycin-based therapy were randomly assigned (1:1, permuted block sizes of four) to receive levofloxacin-based sequential quadruple therapy for 14 days (EAML14; esomeprazole 40 mg and amoxicillin 1 g for 7 days, followed by esomeprazole 40 mg, metronidazole 500 mg, and levofloxacin 250 mg for 7 days, all twice-daily) or bismuth-based quadruple therapy for 10 days (BQ10; esomeprazole 40 mg twice daily, bismuth tripotassium dicitrate 300 mg four times a day, tetracycline 500 mg four times a day, and metronidazole 500 mg three times a day). All investigators were masked to the randomisation sequence. The primary endpoint was H pylori eradication rate measured by 13C urea breath test 6 weeks after second-line treatment according to both intention-to-treat (ITT) and per-protocol analysis. The microbiota composition and antibiotic resistome of faecal samples collected at baseline (before treatment) and at 2 weeks, 8 weeks, and 1 year after eradication therapy was profiled by shotgun metagenomic sequencing and 16S rRNA gene sequencing. The frequency of adverse effects and changes in the gut microbiota and antibiotic resistome were assessed in all participants with available data. The trial is complete and registered with ClinicalTrails.gov, NCT03148366. FINDINGS: Between Feb 25, 2015, and Dec 11, 2020, 560 patients were randomly assigned to receive EAML14 or BQ10 (n=280 per group; 261 [47%] men and 299 [53%] women). Mean age was 55·9 years (SD 12·7) in the EAML14 group and 54·9 years (12·3) in the BQ10 group. Eradication of H pylori was achieved in 246 (88%) of 280 participants in the EAML14 group and 245 (88%) of 280 in the BQ10 group according to ITT analysis (risk difference -0·4%, 95% CI -5·8 to 5·1; p=0·90). In the per-protocol analysis, 246 (90%) of 273 participants in the EAML14 group and 245 (93%) of 264 participants in the BQ10 group achieved H pylori eradication (risk difference 2·7%, 95% CI -0·2 to 7·4; p=0·27). Transient perturbation of faecal microbiota diversity at week 2 was largely restored to basal state 1 year after EAML14 or BQ10. Diversity recovery was slower with BQ10, and recovery in species abundance was partial after both therapies. On shotgun sequencing, we observed significant increases in total resistome after EAML14 (p=0·0002) and BQ10 (p=4·3 × 10-10) at week 2, which were restored to pretreatment level by week 8. The resistance rates of Escherichia coli and Klebsiella pneumonia to levofloxacin, ciprofloxacin, ampicillin (ampicillin-sulbactam for K pneumonia), and various cephalosporins were significantly increased in the EAML14 group compared with in the BQ10 group at week 2, which were restored to pretreatment levels and showed no significant differences at week 8 and 1 year. The frequency of any adverse effects was significantly higher after BQ10 therapy (211 [77%] of 273 participants) than after EAML14 therapy (134 [48%] of 277; p<0·0001). INTERPRETATION: We found no evidence of superiority between levofloxacin-based quadruple therapy and bismuth-based quadruple therapy in the second-line treatment of H pylori infection. The transient increase in the antibiotic resistome and perturbation of faecal microbiota diversity were largely restored to pretreatment state from 2 months to 1 year after eradication therapy. FUNDING: The Ministry of Science and Technology of Taiwan, the Ministry of Health and Welfare of Taiwan, National Taiwan University Hospital, Taipei Veteran General Hospital, and the Australian Federal Government through the St George and Sutherland Medical Research Foundation. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

Efficacy of genotypic resistance-guided sequential therapy in the third-line treatment of refractory Helicobacter pylori infection: a multicentre clinical trial.

OBJECTIVES: The efficacy of sequential therapy and the applicability of genotypic resistance to guide the selection of antibiotics in the third-line treatment of Helicobacter pylori have not been reported. We aimed to assess the efficacy of genotypic resistance-guided sequential therapy in third-line treatment. METHODS: Genotypic and phenotypic resistances were determined in patients who failed at least two eradication therapies by PCR with direct sequencing and agar dilution test, respectively. The patients were retreated with sequential therapy containing esomeprazole and amoxicillin for the first 7 days, followed by esomeprazole and metronidazole plus clarithromycin, levofloxacin or tetracycline for another 7 days (all twice daily), according to genotypic resistance determined using gastric biopsy specimens. Eradication status was determined by the (13)C-urea breath test. Trial registered at clinicaltrials.gov (identifier: NCT01032655). RESULTS: The overall eradication rate was 80.7% (109/135, 95% CI 73.3%-86.5%) in the intention-to-treat analysis. The presence of amoxicillin resistance (OR 6.83, 95% CI 1.62-28.86, P = 0.009) and prior sequential therapy (OR 4.77, 95% CI 1.315-17.3, P = 0.017), but not tetracycline resistance (tetracycline group), were associated with treatment failure. The eradication rates in patients who received clarithromycin-, levofloxacin- and tetracycline-based sequential therapies were 78.9% (15/19), 92.2% (47/51) and 71.4% (25/35) in strains susceptible to clarithromycin, levofloxacin and tetracycline, respectively. CONCLUSIONS: A simple molecular method guiding sequential therapy can achieve a high eradication rate in the third-line treatment of refractory H. pylori infection.

Higher complication risk of totally implantable venous access port systems in patients with advanced cancer - a single institution retrospective analysis.

BACKGROUND: Totally implantable port systems are generally recommended for prolonged central venous access in diverse settings, but their risk of complications remains unclear for patients with advanced cancer. AIM: The aim of this study was to assess the risk of port system failure in patients with advanced cancer. DESIGN: We conducted a retrospective cohort study in a comprehensive cancer centre. SETTING/PARTICIPANTS: A detailed chart review was conducted among 566 patients with 573 ports inserted during January-June, 2009 (average 345.3 catheter-days). Cox regression analysis was applied to evaluate factors during insertion and early maintenance that could lead to premature removal of the port systems due to infection or occlusion. RESULTS: Port system-related infection was significantly associated with receiving palliative care immediately after implantation (hazard ratio, HR = 7.3, 95% confidence interval, 95% CI = 1.2-46.0), after adjusting for probable confounders. Primary cancer site also impacted the occurrence of device-related infection. Receiving oncologic/palliative care (HR = 3.0, P = 0.064), advanced cancer stage (HR = 6.5, P = 0.077) and body surface area above 1.71 m(2) (HR = 3.4, P = 0.029) increased the risk of port system occlusion. CONCLUSIONS: Our study indicates that totally implantable port systems yield a higher risk of complications in terminally ill patients. Further investigation should be carefully conducted to compare outcomes of various central venous access devices in patients with advanced cancer and to develop preventive strategies against catheter failure.

Levofloxacin-based and clarithromycin-based triple therapies as first-line and second-line treatments for Helicobacter pylori infection: a randomised comparative trial with crossover design.

BACKGROUND: The efficacy of a levofloxacin-based regimen as the first-line treatment and a clarithromycin-based regimen as the second-line treatment for Helicobacter pylori infection remains unknown. The aim of this study was to assess the eradication rates of these two regimens using different administration sequences. METHODS: Eligible patients were randomised to receive LAL: levofloxacin (750 mg once a day), amoxicillin (1000 mg twice a day) and lansoprazole (30 mg twice a day) for 7 days, or CAL: clarithromycin (500 mg twice a day), amoxicillin (1000 mg twice a day) and lansoprazole (30 mg twice a day) for 7 days. Patients with positive [(13)C]urea breath test after treatment were retreated with the rescue regimen in a crossover manner for 10 days. RESULT: When used as first-line treatment (n=432), the eradication rates of LAL (n=217) and CAL (n=215) were 74.2 and 83.7% (p=0.015) in the intent-to-treat (ITT) analysis, and 80.1 and 87.4% (p=0.046) in the per-protocol (PP) analysis, respectively. When used as second-line treatment, the eradication rates of LAL (n=26) and CAL (n=40) were 76.9 and 60% (p=0.154) in the ITT analysis, and 80 and 61.5% (p=0.120) in the PP analysis, respectively. The overall eradication rates of CAL followed by LAL were better than the reverse sequence in both the ITT analysis (93% vs 85.3%, p=0.01) and the PP analysis (97.6% vs 92.5%, p=0.019). The eradication rate was significantly lower in the presence of levofloxacin resistance in the LAL group (50% vs 84.4%, p=0.018) and clarithromycin resistance in the CAL group (44.4% vs 90.7%, p=0.002). CONCLUSION: CAL achieved a higher eradication rate than LAL as the first-line treatment, but not as the second-line treatment. The strategy of using CAL as the initial treatment and LAL as the rescue regimen achieved higher eradication rates than the reverse sequence.

Calcium chloride prolongs the effects of lidocaine and bupivacaine in rat sciatic nerve.

BACKGROUND AND OBJECTIVES: Elevated extracellular calcium ion has been shown to shift the voltage dependence of Na+- and K+-ion channels rightward, making the nerve less excitable. We hypothesized that calcium chloride (CaCl2) when used as an adjuvant prolongs and intensifies the block by local anesthetics (LAs). We investigated the effects of LAs combined with calcium in rat sciatic nerve blockade and in cultured rat GH3 cells expressing Na+ channels. Furthermore, we tested for histologic changes due to CaCl2. METHODS: We anesthetized rats with sevoflurane, exposed the sciatic nerves, and injected 0.2 mL of 1% lidocaine or 0.1% bupivacaine, alone or coadministered with 0.625%, 1.25%, 2.5%, or 5% CaCl2 (n = 8-10 per group). We assessed the complete-block time and complete-recovery time of proprioception, motor function, and nocifensive reaction. To elucidate the mechanism of nerve block, we performed electrophysiology experiments in cultured rat GH3 cells. Sciatic nerves were harvested at day 7 and stained with hemotoxylin/eosin. RESULTS: The addition of CaCl2 overall prolonged the duration of blockade by lidocaine or bupivacaine. Adding 10 mM CaCl2 to 300 microM lidocaine caused a right shift of the steady-state Na+-channel inactivation curve, indicating that the CaCl2 reduced the potency of lidocaine. Rat sciatic nerves treated with 1% lidocaine coadministered with 5% CaCl2 showed microscopic signs of neurotoxicity. CONCLUSIONS: The mechanism of prolonged nerve block of CaCl2 coadministered with LAs seems to be a raised threshold for nerve excitation. Major histopathologic changes at higher concentrations of CaCl2 are evident, and therefore, clinical application as an adjuvant to LAs seems unlikely.

Magnesium sulfate diminishes the effects of amide local anesthetics in rat sciatic-nerve block.

BACKGROUND AND OBJECTIVES: Magnesium sulfate (MgSO(4)) is well known as an antagonist of N-methyl-d-aspartate receptors and was used for intrathecal analgesia a century ago. However, the effects of MgSO(4) combined with local anesthetics (LAs) on peripheral nerves are unclear. We tested the hypothesis that MgSO(4) could be used as an adjuvant to prolong and intensify conduction block by amide-type LAs in a rat sciatic-nerve block model. Further, the mechanism of possible synergy between LAs and MgSO(4) was investigated in whole-cell mode patch-clamp experiments. METHODS: Sciatic nerves were exposed to 2%/73.9 mM lidocaine, 0.25%/7.7 mM bupivacaine, and 0.5%/15.4 mM ropivacaine, with or without addition of 1.25%, 2.5%, or 5% MgSO(4)/50.7 mM, and nerve block characteristics were assessed. To elucidate the LA-MgSO(4) interaction, voltage-dependent inactivation curves were determined in cultured rat GH(3) cells that expressed neuronal Na(+) channels. RESULTS: Unexpectedly, the addition of MgSO(4) overall significantly shortened the duration of block by lidocaine, bupivacaine, and ropivacaine. The steady-state inactivation of Na(+) channels in the presence of 300 muM lidocaine was almost unchanged by the addition of 10 mM MgSO(4), indicating that MgSO(4) does not affect the potency of lidocaine toward the inactivated Na(+) channel. CONCLUSIONS: MgSO(4) coadministered with amide-type LAs shortened the duration of sciatic-nerve block in rats. Therefore, it does not seem to be useful as an adjuvant for peripheral-nerve block. The mechanism of this observed antagonism is unclear but appears to be independent of the action of LAs and MgSO(4) at the LA receptor within the Na(+) channel.