Trace polymer coated clarithromycin spherulites: Formation mechanism, improvement in pharmaceutical properties and development of high-drug-loading direct compression tablets

Clarithromycin (CLA) is a high dose antibiotic drug exhibiting poor flowability and tabletability, making the tablet development challenging. This study aims to develop spherulitic CLA by introducing trace amount of polymer in crystallization solution. Its formation mechanism, physicochemical properties and potential for the direct compression (DC) tablets development were also investigated. Morphological analyses and the in situ observation on crystallization process revealed that the CLA spherulites are formed by fractal branching growth from both sides of the threadlike precursor fibers. 1H NMR analysis and nucleation time monitoring indicated that the existence of hydroxypropyl cellulose in solution slowed down the crystal nucleation and growth rate by forming hydrogen bonding interactions with CLA molecules, making the system maintain high supersaturation, providing high driving forces for CLA spherulitic growth. In comparison to commercial CLA, the CLA spherulites exhibit profoundly improved flowability, tabletability and dissolution behaviors. XPS, contact angle and Raman mapping analysis confirmed the presence of a thin HPC layer on the surfaces and interior of CLA spherulitic particles, resulting in increasing powder plasticity, interparticulate bonding strength and powder wettability, thus better tabletability and dissolution performances. The improved flowability and tabletability of CLA spherulites also enabled the successful development of DC tablet formulation with a high CLA loading (82.8 wt%) and similar dissolution profiles to reference listed drug. This study provides a novel solid form of CLA with superior manufacturability for further development.

Effects of clarithromycin exposure on the growth of Microcystis aeruginosa and the production of algal dissolved organic matter

Antibiotics are commonly found in the aquatic environment, which can affect microbial community compositions and activities, and even have potential adverse impacts on human and ecosystem health. The current understanding of the effects of antibiotics on microalgae growth and algal dissolved organic matter (DOM) remains indistinct. To understand the toxic effects of antibiotics on the microalgae, Microcystis aeruginosa was exposed to clarithromycin (CLA) in this study. Cell density determination, chlorophyll content determination, and organic spectrum analysis were conducted to show the effect of CLA exposure on the growth, photosynthetic activity, and organic metabolic processes of Microcystis aeruginosa. The findings revealed that the physiological status of algae could be significantly influenced by CLA exposure in aquatic environments. Specifically, exposure to 1 μg/L CLA stimulated the growth and photosynthetic activity of algal cells. Conversely, CLA above 10 μg/L led to the inhibition of algal cell growth and photosynthesis. Notably, the inhibitory effects intensified with the increasing concentration of CLA. The molecular weight of DOM produced by Microcystis aeruginosa increased when exposed to CLA. Under the exposure of 60 μg/L CLA, a large number of algal cells ruptured and died, and the intracellular organic matter was released into the algal liquid. This resulted in an increase in high molecular weight substances and soluble microbial-like products in the DOM. Exposure to 1 and 10 μg/L CLA stimulated Microcystis aeruginosa to produce more humic acid-like substances, which may be a defense mechanism against CLA. The results were useful for assessing the effects of antibiotic pollution on the stability of the microalgae population and endogenous DOM characteristics in aquatic ecosystems.

Rapid detection of clarithromycin resistance in clinical samples of nontuberculous mycobacteria by nucleotide MALDI-TOF MS

The multidrug resistance of nontuberculous mycobacteria (NTM) poses a significant therapeutic challenge. Rapid and reliable drug susceptibility testing is urgently needed for evidence-based treatment decision, especially for macrolides. This study evaluated the utility of nucleotide matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (NMTMS) in detecting clarithromycin resistance. Sixty-four clinical isolates were identified to species by NMTMS, and mutations associated with clarithromycin resistance were detected. Twenty-three M. abscessus (MAB) isolates and 30 M. intracellulare isolates (including M. intracellulare alone and M. intracellulare in combination with other SGM species) were included for analysis. The predictive sensitivity of NMTMS in detecting clarithromycin resistance was 82.35% (95% CI, 56.57% to 96.20%), with an AUC of 0.89 (95% CI, 0.77 to 0.96) in all MAB and M. intracellulare (n = 53), and up to 93.33% (95% CI, 68.05% to 99.83%) in MAB alone (n = 23). The assay provides a rapid, high-throughput, and highly sensitive tool for detecting clarithromycin resistance in NTM, especially in MAB. Optimization of the panel is necessary to enhance diagnostic accuracy.

Efficacy and safety of macrolide therapy for adult asthma: A systematic review and meta-analysis

BACKGROUND

The evidence for macrolide therapy in adult asthma is not properly established and remains controversial. We conducted a systematic review and meta-analysis to examine the efficacy and safety of macrolide therapy for adult asthma.

METHODS

We searched randomized controlled trials from MEDLINE via the PubMed, CENTRAL, and Ichushi Web databases. The primary outcome was asthma exacerbation. The secondary outcomes were serious adverse events (including mortality), asthma-related quality of life (symptom scales, Asthma Control Questionnaire, and Asthma Quality of Life Questionnaire), rescue medication (puffs/day), respiratory function (morning peak expiratory flow, evening peak flow, and forced expiratory volume in 1 s), bronchial hyperresponsiveness, and minimum oral corticosteroid dose. Of the 805 studies, we selected seven studies for the meta-analysis, which was conducted using a random-effects model.

SYSTEMATIC REVIEW REGISTRATION

University Hospital Medical Information Network Clinical Trials Registry (UMIN000050824).

RESULTS

No significant difference between macrolide and placebo for asthma exacerbations was observed (risk ratio 0.71, 95 % confidence interval [CI] 0.46-1.09; p = 0.12). Macrolide therapy for adult asthma showed a significant improvement in rescue medication with short-acting beta-agonists (mean difference -0.41, 95 % CI -0.78 to -0.04; p = 0.03). Macrolide therapy did not show more serious adverse events (odd ratio 0.61, 95 % CI 0.34-1.10; p = 0.10) than those with placebo. The other secondary outcomes were not significantly different between the macrolide and placebo groups.

CONCLUSIONS

Macrolide therapy for adult asthma may be more effective than placebo and could be a treatment option.

The PEP++ study protocol: a cluster-randomised controlled trial on the effectiveness of an enhanced regimen of post-exposure prophylaxis for close contacts of persons affected by leprosy to prevent disease transmission

BACKGROUND

Leprosy is an infectious disease with a slow decline in global annual caseload in the past two decades. Active case finding and post-exposure prophylaxis (PEP) with a single dose of rifampicin (SDR) are recommended by the World Health Organization as measures for leprosy elimination. However, more potent PEP regimens are needed to increase the effect in groups highest at risk (i.e., household members and blood relatives, especially of multibacillary patients). The PEP++ trial will assess the effectiveness of an enhanced preventive regimen against leprosy in high-endemic districts in India, Brazil, Bangladesh, and Nepal compared with SDR-PEP.

METHODS

The PEP++ study is a cluster-randomised controlled trial in selected districts of India, Brazil, Bangladesh, and Nepal. Sub-districts will be allocated randomly to the intervention and control arms. Leprosy patients detected from 2015 - 22 living in the districts will be approached to list their close contacts for enrolment in the study. All consenting participants will be screened for signs and symptoms of leprosy and tuberculosis (TB). In the intervention arm, eligible contacts receive the enhanced PEP++ regimen with three doses of rifampicin (150 - 600 mg) and clarithromycin (150 - 500 mg) administered at four-weekly intervals, whereas those in the control arm receive SDR-PEP. Follow-up screening for leprosy will be done for each individual two years after the final dose is administered. Cox' proportion hazards analysis and Poisson regression will be used to compare the incidence rate ratios between the intervention and control areas as the primary study outcome.

DISCUSSION

Past studies have shown that the level of SDR-PEP effectiveness is not uniform across contexts or in relation to leprosy patients. To address this, a number of recent trials are seeking to strengthen PEP regimens either through the use of new medications or by increasing the dosage of the existing ones. However, few studies focus on the impact of multiple doses of chemoprophylaxis using a combination of antibiotics. The PEP++ trial will investigate effectiveness of both an enhanced regimen and use geospatial analysis for PEP administration in the study communities.

TRIAL REGISTRATION

NL7022 on the Dutch Trial Register on April 12, 2018. Protocol version 9.0 updated on 18 August 2022 https://www.onderzoekmetmensen.nl/en/trial/23060.

Intrinsic clarithromycin heteroresistance in Mycobacterium avium

BACKGROUND

Mycobacterium avium is associated with pulmonary disease in otherwise healthy adults. Several clarithromycin-refractory cases have been reported, including some cases caused by clarithromycin-susceptible strains.

OBJECTIVES

To characterize the reason for the discrepancy between clinical response and antibiotic susceptibility results.

METHODS

We conducted population analysis of clarithromycin-tolerant and heteroresistant subpopulations of M. avium cultured in vitro and in homogenates of infected lungs of mice. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined for 28 M. avium and two M. kansasii strains. Mice were intranasally infected with M. avium and treated with or without clarithromycin (100 mg/kg) thrice weekly. They were sacrificed on day 35 and the bacteria in lung homogenates were tested for clarithromycin resistance. Population analysis assays were performed based on colony growth on plates containing two-fold dilutions of clarithromycin.

RESULTS

The MBC/MIC ratios were ≥8 in all 28 strains of M. avium tested. In the population analysis assay, several colonies were observed on the plates containing clarithromycin concentrations above the MIC (2-64 mg/L). No growth of M. kansasii colonies was observed on the plates containing clarithromycin concentrations ≥2 mg/L. M. avium in the homogenates of infected lungs showed clearer clarithromycin-resistant subpopulations than in vitro, regardless of clarithromycin exposure.

CONCLUSION

M. avium shows intrinsic heterogeneous resistance (heteroresistance) to clarithromycin. This may explain the observed discrepancies between clarithromycin susceptibility testing results and clinical response to clarithromycin treatment. Further studies are needed to confirm a link between heteroresistance and clinical outcomes.

Legionella pneumonia in hospitalized adults with respiratory failure: Quinolones or macrolides?

The optimal antimicrobial regimen for adults with respiratory failure due to Legionella pneumonia remains controversial. A systematic review was performed to assess the impact on outcomes comparing quinolones versus macrolides. A literature search was conducted in PubMed, Cochrane Library and Web of Science between 2012 and 2022. It yielded 124 potentially articles and ten observational studies met the inclusion criteria. A total of 4271 patients were included, 2879 (67 %) were male. A total of 1797 (42 %) subjects required intensive care unit (ICU) admission and 942 (52 %) mechanical ventilation. Fluoroquinolones and macrolides alone were administered in 1397 (33 %) and 1500 (35 %) subjects, respectively; combined therapy in 204 (4.8 %) patients. Overall mortality was 7.4 % (319 patients), with no difference between antibiotics. When data from the three studies with severe pneumonia were pooled together, mortality with fluoroquinolones alone was statistically superior to macrolides alone (72.8 % vs 30.8 %, p value 0.027). Hospital length of stay and complications were comparable. Our findings suggest that macrolides and quinolones were comparable for hospitalized Legionella pneumonia. However, in severe pneumonia, a randomized clinical trial is an unmet clinical need. PROSPERO registration number: CRD42023389308.

Proguanil and chlorhexidine augment the antibacterial activities of clarithromycin and rifampicin against Acinetobacter baumannii

The emergence of Acinetobacter baumannii infections as a significant healthcare concern in hospital settings, coupled with their association with poorer clinical outcomes, has prompted extensive investigation into novel therapeutic agents and innovative treatment strategies. Proguanil and chlorhexidine, both categorized as biguanide compounds, have displayed clinical efficacy as antimalarial and topical antibacterial agents, respectively. In this study, we conducted an investigation to assess the effectiveness of combining proguanil and chlorhexidine with clarithromycin or rifampicin against both laboratory strains and clinical isolates of A. baumannii. The combination therapy demonstrated rapid bactericidal activity against planktonic multidrug-resistant A. baumannii, exhibiting efficacy in eradicating mature biofilms and impeding the development of antibiotic resistance in vitro. Additionally, when administered in conjunction with clarithromycin or rifampicin, proguanil enhanced the survival rate of mice afflicted with intraperitoneal A. baumannii infections, and chlorhexidine expedited wound healing in mice with skin infections. These findings are likely attributable to the disruption of A. baumannii cell membrane integrity by proguanil and chlorhexidine, resulting in heightened membrane permeability and enhanced intracellular accumulation of clarithromycin and rifampicin. Overall, this study underscores the potential of employing proguanil and chlorhexidine in combination with specific antibiotics to effectively combat A. baumannii infections and improve treatment outcomes in clinically challenging scenarios.

A systematic review and meta-analysis of macrolides in the management of adult patients with asthma

BACKGROUND

The efficacy of macrolides in the management of asthma has been studied but remains controversial. We conducted a systematic review and meta-analysis of macrolides in the management of adult patients with asthma.

METHODS

Randomized controlled trials of macrolides used in adult patients with asthma were searched for in MEDLINE, EMBASE, PsycINFO, Cochrane Library, CINAHL, and Igaku Chuo Zasshi databases to evaluate the efficacy and safety of macrolides.

RESULTS

Seventeen reports with macrolide treatment durations ranging from 6 to 48 weeks were included. Macrolides did not reduce exacerbations requiring hospitalization, severe exacerbations, or rescue use of short-acting beta-2 agonist inhalers; improve lung function; decrease peripheral blood or sputum neutrophil counts; or decrease fractional exhaled nitric oxide compared to placebo. Macrolides statistically improved asthma control and quality of life but by less than the minimal clinically important difference. Peripheral blood eosinophil counts as well as serum and sputum eosinophilic cationic protein concentrations were significantly decreased with macrolides compared to placebo. The improvement of asthma symptoms and airway hyperresponsiveness varied by study. The safety profile of macrolides was comparable to that of placebo.

CONCLUSIONS

Although macrolides have some useful clinical aspects, there is not sufficient evidence to recommend their use in the management of adult patients with asthma.

Success of susceptibility-guided eradication of Helicobacter pylori in a region with high secondary clarithromycin and levofloxacin resistance rates

BACKGROUND

Resistance to clarithromycin (CLA) and levofloxacin (LFX) of Helicobacter pylori (H. pylori) is increasing in severity, and successful eradication is essential. Presently, the eradication success rate has greatly declined, leaving a large number of patients with previous treatment histories.

AIM

To investigate secondary resistance rates, explore risk factors for antibiotic resistance, and assess the efficacy of susceptibility-guided therapy.

METHODS

We recruited 154 subjects positive for Urea Breath Test who attended The First Affiliated Hospital of China Medical University between July 2022 and April 2023. Participants underwent a string test after an overnight fast. The gastric juice was obtained and transferred to vials containing storage solution. Subsequently, DNA extraction and the specific DNA amplification were performed using quantitative polymerase chain reaction (qPCR). Demographic information was also analyzed as part of the study. Based on these results, the participants were administered susceptibility-guided treatment. Efficacy was compared with that of the empiric treatment group.

RESULTS

A total of 132 individuals tested positive for the H. pylori ureA gene by qPCR technique. CLA resistance rate reached a high level of 82.6% (n = 109), LFX resistance rate was 69.7% (n = 92) and dual resistance was 62.1% (n = 82). Gastric symptoms [odds ratio (OR) = 2.782; 95% confidence interval (95%CI): 1.076-7.194; P = 0.035] and rural residence (OR = 5.152; 95%CI: 1.407-18.861; P = 0.013) were independent risk factors for secondary resistance to CLA and LFX, respectively. A total of 102 and 100 individuals received susceptibility-guided therapies and empiric treatment, respectively. The antibiotic susceptibility-guided treatment and empiric treatment groups achieved successful eradication rates of 75.5% (77/102) and 59.0% (59/411) by the intention-to-treat (ITT) analysis and 90.6% (77/85) and 70.2% (59/84) by the per-protocol (PP) analysis, respectively. The eradication rates of these two treatment strategies were significantly different in both ITT (P = 0.001) and PP (P = 0.012) analyses.

CONCLUSION

H. pylori presented high secondary resistance rates to CLA and LFX. For patients with previous treatment failures, treatments should be guided by antibiotic susceptibility tests or regional antibiotic resistance profile.

Prevalence of Clarithromycin-Resistant Helicobacter pylori Strains in Zambia: A Sub-Saharan African Country

INTRODUCTION

Helicobacter pylori (H. pylori) is one of the most important infections globally, affecting more than 50% of the human population. Clarithromycin (CLA)-containing regimens are recommended for empirical eradication of H. pylori in populations with less than 15% resistance. The aim of this study was to estimate the prevalence of CLA resistance in samples collected from Zambian patients to determine if CLA is suitable for first-line H. pylori empirical treatment.

METHODOLOGY

We used archival biopsy samples collected from dyspeptic patients undergoing endoscopy. The samples had been snap-frozen immediately after collection and stored at -80°C. We performed multiplex real-time PCR using Bosphore Helicobacter pylori Genotyping Kits v1, Istanbul, Turkey, to determine the presence of wild-type H. pylori and three mutations, A2142G, A2142C, and A2143G, of domain V in 23s rRNA gene.

RESULTS

We tested 259 gastric biopsy samples from patients with dyspepsia, of which 136 (53%) were from females. The median age was 48 years (IQR 40-61 years). Endoscopically, most of the patients, 164 (63%), had a normal gastric mucosa. CLA resistance was found in 48 (28%) samples, with A2142G mutation in 23 (13%), A2143G mutation in 32 (18%), and double mutations A2142C and A2143G in 6 (3%).

CONCLUSIONS

The presence of significant levels of CLA resistance in Zambia suggests that it should not be used as first-line empirical treatment for H. pylori infection. However, with a limitation of suitable alternatives, there is an urgent need to formulate new treatment approaches.

In Vitro Activity of Benzimidazole (SPR719) Against Clinical Isolates of Nontuberculous Mycobacteria With and Without Clarithromycin or Amikacin Resistance

Limited data are available regarding the in vitro activity of SPR719, a derivative of benzimidazole, against diverse nontuberculous mycobacteria (NTM) species. We investigated the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of SPR719 against clinical NTM isolates, including clarithromycin- and amikacin-resistant strains. NTM isolates were obtained from patients with NTM-pulmonary disease caused by various NTM species, including Mycobacterium avium complex, M. abscessus (subspecies abscessus and massiliense), M. kansasii, and M. fortuitum. Regardless of clarithromycin or amikacin resistance, the MIC and MBC values of SPR719 were comparable among these major pathogenic NTM species. In over 70% of the isolates, the MIC values were ≤2 μg/mL with MBC values of ≤4 μg/mL. The MIC and MBC values of M. kansasii were relatively lower than those of the other species with little difference between them, demonstrating the bactericidal properties of SPR719. The in vitro activity of SPR719 against major clinical NTM species suggests that SPR719 can serve as a novel treatment option for NTM-pulmonary disease.

Study of vacuolating cytotoxin A (vacA) genotypes of ulcerogenic and non-ulcerogenic strains of Helicobacter pylori and its association with gastric disease

Globally, Helicobacter pylori (H. pylori), a stomach pathogen, is present in around 50 % of the population. This bacterial infection produces persistent inflammation, which significantly raises the risk of duodenal, gastric ulcer, and stomach cancer. The goal of this study is to identify the vacA genotypes in H. pylori and analyze how they relate to medical conditions brought on by the bacteria and clarithromycin resistance. PCR was used to describe 115 endoscopic stomach samples from infected patients and identify vacA gene. Of the 115 research participants, H. pylori was found in 81 (70.4 %) of them. Of the isolated cultures, only 38 (69.1 %) were resistant to clarithromycin. VacA was discovered in 55 (67.9 %) of the samples that had H. pylori in them. Patients with gastritis were more likely to have s2m2 strains of infection (66.7 %), while those with gastric and duodenal ulcers were more likely to have s1m1 strains (64.7 %). VacA-positive H. pylori strains (60 % n = 33) were more resistant to clarithromycin versus (19.2 % n = 5) for vacA-negative bacteria. Clarithromycin resistance was significantly linked to vacA s2m2 in H. pylori isolates (75.9 %). According to the study's results, the vacA variants s1m1 and s2m2 have a strong connection with the emergence of H. pylori infections that cause peptic ulcer disease in the population of Iraq. Genetic testing is essential in predicting both the course of treatment and the outcome of H. pylori disease.

The pipeline for drugs for control and elimination of neglected tropical diseases: 2. Oral anti-infective drugs and drug combinations for off-label use

In its 'Road map for neglected tropical diseases 2021-2030', the World Health Organization outlined its targets for control and elimination of neglected tropical diseases (NTDs) and research needed to achieve them. For many NTDs, this includes research for new treatment options for case management and/or preventive chemotherapy. Our review of small-molecule anti-infective drugs recently approved by a stringent regulatory authority (SRA) or in at least Phase 2 clinical development for regulatory approval showed that this pipeline cannot deliver all new treatments needed. WHO guidelines and country policies show that drugs may be recommended for control and elimination for NTDs for which they are not SRA approved (i.e. for 'off-label' use) if efficacy and safety data for the relevant NTD are considered sufficient by WHO and country authorities. Here, we are providing an overview of clinical research in the past 10 years evaluating the anti-infective efficacy of oral small-molecule drugs for NTD(s) for which they are neither SRA approved, nor included in current WHO strategies nor, considering the research sponsors, likely to be registered with a SRA for that NTD, if found to be effective and safe. No such research has been done for yaws, guinea worm, Trypanosoma brucei gambiense human African trypanosomiasis (HAT), rabies, trachoma, visceral leishmaniasis, mycetoma, T. b. rhodesiense HAT, echinococcosis, taeniasis/cysticercosis or scabies. Oral drugs evaluated include sparfloxacin and acedapsone for leprosy; rifampicin, rifapentin and moxifloxacin for onchocerciasis; imatinib and levamisole for loiasis; itraconazole, fluconazole, ketoconazole, posaconazole, ravuconazole and disulfiram for Chagas disease, doxycycline and rifampicin for lymphatic filariasis; arterolane, piperaquine, artesunate, artemether, lumefantrine and mefloquine for schistosomiasis; ivermectin, tribendimidine, pyrantel, oxantel and nitazoxanide for soil-transmitted helminths including strongyloidiasis; chloroquine, ivermectin, balapiravir, ribavirin, celgosivir, UV-4B, ivermectin and doxycycline for dengue; streptomycin, amoxicillin, clavulanate for Buruli ulcer; fluconazole and isavuconazonium for mycoses; clarithromycin and dapsone for cutaneous leishmaniasis; and tribendimidine, albendazole, mebendazole and nitazoxanide for foodborne trematodiasis. Additional paths to identification of new treatment options are needed. One promising path is exploitation of the worldwide experience with 'off-label' treatment of diseases with insufficient treatment options as pursued by the 'CURE ID' initiative.

Rapid Mycobacterium abscessus antimicrobial susceptibility testing based on antibiotic treatment response mapping via Raman Microspectroscopy

OBJECTIVES

Antimicrobial susceptibility tests (ASTs) are pivotal tools for detecting and combating infections caused by multidrug-resistant rapidly growing mycobacteria (RGM) but are time-consuming and labor-intensive.

DESIGN

We used a Mycobacterium abscessus-based RGM model to develop a rapid (24-h) AST from the beginning of the strain culture, the Clinical Antimicrobials Susceptibility Test Ramanometry for RGM (CAST-R-RGM). The ASTs obtained for 21 clarithromycin (CLA)-treated and 18 linezolid (LZD)-treated RGM isolates.

RESULTS

CAST-R-RGM employs D2O-probed Raman microspectroscopy to monitor RGM metabolic activity, while also revealing bacterial antimicrobial drug resistance mechanisms. The results of clarithromycin (CLA)-treated and linezolid (LZD)-treated RGM isolates exhibited 90% and 83% categorical agreement, respectively, with conventional AST results of the same isolates. Furthermore, comparisons of time- and concentration-dependent Raman results between CLA- and LZD-treated RGM strains revealed distinct metabolic profiles after 48-h and 72-h drug treatments, despite similar profiles obtained for both drugs after 24-h treatments.

CONCLUSIONS

Ultimately, the rapid, accurate, and low-cost CAST-R-RGM assay offers advantages over conventional culture-based ASTs that warrant its use as a tool for improving patient treatment outcomes and revealing bacterial drug resistance mechanisms.

Polymorphism of virulence genes and biofilm associated with in vitro induced resistance to clarithromycin in Helicobacter pylori

BACKGROUND

Clarithromycin-containing triple therapy is commonly used to treat Helicobacter pylori infections. Clarithromycin resistance is the leading cause of H. pylori treatment failure. Understanding the specific mutations that occur in H. pylori strains that have evolved antibiotic resistance can help create a more effective and individualised antibiotic treatment plan. However, little is understood about the genetic reprogramming linked to clarithromycin exposure and the emergence of antibiotic resistance in H. pylori. Therefore, this study aims to identify compensatory mutations and biofilm formation associated with the development of clarithromycin resistance in H. pylori. Clarithromycin-sensitive H. pylori clinical isolates were induced to develop clarithromycin resistance through in vitro exposure to incrementally increasing concentration of the antibiotic. The genomes of the origin sensitive isolates (S), isogenic breakpoint (B), and resistant isolates (R) were sequenced. Single nucleotide variations (SNVs), and insertions or deletions (InDels) associated with the development of clarithromycin resistance were identified. Growth and biofilm production were also assessed.

RESULTS

The S isolates with A2143G mutation in the 23S rRNA gene were successfully induced to be resistant. According to the data, antibiotic exposure may alter the expression of certain genes, including those that code for the Cag4/Cag protein, the vacuolating cytotoxin domain-containing protein, the sel1 repeat family protein, and the rsmh gene, which may increase the risk of developing and enhances virulence in H. pylori. Enhanced biofilm formation was detected among R isolates compared to B and S isolates. Furthermore, high polymorphism was also detected among the genes associated with biofilm production.

CONCLUSIONS

Therefore, this study suggests that H. pylori may acquire virulence factors while also developing antibiotic resistance due to clarithromycin exposure.

pylori infection

OBJECTIVE

This study aimed to assess the pharmacokinetic (PK) interactions of anaprazole, clarithromycin, and amoxicillin using physiologically based pharmacokinetic (PBPK) models.

METHODS

The PBPK models for anaprazole, clarithromycin, and amoxicillin were constructed using the GastroPlus™ software (Version 9.7) based on the physicochemical data and PK parameters obtained from literature, then were optimized and validated in healthy subjects to predict the plasma concentration-time profiles of these three drugs and assess the predictive performance of each model. According to the analysis of the properties of each drug, the developed and validated models were applied to evaluate potential drug-drug interactions (DDIs) of anaprazole, clarithromycin, and amoxicillin.

RESULTS

The developed PBPK models properly described the pharmacokinetics of anaprazole, clarithromycin, and amoxicillin well, and all predicted PK parameters (Cmax,ss, AUC0-τ,ss) ratios were within 2.0-fold of the observed values. Furthermore, the application of these models to predict the anaprazole-clarithromycin and anaprazole-amoxicillin DDIs demonstrates their good performance, with the predicted DDI Cmax,ss ratios and DDI AUC0-τ,ss ratios within 1.25-fold of the observed values, and all predicted DDI Cmax,ss, and AUC0-τ,ss ratios within 2.0-fold. The simulated results show no need to adjust the dosage when co-administered with anaprazole in patients undergoing eradication therapy of H. pylori infection since the dose remained in the therapeutic range.

CONCLUSION

The whole-body PBPK models of anaprazole, clarithromycin, and amoxicillin were built and qualified, which can predict DDIs that are mediated by gastric pH change and inhibition of metabolic enzymes, providing a mechanistic understanding of the DDIs observed in the clinic of clarithromycin, amoxicillin with anaprazole.

Curcumin clarithromycin nano-form a promising agent to fight Helicobacter pylori infections

Helicobacter pylori (H. pylori) is the main cause of gastric diseases. However, the traditional antibiotic treatment of H. pylori is limited due to increased antibiotic resistance, low efficacy, and low drug concentration in the stomach. This study developed a Nano-emulsion system with ability to carry Curcumin and Clarithromycin to protect them against stomach acidity and increase their efficacy against H. pylori. We used oil in water emulsion system to prepare a novel Curcumin Clarithromycin Nano-Emulsion (Cur-CLR-NE). The nano-emulsion was validated by dynamic light scattering (DLS) technique, zeta potential; transmission electron microscopy (mean particle size 48 nm), UV-visible scanning and Fourier transform infrared spectroscopy (FT-IR). The in vitro assay of Cur-CLR-NE against H. pylori was evaluated by minimum inhibitory concentration (12.5 to 6.26 µg/mL), minimum bactericidal concentration (MBC) and anti-biofilm that showed a higher inhibitory effect of Cur-CLR-NE in compere with, free curcumin and clarithromycin against H. pylori. The in vivo results indicated that Cur-CLR-NE showed higher H. pylori clearance effect than free clarithromycin or curcumin under the same administration frequency and the same dose regimen. Histological analysis clearly showed that curcumin is highly effective in repairing damaged tissue. In addition, a potent synergistic effect was obvious between clarithromycin and curcumin in nano-emulsion system. The inflammation, superficial damage, the symptoms of gastritis including erosion in the mouse gastric mucosa, necrosis of the gastric epithelium gastric glands and interstitial oedema of tunica muscularis were observed in the positive control infected mice and absent from treated mice with Cur-CLR-NE.

Surveillance of Helicobacter pylori resistance over 22 Years (2000-2021) in Northern Spain

OBJECTIVES

Helicobacter pylori gastritis is considered an infectious disease, regardless of symptoms and stage of disease. Most consensus documents recommend empirical therapy based on local antimicrobial susceptibility patterns. We aimed to provide clinically useful information about primary and secondary antimicrobial resistance to antimicrobials commonly prescribed for H. pylori.

METHODS

Overall, 31,406 gastroduodenal biopsies and 2,641 string tests from patients over 15 years of age were plated on selective media, isolating H. pylori in 36.7% of biopsies and 50.7% of string tests. Susceptibility testing could be performed in 96.6% (12,399/12,835) of H. pylori isolates. Polymerase chain reaction (PCR) was also used to detect H. pylori and its resistance to clarithromycin, providing susceptibility data for 112 patients with negative culture results.

RESULTS

Resistance to amoxicillin and tetracycline was unusual (0.6% and 0.2%, respectively). Rates of primary resistance to clarithromycin and metronidazole remained steady over the 22-year study period, at around 14% for clarithromycin and 30% for metronidazole, while primary resistance to levofloxacin tripled (from 7.6% in 2000 to 21.7% in 2021, P < 0.001) and increased with patient age. Notably, 1.8% of isolates were multiresistant to clarithromycin, metronidazole, and levofloxacin. Overall, secondary resistance rates were higher (P < 0.0001) than primary resistance rates for clarithromycin (42.5% vs 14.1%), metronidazole (40.9% vs 32%), and levofloxacin (21.5% vs 17.1%).

CONCLUSION

Determination of susceptibility for H. pylori by culture and/or PCR in patients undergoing endoscopy could facilitate the implementation of tailored therapy and guide the choice of empirical therapy when susceptibility testing cannot be performed, potentially helping limit the emergence of antimicrobial resistance.

Efficacy of 7-day Tailored Therapy for Helicobacter pylori Eradication based on Clarithromycin Resistance

Background/Aims

Increasing resistance to clarithromycin (CAM) of Helicobacter pylori (H. pylori) is one of the main causes of recent decrease in eradication rate of standard triple therapy. The aim of this study was to evaluate the usefulness of 7-day tailored therapy based on the existence of CAM resistance.

Methods

From January 2017 to May 2022, a total of 481 consecutive patients with H. pylori infection were recruited in Daegu Catholic University Medical Center. Treatment regimen was selected based on the result of CAM resistance test. Patients with CAM resistance (R group) were treated with bismuth-based quadruple therapy for 7 days. Patients without CAM resistance (S group) were treated with standard triple therapy for 7 days.

Results

The overall H. pylori eradication rate was 89.4% (379 of 424) by per-protocol (PP) analysis. Patients with CAM resistance mutation included 166 patients (34.5%). The eradication rates of each group were 88.8% (135 of 152) and 89.7% (244 of 272) by PP analysis, for R and S group respectively. By intention-to-treat (ITT) analysis, the eradication rates were 81.3% (135 of 166) and 77.5% (244 of 315) for R and S group. CAM resistance was identified with a dual-priming oligonucleotide-based multiplex PCR.

Conclusions

In spite of this high CAM resistance (34.5%), the eradication rate of 7-day tailored therapy based on the existence of CAM resistance was 89.4%. The 7-day tailored therapy based on CAM resistance could be an acceptable treatment selection strategy for H. pylori eradication.

Mycobacterium shinjukuense infection successfully treated with clarithromycin, rifampicin, and ethambutol

We present the case of a 59-year-old woman diagnosed with Mycobacterium shinjukuense infection using mass spectrometry of bronchioalveolar lavage fluid. We initiated treatment with clarithromycin, rifampicin, and ethambutol based on the results of drug susceptibility testing, which improved lung opacities. Most previous cases were treated with the standard regimen for Mycobacterium tuberculosis. However, our regimen may provide a therapeutic option for this rare nontuberculous Mycobacterium infection.

Pyrosequencing analysis for rapid and accurate detection of clarithromycin resistance-associated mutations in Iranian Helicobacter pylori isolates

BACKGROUND

Treatment of Helicobacter pylori (H. pylori) infection has become challenging following the development of primary antibiotic resistance. A primary therapeutic regimen for H. pylori eradication includes clarithromycin; however, the presence of point mutations within the 23S rRNA sequence of H. pylori contributes to clarithromycin resistance and eradication failure. Thus, we aimed to develop a rapid and precise method to determine clarithromycin resistance-related point mutations using the pyrosequencing method.

METHODS AND RESULTS

H. pylori was isolated from 82 gastric biopsy samples and minimal inhibitory concentration (MIC) was evaluated using the agar dilution method. Clarithromycin resistance-associated point mutations were detected by Sanger sequencing, from which 11 isolates were chosen for pyrosequencing. Our results demonstrated a 43.9% (36/82) prevalence in resistance to clarithromycin. The A2143G mutation was detected in 8.3% (4/48) of H. pylori isolates followed by A2142G (6.2%), C2195T (4.1%), T2182C (4.1%), and C2288T (2%). Although the C2195T mutation was only detected by Sanger sequencing, the overall results from pyrosequencing and Sanger sequencing platforms were comparable.

CONCLUSIONS

Pyrosequencing could be used as a rapid and practical platform in clinical laboratories to determine the susceptibility profile of H. pylori isolates. This might pave the way for efficient H. pylori eradication upon detection.

Effective bioremediation of clarithromycin and diclofenac in wastewater by microbes and Arundo donax L

Bioremediation of pharmaceuticals has gained large research efforts, but there is still a need to improve the performance of bioremediation systems by selecting effective organisms. In this study, we characterized the capability to remove clarithromycin (CLA) and diclofenac (DCF) by the bacterium Streptomyces rochei, and the fungi Phanerochaete chrysosporium and Trametes versicolor. The macrolide antibiotic CLA and the non-steroid anti-inflammatory DCF were selected because these are two of the most frequently detected drugs in water bodies. Growth and content of the PhCs and a DCF metabolite (MET) by the energy crop Arundo donax L. were also evaluated under hydroponic conditions. The removal rate (RR) by S. rochei increased from 24 to 40% at 10 and 100 µg CLA L-1, respectively, averaged over incubation times. At 144 h, the RR by P. chrysosporium was 84%, while by T. versicolor was 70 and 45% at 10 and 100 CLA µg L-1. The RR by S. rochei did not exceed 30% at 1 mg DCF L-1 and reached 60% at 10 mg DCF L-1, whereas approached 95% and 63% by P. chrysosporium and T. versicolor, respectively, at both doses. Root biomass and length of A. donax were strongly affected at 100 µg CLA L-1. CLA concentration in roots and shoots increased with the increase of the dose and translocation factor (TF) was about 1. DCF severely affected both shoot fresh weight and root length at the highest dose and concentration in roots and shoots increased with the increase of the dose. DCF concentrations were 16-19 times higher in roots than in shoots, and TF was about 0.1. MET was detected only in roots and its proportion over the parent compound decreased with the increase of the DCF dose. This study highlights the potential contribution of A. donax and the tested microbial inoculants for improving the effectiveness of bioremediation systems for CLA and DCF removal.

Ten-day tegoprazan-based concomitant therapy as a first-line treatment for Helicobacter pylori eradication

Background/Aims

Tegoprazan, a novel potassium-competitive acid blocker, has shown rapid action and gastric acid inhibition. In this study, we evaluated the efficacy of a tegoprazan-based, nonbismuth-containing quadruple (concomitant) therapy for the primary eradication of Helicobacter pylori.

Methods

We conducted a prospective, single-arm, single-center, primitive study to verify the efficacy of a 10-day tegoprazan- based (50-mg dose) concomitant therapy, including amoxicillin (1,000-mg dose), clarithromycin (CLA; 500-mg dose), and metronidazole (MET; 500-mg dose) twice daily as a first-line treatment for H. pylori eradication.

Results

We tested consecutive cultures for antibiotic susceptibility and minimum inhibitory concentrations. We enrolled 84 participants; 79 (94.0%) completed first-line therapy. The overall intention-to-treat and per-protocol eradication rates were 90.5% (95% confidence interval [CI], 82.1-95.8) and 96.2% (95% CI, 83.4-97.6), respectively. Of the 73 participants evaluated for antibiotic resistance, 19 (26.0%), 32 (42.5%), and 8 (11.0%) exhibited CLA, MET, and CLA and MET dual resistance, respectively. Of these, 39 participants (66.1%) exhibited successful eradication after the therapeutic regimen despite antibiotic resistance.

Conclusions

The 10-day tegoprazan-based concomitant therapy may be an effective first-line treatment for eradicating H. pylori.

Evaluation of pharmacokinetic drug-drug interaction between tegoprazan and clarithromycin in healthy subjects

Tegoprazan is a novel potassium-competitive acid blocker that treats gastric acid-related diseases. Clarithromycin was widely used as one of various regimens for eradicating Helicobacter pylori. This study compared the pharmacokinetic and safety profile of tegoprazan and clarithromycin between combination therapy and monotherapy to evaluate the potential drug-drug interaction. An open-label, randomized, 6-sequence, 3-period crossover study was conducted in 24 healthy subjects. According to the assigned sequence, the subject was administered the assigned treatment during 5 days in each period. PK parameters of tegoprazan and clarithromycin administered in combination were compared with those of the respective monotherapies. The co-administration of tegoprazan with clarithromycin increased maximum steady-state plasma concentration (C_ss,max) and area under the plasma concentration-time curve in dosing interval at steady-state (AUC_ss,tau) of tegoprazan (1.6-fold in C_ss,max and 2.5-fold in AUC_ss,tau) and M1 (2.0-fold in C_ss,max, 2.5-fold in AUC_ss,tau) than tegoprazan alone. The C_ss,max and AUC_ss,tau of 14-hydroxyclarithromycin increased 1.8- and 2.0-fold in co-administration, respectively. The AUC_ss.tau of clarithromycin was slightly increased in co-administration, but C_ss,max was not changed. Combination of tegoprazan and clarithromycin and those of the respective monotherapies were tolerated in 24 healthy subjects. There may exist drug interaction that lead to reciprocal increase in plasma drug concentrations when tegoprazan and clarithromycin were administrated in combination and no safety concerns were raised. It is suggested that an in-depth analysis of the concentration-response relationship is necessary to determine whether these concentration changes warrant clinical action.

Trial Registration

ClinicalTrials.gov Identifier: NCT02052336.

Integrated lipidomic and transcriptomic analysis reveals clarithromycin-induced alteration of glycerophospholipid metabolism in the cerebral cortex of mice

Clarithromycin (CLA) has been widely used in the treatment of bacterial infection. Research reveals the adverse effects on the central nervous system among patients receiving CLA treatment; whereas, a relevant underlying mechanism remains considerably unclear. According to our research, an integrated lipidomic and transcriptomic analysis was applied to explore the effect of CLA on neurobehavior. CLA treatment caused anxiety-like behaviors dose-dependently during open field as well as elevated plus maze trials on mice. Transcriptomes and LC/MS-MS-based metabolomes were adopted for investigating how CLA affected lipidomic profiling as well as metabolic pathway of the cerebral cortex. CLA exposure greatly disturbed glycerophospholipid metabolism and the carbon chain length of fatty acids. By using whole transcriptome sequencing, we found that CLA significantly downregulated the mRNA expression of CEPT1 and CHPT1, two key enzymes involved in the synthesis of glycerophospholipids, supporting the findings from the lipidomic profiling. Also, CLA causes changes in neuronal morphology and function in vitro, which support the existing findings concerning neurobehavior in vivo. We speculate that altered glycerophospholipid metabolism may be involved in the neurobehavioral effect of CLA. Our findings contribute to understanding the mechanisms of CLA-induced adverse effects on the central nervous system. 1. Clarithromycin treatment caused anxiety-like behavior with dose-dependent response both in the open field and elevated plus maze test in mice; 2. Clarithromycin exposing predominately disturbed the metabolism of glycerophospholipids in the cerebral cortex of mice; 3. Clarithromycin application remarkably attenuated CEPT1 and CHPT1 gene expression, which participate in the last step in the synthesis of glycerophospholipids; 4. The altered glycerophospholipid metabolomics may be involved in the abnormal neurobehavior caused by clarithromycin.

Clarithromycin-induced eosinophilic granulomatosis with polyangiitis: A case report

A 75-year-old man presented to our hospital with chronic sinusitis, bronchiectasis, and chronic lower respiratory tract infections. He began taking erythromycin in August, X-2. The chronic lower respiratory tract infection gradually worsened, and clarithromycin was started on May 11, X. He became aware of fever and numbness in his lower legs on June 4, X. The sign occurred soon after oral clarithromycin and blood tests showed an elevated eosinophil count and C-reactive protein (CRP) levels, positive MPO-ANCA antibodies, and positive for drug-induced lymphocyte stimulation test (DLST); we diagnosed eosinophilic granulomatosis with polyangiitis (EGPA) associated with clarithromycin administration.

Determination of metronidazole and clarithromycin in plasma samples using surfactant-modified amorphous carbon-based DSPE combined with DLLME followed by HPLC

This work offers preparation of surfactant-modified amorphous carbon and its application in dispersive solid phase extraction of metronidazole and clarithromycin from plasma samples. The extraction procedure was combined with dispersive liquid-liquid microextraction for further preconcentration of the analytes for sensitive determination of the analytes followed by high performance liquid chromatography-diode array detector. In this work, first, the sorbent was added to the sample and the mixture vortexed to adsorb the analytes. Then, the obtained supernatant after centrifuging is discarded and the loaded analytes onto the sorbent surface were eluted with a water-miscible organic solvent. In the following, to further enrichment of the analytes the microextraction step was done. For this purpose, the eluate is taken, mixed with a water-immiscible organic solvent, and injected into deionized water. After centrifuging, an aliquat of the sedimented phase is taken and injected into the analytical instrument for the quantitative analysis. Under the optimum extraction conditions, high extraction recoveries (79 and 89% for metronidazole and clarithromycin, respectively), low limits of detection (2.1 and 1.9 ng mL^-1 for metronidazole and clarithromycin, respectively) and quantification (7.0 and 6.3 ng mL^-1 for metronidazole and clarithromycin, respectively), good repeatability (relative standard deviations less than 4.3% for intra- and 6.3% inter-day precisions), and wide linear ranges (7.3-1000 and 6.3-1000 ng mL^-1 for metronidazole and clarithromycin, respectively) were obtained. At the end, the introduced method was applied on the plasma samples of the patients treated with metronidazole and clarithromycin successfully.

Identifying antimicrobials and their metabolites in wastewater and surface water with effect-directed analysis

This study aimed to identify antimicrobial contaminants in the aquatic environment with effect-directed analysis. Wastewater influent, effluent, and surface water (up- and downstream of the discharge location) were sampled at two study sites. The samples were enriched, subjected to high-resolution fractionation, and the resulting 80 fractions were tested in an antibiotics bioassay. The resulting bioactive fractions guided the suspect and nontargeted identification strategy in the high-resolution mass spectrometry data that was recorded in parallel. Chemical features were annotated with reference databases, assessed on annotation quality, and assigned identification confidence levels. To identify antibiotic metabolites, Phase I metabolites were predicted in silico for over 500 antibiotics and included as a suspect list. Predicted retention times and fragmentation patterns reduced the number of annotations to consider for confirmation testing. Overall, the bioactivity of three fractions could be explained by the identified antibiotics (clarithromycin and azithromycin) and an antibiotic metabolite (14-OH(R) clarithromycin), explaining 78% of the bioactivity measured at one study site. The applied identification strategy successfully identified antibiotic metabolites in the aquatic environment, emphasizing the need to include the toxic effects of bioactive metabolites in environmental risk assessments.

Effect of Clarithromycin, a Strong CYP3A and P-glycoprotein Inhibitor, on the Pharmacokinetics of Edoxaban in Healthy Volunteers and the Evaluation of the Drug Interaction with Other Oral Factor Xa Inhibitors by a Microdose Cocktail Approach

PURPOSE

We assessed the differential effect of clarithromycin, a strong inhibitor of cytochrome P450 (CYP) 3A4 and P-glycoprotein, on the pharmacokinetics of a regular dose of edoxaban and on a microdose cocktail of factor Xa inhibitors (FXaI). Concurrently, CYP3A activity was determined with a midazolam microdose.

METHODS

In an open-label fixed-sequence trial in 12 healthy volunteers, the pharmacokinetics of a microdosed FXaI cocktail (μ-FXaI; 25 μg apixaban, 50 μg edoxaban, and 25 μg rivaroxaban) and of 60 mg edoxaban before and during clarithromycin (2 x 500 mg/d) dosed to steady-state was evaluated. Plasma concentrations of study drugs were quantified using validated ultra-performance liquid chromatography-tandem mass spectrometry methods.

RESULTS

Therapeutic clarithromycin doses increased the exposure of a therapeutic 60 mg dose of edoxaban with a geometric mean ratio (GMR) of the area under the plasma concentration-time curve (AUC) of 1.53 (90 % CI: 1.37-1.70; p < 0.0001). Clarithromycin also increased the GMR (90% CI) of the exposure of microdosed FXaI apixaban to 1.38 (1.26-1.51), edoxaban to 2.03 (1.84-2.24), and rivaroxaban to 1.44 (1.27-1.63). AUC changes observed for the therapeutic edoxaban dose were significantly smaller than those observed with the microdose (p < 0.001).

CONCLUSION

Clarithromycin increases FXaI exposure. However, the magnitude of this drug interaction is not expected to be clinically relevant. The edoxaban microdose overestimates the extent of the drug interaction with the therapeutic dose, whereas AUC ratios for apixaban and rivaroxaban were comparable to the interaction with therapeutic doses as reported in the literature.

TRIAL REGISTRATION

EudraCT Number: 2018-002490-22.

Preparation and Characterization of Patch Loaded with Clarithromycin Nanovesicles for Transdermal Drug Delivery

Clarithromycin (CLR), categorized as a Biopharmaceutical Classification System class II drug, has several gastrointestinal tract side effects and an extremely unpalatable bitter taste. The current study aimed to design transdermal patch-embedded CLR niosomes to overcome the aforementioned CLR-related challenges. Various niosomal formulations were successfully fabricated and characterized for their morphology, size, in vitro release, and antimicrobial efficacy. Subsequently, the CLR niosomes were loaded into transdermal patches using the solvent casting method. The polydispersity index of the niosomes ranged from 0.005 to 0.360, indicating the uniformity of the niosomes. The encapsulating efficiency (EE)% varied from 12 to 86%. The optimal Chol: surfactant ratio for drug release was found to be 0.5:1. In addition, the encapsulation of CLR into niosomal nanovesicles did not reduce the antibacterial activity of the CLR. The niosomal patch had a significantly higher permeability coefficient of CLR than the conventional patch. In addition to that, a shear-thinning behavior was observed in the niosomal gels before loading them into a niosomal patch. The flux (Jss) of the niosomal patch was significantly higher than the conventional patch by more than 200 times. In conclusion, niosome-based transdermal patches could be a promising method for the transdermal drug delivery of class II drugs and drugs experiencing GIT side effects.

Blood Concentration of Cabazitaxel in a Patient Whose General Condition Worsened with Concomitant Use of Clarithromycin

We encountered a case in which the general condition of a patient receiving cabazitaxel worsened with concomitant use of clarithromycin. Cabazitaxel is metabolized mainly by CYP3A4, and the frequency of adverse events is known to increase with increasing exposure. Although these drugs are not often quantified in daily practice, we quantified them because we considered it possible that the blood concentration of cabazitaxel had increased due to CYP3A4 inhibition of clarithromycin and that cabazitaxel-related adverse events had occurred. However, the concentration of cabazitaxel was not increased and we attributed the patient's deterioration to decreased tolerability of cabazitaxel. At least at a trough concentration of 70 ng/mL, which is the trough concentration when a normal dose of clarithromycin is administered, clarithromycin does not appear to have a significant effect on the blood concentration of cabazitaxel. This case suggests that the administration of the normal dose of clarithromycin might be relatively safe in patients receiving cabazitaxel.

Comparison of 10 and 14 days of antofloxacin-based versus 14 days of clarithromycin-based bismuth quadruple therapy for Helicobacter pylori eradication: A randomized trial

OBJECTIVE

Our team previously reported the use of antofloxacin-based bismuth quadruple therapy for the eradication of Helicobacter pylori (H. pylori). This study aimed to compare the efficacy and safety of 10 and 14 days of antofloxacin-based versus 14 days of clarithromycin-based bismuth quadruple therapy in the first-line treatment for H. pylori infection.

METHODS

1174 patients with H. pylori infection were randomized into three groups: 10-days and 14-days antofloxacin (ANT10 and ANT14) groups who received 10 and 14 days of antofloxacin-based bismuth quadruple therapy (colloidal bismuth pectin 200 mg t.i.d., esomeprazole 20 mg b.i.d., amoxicillin 1 g b.i.d., and antofloxacin 200 mg q.d.), 14-days clarithromycin (CLA14) group who received 14 days of clarithromycin-based bismuth quadruple therapy (colloidal bismuth pectin 200 mg t.i.d., esomeprazole 20 mg b.i.d., amoxicillin 1 g b.i.d., and clarithromycin 500 mg b.i.d.). Eradication rate, antibiotic resistance and adverse events were analyzed.

RESULTS

The intention-to-treat (ITT) and per-protocol (PP) analyses have showed statistically different eradication rates between ANT14 group and ANT10 group (ITT p = 0.001; PP p < 0.001), but no statistical difference between ANT10 group and CLA14 group (ITT p = 0.340; PP p = 0.092). Treatment regimen, drug resistance and therapy duration were important clinical factors related to H. pylori eradication rates in multivariate logistic analysis. Longer durations had significantly higher eradication rates in patients with antibiotic-resistant strains or antibiotic-susceptible strains. The incidences of nausea and bitter taste were significantly higher in CLA group compared with ANT group (p = 0.002 for nausea; p = 0.002 for bitter taste). The ANT10 and ANT14 group had similar adverse event rates of gastrointestinal reactions.

CONCLUSION

The study showed that the H. pylori eradication rate with ANT14 therapy was higher than that with ANT10 and CLA14 therapy without significantly increasing the rates of adverse event. 14 days of antofloxacin-based bismuth quadruple therapy may be a more effective way as the first-line treatment for H. pylori infection.

Isolation and Antimicrobial Susceptibility of Nontuberculous Mycobacteria in a Tertiary Hospital in Korea, 2016 to 2020

BACKGROUND

There is a global increase in isolation of nontuberculous mycobacteria (NTM). The aim of the study was to analyze longitudinal trends of NTM identification and pattern of antimicrobial susceptibility testing.

METHODS

NTM recovery rates, distribution of NTM species identification, and antimicrobial susceptibility pattern of NTM at Pusan National University Yangsan Hospital between January 2016 and December 2020 were retrospectively analyzed.

RESULTS

A total of 52,456 specimens from 21,264 patients were submitted for mycobacterial culture, of which 2,521 from 1,410 patients were NTM positive over five years (January 2016 to December 2020). NTM isolation showed an increasing trend from 2016 to 2020 (p&lt;0.001, test for trend) mainly caused by Mycobacterium avium complex. The vast majority of M. avium complex were susceptible to key agents clarithromycin and amikacin. For Mycobacterium kansasii, resistance to rifampin and clarithromycin is rare. Amikacin was the most effective drug against Mycobacterium abscessus subspecies abscessus and Mycobacterium subspecies massiliense. Most of M. subspecies massiliense were susceptible to clarithromycin, while the majority of M. abscessus subspecies abscessus were resistant to clarithromycin (p&lt;0.001).

CONCLUSION

There was an increasing trend of NTM isolation in our hospital. Resistance to key drugs was uncommon for most NTM species except for M. abscessus subspecies abscessus against clarithromycin.

The prevalence of clarithromycin-resistant Helicobacter pylori isolates: a systematic review and meta-analysis

Background

Knowledge of global clarithromycin (CLA)-resistant rates of Helicobacter pylori (H. pylori) is crucial for decision of the most appropriate eradication therapies with good clinical outcomes. Therefore, this review and meta-analysis aimed to evaluate the global prevalence of the CLA resistance in H. pylori to provide some guidance for selecting the first-line antibiotics.

Method

A comprehensive search was performed for relevant literature until April 2021 in PubMed, Embase, and Web of Science databases. Freeman-Tukey double arcsine transformation was performed to estimate the weighted pooled prevalence of resistance.

Results

The meta-analysis included 248 articles. The prevalence of CLA-resistant H. pylori was 27.53% (95% CI [25.41-29.69]). The heterogeneity between reports was significant (I² = 97.80%, P < 0.01). The resistance rate increased from 24.28% in 2010-2017 to 32.14% in 2018-2021 (P < 0.01). Iran, with 38 articles, has the most report. Nevertheless, Switzerland, Portugal, and Israel had the highest resistance rates (67.16%, 48.11%, and 46.12%, respectively). The heterogeneity between the continents and the antimicrobial susceptibility methods also interpreted standard guidelines and breakpoints was insignificant (P > 0.05).

Conclusion

Overall CLA resistance rate was 27.53%, worldwide. The difference in CLA resistance rate among the included studies can be due to several reasons such as differences in antibiotic prescription rates in various geographic areas, use of different breakpoints or inaccurate criteria in performed studies, and the emergence of multidrug-resistant (MDR) strains.

Pregnancy outcomes following maternal macrolide use: A systematic review and meta-analysis

To determine whether gestational use of all or specific macrolides (azithromycin, clarithromycin, roxithromycin or erythromycin) lead to an increase in rates of overall major congenital malformations, organ-specific malformations, and other adverse pregnancy outcomes in infants. PubMed/MEDLINE, Cochrane Central Register of Controlled Trials and Reprotox® databases were searched. Dichotomous outcomes or calculated log odds ratios and standard errors from observational studies are combined using the random-effects method in Review Manager 5.3. No significant increased risks for major congenital malformation (OR 1.06 [95% CI 0.99, 1.13]) and congenital heart defect (OR 1.05 [95% CI 0.92, 1.19]) following all macrolides use during the first trimester were detected. Prenatal azithromycin use was associated with a significantly increased risk of major congenital malformations in the analysis of cohort studies (OR 1.21 [95% CI 1.08-1.36]). This significance was also present in the sensitivity analysis. There were no statistically significant associations between the risk of organ specific malformations and all or specific macrolide exposures except for the decreased risk in hypospadias following erythromycin use in the meta-analysis of case-control studies (OR 0.38 [95% CI 0.18, 0.81]. Also, a significant 1.5-fold increased risk for spontaneous abortion following macrolide use was detected. A slight yet significantly increased rate of major congenital malformation with azithromycin exposure during pregnancy may be associated with maternal confounders. Nevertheless, level II ultrasound can be suggested following maternal azithromycin use during the first trimester. Future studies should take into account the inclusion of a disease-matched control group and accurate classification of the malformations.

Effects of 14-days bismuth- and tetracycline-containing quadruple therapy with concomitant regimen for the first line Helicobacterpylori eradication

Background

Helicobacter pylori (H. pylori) has infected about 50% of the world's population and it is the main cause for peptic ulcer, gastric adenocarcinoma and even a major cause for gastric MALT lymphoma.

Methods

This study was performed in Mazandaran, Sari, situated in North of Iran. Three-hundred and twenty-eight adult patients with endoscopically approved gastric or duodenal ulcers or erosions and H. pylori infection were randomly divided into 2 groups to receive either 14 days PABT (Pantoprazole 40 mg, Amoxicillin 1 g, Bismuth 425 mg (all twice daily) and Tetracycline 500 mg four times a day) and PACM (Pantoprazole 40 mg, Amoxicillin 1g, Clarithromycin 500 mg, and Metronidazole 500 mg, all twice daily). To evaluate H. pylori eradication, fecal H. pylori antigen test was performed 8 weeks after treatment.

Results

The eradication rates were 94.51% in the PABT and 91.46% in PACM group based on the intention to treat analysis. Moreover, the eradication rates were 95.58% and 92.72% according to per-protocol analysis, respectively. Also, both groups had very low rates of severe side effects.

Conclusion

Regarding the ideal eradication rates achieved by both treatment groups and the low rates of severe side effects, both treatment protocols can be prescribed for H. pylori eradication in North of Iran.

Doxycycline vs. macrolides in combination with a β-lactam antibiotic for the treatment of community-acquired pneumonia in inpatients

BACKGROUND

Hospitalized patients with non-severe community-acquired pneumonia (CAP) are treated with a β-lactam plus either a macrolide or doxycycline. Limited data exist on the effectiveness of the latter combination. Therefore, we aimed to compare the combination of doxycycline vs. macrolide when either is combined with a β-lactam from effectiveness and safety perspectives.

METHODS

This was a retrospective cohort study in CAP inpatients between December 2013 and November 2020. Patients were divided into BL-D (β-lactam plus doxycycline) and BL-M (β-lactam plus a macrolide [azithromycin or clarithromycin]) groups. The primary endpoint was time to clinical stability. Secondary endpoints included length of stay (LOS) and in-hospital mortality.

RESULTS

Of 197 patients included, 57 were in the BL-D arm and 140 were in the BL-M arm. Patients were similar at baseline, except for the presence of leukocytosis, risk factors for drug resistance, and duration of therapy (P < 0.05 for all comparisons). No difference in clinical cure rate was observed (94.7% vs. 91.4%; P = 0.43). Time to clinical stability and LOS were similar in both groups at 4 (P = 0.82) and 7 days (P = 0.62), respectively. While only three patients died, only one (from the BL-M group) was due to sepsis. Liver enzymes elevation was more prominent in the BL-M group (21.4% vs. 5.3%; P = 0.01). A subgroup analysis showed shorter time to clinical stability with clarithromycin but higher cure rates with azithromycin.

CONCLUSIONS

Data on doxycycline use with a β-lactam are scarce. Our study showed that such regimen was comparable in effectiveness to regimens involving macrolides with a better safety profile.

Ten-day concomitant and sequential therapy for Helicobacter pylori effective in region with high antibiotic resistance rates

BACKGROUND

Increasing antibiotic-resistant Helicobacter pylori (H. pylori) strains complicate efforts to eradicate infection. In regions with high dual resistance to both clarithromycin and metronidazole, bismuth quadruple therapy is recommended. But, with lack of easy availability of bismuth, the (non-bismuth) concomitant and sequential regimens are used commonly as first-line therapy. Recent reports indicate suboptimal results with sequential therapy in such regions. We aimed to compare the efficacy of concomitant therapy vs. sequential therapy in the eradication of H. pylori in a region with high antibiotic resistance rates, and to compare adherence rates and adverse events with the regimens.

METHODS

One hundred and twenty-four consecutive H. pylori-infected patients (diagnosed using rapid urease test or urea breath test) were randomized to receive sequential or concomitant therapy for 10 days each. Four weeks after treatment completion, urea breath test was done to confirm eradication of the infection. Cure rates were compared between the two regimens and note was made of adherence rates and adverse events.

RESULTS

Concomitant therapy showed a statistically non-significant higher cure rate compared to sequential therapy in intention-to-treat (87.1% vs. 81.4%%, p = 0.46) and per-protocol (94.7% vs. 83.9%, p = 0.07) analyses. Both the regimens were well tolerated and showed similar adherence rates (p = 1.00) and incidence of adverse events (p = 0.44).

CONCLUSION

In a region with high dual resistance, both concomitant and sequential therapy for H. pylori infection achieved eradication rates >80%, but concomitant therapy showed a statistically non-significant higher cure rate, with similar adherence and adverse event profiles.

Possible convulsion and electroencephalographic abnormality in a patient taking long-term oral clarithromycin: A case report

BACKGROUND

Clarithromycin is a macrolide antibiotic commonly prescribed to patients with upper respiratory and otolaryngological infections. Neuropsychiatric adverse effects of clarithromycin include agitation, insomnia, delirium, psychosis, and seizure.

CASE SUMMARY

A 52-year-old man was admitted to our hospital with a convulsion. He had > 10-year history of clarithromycin intake for chronic sinusitis. One week before admission, he started to take diltiazem for angina pectoris. On admission, his convulsion subsided. His electroencephalography showed frontal intermittent rhythmic delta activity. One week after he ceased clarithromycin, his electroencephalographic abnormalities disappeared. We suggested that the patient developed convulsions due to increased blood levels of clarithromycin caused by oral administration of diltiazem, which is involved in CYP3A metabolism.

CONCLUSION

Clarithromycin has a relatively high safety profile and is a frequently prescribed drug. However, there are a few previous reports of clarithromycin-related convulsive disorders. Clinicians should be aware of the drug interaction and rare side effects of seizures.

Empirical Second-Line Therapy in 5000 Patients of the European Registry on Helicobacter pylori Management (Hp-EuReg)

BACKGROUND & AIMS

After a first Helicobacter pylori eradication attempt, approximately 20% of patients will remain infected. The aim of the current study was to assess the effectiveness and safety of second-line empiric treatment in Europe.

METHODS

This international, multicenter, prospective, non-interventional registry aimed to evaluate the decisions and outcomes of H pylori management by European gastroenterologists. All infected adult cases with a previous eradication treatment attempt were registered with the Spanish Association of Gastroenterology-Research Electronic Data Capture until February 2021. Patients allergic to penicillin and those who received susceptibility-guided therapy were excluded. Data monitoring was performed to ensure data quality.

RESULTS

Overall, 5055 patients received empiric second-line treatment. Triple therapy with amoxicillin and levofloxacin was prescribed most commonly (33%). The overall effectiveness was 82% by modified intention-to-treat analysis and 83% in the per-protocol population. After failure of first-line clarithromycin-containing treatment, optimal eradication (&gt;90%) was obtained with moxifloxacin-containing triple therapy or levofloxacin-containing quadruple therapy (with bismuth). In patients receiving triple therapy containing levofloxacin or moxifloxacin, and levofloxacin-bismuth quadruple treatment, cure rates were optimized with 14-day regimens using high doses of proton pump inhibitors. However, 3-in-1 single capsule or levofloxacin-bismuth quadruple therapy produced reliable eradication rates regardless of proton pump inhibitor dose, duration of therapy, or previous first-line treatment. The overall incidence of adverse events was 28%, and most (85%) were mild. Three patients developed serious adverse events (0.3%) requiring hospitalization.

CONCLUSIONS

Empiric second-line regimens including 14-day quinolone triple therapies, 14-day levofloxacin-bismuth quadruple therapy, 14-day tetracycline-bismuth classic quadruple therapy, and 10-day bismuth quadruple therapy (as a single capsule) provided optimal effectiveness. However, many other second-line treatments evaluated reported low eradication rates. ClincialTrials.gov number: NCT02328131.

A nationwide cohort study suggests clarithromycin-based therapy for Helicobacter pylori eradication is safe in patients with stable coronary heart disease and subsequent peptic ulcer disease

Background

Clarithromycin-based therapy is important for Helicobacter pylori eradication treatment. However, clarithromycin may increase cardiovascular risk. Hence, we investigated the association between clarithromycin use and outcomes in adults with stable coronary heart disease (CHD) and subsequent peptic ulcer disease (PUD).

Methods

This nationwide cohort study used a national health insurance database to screen 298,417 Taiwanese residents who were diagnosed with coronary heart disease from 2001 to 2015 for eligibility in the study and to evaluate select eligible patients with CHD–PUD from 2004 to 2015. Data were obtained from new users of clarithromycin (n = 4183) and nonusers of clarithromycin (n = 24,752) during follow-up. A total of 4070 eligible clarithromycin users and 4070 nonusers were subject to final analysis by 1:1 propensity score matching. Participants were followed up after receiving clarithromycin or at the corresponding date until the occurrence of cardiovascular morbidity in the presence of competing mortality, overall mortality and cardiovascular mortality, or through the end of 2015. The incidence rates and risks of overall mortality and cardiovascular outcomes were evaluated. The associations between clarithromycin and arrhythmia risk, as well as its dose and duration and overall mortality and cardiovascular outcomes were also addressed.

Results

Clarithromycin users were associated with adjusted hazard ratios of 1.08 (95% confidence interval, 0.93–1.24; 21.5 compared with 21.2 per 1000 patient-years) for overall mortality, 0.95 (0.57–1.59; 1.5 compared with 1.8 per 1000 patient-years) for cardiovascular mortality, and 0.94 (0.89–1.09; 19.6 compared with 20.2 per 1000 patient-years) for cardiovascular morbidity in the presence of competing mortality, as compared with nonusers. We found no relationship between dose and duration of clarithromycin and overall mortality and cardiovascular outcomes and no increased risk of arrhythmia during follow-up period. After inclusion of arrhythmia events to re-estimate the risks of all study outcomes, the results remained insignificant.

Conclusion

Concerning overall mortality, cardiovascular mortality, and cardiovascular morbidity, our results suggest clarithromycin-based therapy for Helicobacter pylori eradication may be safe in patients with stable CHD and subsequent PUD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02498-1.

Comparative Study of Helicobacter Pylori Resistance to Clarithromycin and Metronidazole and Its Association with Epidemiological Factors in A Moroccan Population

OBJECTIVE

Knowledge of local antibiotic resistance is crucial to the adaption of the effective empirical first-line treatment for Helicobacter Pylori (H. pylori) infection. This study aimed to evaluate the prevalence of H. pylori resistance to clarithromycin and compare it with that of metronidazole, and highlight the impact of epidemiological factors and gastric lesions severity on H. pylori resistance.

METHODS

The susceptibility to clarithromycin of 96 isolates was determined by PCR-RFLP and the susceptibility to metronidazole of 185 isolates was determined by classic PCR.

RESULT

Our results showed that the prevalence of H. pylori resistance to clarithromycin (‎14.6%) was low compared to that recorded with metronidazole (‎62.7%). Moreover, we remarked that 7.3% of isolates were co-resistant to both antibiotics. The assessment of epidemiological factors' impact on the resistance to studied antibiotics has revealed no association. Besides, our results had demonstrated that the metronidazole and clarithromycin resistance was not related to the severity of gastric lesions.

CONCLUSION

In our population, clarithromycin seems to be an effective antibiotic as long as the resistance rate of H. pylori is low. In contrast to metronidazole, it appears that this antibiotic will lose its efficacy, due to the high rate of resistance among our population. Therefore, each population must conduct their epidemiologic studies separately to survey the resistance profile of strains and choose the appropriate antibiotic, in order to avoid the failure of H. pylori eradication and the development of severe gastric diseases.

Clarithromycin-treated chronic spontaneous urticaria with the negative regulation of FcεRΙ and MRGPRX2 activation via CD300f

Mast cells (MCs) are main effector cells in chronic spontaneous urticaria (CSU). Both Fc epsilon RI (FcεRΙ)- and MAS-related G coupled receptor-X2 (MRGPRX2)-mediated MC activations affect CSU course. Leukocyte mono-immunoglobulin-like receptor 3 (CD300f) has been shown to regulate FcεRΙ activation. However, no study has verified CD300f is a target to cure CSU. Therefore this study aimed to verify whether clarithromycin (CLA) regulates FcεRΙ- and MRGPRX2-mediated MC activations via CD300f and shows therapeutic effect on CSU. The target of CLA was verification. CLA inhibited FcεRΙ- and MRGPRX2-mediated MC activations were shown in vivo and in vitro. A single-center, self-comparison study was performed, and CLA-treated CSU was investigated in 28 patients who were not sensitive to the third-generation antihistamines. Serum inflammatory mediators in patients before and after CLA administration were analyzed. CLA effectively inhibited type Ι anaphylactic reactions and pseudo-allergic reactions in mice. Moreover, CLA inhibited FcεRΙ- and MRGPRX2-mediated MC signaling pathway activation. Regulatory effects of CLA were decreased significantly after CD300f knockdown. CLA effectively alleviated the symptoms of wheal and itch and reduced serum cytokine levels in patients. CLA negatively regulated FcεRΙ- and MRGPRX2-mediated MC activation via CD300f and showed significant therapeutic effect on CSU.

Analysis of adverse drug events in pulmonary Mycobacterium avium complex disease using spontaneous reporting system

Background

In Japan, Mycobacterium avium complex lung disease (MAC-LD) is the most common in nontuberculous mycobacterial lung disease. Patients often experience adverse events, resulting in the discontinuation of treatment, which causes treatment failure. The JADER (Japanese Adverse Drug Event Report) database is a database of adverse events that allows us to collect real-world data on adverse events. We can collect large-scale data cost-effectively and detect signals of potential adverse events such as reporting odds ratio (ROR) by using spontaneous reporting systems. In this study, we aimed to elucidate the adverse events of clarithromycin (CAM), ethambutol (EB), and rifampicin (RFP) using the JADER database.

Methods

We included cases of MAC-LD between April 2004 and June 2017. We investigated sex, age, and medications that may have caused the adverse events, outcomes, and time of onset. We calculated the safety signal index as the ROR. Time-to-event analysis was performed using the Weibull distribution.

Results

The total number of adverse events of CAM, EB, and RFP was 2780, with 806 patients. In the overall adverse events, hematologic and lymphatic disorders were the most common adverse events, with 17.3%, followed by eye disorders (16.6%), and hepatobiliary disorders (14.0%). The outcomes were as follows: recovery, 40.0%; remission, 27.1%; non-recovery, 11.2%; and death, 7.1%. Regarding the most common onset time of CAM, EB, and RFP was within 120 days at 40%, 181–300 days at 43.6%, and within 120 days at 88.5%. For CAM, the RORs of infections and infestations, hepatobiliary system disorders, and immune system disorders were 4.13 (95% confidence interval [CI], 2.3–7.44), 2.61 (95% CI, 1.39–4.91), and 2.38 (95% CI, 1.04–5.44). For EB, the ROR of eye disorders was 215.79 (95% CI, 132.62–351.12). For RFP, the RORs of renal and urinary tract disorders and investigations were 7.03 (95% CI, 3.35–14.77) and 6.99 (95% CI, 3.22–15.18). The β value of EB was 2.07 (95% CI, 1.48–2.76), which was classified as a wear-out failure type.

Conclusions

For MAC-LD, the adverse event which has the highest ROR is infections and infestations in CAM, eye disorders in EB, renal and urinary tract disorders in RFP. Adverse events of EB occur after 180 days, whereas the adverse events of CAM and RFP occur early in the course of treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07568-z.

Genotypic detection of metronidazole and clarithromycin resistance in dyspeptic patients with helicobacter pylori

In Egypt, antibiotic sensitivity analysis for Helicobacter pylori is not routinely performed. We aimed to identify the clarithromycin and metronidazole resistance directly from gastric biopsies for better guide treatment regimens. This cross-sectional descriptive study included 75 adult dyspeptic patients referred to the upper endoscopy unit in Suez Canal University Hospital, Ismailia, Egypt. Gastric biopsies were taken for rapid urease test (RUT) and cultured on brucella agar with antibiotic supplements. Genomic DNA was extracted directly from the specimen, and PCR was performed for direct detection of H. pylori. Also, to explore clarithromycin and metronidazole resistance, mutations in the 23S rRNA gene and the rdxA gene were investigated. We found that 60 samples were positive to RUT (80%), and only 4 samples were positive by culture. UreC gene was detected in 45 specimens. Meanwhile, 26 isolates were contained mutations at positions 2142 and 2143. Amplification of the metronidazole rdx gene was performed by conventional PCR. Out of 45 isolates, DNA sequence analysis of PCR product showed the wild type (ACA) in 9 isolates, while the mutant type (ATA) was detected in 28 isolates. We found a significant proportion of clarithromycin and metronidazole resistance among H. pylori infected patients in our region.

Efficacy of erythromycin compared to clarithromycin and azithromycin in adults or adolescents with community-acquired pneumonia: A Systematic Review and meta-analysis of randomized controlled trials

BACKGROUND

It is debatable whether erythromycin has similar efficacy to other macrolides in treating community-acquired pneumonia (CAP). The aim of this meta-analysis is to compare the efficacy of erythromycin with clarithromycin and azithromycin.

METHODS

We performed this meta-analysis of randomized controlled trials (RCTs) of adults or adolescents with CAP which compared the efficacy of erythromycin monotherapy to either azithromycin or clarithromycin. We searched PubMed and EMBASE and Cochrane Library databases and three clinical trial registries up to November 02, 2021. We evaluated heterogeneity and used random-effects models to perform risk ratios with 95% confidence intervals.

RESULTS

We included four RCTs (total of 472 patients), which compared the clinical efficacy of erythromycin versus clarithromycin. No studies comparing monotherapy of erythromycin versus azithromycin were found. Erythromycin use was associated with significantly lower rates of clinical success (RR, 0.79; 95% CI, 0.64 to 0.98; P-value = 0.033; I² = 20.27%), clinical cure (RR,0.67; 95% CI, 0.48 to 0.92; P-value = 0.014; I² = 8.75%), and radiological success (RR, 0.84; 95% CI, 0.71 to 0.996; P-value = 0.045; I² = 20.12%) than clarithromycin.

CONCLUSION

Erythromycin is less effective than clarithromycin as empiric treatment of CAP in adults and adolescents. Because of this and the higher rate of adverse reactions, erythromycin should not be used in the majority of CAP patients when azithromycin and clarithromycin are available.

V Spanish Consensus Conference on Helicobacter pylori infection treatment

Helicobacter pylori infection is very common in the Spanish population and represents the main cause of chronic gastritis, peptic ulcer, and gastric cancer. The last iteration of Spanish consensus guidelines on H. pylori infection was conducted in 2016. Recent changes in therapeutic schemes along with increasing supporting evidence were key for developing the V Spanish Consensus Conference (May 2021). Fourteen experts performed a systematic review of the scientific evidence and developed a series of recommendations that were subjected to an anonymous Delphi process of iterative voting. Scientific evidence and the strength of the recommendation were classified using GRADE guidelines. An eradication therapy, when prescribed empirically, is considered acceptable when it reliably achieves, or preferably surpass, 90% cure rates. Currently, only quadruple therapies (with or without bismuth) and generally lasting 14 days, accomplish this goal in first- and second-line therapies. A non-bismuth quadruple concomitant regimen (proton pump inhibitor, clarithromycin, amoxicillin, and metronidazole) or a quadruple bismuth-based combination (proton pump inhibitor, bismuth, tetracycline, and metronidazole), are recommended as first-line regimens. Rescue therapies after eradication failure and management of H. pylori infection in peptic ulcer disease were also reviewed.

Experimental design and optimization of a novel dual-release drug delivery system with therapeutic potential against infection with Helicobacter pylori

The objective of this study was to develop clarithromycin-loaded lipid nanocarriers and incorporate them into microcapsules for pH-specific localized release of clarithromycin in the Helicobacter pylori microenvironment in order to obtain a gastro-retentive and pH-sensitive formulation. A Plackett-Burman design was applied to identify the effect of 5 factors on 3 responses. Then, a central composite design was applied to estimate the most important factors leading to the best compromise between lower particle size, polydispersity index and particle size changes. The optimized clarithromycin-loaded nanocapsules were employed to generate microcapsules by different methodologies. Nanocarriers and microcapsules were characterized in vitro. Experimental design and conditions were optimized to obtain nanocapsules of around 100 nm by a modified phase inversion-based process. High particle size homogeneity and high stability were achieved. At 4 °C both optimized lipid nanocapsules were stable during at least 365 days, confirming stability under those conditions. Clarithromycin incorporation in the nanocarrier was effective. Both types of microcoating were evaluated regarding their pH sensitivity. Spray drying microcapsules exhibited similar and uncontrolled release profiles at pH 2 and 7.4. Alternatively, when microcoatings were generated using an Encapsulator, release was insignificant at pH 2, while at pH 7.4 release was triggered, and appeared more appropriate to formulate microcapsules that release nanocarriers under pH neutral Helicobacter pylori microenvironment conditions, thereby permitting effective drug delivery in infected locations. The release of clarithromycin from lipid nanocarrier loaded microcapsules was pH-sensitive suggesting that this could be an effective strategy for clarithromycin delivery to the Helicobacter pylori microenvironment. Clarithromycin nanocapsules with and without microcoating showed a high anti-Helicobacter pylori activity in vitro.

Synergistic activity and molecular modelling of fosfomycin combinations with some antibiotics against multidrug resistant Helicobacter pylori

Antibiotic resistance represents the main challenge of Helicobacter pylori infection worldwide. This study investigates the potential bactericidal effects of fosfomycin combinations with clarithromycin, metronidazole, ciprofloxacin, amoxicillin, rifampicin, and doxycycline against thirty-six H. pylori strains using the checkerboard and time-kill assay methods. The results showed that ≥ 50% of the strains were resistant to the six antibiotics. Remarkably, only six strains exerted resistance to these antibiotics, with the minimum inhibitory concentrations (MICs) ranges of (3.2–12.8 mg/l), (32–256 mg/l), (3.2–51.2 mg/l), (3.2–25.6 mg/l), (1.6–3.2 mg/l), and (25.6 > 51.2 mg/l), respectively. The seven antibiotics were evaluated through in silico studies for their permeability and ability to bind UDP-N-acetylglucosamine1-carboxyvinyltransferase (MurA) of H. pylori. The results indicated that fosfomycin exhibited the highest predicted membrane permeability (membrane ∆G insert = − 37.54 kcal/mol) and binding affinity (docking score = − 5.310 kcal/mol) for H. pylori MurA, compared to other tested antibiotics. The combinations of fosfomycin with these antibiotics exerted synergistic interactions (Fractional inhibitory concentration, FIC index < 1) against the six strains. Importantly, the combinations of fosfomycin with clarithromycin, doxycycline and rifampicin achieved bactericidal effects (reduction ≥ 3.0 Log₁₀ cfu/ml) against the most resistant H. pylori strain. Notably, these effects increased with presence of metronidazole, which enhanced the activity of the fosfomycin combination with amoxicillin from a weak inhibition to bactericidal effect. This study provides evidence that the combination of fosfomycin with either clarithromycin, amoxicillin, doxycycline, or rifampicin (especially with the presence of metronidazole) could be a promising option for treating MDR H. pylori infection.