Antibacterial activity of ibezapolstat against antimicrobial-resistant clinical strains of Clostridioides difficile.

Antimicrobial resistance is emerging in clinical strains of Clostridioides difficile. Ibezapolstat (IBZ) is a DNA polymerase IIIC inhibitor that has completed phase II clinical trials. IBZ has potent in vitro activity against wild-type, susceptible strains but its effect on C. difficile strains with reduced susceptibility to metronidazole (MTZ), vancomycin (VAN), or fidaxomicin (FDX) has not been tested. The primary objective of this study was to test the antibacterial properties of IBZ against multidrug-resistant C. difficile strains. The in vitro activity, bactericidal, and time-kill activity of IBZ versus comparators were evaluated against 100 clinical strains of which 59 had reduced susceptibility to other C. difficile antibiotics. Morphologic changes against a multidrug resistance strain were visualized by light and scanning electron microscopy. The overall IBZ MIC50/90 values (µg/mL) for evaluated C. difficile strains were 4/8, compared with 2/4 for VAN, 0.5/1 for FDX, and 0.25/4 for MTZ. IBZ MIC50/90 values did not differ based on non-susceptibility to antibiotic class or number of classes to which strains were non-susceptible. IBZ bactericidal activity was similar to the minimum inhibitory concentration (MIC) and maintained in wild-type and non-susceptible strains. Time-kill assays against two laboratory wild-type and two clinical non-susceptible strains demonstrated sustained IBZ activity despite reduced killing by comparator antibiotics for IBZ and VAN non-susceptible strains. Microscopy visualized increased cell lengthening and cellular damage in multidrug-resistant strains exposed to IBZ sub-MIC concentrations. This study demonstrated the potent antibacterial activity of IBZ against a large collection of C. difficile strains including multidrug-resistant strains. This study highlights the therapeutic potential of IBZ against multidrug-resistant strains of C. difficile.

Bezlotoxumab during the first episode of Clostridioides difficile infection in patients at high risk of recurrence.

PURPOSE: To describe a cohort with a high risk of recurrence who received bezlotoxumab during the first episode of Clostridioides difficile infection (CDI) and to compare this cohort with patients with similar characteristics who did not receive the monoclonal antibody. METHODS: A prospective and multicentre study of patients with a high risk of recurrence (expected recurrence rate>35%) who were treated with bezlotoxumab during their first episode of CDI was conducted. A propensity score-matched model 1:2 was used to compare both cohorts that were weighed according to basal characteristics (hospital-acquisition, creatinine value, and fidaxomicin as a CDI treatment). RESULTS: Sixty patients (mean age:72 years) were prospectively treated with bezlotoxumab plus anti-Clostridioides antibiotic therapy. Vancomycin (48 patients) and fidaxomicin (12 patients) were prescribed for CDI treatment, and bezlotoxumab was administered at a mean of 4.2 (SD:2.1) days from the beginning of therapy. Recurrence occurred in nine out of 54 (16.7%) evaluable patients at 8 weeks. Forty bezlotoxumab-treated patients were matched with 69 non-bezlotoxumab-treated patients. Recurrence rates at 12 weeks were 15.0% (6/40) in bezlotoxumab-treated patients vs. 23.2% (16/69) in non-bezlotoxumab-treated patients (OR:0.58 [0.20-1.65]). No adverse effects were observed related to bezlotoxumab infusion. Only one of 9 patients with previous heart failure developed heart failure. CONCLUSION: We observed that patients treated with bezlotoxumab in a real-world setting during a first episode of CDI having high risk of recurrence, presented low rate of recurrence. However, a significant difference in recurrence could not be proved in comparison to the controls. We did not detect any other safety concerns.

An Open-Label, Randomized Trial Comparing Fidaxomicin With Oral Vancomycin for the Treatment of Clostridioides difficile Infection in Hospitalized Patients Receiving Concomitant Antibiotics for Concurrent Infections.

BACKGROUND: Recurrent Clostridioides difficile infection (rCDI) occurs frequently, and concomitant antibiotic (CA) during the initial episode for treatment of non-CDI is a major risk factor. We sought to address the comparative efficacy of fidaxomicin versus vancomycin in the setting of CA during the initial CDI episode. METHODS: We conducted a randomized, controlled, open-label trial at 2 hospitals in Ann Arbor, Michigan. We consecutively consented and enrolled hospitalized patients ≥18 years old with diarrhea, a positive test for C. difficile, and ≥1 qualifying CA. Complicated CDI, CDI treatment for >24 hours prior to enrollment, and planned long-term (>12 weeks) CA use were notable exclusions. Clinical cure was defined as resolution of diarrhea for 2 consecutive days maintained until 2 days after therapy, and rCDI as recurrent diarrhea with positive testing ≤30 days after initial treatment. Patients were randomized to fidaxomicin or vancomycin. RESULTS: Baseline characteristics were similar in the 2 groups of 144 patients. Rates of clinical cure (73% vs 62.9%, P = .195) and rCDI (3.3% vs 4.0%; P > .99) were similar for fidaxomicin and vancomycin in the intention-to-treat and per-protocol cohorts, respectively. Only 4 patients developed rCDI. CONCLUSIONS: In this study of patients with CDI receiving CA, a numerically higher proportion were cured with fidaxomicin versus vancomycin, but this result did not reach statistical significance. Overall recurrence was lower than anticipated in both arms compared with previous studies that did not extend duration of CDI treatment during CA. CLINICAL TRIALS REGISTRATION: www.clinicaltrials.gov (NCT02692651).

The effect of antibiotic therapy for Clostridioides difficile infection on mortality and other patient-relevant outcomes: a systematic review and meta-analysis.

BACKGROUND: Current practice guidelines favour fidaxomicin over vancomycin and exclude metronidazole from the recommended standard regimen for Clostridioides difficile infection (CDI), based on lower recurrence rates with fidaxomicin, giving little weight to mortality or the clinical implications of recurrences. OBJECTIVES: To compile the effects of metronidazole, glycopeptides (vancomycin or teicoplanin), and fidaxomicin for CDI on mortality and other patient-relevant outcomes. DATA SOURCES: PubMed, the Cochrane Library, ClinicalTrials.gov, conference proceedings, and Google Scholar, until August 2023. STUDY ELIGIBILITY CRITERIA: Randomized controlled trials (RCTs). PARTICIPANTS: Adult patients experiencing primary or recurrent CDI. INTERVENTIONS: Glycopeptides versus fidaxomicin or metronidazole (comparators). ASSESSMENT OF RISK OF BIAS: We used the Risk of Bias 2 (RoB 2) tool for randomized trials, focusing on the outcome of all-cause mortality. METHODS OF DATA SYNTHESIS: Random effects meta-analyses were performed for dichotomous outcomes. Outcomes were summarized preferentially for all randomly assigned patients. RESULTS: Thirteen trials were included. There was no significant difference in all-cause mortality (risk ratio [RR] < 1 favouring the comparator) between vancomycin and fidaxomicin (RR 0.86, 95% CI 0.64-1.14, 8 RCTs, 1951 patients) or metronidazole (RR 0.78, 95% CI 0.46-1.32, 4 RCTs, 808 patients), with low and very low certainty of evidence, respectively. No significant difference in initial treatment failure between fidaxomicin and vancomycin was found, however, initial treatment failure was higher with metronidazole (RR 1.58, 95% CI 1.10-2.27, 5 RCTs, 843 patients). No study reported on symptomatic recurrence necessitating re-treatment among all randomly assigned patients. Among initially cured patients, symptomatic recurrence necessitating re-treatment was lower with fidaxomicin than with vancomycin (RR 0.54, 95% CI 0.42-0.71, 6 RCTs, 1617 patients). None of the studies reported on other CDI complications or the burden of infection on daily activities. CONCLUSIONS: Setting patient-relevant outcomes for CDI independently of the RCT definitions and results might lead to less confidence in the guidance for CDI management.

Clostridioides difficile infections; new treatments and future perspectives.

PURPOSE OF REVIEW: As a significant cause of global morbidity and mortality, Clostridioides difficile infections (CDIs) are listed by the Centres for Disease Control and prevention as one of the top 5 urgent threats in the USA. CDI occurs from gut microbiome dysbiosis, typically through antibiotic-mediated disruption; however, antibiotics are the treatment of choice, which can result in recurrent infections. Here, we highlight new treatments available and provide a perspective on different classes of future treatments. RECENT FINDINGS: Due to the reduced risk of disease recurrence, the microbiome-sparing antibiotic Fidaxomicin has been recommended as the first-line treatment for C. difficile infection. Based on the success of faecal microbiota transplantations (FMT) in treating CDI recurrence, defined microbiome biotherapeutics offer a safer and more tightly controlled alterative as an adjunct to antibiotic therapy. Given the association between antibiotic-mediated dysbiosis of the intestinal microbiota and the recurrence of CDI, future prospective therapies aim to reduce the dependence on antibiotics for the treatment of CDI. SUMMARY: With current first-in-line antibiotic therapy options associated with high levels of recurrent CDI, the availability of new generation targeted therapeutics can really impact treatment success. There are still unknowns about the long-term implications of these new CDI therapeutics, but efforts to expand the CDI treatment toolbox can offer multiple solutions for clinicians to treat this multifaceted infectious disease to reduce patient suffering.

Microbiome-preserving antibiotics for the treatment of Clostridioides difficile infection: a systematic review and meta-analysis.

BACKGROUND: Newer antibiotics that specifically target Clostridioides difficile while preserving the host microbiome have emerged to treat C. difficile infection (CDI): cadazolid, fidaxomicin, ridinilazole, and surotomycin. The aim of the present study was to perform a systematic review and meta-analysis of efficacy for each antibiotic. METHODS: Only randomized clinical trials of patients being treated for Clostridioides disease infection were included. Studies were sought in MEDLINE, EMBASE, the Cochrane Register of Controlled Trials, ClinicalTrials.gov, and the World Health Organization clinical trials register portal (up to December 9, 2022). Sustained clinical cure was the outcome of treatment comparison, defined as the resolution of diarrhea without recurrence. Vancomycin was the standard treatment comparator. Meta-analysis was performed for each antibiotic. The overall certainty of evidence was assessed using Grading of Recommendations Assessment, Development, and Evaluation (GRADE)-classified as either high, moderate, low, or very low. RESULTS: Fourteen eligible studies were included in the meta-analysis with 4837 patients from 773 sites. Cadazolid did not increase sustained clinical cure relative to vancomycin (risk ratio (RR) 1.04, 95% confidence intervals (CI) 0.96-1.13; moderate-certainty evidence). Fidaxomicin demonstrated a significant increase (RR 1.14, 95% CI 1.07-1.21; low-certainty evidence). In one phase 2 study, ridinilazole demonstrated a significant increase in sustained clinical cure (RR 1.71, 95% CI 1.01-2.91; very low-quality evidence). Surotomycin did not show significant improvement (RR 1.05, 95% CI 0.96-1.14; moderate-certainty evidence). CONCLUSIONS: Fidaxomicin (in seven studies) demonstrated significant improvement in achieving sustained clinical cure. A limitation of this study may that more studies are needed to compare fidaxomicin with other antibiotics.

Clostridioides difficile infection in the allogeneic hematopoietic cell transplant recipient.

Clostridioides difficile (CD) is one of the most important causes of diarrhea in hospitalized patients, in particular those who undergo an allogeneic hematopoietic cell transplant (allo-HCT) and who are more at risk of developing a CD infection (CDI) due to frequent hospitalizations, iatrogenic immunosuppression, and prolonged antibiotic cycles. CDI may represent a severe condition in allo-HCT patients, increasing the length of hospitalization, influencing the intestinal microbiome with a bidirectional association with graft-versus-host disease, and leading to unfavorable outcomes, including death. The diagnosis of CDI requires the exclusion of other probable causes of diarrhea in HCT patients and is based on highly sensitive and highly specific tests to distinguish colonization from infection. In adult patients, fidaxomicin is recommended as first-line, with oral vancomycin as an alternative agent. Bezlotoxumab may be used to reduce the risk of recurrence. In pediatric patients, vancomycin and metronidazole are still suggested as first-line therapy, but fidaxomicin will probably become standard in pediatrics in the near future. Because of insufficient safety data, fecal microbiota transplantation is not routinely recommended in HCT in spite of promising results for the management of recurrences in other populations.

Therapeutics for Clostridioides difficile infection: molecules and microbes.

INTRODUCTION: Clostridioides difficile infection (CDI) is a major healthcare problem in the developed world, and effective management of recurrent infection remains one of the biggest challenges. Several advances have occurred in the management of CDI, and in the last 15 years, multiple new agents have been tested. Since 2011, four new products have been approved by the US FDA for treatment of CDI or prevention of recurrent CDI. AREAS COVERED: This review focuses on therapeutics of CDI and includes sections on primary prevention, management of active infection, and prevention of recurrent CDI. Specifically, data are included on fecal microbiota transplantation and live biotherapeutics. A comprehensive search of several databases including Ovid MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, and Daily, Ovid EMBASE, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus from inception to 1 May 2023 was conducted. EXPERT OPINION: Metronidazole is no longer advised for management of outpatient CDI. The preferred medication of choice for a first episode is oral vancomycin or fidaxomicin. For those patients who recur after the first episode, vancomycin taper pulse or fidaxomicin can be used. Intravenous bezlotoxumab, a monoclonal antibody, is available to prevent recurrences. There are now two FDA-approved microbiome-based therapies or live biotherapeutics for prevention of recurrent CDI, for any recurrent CDI and not necessarily multiply recurrent C difficile. Fecal microbiota transplantation remains available in limited settings for recurrent CDI.

In vivo emergence of a still uncommon resistance to fidaxomicin in the urgent antimicrobial resistance threat Clostridioides difficile.

BACKGROUND: Fidaxomicin is a first-line treatment for Clostridioides difficile infections (CDIs). Fidaxomicin resistance has rarely been reported in this urgent antimicrobial resistance threat as defined by the CDC. OBJECTIVES: To report a case of fidaxomicin-resistant C. difficile isolation in a patient treated by fidaxomicin, characterize the genetic determinant for resistance and the consequences on pathophysiological traits, and review the literature. PATIENT AND METHODS: A 38-year-old male patient with several risk factors for CDI experienced three episodes of hospital-acquired CDI and received fidaxomicin for the first episode. The successive isolates were subjected to phenotypic characterization (antimicrobial susceptibility, growth, sporulation ability and toxin production) and WGS analysis to evaluate clonality and modifications associated with resistance. RESULTS: Resistance to fidaxomicin arose in isolates from the recurrences of CDI (MIC: 16 mg/L). WGS analysis showed a close genetic link between strains suggestive of relapses in this patient. A T3428G mutation in the rpoB gene might be associated with fidaxomicin resistance. The resistance was associated with defects in growth, sporulation and production of toxins. A review of the literature found only three previous fidaxomicin-resistant C. difficile clinical strains. CONCLUSIONS: Although rarely reported, resistance to fidaxomicin may quickly emerge in vivo after a single course of treatment. This observation supports the need for prospective surveillance of the susceptibility of C. difficile to treatment antibiotics. However, the clinical relevance of fidaxomicin resistance still needs to be elucidated, particularly due to its apparent rareness and associated fitness cost.

[Clostridioides difficile - New Insights and Therapy Recommendations]. / Clostridioides difficile ­ Neue Erkenntnisse und Therapieempfehlungen.

After an increase in Clostridioides difficile infections (CDI) until 2013 due to epidemic ribotypes such as 027 and 078, CDI incidence in Germany is now declining, as confirmed by recent epidemiological data. Despite this success through antimicrobial stewardship and hospital hygiene, the burden of disease remains high, especially in older patients (>65 years) with comorbidities. The main risk factor for CDI is the use of broad-spectrum antibiotics, which disrupt the gut microbiota, allowing C. difficile colonization. Coinfection with other intestinal pathogens such as enterococci can further increase the virulence of C. difficile. The updated 2021 ESCMID guidelines recommend fidaxomicin instead of vancomycin as the antibiotic of choice for the treatment of CDI because of its lower recurrence rate. Vancomycin remains a good alternative; however, metronidazole should only be used if neither antibiotic is available. In the future, ridinilazole may be available as another therapeutic option that has a narrow spectrum of activity and low intestinal absorption. For the treatment of recurrent CDI, the new guidelines also include the use of the monoclonal antibody bezlotoxumab. In addition, a new oral microbiome therapy, SER-109 (capsules containing purified Firmicutes spores), which showed promising results in a phase 3 study, may provide an easy-to-administer alternative to fecal microbiota transplantation. Hopes for a well-performing toxoid vaccine for primary and secondary prevention of CDI have unfortunately not been fulfilled in the CLOVER trial.

Predicted Bezlotoxumab Exposure in Patients Who Have Received a Hematopoietic Stem Cell Transplant.

PURPOSE: Bezlotoxumab is approved for prevention of recurrent Clostridioides (Clostridium) difficile infection (CDI) in adults receiving antibacterial treatment for CDI who are at high risk for recurrent CDI. Previous studies have shown that although serum albumin levels are an important predictor for bezlotoxumab exposure, this has no clinically meaningful impact on efficacy. This pharmacokinetic modeling study assessed whether hematopoietic stem cell transplant (HSCT) recipients, at increased risk of CDI and exhibiting decreased albumin levels within the first month posttransplant, are at risk of clinically relevant reductions in bezlotoxumab exposure. METHODS: Observed bezlotoxumab concentration-time data pooled from participants in Phase III trials MODIFY I and II (ClinicalTrials.gov identifiers NCT01241552/NCT01513239) and three Phase I studies (PN004, PN005, and PN006) were used to predict bezlotoxumab exposures in two adult post-HSCT populations: A Phase Ib study of posaconazole including allogeneic HSCT recipients (ClinicalTrials.gov identifier NCT01777763; posaconazole-HSCT population); and a Phase III study of fidaxomicin for CDI prophylaxis (ClinicalTrials.gov identifier NCT01691248; fidaxomicin-HSCT population). The bezlotoxumab PK model used the minimum albumin level for each individual in post-HSCT populations to mimic a "worst-case scenario." FINDINGS: Predicted worst-case bezlotoxumab exposures for the posaconazole-HSCT population (N = 87) were decreased by 10.8% versus bezlotoxumab exposures observed in the pooled Phase III/Phase I data set (N = 1587). No further decrease was predicted for the fidaxomicin-HSCT population (N = 350). IMPLICATIONS: Based on published population pharmacokinetic data, the predicted decrease in bezlotoxumab exposure in the post-HSCT populations is not expected to have a clinically meaningful effect on bezlotoxumab efficacy at the recommended 10 mg/kg dose. Dose modification is therefore not required in the hypoalbuminemia setting expected post-HSCT.

[A case of recurrent Clostridium difficile infection with type 2 diabetes mellitus indicating the usefulness of metformin hydrochloride].

A 76-year-old woman undergoing insulin treatment for type 2 diabetes mellitus at our hospital was diagnosed with Clostridium difficile infection (CDI). She was treated with metronidazole, vancomycin hydrochloride, and fidaxomicin. Metformin hydrochloride in combination with fidaxomicin was administered to control the exacerbated symptoms. The diarrhea disappeared two days later, and colonoscopy confirmed the resolution of pseudomembranes eight days later. Till approximately two years after discharge, no recurrence was observed. Here metformin hydrochloride was suggested to be useful for the treatment of recurrent CDI with type 2 diabetes mellitus.

Evaluation of fidaxomicin use in community hospitals after a clinical guideline change at a large health system and opportunities for stewardship.

After updating our health system's Clostridioides difficile treatment protocols in 2018, we reviewed 104 unique hospital encounters involving fidaxomicin at 10 community hospitals. Half (50%) of regimens were adherent to our guidelines, with infectious diseases (ID) providers were frequently nonadherent. Antimicrobial stewardship programs are important for facilitating best practices, even among ID specialists.

Management of Clostridioides difficile infection in adults and challenges in clinical practice: review and comparison of current IDSA/SHEA, ESCMID and ASID guidelines.

Clostridioides difficile infection (CDI) remains a significant clinical challenge both in the management of severe and severe-complicated disease and the prevention of recurrence. Guidelines released by the Infectious Diseases Society of America and Society for Healthcare Epidemiology of America (IDSA/SHEA) and ESCMID had some consensus as well as some discrepancies in disease severity classification and treatment recommendations. We review and compare the key clinical strategies from updated IDSA/SHEA, ESCMID and current Australasian guidelines for CDI management in adults and discuss relevant issues for clinicians, particularly in the management of severe-complicated infection. Updated IDSA/SHEA and ESCMID guidelines now reflect the increased efficacy of fidaxomicin in preventing recurrence and have both promoted fidaxomicin to first-line therapy with an initial CDI episode in both non-severe and severe disease and endorsed the role of bezlotoxumab in the prevention of recurrent infection. Vancomycin remains acceptable therapy and metronidazole is not preferred. For severe-complicated infection the IDSA/SHEA recommends high-dose oral ±â€Šrectal vancomycin and IV metronidazole, whilst in an important development, ESCMID has endorsed fidaxomicin and tigecycline as part of combination anti-CDI therapy, for the first time. The role of faecal microbiota transplantation (FMT) in second CDI recurrence is now clearer, but timing and mode of FMT in severe-complicated refractory disease still requires further study.

Path of least recurrence: A systematic review and meta-analysis of fidaxomicin versus vancomycin for Clostridioides difficile infection.

STUDY OBJECTIVE: Current Clostridioides difficile infection (CDI) treatment guidelines recommend either fidaxomicin or vancomycin as first-line therapy for initial and recurrent CDI. The objective of this study was to compare recurrence rates of fidaxomicin and vancomycin for the treatment of CDI in clinically relevant and real-world subgroups via systematic review and meta-analysis. DESIGN & DATA SOURCES: A systematic literature review was performed by searching PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov from inception to September 1, 2021, for randomized and observational studies comparing vancomycin and fidaxomicin for CDI treatment in adults. The meta-analysis was performed with Review Manager 5.4 software (Cochrane Library, Oxford, United Kingdom) using a random-effects model. The primary end point was CDI recurrence after treatment with fidaxomicin or vancomycin. Subgroup analyses were conducted. PATIENTS, INTERVENTION, MEASUREMENTS & MAIN RESULTS: The literature search identified six randomized controlled trials and eight observational trials, with a total of 3944 patients (fidaxomicin 32%; vancomycin 68%) included in the meta-analysis. The mean age of study patients ranged from 46 to 75 years. The CDI recurrence rate was 22.4% (fidaxomicin 16.1%, vancomycin 25.4%). Compared to vancomycin, treatment with fidaxomicin was associated with a 31% reduction in the risk of recurrence (risk ratio 0.69; 95% confidence interval: 0.52-0.91, I2  = 62%). This reduction in recurrence risk was also seen in subgroup analyses for patients with initial CDI, first recurrent CDI, non-severe and severe CDI, and in both inpatient and outpatient settings. CONCLUSION: Our systematic review and meta-analysis found fidaxomicin was consistently associated with a lower risk of CDI recurrence than vancomycin. These results confirm CDI guideline recommendations and indicate that fidaxomicin may be preferred over vancomycin to minimize CDI recurrence across multiple clinical scenarios, although further studies are warranted.

[Clostridioides difficile infection: various therapeutic approaches]. / Infection à Clostridioides difficile : approches thérapeutiques diverses.

In 2021, the European and American Infectious Diseases Societies published new guidelines for the treatment of Clostridiodes difficile colitis. They have opted for a change in practice with fidaxomicin being recommended as the first line of treatment, and vancomycin as a second choice. Metronidazole remains recommended only in cases where other treatments are not available. These choices have not been endorsed by the Swiss Infectious Diseases Society, which still proposes metronidazole as first-line treatment. As a matter of fact, this inexpensive treatment still presents a satisfactory efficacy on the strains of Clostridoides difficile found in Switzerland in the context of patients without risk factors and with low probability of relapse.

En 2021, les sociétés d'infectiologie européenne et américaine ont publié des guidelines relatives au traitement des colites à Clostridioides difficile. Elles ont opté pour un changement des pratiques avec la recommandation en première ligne de la fidaxomicine, la vancomycine devenant un deuxième choix. Le métronidazole est préconisé uniquement dans les cas où les autres traitements ne seraient pas disponibles. Ces choix n'ont pas été repris par la Société suisse d'infectiologie, qui propose toujours le métronidazole en première intention. En effet, ce traitement peu coûteux présente encore une efficacité satisfaisante sur les souches retrouvées en Suisse dans le cadre des colites à Clostridioides difficile sans facteurs de risque et à faible probabilité de rechute.

Clostridioides difficile infection: are the three currently used antibiotic treatment options equal from pharmacological and microbiological points of view?

Recently, the recommendations for the treatment of Clostridioides difficile infection (CDI) have been updated. However, in addition to the clinical efficacy data, the drug of choice should ideally represent optimal antimicrobial stewardship, with an emphasis on rapid restoration of the gut microbiota to minimize the risk of infection relapses. Oral administration of metronidazole results in low concentration in stool, and interaction with fecal microbiota reduces its antimicrobial bioactivity. Reported elevated minimum inhibitory concentrations of metronidazole in epidemic C. difficile ribotypes and the emergence of plasmid-mediated resistance to metronidazole represent additional potential risks for clinical failure. If metronidazole is the only CDI treatment option, antimicrobial susceptibility testing on agar containing heme should be performed in C. difficile isolate. Compared with metronidazole, oral vancomycin and fidaxomicin reach very high concentrations in the stool, and therefore can quickly reduce C. difficile shedding. Health care facilities with higher CDI incidence and/or occurrence of epidemic ribotypes should not use metronidazole because prolonged C. difficile shedding can increase the risk for further C. difficile transmission. Only fidaxomicin has a narrow spectrum of antimicrobial activity, which might be, together with persistence on spores, the main contributing factor to reduce the recurrent CDI rates.

Real-world comparison of fidaxomicin versus vancomycin or metronidazole in the treatment of Clostridium difficile infection: a systematic review and meta-analysis.

PURPOSE: There is a lack of real-world evidence of the comparative effectiveness of fidaxomicin versus vancomycin or metronidazole for treating patients with Clostridium difficile (CDI) infection. No systematic evidence comparing these treatment regimens using real-world observational studies was published up to date. The goal of this study is to compare the fidaxomicin and vancomycin/metronidazole regimens in terms of treatment outcomes in CDI patients. METHODS: Systematic and comprehensive search was carried out in the following databases and search engines: EMBASE, Cochrane, MEDLINE, ScienceDirect, and Google Scholar from 1954 until January 2022. Newcastle-Ottawa (NO) scale was used to assess the risk of bias. Meta-analysis was carried out using random effects model, and pooled odds ratios (OR) with 95% confidence interval (CI) were reported. RESULTS: A total of 10 studies satisfied the inclusion criteria, most of them were with poorer quality. The pooled OR was 0.40 (95% CI: 0.09-1.68; I2 = 82.4%) for clinical cure and 2.02 (95% CI: 0.36-11.39; I2 = 88.4%) for sustained cure. We reported pooled OR of 0.69 (95% CI: 0.40-1.20; I2 = 65.7%) for the recurrence rate, 2.81 (95% CI: 1.08-7.29; I2 = 70.6%) for the treatment failure, and 0.73 (95% CI: 0.50-1.07; I2 = 0%) for all-cause mortality between patients that received fidaxomicin and vancomycin. The pooled OR was 0.71 (95% CI: 0.05-9.47; I2 = 69.6%) in terms of recurrence between patients receiving fidaxomicin and metronidazole. CONCLUSION: Fidaxomicin and vancomycin/metronidazole regimens did not have significant difference in terms of treatment outcomes, such as clinical cure, sustained cure, recurrence, and all-cause mortality. However, there was significantly higher risk of treatment failure in CDI patients taking fidaxomicin.

Oral fidaxomicin versus vancomycin for the treatment of Clostridioides difficile infection: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Fidaxomicin (FDX) has received considerable attention as a novel therapeutic alternative agent to vancomycin (VCM) for Clostridioides difficile infection (CDI). However, the superiority and efficacy profile of FDX are not sufficiently determined by high-quality evidence. This study aimed to clarify the superiority of FDX for CDI treatment through a systematic review and meta-analysis. METHODS: We conducted a meta-analysis of randomized controlled trials (RCTs) which evaluated the efficacy and safety of FDX and VCM in patients with CDI. Electronic databases (PubMed, Cochrane Library, Web of Science, and Clinicaltrials.gov) were searched for studies published until October 15, 2021. The primary endpoint was global cure. The secondary endpoints were clinical cure, recurrence, and adverse event. Risk ratios (RRs), risk differences (RDs), and 95% confidence intervals were calculated using Mantel-Haenszel random-effects model. The risk of bias was assessed using Cochrane Handbook for Systematic Reviews of Interventions and Assessment Criteria. RESULTS: Six RCTs were included in this meta-analysis. Compared to VCM, FDX was associated with significantly higher global cure rates (RR = 1.18, P < 0.00001; RD = 0.11, 95% CI = 0.07-0.16). In addition, clinical cure rates were comparable between FDX and VCM (P = 0.31). FDX was associated with significantly lower recurrence rates compared to VCM (RR = 0.59, P < 0.0001). In addition, adverse event rates were not significantly different between the drugs (P = 0.41). CONCLUSION: FDX achieves significantly higher global cure rates and lower recurrence rates and is comparable to VCM in clinical cure rates and adverse event rates in patients with CDI. Collectively, FDX is superior to VCM as a therapeutic agent for CDI.