Multicenter Cohort Study of Ceftaroline Versus Daptomycin for Treatment of Methicillin-Resistant Staphylococcus aureus Bloodstream Infection.

BACKGROUND: Observational data suggest ceftaroline may be effective for methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection (BSI), but comparative data with standard of care are limited. This analysis compares the outcomes of MRSA BSI treated with ceftaroline or daptomycin. METHODS: Multicenter, retrospective, observational cohort study of adult patients with MRSA BSI from 2010 to 2017. Patients treated with ≥72 hours of ceftaroline or daptomycin were included. Those clearing BSI before study drug and those with a pneumonia source were excluded. The primary outcome was composite treatment failure, defined as 30-day mortality, BSI duration ≥7 days on study drug, and 60-day MRSA BSI recurrence. Inverse probability of treatment weighted risk difference in composite failure between daptomycin and ceftaroline groups was computed and 15% noninferiority margin applied. RESULTS: Two hundred seventy patients were included; 83 ceftaroline and 187 daptomycin. Ceftaroline was noninferior to daptomycin with respect to composite failure (39% daptomycin, 32.5% ceftaroline; weighted risk difference, 7.0% [95% confidence interval, -5.0% to 19.0%]). No differences between treatment groups was observed for 30-day mortality or other secondary efficacy outcomes. Creatine phosphokinase elevation was significantly more common among daptomycin patients (5.3% vs 0%, P = .034). Rash was significantly more common among ceftaroline patients (10.8 vs 1.1%, P = .001). CONCLUSIONS: No difference in treatment failure or mortality was observed between MRSA BSI treated with ceftaroline or daptomycin. These data support future study of ceftaroline as a primary MRSA BSI treatment and current use of ceftaroline when an alternative to vancomycin and daptomycin is required.

The Real-World Economic and Clinical Management of Adult Patients with Skin and Soft Tissue Infections (SSTIs) with Oritavancin: Data from Two Multicenter Observational Cohort Studies.

BACKGROUND: Oritavancin is a FDA-approved single-dose IV therapy for the treatment of acute bacterial skin and skin structure infections caused (or suspected to be caused) by certain Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus (MRSA). Published data describing the outcomes of patients with skin and soft tissue infections (SSTIs) who received oritavancin beyond its pivotal phase III clinical trials are scant. OBJECTIVE: The purpose of this report was to describe the results of two separate multicenter observational cohort studies that described the outcomes associated with two unique real-world usage patterns of oritavancin. METHODS: The first cohort (n = 115) examined patients 18 years or older who were treated with oritavancin at three outpatient sites for SSTIs caused by suspected or confirmed Gram-positive pathogens, including MRSA, to avoid hospital admission. Patients were included if they had not been discharged from the inpatient setting within the previous 24 h and received their single-dose oritavancin treatment at a hospital-based outpatient infusion center. The primary outcomes measured were 30-day healthcare costs and admissions (all cause and infection related). The second cohort (n = 151) was a multicenter, retrospective chart review of adult patients who were discharged early from seven hospitals in 2015 on oritavancin for SSTIs. The primary outcome was readmission of patients within 30 days (all cause and infection related). RESULTS: In cohort 1, 30-day mean healthcare costs were USD 3698. In the study of patients who started oritavancin in the outpatient setting, 7 patients (6.1%) were admitted to hospital within 30 days of the index treatment, and 3 of those (2.6% overall) were deemed to be due to an infection. In cohort 2, all-cause and infection-related 30-day readmission rates were 6.6% and 2.6%, respectively, among patients who received oritavancin at hospital discharge. CONCLUSIONS: Findings from these studies suggest that oritavancin may be a potentially useful agent to avoid hospitalization or shorten hospital length of stay among appropriate SSTI patients. Future comparator studies are required to properly ascertain the outcomes and potential benefits associated with oritavancin relative to other commonly used antibiotics in patients with SSTIs.

Multicenter, Observational Cohort Study Evaluating Third-Generation Cephalosporin Therapy for Bloodstream Infections Secondary to Enterobacter, Serratia, and Citrobacter Species.

OBJECTIVES: There is debate on whether the use of third-generation cephalosporins (3GC) increases the risk of clinical failure in bloodstream infections (BSIs) caused by chromosomally-mediated AmpC-producing Enterobacterales (CAE). This study evaluates the impact of definitive 3GC therapy versus other antibiotics on clinical outcomes in BSIs due to Enterobacter, Serratia, or Citrobacter species. METHODS: This multicenter, retrospective cohort study evaluated adult hospitalized patients with BSIs secondary to Enterobacter, Serratia, or Citrobacter species from 1 January 2006 to 1 September 2014. Definitive 3GC therapy was compared to definitive therapy with other non-3GC antibiotics. Multivariable Cox proportional hazards regression evaluated the impact of definitive 3GC on overall treatment failure (OTF) as a composite of in-hospital mortality, 30-day hospital readmission, or 90-day reinfection. RESULTS: A total of 381 patients from 18 institutions in the southeastern United States were enrolled. Common sources of BSIs were the urinary tract and central venous catheters (78 (20.5%) patients each). Definitive 3GC therapy was utilized in 65 (17.1%) patients. OTF occurred in 22/65 patients (33.9%) in the definitive 3GC group vs. 94/316 (29.8%) in the non-3GC group (p = 0.51). Individual components of OTF were comparable between groups. Risk of OTF was comparable with definitive 3GC therapy vs. definitive non-3GC therapy (aHR 0.93, 95% CI 0.51-1.72) in multivariable Cox proportional hazards regression analysis. CONCLUSIONS: These outcomes suggest definitive 3GC therapy does not significantly alter the risk of poor clinical outcomes in the treatment of BSIs secondary to Enterobacter, Serratia, or Citrobacter species compared to other antimicrobial agents.

Real-World Experience with Ceftolozane-Tazobactam for Multidrug-Resistant Gram-Negative Bacterial Infections.

Our objective was to describe the prescribing practices, clinical characteristics, and outcomes of patients treated with ceftolozane-tazobactam (C/T) for multidrug-resistant (MDR) Gram-negative infections. This was a multicenter, retrospective, cohort study at eight U.S. medical centers (2015 to 2019). Inclusion criteria were age ≥18 years and receipt of C/T (≥72 hours) for suspected or confirmed MDR Gram-negative infection. The primary efficacy outcome, evaluated among patients with MDR Pseudomonas aeruginosa infections, was composite clinical failure, namely, 30-day all-cause mortality, 30-day recurrence, and/or failure to resolve or improve infection signs or symptoms after C/T treatment. In total, 259 patients were included, and P. aeruginosa was isolated in 236 (91.1%). The MDR and extremely drug-resistant phenotypes were detected in 95.8% and 37.7% of P. aeruginosa isolates, respectively. The most common infection source was the respiratory tract (62.9%). High-dose C/T was used in 71.2% of patients with a respiratory tract infection (RTI) overall but in only 39.6% of patients with an RTI who required C/T renal dose adjustment. In the primary efficacy population (n = 226), clinical failure and 30-day mortality occurred in 85 (37.6%) and 39 (17.3%) patients, respectively. New C/T MDR P. aeruginosa resistance was detected in 3 of 31 patients (9.7%) with follow-up cultures. Hospital-acquired infection and Acute Physiological and Chronic Health Evaluation II (APACHE II) score were independently associated with clinical failure (adjusted odds ratio [aOR], 2.472 and 95% confidence interval [CI], 1.322 to 4.625; and aOR, 1.068 and 95% CI, 1.031 to 1.106, respectively). Twenty-five (9.7%) patients experienced ≥1 adverse effect (9 acute kidney injury, 13 Clostridioides difficile infection, 1 hepatotoxicity, 2 encephalopathy, and 2 gastrointestinal intolerance). C/T addresses an unmet medical need in patients with MDR Gram-negative infections.

Learning Experiences Within Infectious Diseases Pharmacy Residency Programs in the United States: A Cross-Sectional Survey.

BACKGROUND: Pharmacists with residency training in infectious diseases (ID) optimize antimicrobial therapy outcomes in patients and support antimicrobial stewardship (AS) programs. Although most ID residencies are accredited and assessed by certain standards, the degree to which these programs are similar is not known. METHODS: A 19-item, cross-sectional, multicentered, electronic survey was distributed via e-mail to pharmacy residency program directors (RPDs) of all 101 second-year postgraduate (PGY-2) ID residency programs in the United States. RESULTS: Survey responses were collected from 71 RPDs (70.3%); 64.8% were associated with an academic medical center and 97.2% focused primarily in adult ID. Rotations in the microbiology laboratory, adult AS, and adult ID consult were required in 98.6% of residency programs. Only 28.2% of responding programs required pediatric AS and pediatric ID consult rotations. Programs at academic medical centers were more likely to offer immunocompromised host ID consult (P = .003), pediatric ID consult (P = .006), and hospital epidemiology (P = .047) rotations but less frequently offered outpatient AS (P = .003), viral hepatitis clinics (P = .001), and travel medicine clinics (P = .007) rotations compared to programs at nonacademic medical centers. Residents were frequently involved in AS committees (97.2%), pharmacokinetic dosing of antimicrobials (83.1%), precepting pharmacy trainees (80.3%), and performing research projects (91.5%). CONCLUSIONS: The PGY-2 ID pharmacy residency programs demonstrated consistency in required adult ID consult, antimicrobial management activities, committee service, and teaching and research opportunities. Pediatric experiences were less common. The PGY-2 ID residency programs prepare pharmacists to become antimicrobial stewards for adult patients.

Impact of the use of local fidaxomicin treatment algorithms for managing Clostridium difficile infection in hospitalized patients in southeastern United States.

BACKGROUND: Clostridium difficile-associated diarrhea (CDAD) is a major public health threat that results in increased length of stay, hospital readmissions, deaths, and economic burden. CDAD treatment is often guided by severity of disease. Although various tools exist to determine CDAD severity, real-world data evaluating the use of such tools in treatment algorithms are sparse. METHODS: A local CDAD treatment pathway was developed independently to guide fidaxomicin prescribing at wellStar Health System (WellStar) and at Lee Health (LH) and Sarasota Memorial Hospital (SMH). Each algorithm was designed locally by the stewardship pharmacist and was utilized to identify patients at high risk for C. difficile recurrence. Patient and clinical data was retrospectively gathered to evaluate the utility and outcomes of the treatment pathway. RESULTS: There were 262 patients that received fidaxomicin at these three hospitals during the study time period. Only 30% at WellStar and 20% at LH or SMH met the study criteria and adhered to the pathway requirements. After completion of fidaxomicin, 30-day recurrence rates at WellStar was 0 and at LH and SMH 7%. Clinical cure rates were 83% in WellStar and 93% in LH and SMH. CONCLUSIONS: The results from these two pathways show positive outcomes for the use of fidaxomicin in patients at high risk for CDAD recurrence. This data supports the potential utility of fidaxomicin against CDAD.

Successful Treatment of Methicillin Susceptible Staphylococcus aureus Osteomyelitis with Oritavancin.

Staphylococcus aureus remains the most common causative pathogen in osteomyelitis. New or alternative therapies are often needed to treat S. aureus infections adequately in patients with drug allergies, treatment failures, or drug interactions. Oritavancin is a novel long-acting lipoglycopeptide approved by the U.S. Food and Drug Administration in 2014 for the treatment of acute bacterial skin and skin structure infections. With a terminal half-life of 8-10 days, oritavancin dosing regimens with infrequent parenteral administration now exist to treat infectious diseases such as osteomyelitis that would otherwise require daily dosing of intravenous antimicrobials for weeks; however, clinical experience is lacking. In this article, the first case of S. aureus osteomyelitis resulting from traumatic injury, successfully treated with oritavancin, is presented. Removal of the nail used for a comminuted tibial shaft fracture repair followed by a 6-week treatment course with oritavancin resulted in clinical response.

Neisseria gonorrhoeae and fosfomycin: Past, present and future.

Drug-resistant Neisseria gonorrhoeae has become a global health concern that requires immediate attention. Due to increasing resistance to cephalosporins, pursuing novel alternatives for treating N. gonorrhoeae infections is paramount. Whilst new drug development is often cumbersome, reviving antiquated antibiotic agents for treatment of modern infections has become prevalent in clinical practice. Fosfomycin exhibits bactericidal activity through a unique mechanism of action, and a variety of organisms including N. gonorrhoeae are susceptible. In vitro studies have demonstrated that fosfomycin can retain activity against ceftriaxone-resistant N. gonorrhoeae; however, it remains unclear whether there is synergy between fosfomycin and other antibiotics. Clinical investigations evaluating fosfomycin for the treatment of N. gonorrhoeae infections are confounded by methodological limitations, none the less they do provide some perspective on its potential role in therapy. Future studies are needed to establish a safe, convenient and effective fosfomycin regimen for treating N. gonorrhoeae infections.

Ceftolozane/Tazobactam: A Novel Cephalosporin/ß-Lactamase Inhibitor Combination.

Ceftolozane/tazobactam is a novel antipseudomonal ß-lactam/ß-lactamase inhibitor combination that is currently approved by the United States Food and Drug Administration for the treatment of complicated intraabdominal infections (cIAI) and complicated urinary tract infections (cUTI). It exhibits bactericidal properties through inhibition of bacterial cell wall biosynthesis, which is mediated through penicillin-binding proteins (PBPs). Ceftolozane is a potent PBP3 inhibitor and has a higher affinity for PBP1b compared with other ß-lactam agents. Ceftolozane/tazobactam differs from other cephalosporins due to its increased activity against some AmpC ß-lactamases and Pseudomonas aeruginosa. The addition of tazobactam provides enhanced activity against extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae and certain anaerobic organisms. Population pharmacokinetic studies for ceftolozane and ceftolozane/tazobactam are best described by a two-compartment model with zero-order input and linear elimination. Similar to other cephalosporins, the best pharmacodynamic property to predict efficacy for ceftolozane/tazobactam is a concentration that remains above the minimum inhibitory concentration (MIC) for 40-50% of the dosing interval. For Enterobacteriaceae and P. aeruginosa strains, the time above the MIC (T > MIC) needed to produce bactericidal activity was much less with ceftolozane than other cephalosporins, with T > MIC requirements of approximately 30%. For currently approved indications, the dose of ceftolozane/tazobactam is 1.5 g (ceftolozane 1 g/tazobactam 0.5 g) intravenously every 8 hours given as a 1-hour infusion. Ceftolozane has low plasma protein binding (20%) and is predominantly excreted unchanged in the urine (≥ 92%). Dosage adjustments are required for moderate-to-severe renal impairment and in patients receiving hemodialysis. Based on data from clinical trials, adverse effects due to ceftolozane/tazobactam do not differ considerably from other cephalosporins, with the most common being nausea, diarrhea, headache, and pyrexia. Ceftolozane/tazobactam is a promising new agent for the treatment of cIAI and cUTI, including those caused by multidrug-resistant gram-negative organisms.

Breaking down the barriers: challenges with development and implementation of an industry-sponsored antimicrobial stewardship data collection and analysis tool.

Partnership between clinicians and the pharmaceutical industry with a focus on antimicrobial stewardship research initiatives is a necessary step toward meeting the shared goals of combating inappropriate antimicrobial use, improving patient outcomes, and minimizing resistance development. Achieving these goals requires outcomes-focused data collection and monitoring tools for antimicrobial stewardship programs (ASP) that consider real-world data about how antimicrobials are used to treat patients. Here we highlight the experiences and challenges associated with the development and implementation of an industry-sponsored electronic antimicrobial stewardship data collection and analysis tool (AS-DCAT). The benefits and risks of the industry-sponsored AS-DCAT from the perspectives of the sponsoring company and participating sites are discussed. Barriers encountered as well as general considerations and recommendations for preventing or overcoming those barriers for future studies and tool development are provided.

Bedaquiline: a novel antitubercular agent for the treatment of multidrug-resistant tuberculosis.

Bedaquiline is a diarylquinoline antitubercular drug with a novel mechanism of action against Mycobacterium tuberculosis. Bedaquiline works by inhibiting bacterial adenosine triphosphate (ATP) synthase and represents the first novel class of antituberculosis agents in more than 40 years. Bedaquiline is indicated for the treatment of multidrug-resistant tuberculosis (MDR TB) in combination with at least three other antitubercular drugs when no other effective regimen is available. The recommended bedaquiline dosage is 400 mg orally once/day for 2 weeks followed by 200 mg orally 3 times/week for 22 weeks. Bedaquiline should be administered with food, which increases the bioavailability 2-fold. Bedaquiline is metabolized by cytochrome P450 isoenzyme 3A4 and is impacted by both inducers and inhibitors of this isoenzyme. Concentration-dependent bactericidal activity was observed in laboratory and murine studies. Accelerated approval was granted in the United States and European Union based on the results of two phase IIb clinical studies that used sputum culture clearance as a surrogate end point for clinical efficacy. These studies showed greater sputum culture clearance up to week 24 for the bedaquiline group compared with placebo. Common adverse events in clinical trials included nausea, arthralgia, and headache. Serious adverse events included elevated serum transaminase levels and rate-corrected QT-interval prolongation. Unexplained higher mortality was seen in patients receiving bedaquiline versus those receiving placebo. Bedaquiline is a novel agent with a unique mechanism of action and has the potential to meet a great need in patients with MDR TB who have no other treatment options. Due to safety concerns and limited clinical information, phase III trials are needed to fully determine its place in therapy.