Comparing the Outcomes of Ceftaroline Plus Vancomycin or Daptomycin Combination Therapy Versus Monotherapy in Adults with Complicated and Prolonged Methicillin-Resistant Staphylococcus Aureus Bacteremia Initially Treated with Supplemental Ceftaroline

Getting to the heart of the matter-are two agents really better than one for the treatment of staphylococcal infective endocarditis?

The recently published European Society of Cardiology guidelines for infective endocarditis management recommends daptomycin combination therapy for the treatment of staphylococcal endocarditis in severe penicillin allergy, rather than daptomycin monotherapy. We discuss the evidence base behind this recommendation, highlighting concerns regarding the lack of robust clinical studies, increased cost and logistical considerations, and adverse effects of combination therapy. Although further studies are required to elucidate the role of combination vs monotherapy in these patients, we propose a pragmatic management approach to reduce the risk of adverse antimicrobial side effects and limit costs, while aiming to maintain treatment efficacy.

Safety and effectiveness of fifth generation cephalosporins for the treatment of methicillin-resistant staphylococcus aureus bloodstream infections: a narrative review exploring past, present, and future

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection (BSI) is a major issue in healthcare, since it is often associated with endocarditis or deep site foci. Relevant morbidity and mortality associated with MRSA-BSIs forced the development of new antibiotic strategies; in particular, this review will focus the attention on fifth-generation cephalosporins (ceftaroline/ceftobiprole), that are the only ß-lactams active against MRSA.

AREAS COVERED

The review discusses the available randomized controlled trials and real-world observational studies conducted on safety and effectiveness of ceftaroline/ceftobiprole for the treatment of MRSA-BSIs. Finally, a proposal of MRSA-BSI treatment flowchart, based on fifth-generation cephalosporins, is described.

EXPERT OPINION

The use of anti-MRSA cephalosporins is an acceptable choice either in monotherapy or combination therapy for the treatment of MRSA-BSIs due to their relevant effectiveness and safety. Particularly, their use may be advisable in combination therapy in case of severe infections (including endocarditis or persistent bacteriemia) or in monotherapy in subjects at higher risk of drugs-induced toxicity with older regimens. On the contrary, caution should be taken in case of suspected/ascertained central nervous system infections due to inconsistent data regarding penetration of these drugs in cerebrospinal fluid and brain tissues.

New Antimicrobials and New Therapy Strategies for Endocarditis: Weapons That Should Be Defended

The overall low-quality evidence concerning the clinical benefits of different antibiotic regimens for the treatment of infective endocarditis (IE), which has made it difficult to strongly support or reject any regimen of antibiotic therapy, has led to a discrepancy between the available guidelines and clinical practice. In this complex scenario, very recently published guidelines have attempted to fill this gap. Indeed, in recent years several antimicrobials have entered the market, including ceftobiprole, ceftaroline, and the long-acting lipoglycopeptides dalbavancin and oritavancin. Despite being approved for different indications, real-world data on their use for the treatment of IE, alone or in combination, has accumulated over time. Furthermore, an old antibiotic, fosfomycin, has gained renewed interest for the treatment of complicated infections such as IE. In this narrative review, we focused on new antimicrobials and therapeutic strategies that we believe may provide important contributions to the advancement of Gram-positive IE treatment, providing a summary of the current in vitro, in vivo, and clinical evidence supporting their use in clinical practice.

Targeted Therapy of Severe Infections Caused by Staphylococcus aureus in Critically Ill Adult Patients: A Multidisciplinary Proposal of Therapeutic Algorithms Based on Real-World Evidence

(1) Introduction: To develop evidence-based algorithms for targeted antibiotic therapy of infections caused by Staphylococcus aureus in critically ill adult patients. (2) Methods: A multidisciplinary team of four experts had several rounds of assessment for developing algorithms concerning targeted antimicrobial therapy of severe infections caused by Staphylococcus aureus in critically ill patients. The literature search was performed by a researcher on PubMed-MEDLINE (until August 2022) to provide evidence for supporting therapeutic choices. Quality and strength of evidence was established according to a hierarchical scale of the study design. Two different algorithms were created, one for methicillin-susceptible Staphylococcus aureus (MSSA) and the other for methicillin-resistant Staphylococcus aureus (MRSA). The therapeutic options were categorized for each different site of infection and were selected also on the basis of pharmacokinetic/pharmacodynamic features. (3) Results: Cefazolin or oxacillin were the agents proposed for all of the different types of severe MSSA infections. The proposed targeted therapies for severe MRSA infections were different according to the infection site: daptomycin plus fosfomycin or ceftaroline or ceftobiprole for bloodstream infections, infective endocarditis, and/or infections associated with intracardiac/intravascular devices; ceftaroline or ceftobiprole for community-acquired pneumonia; linezolid alone or plus fosfomycin for infection-related ventilator-associated complications or for central nervous system infections; daptomycin alone or plus clindamycin for necrotizing skin and soft tissue infections. (4) Conclusions: We are confident that targeted therapies based on scientific evidence and optimization of the pharmacokinetic/pharmacodynamic features of antibiotic monotherapy or combo therapy may represent valuable strategies for treating MSSA and MRSA infections.

Vancomycin plus ceftaroline for persistent methicillin-resistant Staphylococcus aureus bacteremia

STUDY OBJECTIVE

The preferred antibiotic salvage regimen for persistent methicillin-resistant Staphylococcus aureus bacteremia (MRSAB) is unclear. We sought to evaluate the effectiveness and safety of vancomycin plus ceftaroline for persistent MRSAB. The primary outcome was time to MRSAB clearance post-ceftaroline initiation. Secondary outcomes included microbiological cure, hospital length of stay, 90-day readmission for MRSAB, 90-day all-cause mortality, MRSAB-related mortality, and incidence of antibiotic-associated adverse effects.

DESIGN

Single-center, retrospective cohort study between January 1, 2016, and December 31, 2021.

SETTING

State University of New York Upstate University Hospital, a 748-bed tertiary care, academic medical center in Syracuse, NY.

PATIENTS

Adult patients were included if they had blood cultures positive for MRSA ≥72 h, received vancomycin monotherapy initially, and received vancomycin plus ceftaroline for ≥24 h. Patients were excluded if they received other anti-MRSA antibiotics, were pregnant, or were incarcerated. Of the 178 patients identified, 30 unique patients were evaluated.

MEASUREMENTS AND MAIN RESULTS

Patients were medically complex with a median Pitt bacteremia score of 3, 63.3% (19/30) were admitted to the intensive care unit, and 66.7% (20/30) had infective endocarditis. Vancomycin-associated acute kidney injury was observed in 10% (3/30) of patients, which resulted in dose adjustments. No patients experienced ceftaroline-associated neutropenia or Clostridioides difficile infection, but 6.7% (2/30) developed a rash attributed to ceftaroline. Median time to MRSAB clearance post-ceftaroline initiation was 2.6 days. Microbiologic cure occurred in nearly all patients 96.7% (29/30). Median hospital length of stay was 19.5 days, and 6.7% (2/30) of patients had 90-day readmission for MRSAB. 90-day all-cause mortality and MRSAB-related mortality occurred in 26.7% (8/30) and 13.3% (4/30) of patients, respectively.

CONCLUSIONS

Vancomycin plus ceftaroline may represent an effective and well-tolerated salvage regimen option for persistent MRSAB.

Daptomycin synergistic properties from in vitro and in vivo studies: a systematic review

INTRODUCTION

Daptomycin is a bactericidal lipopeptide antibiotic approved for the treatment of systemic infections (i.e. skin and soft tissue infections, bloodstream infections, infective endocarditis) caused by Gram-positive cocci. It is often prescribed in association with a partner drug to increase its bactericidal effect and to prevent the emergence of resistant strains during treatment; however, its synergistic properties are still under evaluation.

METHODS

We performed a systematic review to offer clinicians an updated overview of daptomycin synergistic properties from in vitro and in vivo studies. Moreover, we reported all in vitro and in vivo data evaluating daptomycin in combination with other antibiotic agents, subdivided by antibiotic classes, and a summary graph presenting the most favourable combinations at a glance.

RESULTS

A total of 92 studies and 1087 isolates (723 Staphylococcus aureus, 68 Staphylococcus epidermidis, 179 Enterococcus faecium, 105 Enterococcus faecalis, 12 Enterococcus durans) were included. Synergism accounted for 30.9% of total interactions, while indifferent effect was the most frequently observed interaction (41.9%). Antagonistic effect accounted for 0.7% of total interactions. The highest synergistic rates against S. aureus were observed with daptomycin in combination with fosfomycin (55.6%). For S. epidermidis and Enterococcus spp., the most effective combinations were daptomycin plus ceftobiprole (50%) and daptomycin plus fosfomycin (63.6%) or rifampicin (62.8%), respectively.

FUTURE PERSPECTIVES

We believe this systematic review could be useful for the future updates of guidelines on systemic infections where daptomycin plays a key role.

Comparing the Outcomes of Ceftaroline plus Vancomycin or Daptomycin Combination Therapy versus Vancomycin or Daptomycin Monotherapy in Adults with Methicillin-Resistant Staphylococcus aureus Bacteremia—A Meta-Analysis

Introduction: Combination therapy with daptomycin plus ceftaroline to treat methicillin-resistant Staphylococcus aureus bacteremia has been reported to reduce methicillin-resistant Staphylococcus aureus bacteremia-related mortality. The purpose of the current meta-analysis was to compare the clinical outcome of methicillin-resistant Staphylococcus aureus bacteremia in patients treated with daptomycin or vancomycin plus ceftaroline combination therapy versus daptomycin or vancomycin monotherapy. Methods: Studies were included if they directly compared the efficacy of daptomycin or vancomycin plus ceftaroline combination therapy with that of daptomycin or vancomycin monotherapy in the treatment of methicillin-resistant Staphylococcus aureus bacteremia in adult patients. Results: One randomized controlled trial and five retrospective studies were included in the meta-analysis. The combination therapy group had an in-hospital mortality, duration of bacteremia, and adverse event rate similar to those patients who had monotherapy. There was less bacteremia recurrence in the combination group. Initial combination therapy with ceftaroline for the treatment of methicillin-resistant Staphylococcus aureus bacteremia showed a trend of reducing the risk of in-hospital mortality in the current meta-analysis. Conclusions: Randomized controlled trials are needed to further study the role of initial combination therapy with daptomycin or vancomycin plus ceftaroline in the treatment of methicillin-resistant Staphylococcus aureus bacteremia.

Incidence and risk factors for mortality in patients treated with combined ceftaroline for Gram-positive infective endocarditis

BACKGROUND

Ceftaroline is a fifth-generation cephalosporin and represents an alternative in the treatment of infective endocarditis (IE). The main objective of this study was to describe the incidence of in-hospital and 42-day mortality in patients with IE treated with ceftaroline.

METHODS

An observational retrospective study included adult patients with IE admitted during a 3.5-year period (January 2018-June 2021) and treated with ceftaroline in a single center. All cases were definite or possible IE according to the modified Duke criteria.

RESULTS

Seventy cases were analyzed. The mean age was 67.35 ± 16.62 (16-89) and 39 (55.7%) were males. The mean number of days of treatment with ceftaroline was 21.26 ± 16.17 (1-75). Overall mortality at 42 days was 30%, 20.7% in the first line, and 36.6% in rescue therapy. Predictors of 42 days-mortality were increased Charlson comorbidity index (CCI) (OR of 1.7 per 1 point increment, 95% CI 1.2-2.4, P 0.001), presence of methicillin-resistance (OR 6.8, 95% CI 1.3-36.8, P 0.026) and evidence of septic shock (OR 8.6 95% CI 1.7-44.2, P 0.01). Predictors of 42 days of therapeutic failure were the increase in the CCI (OR of 1.6 per 1 point increment, 95% CI 1.3-2.1, P 0.000) and septic shock (OR 4.5 95% CI 1.1-18 P 0.036). Adverse effects were described in 6/70 (8.6%) of the patients, precipitating in 4/70 (5.7%) the definitive withdrawal of the antibiotic.

CONCLUSIONS

The incidence of in-hospital and 42 day-mortality of IE patients treated with ceftaroline remains similar to literature data. Increased CCI, septic shock, and methicillin resistance are associated with poor prognosis.

The Effect of Combination Therapy on Mortality and Adverse Events in Patients with Staphylococcus aureus Bacteraemia: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Introduction

The findings of randomized controlled trials (RCTs), observational studies, and meta-analyses vary regarding the effectiveness and safety of combination therapy for patients with Staphylococcus aureus bacteraemia (SAB). We aimed to identify the effectiveness and safety of combination therapy in patients with SAB compared with those of monotherapy.

Methods

We performed a systematic review and meta-analysis to compare combination therapy versus monotherapy in patients with SAB. Two authors independently searched PubMed, Embase, and the Cochrane Library of clinical trials until 17 February 2021. Any RCT comparing mortality or adverse events (AEs) of combination therapy versus monotherapy for patients with SAB was eligible. Summary risk ratios (RRs) and 95% confidence intervals (CIs) were evaluated using a random-effects model. The primary outcome was all-cause mortality at any time point. This meta-analysis is registered with the PROSPERO database (CRD42020188176) and reported according to PRISMA guidelines.

Results

In total, 1906 articles were identified and screened, and 14 studies (2367 patients) were included in the meta-analysis. There was no significant difference in the risk of all-cause mortality between the two groups (RR = 1.00; 95% CI 0.83–1.20; P = 0.99; I² = 0%). Similar results were obtained by subgroup analysis of mortality recording time, endocarditis, pathogen resistance, article publication time, number of patients, and adjuvant antibiotics. Notably, combination treatment might significantly increase the risk of drug-related AEs (RR = 1.68; 95% CI 1.06–2.66; P = 0.03; I² = 67%) and nephrotoxicity (RR = 2.30; 95% CI 1.68–3.16; P < 0.00001; I² = 0%), although the occurrences of AEs leading to treatment discontinuation and serious AEs were not significantly different between the two groups.

Conclusions

The meta-analysis suggested that combination therapy could not reduce mortality but might increase the risk of drug-related AEs and nephrotoxicity and should be applied very cautiously. Future studies on combined drug therapy for SAB need careful and rigorous design for specific antibiotic combinations.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-021-00539-y.

Select controversies in the management of methicillin-resistant Staphylococcus aureus bacteremia: answers and remaining questions from recent evidence

Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia continues to cause significant morbidity and mortality despite advances in medical therapy. Vancomycin therapy remains the standard of care for most cases of MRSA bacteremia but has pharmacokinetic and pharmacodynamic limitations, dosing complications, and known toxicity. Welcomed clinical trials have recently addressed some of the controversies that plague this field, including optimization of vancomycin dosing and use of combination therapy. In this review, we discuss these trials and their implications for clinical care and future research.

Use of Ceftaroline in Hospitalized Patients with and without COVID-19: A Descriptive Cross-Sectional Study

A single-center cross-sectional study was conducted to describe the use of ceftaroline in a large teaching hospital in Northern Italy, during a period also including the first months of the coronavirus disease 2019 (COVID-19) pandemic. The primary objective was to describe the use of ceftaroline in terms of indications and characteristics of patients. A secondary objective was to describe the rate of favorable clinical response in patients with bloodstream infections (BSI) due to methicillin-resistant Staphylococcus aureus (MRSA-BSI) receiving ceftaroline. Overall, 200 patients were included in the study. Most of them had COVID-19 (83%, 165/200) and were hospitalized in medical wards (78%, 155/200). Included patients with COVID-19 pneumonia were given empirical ceftaroline in the suspicion of bacterial co-infection or superinfection. Among patients with MRSA-BSI, ceftaroline was used as a first-line therapy and salvage therapy in 25% (3/12) and 75% (9/12) of cases, respectively, and as a monotherapy or in combination with daptomycin in 58% (7/12) and 42% (5/12) of patients, respectively. A favorable response was registered in 67% (8/12) of patients. Improving etiological diagnosis of bacterial infections is essential to optimize the use of ceftaroline in COVID-19 patients. The use of ceftaroline for MRSA-BSI, either as a monotherapy or in combination with other anti-MRSA agents, showed promising rates of favorable response.

Clinical Outcomes With Definitive Treatment of Methicillin-Resistant Staphylococcus aureus Bacteremia With Retained Daptomycin and Ceftaroline Combination Therapy vs De-escalation to Monotherapy With Vancomycin, Daptomycin, or Ceftaroline

Background

Lower mortality has been observed with combination therapy compared to monotherapy for methicillin-resistant Staphylococcus aureus (MRSA) bacteremia; however, there is a lack of evidence for continued combination therapy over de-escalation to monotherapy following bacteremia clearance.

Methods

This was a single-center, retrospective study evaluating patients with MRSA bacteremia hospitalized from November 1, 2011, through July 31, 2019. Patients who received three to ten days of combination therapy followed by de-escalation to monotherapy were directly compared to patients retained on combination therapy. The primary composite outcome included inpatient infection-related mortality, 60-day readmission, and 60-day bacteremia recurrence.

Results

A total of 286 patients with MRSA bacteremia were identified, with 146 patients omitted based on exclusion criteria. The study population included 66 in the combination therapy group and 74 in the monotherapy group. Study population was 51% female (n = 71) and 78% white (n = 109) with median age of 46 years (IQR 34.5-61). No significant difference was observed in the primary composite outcome (21% combination therapy group vs 24% monotherapy group; P =.66), with retained observations after controlling for confounders. Within this outcome, there was no significant difference in 60-day readmission (20% combination therapy group vs 18% monotherapy group; P =.75), bacteremia recurrence (3% combination therapy group vs 7% monotherapy group; P =.45), or inpatient infection-related mortality (2% combination therapy group vs 5% monotherapy group; P = 1.00).

Conclusions

No difference was found in the composite outcome of 60-day bacteremia recurrence, readmission, or inpatient infection-related mortality for patients with MRSA bacteremia retained on combination therapy versus those de-escalated to monotherapy.

Losing the Battle but Winning the War: Can Defeated Antibacterials Form Alliances to Combat Drug-Resistant Pathogens?

Despite the recent development of antibacterials that are active against multidrug-resistant pathogens, drug combinations are often necessary to optimize the killing of difficult-to-treat organisms. Antimicrobial combinations typically are composed of multiple agents that are active against the target organism; however, many studies have investigated the potential utility of combinations that consist of one or more antibacterials that individually are incapable of killing the relevant pathogen. The current review summarizes in vitro, in vivo, and clinical studies that evaluate combinations that include at least one drug that is not active individually against Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumannii, or Staphylococcus aureus. Polymyxins were often included in combinations against all three of the Gram-negative pathogens, and carbapenems were commonly incorporated into combinations against K. pneumoniae and A. baumannii. Minocycline, sulbactam, and rifampin were also frequently investigated in combinations against A. baumannii, whereas the addition of ceftaroline or another β-lactam to vancomycin or daptomycin showed promise against S. aureus with reduced susceptibility to vancomycin or daptomycin. Although additional clinical studies are needed to define the optimal combination against specific drug-resistant pathogens, the large amount of in vitro and in vivo studies available in the literature may provide some guidance on the rational design of antibacterial combinations.

What do beta-lactams add to vancomycin or daptomycin in the treatment of patients with methicillin-resistant Staphylococcus aureus bacteraemia? A review

Several studies have documented the synergy between vancomycin/daptomycin and various beta-lactams, and clinical studies have studied this combination therapy in humans. We review the published literature on this topic to know the utility of the combined treatment with beta-lactams in treating bacteraemia methicillin-resistant Staphylococcus aureus (MRSA) infections. Fifteen observational studies, three randomised clinical trials and three systematics reviews are analysed in this article. Observational studies used ceftaroline, cefazolin, piperacillin/tazobactam or cefepime among the beta-lactams. Clinical trials used cloxacillin or flucloxacillin as the most used beta-lactam in two trials and ceftaroline in one. Three systematic reviews are published. One of them only includes studies with vancomycin and included six studies. The other two systematic reviews include patients with daptomycin or vancomycin and included 15 and 9 studies, respectively. Adding a beta-lactam to vancomycin or daptomycin may help shorten bacteraemia and avoid recurrences in patients with MRSA bacteraemia. There is no evidence that combined therapy improves mortality. Nephrotoxicity in clinical trials precludes the use of combination therapy mainly with cloxacillin or flucloxacillin, but systematic reviews have not found a significant difference in this point in observational studies with other beta-lactams. The role of other beta-lactams such as ceftaroline should be thoroughly studied in these patients.

Adjuvant β-Lactam Therapy Combined with Vancomycin or Daptomycin for Methicillin-Resistant Staphylococcus aureus Bacteremia: a Systematic Review and Meta-analysis

Infections due to methicillin-resistant Staphylococcus aureus bacteremia (MRSAB) seriously threaten public health due to poor outcomes and high mortality. The objective of this study is to perform a systematic review and meta-analysis of the current evidence on adjuvant β-lactam (BL) therapy combined with vancomycin (VAN) or daptomycin (DAP) for MRSAB. PubMed, Embase, and Cochrane Library were systematically searched for publications reporting clinical outcomes of BLs+VAN or BLs+DAP for adult patients with MRSAB through 5 April 2020. Meta-analysis techniques were applied using random effects modeling. Three randomized controlled trials and 12 retrospective cohort studies were identified, totaling 2,594 patients. Combination treatment significantly reduced the risk of clinical failure (risk ratio [RR] = 0.80; 95% confidence interval [CI], 0.66 to 0.96; P = 0.02; I² = 39%), bacteremia recurrence (RR = 0.66; 95% CI, 0.50 to 0.86; P = 0.002; I² = 0%), and persistent bacteremia (RR = 0.65; 95% CI, 0.55 to 0.76; P < 0.00001; I² = 0%) and shortened the duration of bacteremia (standardized mean difference [SMD] = -0.37; 95% CI, -0.48 to -0.25; P < 0.00001; I² = 0%). There was no significant difference in the risk of crude mortality, nephrotoxicity, or thrombocytopenia between groups. Notably, combination treatment might nonsignificantly increase the risk of Clostridium difficile infection (CDI) (RR = 2.13; 95% CI, 0.98 to 4.63; P = 0.06; I² = 0%). Subgroup analysis suggested that DAP+BLs could reduce crude mortality (RR = 0.53; 95% CI, 0.28 to 0.98; P = 0.04; I² = 0%). The meta-analysis suggested that although combination therapy with BLs could improve some microbial outcomes, it could not reduce crude mortality but might increase the risk of CDI and should be applied very cautiously. Regarding mortality reduction, the combination of DAP+cephalosporins appears more promising.

Combination of Vancomycin or Daptomycin and Beta-lactam Antibiotics: A Meta-analysis

INTRODUCTION

Observational and randomized controlled trials of the combination of vancomycin or daptomycin with a beta-lactam (BL) in patients with methicillin-resistant Staphylococcus aureus (MRSA) bacteremia have shown conflicting results on patient outcomes.

OBJECTIVES

The primary purpose of this meta-analysis was to compare clinical failure with the combination of vancomycin or daptomycin with a BL versus vancomycin or daptomycin monotherapy in MRSA bacteremia or endocarditis.

METHODS

A systematic literature search of PubMed, Embase, CINAHL, and meeting proceedings was conducted from inception through February 11, 2020, to identify relevant studies. The primary outcome was clinical failure and secondary outcomes were mortality, nephrotoxicity, and bacteremia. The meta-analysis was performed using Comprehensive Meta Analysis (version 3.0) with a random effects model. Outcomes were reported as odds ratios (ORs) with corresponding 95% confidence intervals (CIs).

RESULTS

Nine studies of 1636 patients receiving vancomycin or daptomycin monotherapy versus the combination of vancomycin or daptomycin plus BL for MRSA bacteremia were included. Results showed combination therapy was associated with significantly lower clinical failure rates (OR 0.56, 95% CI 0.39-0.79, I²  = 26.22%, p=0.001). Improvement in clinical failure was driven by lower rates of bacteremia relapse and persistence. However, no difference was seen with mortality.

CONCLUSIONS

Combination therapy with vancomycin or daptomycin plus BL for MRSA bacteremia showed lower clinical failure rates, however, no significant difference was seen in mortality.

The Emerging Role of β-Lactams in the Treatment of Methicillin-Resistant Staphylococcus aureus Bloodstream Infections

Methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections (BSI) are associated with substantial morbidity and mortality. Monotherapy with first-line antimicrobials such as vancomycin (VAN; glycopeptide) and daptomycin (DAP; lipopeptide) are inadequate in some cases due to reduced antibiotic susceptibilities or therapeutic failure. In recent years, β-lactam antibiotics have emerged as a potential option for combination therapy with VAN and DAP that may meet an unmet therapeutic need for MRSA BSI. Ceftaroline (CPT), the only commercially available β-lactam in the United States with intrinsic in vitro activity against MRSA, has been increasingly studied in the setting of VAN and DAP failures. Novel combinations of first-line agents (VAN and DAP) with β-lactams have been the subject of many recent investigations due to in vitro findings such as the "seesaw effect," where β-lactam susceptibility may be improved in the presence of decreased glycopeptide and lipopeptide susceptibility. The combination of CPT and DAP, in particular, has become the focus of many scientific evaluations, due to intrinsic anti-MRSA activities and potent in vitro synergistic activity against various MRSA strains. This article reviews the available literature describing these innovative therapeutic approaches for MRSA BSI, focusing on preclinical and clinical studies, and evaluates the potential benefits and limitations of each strategy.