Influence of daptomycin doses on the outcomes of VRE bloodstream infection treated with high-dose daptomycin

Pharmacotherapies for multidrug-resistant gram-positive infections: current options and beyond

INTRODUCTION

Infections due to multidrug-resistant organisms (MDRO) are a serious concern for public health with high morbidity and mortality. Though many antibiotics have been introduced to manage these infections, there are remaining concerns regarding the optimal management of Gram-positive MDROs.

AREAS COVERED

A literature search on the PubMed/Medline database was conducted. We applied no language and time limits for the search strategy. In this narrative review, we discuss the current options for managing Gram-positive MDROs as well as non-traditional antibacterial agents in development.

EXPERT OPINION

Despite their introduction more than 70 years ago, glycopeptides are still the cornerstone in treating Gram-positive infections: all registrative studies of new antibiotics have glycopeptides as control; these studies are designed as not inferior studies, therefore it is almost impossible to give recommendations other than the use of glycopeptides in the treatment of Gram-positive infections. The best evidence on treatments different from glycopeptides comes from post-hoc analysis and meta-analysis. Non-traditional antibacterial agents are being studied to aid in short and effective antibiotic therapies. The use of non-traditional antibacterial agents is not restricted to replacing traditional antibacterial agents with alternative therapies; instead, they should be used in combination with antibiotic therapies.

[Potential Nephrotoxicity of Combination of Vancomycin and Piperacillin-Tazobactam: Recommendations from the AG ABS of the DGPI supported by experts of the GPN]

The combination of vancomycin and piperacillin/tazobactam (V+P/T) is used for empirical antibiotic treatment of severe infections, especially in immunocompromised patients and those colonized with multidrug-resistant bacteria. Nephrotoxicity is a frequently observed adverse effect of vancomycin. Its risk can be reduced by therapeutic drug monitoring and adjusted dosing. Piperacillin/tazobactam (P/T) rarely causes interstitial nephritis. The results of retrospective cohort studies in children predominantly show a low, clinically irrelevant, additive nephrotoxicity (defined as an increase in creatinine in the serum) of both substances. Due to the limitations of the existing publications, the ABS working group of the DGPI and experts of the GPN do not recommend against the use of P/T plus vancomycin. Preclinical studies and a prospective study with adult patients, which evaluated different renal function tests as well as clinical outcomes, do not support previous findings of additive nephrotoxicity. Time-restricted use of V+P/T can minimize exposure and the potential risk of nephrotoxicity. Local guidelines, developed in collaboration with the antibiotic stewardship team, should define the indications for empirical and targeted use of P/T and V+P/T. When using combination therapy with V+P/T, kidney function should be monitored through clinical parameters (volume status, balancing, blood pressure) as well as additional laboratory tests such as serum creatinine and cystatin C.

A Pharmacovigilance Analysis of Daptomycin Use Based on CLSI Susceptible Dose-Dependent Category

INTRODUCTION

Daptomycin doses 8-12 mg/kg are recommended for susceptible dose-dependent Enterococcus species. However, data remain limited on safety outcomes of such dosing, compared to standard 4-6 mg/kg dosing.

METHODS

In this retrospective cohort study, patients were stratified into daptomycin standard-dose (≤ 6.5 mg/kg) versus high-dose (≥ 7.5 mg/kg) groups. The primary outcome was daptomycin safety based on a composite of creatine kinase elevation, daptomycin-related peripheral blood eosinophilia, eosinophilic pneumonitis, alanine aminotransferase elevation, and alkaline phosphatase elevation. A secondary aim was to identify risk factors for daptomycin adverse effects. Inclusion criteria were age ≥ 18 years old, daptomycin receipt for ≥ 48 h, and Enterococcus cultures with a daptomycin minimal inhibitory concentration 2-4 mg/L.

RESULTS

A total of 119 patients were included for analysis. Median daptomycin doses were 6.0 mg/kg (IQR 5.4, 6.1) and 8.1 mg/kg (IQR 7.9, 9.6) in the standard- and high-dose cohorts, respectively. Median durations were 13.5 days (standard-dose) and 16 days (high-dose) (p = 0.02). The composite safety endpoint occurred in 32.0% of the standard-dose group and 32.5% of the high-dose group (p = 0.96). Daptomycin was dose-reduced or held in 8.1% of patients experiencing an adverse effect. Concurrent antihistamine usage was associated with the composite outcome; however, there was no association with daptomycin dose or concurrent statin use.

CONCLUSION

High-dose daptomycin was not associated with increased laboratory abnormalities or adverse drug reactions compared to standard-dose daptomycin.

Therapeutics for Vancomycin-Resistant Enterococcal Bloodstream Infections

Vancomycin-resistant enterococci (VRE) are common causes of bloodstream infections (BSIs) with high morbidity and mortality rates. They are pathogens of global concern with a limited treatment pipeline. Significant challenges exist in the management of VRE BSI, including drug dosing, the emergence of resistance, and the optimal treatment for persistent bacteremia and infective endocarditis. Therapeutic drug monitoring (TDM) for antimicrobial therapy is evolving for VRE-active agents; however, there are significant gaps in the literature for predicting antimicrobial efficacy for VRE BSIs. To date, TDM has the greatest evidence for predicting drug toxicity for the three main VRE-active antimicrobial agents daptomycin, linezolid, and teicoplanin. This article presents an overview of the treatment options for VRE BSIs, the role of antimicrobial dose optimization through TDM in supporting clinical infection management, and challenges and perspectives for the future.

Treatment decisions in VRE bacteraemia: a survey of infectious diseases pharmacists

Background

VRE infections increased in 2020. High-dose daptomycin (≥10 mg/kg) has shown mortality benefit over other regimens, though daptomycin resistance is increasing. Limited data exist on the practice patterns of ID pharmacists for VRE bloodstream infections (VRE BSIs).

Objectives

To describe practice patterns for VRE BSI in ID pharmacists.

Methods

A 22-question REDCap survey was distributed to ID pharmacist members of the American College of Clinical Pharmacy (ACCP) Infectious Diseases Practice and Research Network (ID PRN) via e-mail listserv. The survey was distributed on 7 April 2022 and remained open for 4 weeks.

Results

Sixty-eight pharmacists responded. All pharmacists completed additional training or certification in infectious diseases past their PharmD, and most (70.5%) had been practising for 10 years or less. Pharmacists at academic medical centres (80.0%) were more likely (P = 0.001) to have implemented the updated CLSI breakpoints than pharmacists at other types of institutions (55.2%). Daptomycin was the preferred drug for VRE BSI (92.6%), with 10 mg/kg (72.1%) being the preferred dose. Adjusted body weight was the most common weight (61.2%) used for obese patients. Fourteen days (76.1%) was the most common treatment duration for VRE BSI. Pharmacists defined persistent VRE BSI as 5 days (68.7%) after first blood culture.

Conclusions

ID pharmacists overwhelmingly selected high-dose daptomycin for VRE BSI. There were variations in practice and response rate when selecting combination therapy, managing persistent bacteraemia, and treating patients with high daptomycin MICs or previous exposure to daptomycin.

Antimicrobial susceptibility testing: An updated primer for clinicians in the era of antimicrobial resistance: Insights from the Society of Infectious Diseases Pharmacists

Antimicrobial susceptibility testing (AST) is a critical function of the clinical microbiology laboratory and is essential for optimizing care of patients with infectious diseases, monitoring antimicrobial resistance (AMR) trends, and informing public health initiatives. Several methods are available for performing AST including broth microdilution, agar dilution, and disk diffusion. Technological advances such as the development of commercial automated susceptibility testing platforms and the advent of rapid diagnostic tests have improved the rapidity, robustness, and clinical application of AST. Numerous accrediting and regulatory agencies are involved in the process of AST and setting and revising breakpoints, including the U.S. Food and Drug Administration and the Clinical and Laboratory Standards Institute. Challenges to optimizing AST include the emergence of new resistance mechanisms, the development of new antimicrobial agents, and generation of new data requiring updates and revisions to established methods and breakpoints. Together, the challenges in AST methods and their interpretation create important opportunities for well-informed clinicians to improve patient outcomes and provide value to antimicrobial stewardship programs, especially in the setting of rapidly changing and increasing AMR. Addressing AST challenges will involve continued development of new technologies along with collaboration between clinicians and the laboratory to facilitate optimal antimicrobial use, combat the increasing burden of AMR, and inform the development of novel antimicrobials. This updated primer serves to reinforce important principles of AST, and to provide guidance on their implementation and optimization.

The Combination of Daptomycin with Fosfomycin is More Effective than Daptomycin Alone in Reducing Mortality of Vancomycin-Resistant Enterococcal Bloodstream Infections: A Retrospective, Comparative Cohort Study

INTRODUCTION

High-dose daptomycin-based combinations are recommended for vancomycin-resistant Enterococcus (VRE) bloodstream infection (BSI). Preclinical data have shown a synergistic effect of daptomycin/fosfomycin combinations against VRE. However, clinical studies comparing daptomycin monotherapy with daptomycin/fosfomycin combinations are unavailable.

METHODS

An observational study of VRE-BSI was performed between 2010-2021 on patients receiving daptomycin monotherapy (≥ 8 mg/kg) or daptomycin combined with intravenous fosfomycin. Patients treated with concomitant β-lactam combinations were excluded. The primary outcome was in-hospital mortality. Outcomes were analyzed using multivariable logistic regression and augmented inverse probability weighting (AIPW) analyses.

RESULTS

Among 224 patients, 176 received daptomycin monotherapy, and 48 received fosfomycin combinations. The median daptomycin and fosfomycin doses were 9.8 mg/kg and 12 g/day, respectively. In-hospital mortality was 77.3% and 47.9% in the daptomycin monotherapy and fosfomycin combination groups (P < 0.001), respectively. Multivariable logistic regression analysis predicted lower mortality with fosfomycin combination treatment (adjusted odds ratio, 0.35; 95% confidence interval (CI), 0.17-0.73; P = 0.005). AIPW demonstrated a 17.8% reduced mortality with fosfomycin combinations (95% CI, - 30.6- - 4.9%; P = 0.007). The survival benefit was significant, especially among patients with a lower Pitt bacteremia score or fosfomycin minimum inhibitory concentration (MIC) ≤ 64 mg/l. Fosfomycin combination resulted in higher hypernatremia (10.4% vs. 2.8%, P = 0.04) and hypokalemia (33.3% vs. 15.3%, P = 0.009) compared to daptomycin monotherapy.

CONCLUSION

The combination of high-dose daptomycin with fosfomycin improved the survival rate of patients with VRE-BSI compared to daptomycin alone. The benefit of the combination was most pronounced for VRE with fosfomycin MIC ≤ 64 mg/l and for patients with a low Pitt bacteremia score.