Postmarketing clinical experience in patients with skin and skin-structure infections treated with daptomycin

Management of complicated skin and soft tissue infections with a special focus on the role of newer antibiotics

Complicated skin and soft tissue infections (cSSTIs) represent the severe form of infectious disease that involves deeper soft tissues. Involvement of methicillin-resistant Staphylococcus aureus (MRSA) further complicates cSSTI with increased hospitalization, health care costs, and overall mortality. Various international guidelines provide recommendations on the management of cSSTIs, with the inclusion of newer antibiotics. This literature-based review discusses the overall management of cSSTI, including appropriate use of antibiotics in clinical practice. Successful treatment of cSSTIs starts with early and precise diagnosis, including identification of causative pathogen and its load, determination of infection severity, associated complications, and risk factors. The current standard-of-care for cSSTIs involves incision, drainage, surgical debridement, broad-spectrum antibiotic therapy, and supportive care. In recent years, the emergence of newer antibiotics (eg, ceftaroline, tigecycline, daptomycin, linezolid, etc) has provided clinicians wider options of antimicrobial therapy. Selection of antibiotics should be based on the drug characteristics, effectiveness, safety, and treatment costs, alongside other aspects such as host factors and local multidrug resistance rates. However, larger studies on newer antibiotics are warranted to refine the decision making on the appropriate antimicrobial therapy. Local Antimicrobial Stewardship Program strategies in health care settings could guide clinicians for early initiation of specific treatments to combat region-specific antimicrobial resistance, minimize adverse effects, and to improve outcomes such as reduction in Clostridium difficile infections. These strategies involving iv-to-oral switch, de-escalation to narrow-spectrum antibiotics, and dose optimization have an impact on the overall improvement of cSSTI therapy outcomes, especially in countries like Singapore that has a high disease burden.

Real-world daptomycin use across wide geographical regions: results from a pooled analysis of CORE and EU-CORE

Background

Pooled data from two large registries, Cubicin^® Outcomes Registry and Experience (CORE; USA) and European Cubicin^® Outcomes Registry and Experience (EU-CORE; Europe, Latin America, and Asia), were analyzed to determine the characteristics and clinical outcomes of daptomycin therapy in patients with Gram-positive infections across wide geographical regions.

Methods

Patients receiving at least one dose of daptomycin between 2004 and 2012 for the treatment of Gram-positive infections were included. Clinical success was defined as an outcome of ‘cured’ or ‘improved’. Post-treatment follow-up data were collected for a subset of patients (CORE: osteomyelitis and orthopedic foreign body device infection; EU-CORE: endocarditis, intracardiac/intravascular device infection, osteomyelitis, and orthopedic device infection). Safety was assessed for up to 30 days after daptomycin treatment.

Results

In 11,557 patients (CORE, 5482; EU-CORE, 6075) treated with daptomycin (median age, 62 [range, 1–103] years), the most frequent underlying conditions were cardiovascular disease (54.7 %) and diabetes mellitus (28.0 %). The most commonly treated primary infections were complicated skin and soft tissue infection (cSSTI; 31.2 %) and bacteremia (21.8 %). The overall clinical success rate was 77.2 % (uncomplicated SSTI, 88.3 %; cSSTI, 81.0 %; osteomyelitis, 77.7 %; foreign body/prosthetic infection (FBPI), 75.9 %; endocarditis, 75.4 %; and bacteremia, 69.5 %). The clinical success rate was 79.1 % in patients with Staphylococcus aureus infections (MRSA, 78.1 %). An increasing trend of high-dose daptomycin (>6 mg/kg/day) prescribing pattern was observed over time. Clinical success rates were higher with high-dose daptomycin treatment for endocarditis and FBPI. Adverse events (AEs) and serious AEs possibly related to daptomycin therapy were reported in 628 (5.4 %) and 133 (1.2 %) patients, respectively.

Conclusions

The real-world data showed that daptomycin was effective and safe in the treatment of various Gram-positive infections, including those caused by resistant pathogens, across wide geographical regions.

[Necrotising fasciitis in a patient with common variable immunodeficiency]

Necrotizing fasciitis is a severe infection that leads to necrosis of the tissues and systemic involvement, with a rapid progress and a fatal outcome. Although this condition is rare, it must be suspected and rapidly treated, as the prognosis depends on this. The treatment is based on immediate surgery, wide spectrum antibiotic treatment, and support measures in a critical care unit. We present the case of a patient who was admitted to Recovery room after surgical debridement due to suspicion of fasciitis. The patient also had a common variable immunodeficiency or hypogammaglobulinaemia, characterised by a B lymphocyte deficiency, as well as on treatment with methotrexate for Crohn's disease. Both produced an immune deficiency. After 11 days of treatment there was a clinical, analytical and haemodynamic improvement, and she was discharged.

Treatment of MRSA soft tissue infections: an overview

MRSA is becoming increasingly common worldwide. With the emergence of new highly spreadable strains (community associated or CA-MRSA) novel presentation skin and soft tissue infections (SSTI) are being seen. Recurrent SSTI, including folliculitis, furunculosis and abscesses account for an increasing proportion of SSTI seen in the emergency department. Empirical antimicrobial management choices can be difficult, but clues to the nature of the MRSA may be gleaned from the history and clinical presentation. More severe SSTI due to necrotising fasciitis and purpura fulminans are emerging and warrant the broadest possible empirical Gram-positive cover, ideally with antimicrobials that stop exotoxin production, and sometimes intravenous immunoglobulin to neutralise exotoxins already produced.

[Daptomycin for the treatment of Gram-positive microorganisms in the critically-ill patient]

INTRODUCTION

Infections caused by multiresistant Gram-positive cocci have increased among critically ill patients admitted to the intensive care unit (ICU). In the last few years, treatment of these infections has changed due to better knowledge of the limitations of glycopeptides and the introduction of novel antimicrobials, such as daptomycin.

OBJECTIVES

To describe the characteristics of daptomycin that justify its administration in critically ill patients and to present data on the use of this antibiotic in patients admitted to Spanish ICUs.

MATERIAL AND METHOD

We reviewed the literature on daptomycin to identify the characteristics that may favor clinical response in critically ill patients. To describe the indications and modalities of use in critically patients, information from the European Cubicin(®) Outcome Registry and Experience (EUCORE) database of Spanish patients admitted to the ICU was employed.

RESULTS

The following favorable conditions were identified: a) scarce systemic response, maintaining high bactericidal activity, b) scarce impact on renal function, c) no requirement for monitoring of plasma levels, d) scarce selection of resistance, and d) excellent tolerability. To assess indications and the use of this agent in the ICU, 122 patients from the EUCORE database were analyzed. The indications were bacteremias (36.2%), complicated infections of the skin and soft tissues (27.6%), and endocarditis (19%). Prominent pathogens were Staphylococcus aureus (26%), S. epidermidis (25%), and other coagulase-negative staphylococci (12%). In 85.7% of patients, treatment was administered as second-line (rescue treatment). In 65 patients (52%), a dose of 6 mg/kg/day was used, with a mean treatment duration of 10.2 days. Overall clinical efficacy was 73.7%. No adverse effects leading to treatment withdrawal were recorded and no increases in creatine phosphokinase (CPK) levels greater than 10-fold the initial values were observed.

CONCLUSIONS

Daptomycin is a novel therapeutic option to be considered in the treatment of severe infections caused by Gram-positive cocci in critically-ill patients.

Cost-effectiveness analysis of linezolid, daptomycin, and vancomycin in methicillin-resistant Staphylococcus aureus: complicated skin and skin structure infection using Bayesian methods for evidence synthesis

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) complicated skin and skin structure infection (cSSSI) is a prominent infection encountered in hospital and outpatient settings that is associated with high resource use for the health-care system.

OBJECTIVE

A decision analytic (DA) model was developed to evaluate the cost-effectiveness analysis (CEA) of linezolid, daptomycin, and vancomycin in MRSA cSSSI.

METHODS

Bayesian methods for evidence synthesis were used to generate efficacy and safety parameters for a DA model using published clinical trials. CEA was done from the US health-care perspective. Efficacy was defined as a successfully treated patient at the test of cure without any adverse reaction. Primary outcome was the incremental cost-effectiveness ratio between linezolid and vancomycin, daptomycin and vancomycin, and linezolid and daptomycin in MRSA cSSSI. Univariate and probabilistic sensitivity analyses were performed to test the robustness of the model.

RESULTS

The total direct costs of linezolid, daptomycin, and vancomycin were $18,057, $20,698, and $23,671, respectively. The cost-effectiveness ratios for linezolid, daptomycin, and vancomycin were $37,604, $44,086, and $52,663 per successfully treated patient, respectively. Linezolid and daptomycin were dominant strategies compared to vancomycin. However, linezolid was dominant when compared to daptomycin. The model was sensitive to the duration of daptomycin and linezolid treatment.

CONCLUSION

Linezolid and daptomycin are potentially cost-effective based on the assumptions of the DA model; however, linezolid appears to be more cost-effective compared to daptomycin and vancomycin for MRSA cSSSIs.

Complicated skin and soft tissue infections: literature review of evidence for and experience with daptomycin

Skin and soft tissue infections (SSTIs) are the second most common infection encountered in hospitals. Management decisions have become increasingly complex due to the prevalence of resistant pathogens, the wide array of licensed antimicrobials and the availability of potent oral agents and of out-patient parenteral antibiotic therapy. Daptomycin is one of the newer therapeutic agents licensed for complex SSTI management. Rapid cidality, good soft tissue penetration, once daily IV bolus administration and activity against resistant Gram-positive infections make daptomycin an attractive option both in hospitalized and community treated patients. A comprehensive review of the evidence for and experience with daptomycin and its use in SSTIs is presented.

Prospective, non-comparative study of daptomycin for the treatment of superficial and deep incisional surgical site infections

BACKGROUND

Skin infections, including surgical site infections (SSIs), usually involve gram-positive pathogens and continue to be a leading cause of morbidity and death among hospital patients. The increasing prevalence of methicillin-resistant Staphylococcus aureus and other resistant strains accentuates the need for effective and safe therapies for such infections. This exploratory study evaluated the efficacy and safety of daptomycin in patients with gram-positive SSI according to wound classification.

METHODS

Eligible patients had an SSI with onset < 30 days after surgery, positive gram stain or culture at least three days before daptomycin therapy began, and three or more clinical signs and symptoms of infection. The incisional SSI was classified as superficial or deep according to the U.S. Centers for Disease Control and Prevention criteria. Patients with organ-space infections were excluded, as were those with major concomitant infections, foreign material in the incision that could not be removed, previous systemic antimicrobial therapy, or creatinine clearance < 30 mL/min. Daptomycin 4 mg/kg was administered intravenously once daily for 7-14 days. The primary efficacy endpoint was clinical response at the end of daptomycin therapy, and the safety assessment was based on adverse events (AEs).

RESULTS

Sixty-nine patients were enrolled, 60 of whom were evaluable for efficacy. Extremity wounds predominated among superficial incisional SSIs (n = 30), whereas abdominal wounds predominated among deep SSIs (n = 30). Patients with deep incisional SSI were more likely to be young, male, white, and febrile and to weigh more than patients with superficial SSIs. The overall clinical success rate was 92% (95% confidence interval [CI] 82-97%); the success rate was 100% in superficial incisional SSI and 83% in deep SSI (17% difference; 95% CI 0-33%). Staphylococcus aureus (28/36 methicillin-resistant) was the pathogen isolated most frequently. In 10 patients who were febrile at baseline, the median time to defervescence was five days, and the mean duration of treatment in the series was 11.2 days. Daptomycin was well tolerated. In most patients, AEs were mild or moderate in intensity; in two patients (one superficial, one deep), daptomycin was discontinued because of AEs.

CONCLUSIONS

The results of this exploratory study of SSI are consistent with those of previous studies of daptomycin in the treatment of diverse complicated skin and skin-structure infections, and suggest that wound classification should be treated as an important covariate in future studies of daptomycin and other antibiotics.

Clinical experience with daptomycin in Europe: the first 2.5 years

Objectives

To describe the patient populations and infections being treated with daptomycin, as well as the efficacy and safety outcomes.

Patients and methods

Data from the European Cubicin Outcomes Registry and Experience (EU-CORE^SM), retrospectively collected at 118 institutions between January 2006 and August 2008, were analysed.

Results

Daptomycin treatment was documented in 1127 patients with diverse infections, including complicated skin and soft tissue infections (33%), bacteraemia (22%), endocarditis (12%) and osteomyelitis (6%). It was used empirically, before microbiological results became available, in 53% of patients. Staphylococcus aureus was the most common pathogen (34%), with 52% of isolates resistant to methicillin; coagulase-negative staphylococci and enterococci were also frequent, with 22% of Enterococcus faecium isolates resistant to vancomycin. Daptomycin was used as first-line therapy in 302 (27%) patients. When used second line, the most common reasons for discontinuation of previous antibiotic were treatment failure and toxicity or intolerance. The use of concomitant antibiotics was reported in 65% of patients. Most frequent doses were 6 mg/kg (47%) and 4 mg/kg (32%). The median duration of daptomycin therapy was 10 days (range 1–246 days) in the inpatient setting and 13 days (range 2–189 days) in the outpatient setting. The overall clinical success rate was 79%, with a clinical failure rate of <10% for all infection types. Low failure rates were observed in first- and second-line therapy (6% and 8%, respectively). Daptomycin demonstrated a favourable safety and tolerability profile regardless of treatment duration.

Conclusions

Daptomycin has a relevant role in the treatment of Gram-positive infections.

Daptomycin: a novel lipopeptide antibiotic against Gram-positive pathogens

The aim of this review is to summarize the historical background of drug resistance of Gram-positive pathogens as well as to describe in detail the novel lipopeptide antibiotic daptomycin. Pharmacological and pharmacokinetic aspects are reviewed and the current clinical use of daptomycin is presented. Daptomycin seems to be a reliable drug in the treatment of complicated skin and skin structure infections, infective right-sided endocarditis, and bacteremia caused by Gram-positive agents. Its unique mechanism of action and its low resistance profile, together with its rapid bactericidal action make it a favorable alternative to vancomycin in multi-drug resistant cocci. The role of daptomycin in the treatment of prosthetic material infections, osteomyelitis, and urogenital infections needs to be evaluated in randomized clinical trials.

A retrospective review of clinical experience with daptomycin for a variety of wound types in a burn and wound care facility

OBJECTIVE

Daptomycin is a novel antibiotic with activity against many Gram-positive organisms that has demonstrated efficacy in the management of skin and soft tissue infections (SSTIs). However, data regarding the use of daptomycin for the management of burn wound infections are lacking. We assessed the efficacy and safety of daptomycin in the treatment of complicated skin and soft tissue infections (cSSTIs), including burn wound infections.

METHODS

We performed a retrospective review of patients receiving daptomycin for burn wound infections and other cSSTIs in a referral burn and wound treatment center.

RESULTS

Our review revealed an overall success rate (microbiological cure + clinically improved) of 99.5%, with an overall success rate of 98.5% among burn patients, specifically. The overall success rate was 100% among patients in the three other diagnosis groups (cSSTIs, chronic wounds, and other infections). A success rate of 98% was noted among the subset of patients with wounds associated with bacteremia.

CONCLUSIONS

Our study suggests that daptomycin is a safe and effective agent for the management of burn wound infections, although further study is warranted to confirm these results.

A potential role for daptomycin in enterococcal infections: what is the evidence?

Nosocomial infections caused by enterococci present a challenge for clinicians because treatment options are often limited due to the widespread occurrence of strains resistant to multiple antibiotics, including vancomycin. Daptomycin is a first-in-class cyclic lipopeptide that has proven efficacy for the treatment of Gram-positive infections. Although methicillin-resistant Staphylococcus aureus has been the most prominent target in the clinical development of daptomycin, this agent has demonstrated potent bactericidal activity in enterococcal infection models and has been used for the treatment of enterococcal infections in humans. In recent years, large-scale susceptibility studies have shown that daptomycin is active against >98% of enterococci tested, irrespective of their susceptibility to other antibacterial agents. This lack of cross-resistance reflects the fact that daptomycin has a mode of action distinct from those of other antibiotics, including glycopeptides. While there are limited data available from randomized controlled trials, extensive clinical experience with daptomycin in enterococcal infections (including bacteraemia, endocarditis, skin and soft tissue infections, bone and joint infections and urinary tract infections) has been reported. This growing body of evidence provides useful insights regarding the efficacy of daptomycin against enterococci in clinical settings.

Daptomycin: pharmacology and clinical use

IMPORTANCE OF THE FIELD

Infections caused by Gram-positive organisms have increased in frequency and severity. Daptomycin offers a therapeutic option in an era of increasing resistance.

AREAS COVERED IN THIS REVIEW

Literature from 1986 to present was reviewed for pharmacological, preclinical and clinical studies on daptomycin.

WHAT THE READER WILL GAIN

The pharmacological properties, resistance mechanisms and clinical applications of daptomycin are discussed. Recommendations are offered on the use of this agent for the treatment of resistant Gram-positive infections.

TAKE HOME MESSAGE

Daptomycin is a reliable agent for the treatment of Gram-positive infections. It has been shown to be effective in bacteremia and endocarditis, as well as in soft-tissue infections caused by Gram-positive organisms. Its role in the treatment of bone and joint infections is not well-defined. Resistance is currently uncommon in clinical isolates. However, emergence of resistance during therapy is a concern. This may be prevented by use of higher doses.

New therapeutic choices for infections caused by methicillin-resistant Staphylococcus aureus

In recent years, a marked increase in the incidence of infections caused by methicillin-resistant Staphylococcus aureus (MRSA) has occurred in many countries. This review addresses the effectiveness and limitations of drugs classically used for the treatment of MRSA, e.g. vancomycin, and also newer anti-MRSA antimicrobials, e.g. second-generation glycolipopeptides, tigecycline, and beta-lactams.

Early appropriate parenteral antimicrobial treatment of complicated skin and soft tissue infections caused by methicillin-resistant Staphylococcus aureus

BACKGROUND

Complicated skin and soft tissue infections (cSSTIs) are a major clinical problem, in part because of the increasing resistance of infecting bacteria to our current antibiotic therapies. Prompt appropriate treatment of infections in hospitalized patients reduces the mortality rate. Furthermore, appropriate and timely antibiotic therapy improves outcomes for cSSTIs caused by methicillin-resistant Staphylococcus aureus (MRSA). This review delineates factors to consider in the choice of initial antibiotic treatment for cSSTIs and describes the antimicrobial agents available or under clinical development for the treatment of cSSTIs caused by MRSA.

METHODS

Review of the pertinent literature and recommendations.

RESULTS

The choice of antimicrobial agent for empiric treatment of cSSTIs should be guided by the site and type of infection, the presence of an immunocompromised state or neutropenia, and risk factors for hospital-acquired MRSA (HA-MRSA) or community-associated MRSA (CA-MRSA) infection. Most CA-MRSA strains remain susceptible to ciprofloxacin, clindamycin, gentamicin, and trimethoprim/sulfamethoxazole, although resistance to clindamycin can emerge during treatment. Of the agents available for the treatment of HA-MRSA cSSTIs, vancomycin has been the reference standard, but clinical failures have been reported increasingly. Alternative agents for HA-MRSA include linezolid, which has been well-studied for treatment of cSSTIs, as well as daptomycin and tigecycline. A number of antibiotic agents are undergoing clinical trials or are under development for the treatment of cSSTIs caused by MRSA.

CONCLUSIONS

Severe and progressive cSSTIs should be treated promptly with appropriate antibiotic agents. The choice of agent should be guided by a number of factors, including suspected CA-MRSA or HA-MRSA infection. Available agents should be evaluated carefully for efficacy in the treatment of MRSA cSSTIs.

Daptomycin: rationale and role in the management of skin and soft tissue infections

The emergence of community-associated methicillin-resistant Staphylococcus aureus (MRSA) and glycopeptide tolerance in S. aureus has underlined the importance of the newer anti-MRSA agents, particularly in the management of complicated skin and soft tissue infections (cSSTIs). The novel cyclic lipopeptide antibiotic daptomycin shows marked in vitro cidality against MRSA compared with both vancomycin and linezolid. Although comparative studies in cSSTIs have demonstrated non-inferiority with vancomycin and semi-synthetic penicillins, data from both clinical trials and observational studies suggest in vivo cidality as evidenced by rapid resolution of clinical signs of local inflammation and reduced duration of therapy. Overall success in SSTI post-marketing studies is >90%, and >88% in MRSA-infected patients, with no difference in the outcome observed between those with complicated versus uncomplicated infections. When used at licensed doses (4-6 mg/kg), daptomycin is safe and effective in SSTIs with significant muscle toxicity occurring in only 0.4% to 2.5% of patients. Clinical failure in daptomycin-treated SSTIs is associated with severity of infection (creatinine clearance <30 mL/min, intensive care unit stay and sepsis syndrome). Higher dosing at 6 mg/kg (with increased dosing interval in renal failure) should be considered in such patients as well as those at risk of bacteraemia, osteomyelitis, diabetic foot infection and in situations where there is more rapid drug clearance, such as infections complicating intravenous drug use and thermal burns. Once-daily dosing allows ease of use in both hospital and outpatient settings and may facilitate early discharge or avoided admission in some patient groups with SSTIs. Clinical experience to date suggests potential economic advantages associated with earlier hospital discharge and shorter duration of therapy, although further detailed cost-effectiveness comparisons are required to validate these observations in different healthcare settings.