The efficacy and safety of daptomycin vs. vancomycin for the treatment of cellulitis and erysipelas

Comparison of daptomycin and glycopeptide efficacy and safety for the treatment of Gram-positive infections: a systematic review and meta-analysis

BACKGROUND

The indications of daptomycin have been extended to off-label indications including prosthesis-related infection, and bone and joint infection (BJI). However, efficacy and safety have not been thoroughly demonstrated compared with the standard of care. This systematic review and meta-analysis aimed to compare the treatment effect of daptomycin and glycopeptides for complicated infections.

MATERIALS AND METHODS

MEDLINE, Embase and Web of Science were searched for randomized controlled trials (RCTs) comparing daptomycin and standard of care for Gram-positive infections, published until 30 June 2021. The primary outcome was defined as all-cause mortality. Secondary outcomes were clinical and microbiological success. The main safety outcome was any severe adverse event (SAE) (grade  ≥3).

RESULTS

Overall, eight RCTs were included in the meta-analysis, totalling 1095 patients. Six (75%) were in complicated skin and soft-structure infections, one (12.5%) in bacteraemia and one (12.5%) in a BJI setting. Six RCTs used vancomycin as a comparator and two used either vancomycin or teicoplanin. All-cause mortality and clinical cure were not different between groups. The microbiological cure rate was superior in patients who received daptomycin [risk ratio (RR) = 1.17 (95% CI: 1.01-1.35)]. The risk of SAEs [RR = 0.57 (95% CI: 0.36-0.90)] was lower in the daptomycin arm.

CONCLUSIONS

While daptomycin is associated with a significantly lower risk of SAEs and a better microbiological eradication, substantial uncertainty remains about the best treatment strategy in the absence of good-quality evidence, especially in bacteraemia and endocarditis where further RCTs should be conducted.

Contemporary pharmacologic treatments of MRSA for hospitalized adults: rationale for vancomycin versus non-vancomycin therapies as first line agents

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA) remains an important pathogen in the hospital setting and causes significant morbidity and mortality each year. Since the initial discovery over 60 years ago, vancomycin has remained a first-line treatment for many different types of MRSA infections. However, significant concerns related to target attainment and nephrotoxicity have spurred efforts to develop more effective agents in the last two decades.

AREAS COVERED

Newer anti-MRSA antibiotics that have been approved since 2000 include linezolid, daptomycin, and ceftaroline. As clinical evidence has accumulated, these newer agents have become more frequently used, and some are now recommended as co-first-line options (along with vancomycin) in clinical practice guidelines. For this review, a scoping review of the literature was conducted to support our findings and recommendations.

EXPERT OPINION

Vancomycin remains an important standard of care for MRSA infections but is limited with respect to nephrotoxicity and rapid target attainment. Newer agents such as linezolid, daptomycin, and ceftaroline have specific indications for treating different types of MRSA infections; however, newer agents also have unique attributes which require consideration during therapy.

Reporting of Drug-Induced Myopathies Associated with the Combination of Statins and Daptomycin: A Disproportionality Analysis Using the US Food and Drug Administration Adverse Event Reporting System

BACKGROUND

Myopathy is one of the most common adverse reactions of daptomycin and statins. We aimed to evaluate the muscular toxicity of the combination therapy of daptomycin and statins in a large pharmacovigilance database.

METHODS

This was a retrospective disproportionality analysis based on real-world data. All cases reported between the first quarter of 2004 and the fourth quarter of 2022 where daptomycin and statins were reported were gathered from the US Food and Drug Administration Adverse Event Reporting System (FAERS) database. Disproportionality analyses were conducted by estimating the proportional reporting ratios (PRRs), reporting odds ratio (ROR), and information component (IC).

RESULTS

A total of 971,861 eligible cases were collected from the FAERS database. Data analysis showed that rosuvastatin (ROR: 124.39, 95% CI: 87.35-178.47), atorvastatin (ROR: 68.53, 95% CI: 51.93-90.43), and simvastatin (ROR: 94.83, 95% CI: 71.12-126.46) combined with daptomycin increased the reporting frequency of myopathy. Moreover, myopathy was reported more frequently with the 3-drug combination (ROR: 598.01, 95% CI: 231.81-1542.71). For rhabdomyolysis, the frequency of reports also increased when daptomycin was combined with rosuvastatin (ROR: 156.34, 95% CI: 96.21-254.05), simvastatin (ROR: 72.65, 95% CI: 47.36-111.44), and atorvastatin (ROR: 66.31, 95% CI: 44.06-99.81).

CONCLUSIONS

The combination of daptomycin and statins increased the association of myopathy and rhabdomyolysis, especially with rosuvastatin, simvastatin, and atorvastatin.

Insufficient Representation of Patients With Obesity in Randomized Controlled Trials Evaluating the Efficacy and Safety of Antimicrobials for Treatment of Skin and Skin Structure Infections: A Scoping Review

Persons with obesity (PwO) represent approximately 50% of acute bacterial skin and skin structure infections (ABSSSIs) in the United States (US). There are currently insufficient data in PwO for drugs used for ABSSSIs. We conducted a scoping review of randomized controlled trials (RCTs) published between 2000 and 2022 to describe how frequently body size measures were reported. Weight and/or body mass index (BMI) were recorded in approximately 50% of the 69 RCTs. The average weights or BMIs were lower than US averages for most RCTs reporting data. None evaluated the impact of body size on outcomes in the original publication. Only 30% of newly approved drugs mention PwO representation in the prescribing information. More representative recruitment of PwO into RCTs is needed to help clinicians evaluate efficacy in these patients. We suggest that the Food and Drug Administration require companies to submit plans to ensure adequate PwO inclusion and that authors of RCTs report subgroup results based on body size.

Efficacy and safety of optional parenteral antimicrobial therapy for complicated skin and soft tissue infections: A systematic review and Bayesian network meta-analysis

BACKGROUND

Skin and soft tissue infections (SSTIs) carry significant economic burden, as well as morbidity and mortality, especially when caused by methicillin-resistant Staphylococcus aureus. This study aims to investigate the efficacy and safety of optional antimicrobial therapy for the treatment of complicated SSTIs (cSSTIs).

METHODS

We searched PubMed, Medline (Via Ovid SP), Embase (Via Ovid SP), and the Cochrane Central Register of Controlled Trials from their inception to March 22, 2021 for randomized controlled trials (RCTs) that studied the use of optional antimicrobial therapy for cSSTIs. Citations' screening, study selection, data extraction, and risk of bias assessment were independently performed by 2 authors. The primary outcomes were clinical and microbiological treatment success, and adverse events (AEs) were also assessed.

RESULTS

A total of 48 trials covering 24,381 patients assessing 20 types of antimicrobial treatment modalities were included. Overall, omadacycline was associated with the highest beneficial effect on clinical and microbiological treatment success and with the largest rank probability based on surface under the cumulative ranking curve values, avarofloxacin was closely followed. Both had, however, omadacycline was related to moderately safety profiles. Lefamulin ranked as the best option was associated with the lowest risk of severe AEs. Subgroup analysis showed similar results. The quality of primary outcomes was moderate to low.

CONCLUSIONS

The use of omadacycline was associated with higher rates of clinical and microbiological treatment success for the treatment of cSSTIs, with a relative low risk of AEs. Due to the limitations of the included RCTs, high-quality and well-designed RCTs are needed to further confirm the results.

The impact of antibiotics on clinical response over time in uncomplicated cellulitis: a systematic review and meta-analysis

PURPOSE

Antibiotic treatment of uncomplicated cellulitis is highly variable with respect to agent, dose, and route of administration. As there is uncertainty about optimal/appropriate time to reassess, we aimed to assess time to clinical response.

METHODS

We conducted a systematic review of randomized controlled trials reporting clinical response of uncomplicated cellulitis to antibiotic treatment over multiple timepoints. PubMed, Embase, CENTRAL, WHO ICTRP, and clinicaltrials.gov were searched from inception to June 2021 without language restrictions. The primary outcome was time to clinical response. Other outcomes were components of clinical response (pain, severity score, redness, edema measured at ≥ 2 timepoints) and the proportion of patients with treatment failure. We performed a pooled estimate of the average time to clinical response together with 95% confidence intervals using a random effects model.

RESULTS

We included 32 randomized controlled trials (n = 13,576 participants). The mean time to clinical response was 1.68 days (95%CI 1.48-1.88; I² = 76%). The response to treatment for specific components was as follows: ~ 50% reduction of pain and severity score by day 5, a ~ 33% reduction in area of redness by day 2-3, and a 30-50% reduction of proportion of patients with edema by day 2-4. Treatment failure was variably defined with an overall failure rate of 12% (95%CI 9-16%).

CONCLUSION

The best available data suggest the optimal time to clinical reassessment is between 2 and 4 days, but this must be interpreted with caution due to considerable heterogeneity and small number of included studies.

Factors affecting creatine phosphokinase elevation during daptomycin therapy using a combination of machine learning and conventional methods

AIMS

Musculoskeletal toxicity is a typical side effect of daptomycin (DAP). However, the risk factors have not been well established. Here, we aimed to identify independent factors affecting DAP-induced musculoskeletal toxicity using a combination of machine learning and conventional statistical methods.

METHODS

A population-based, retrospective, observational cohort study was conducted using the Japanese electronic medical record database. Patients who received DAP between October 2011 and December 2020 were enrolled. Two definitions of musculoskeletal toxicity were employed: (1) elevation of creatine phosphokinase (CPK) value more than twice from baseline and >200 IU/L, and (2) >1000 IU/L. First, multiple logistic regression analyses (a conventional statistical method) were performed to identify independent factors affecting CPK elevation. Then, decision tree analyses, a machine learning method, were performed to detect combinations of factors that change CPK elevation risk.

RESULTS

Of the 2970 patients who received DAP, 706 were included. Elevation of CPK values >200 IU/L and >1000 IU/L occurred in 83 (11.8%) and 17 (2.41%) patients, respectively. In multiple logistic regression analysis, baseline CPK value and concomitant use of hydrophobic statins were commonly extracted as independent factors affecting each CPK elevation, but concomitant use of hydrophilic statins was not. In decision tree analysis, patients who received hydrophobic statins and had high baseline CPK values were classified into the high-risk group.

CONCLUSION

Our novel approach revealed new risk factors for CPK elevation. Our findings suggest that high-risk patients require frequent CPK monitoring.

Comparative Efficacy and Safety of Vancomycin, Linezolid, Tedizolid, and Daptomycin in Treating Patients with Suspected or Proven Complicated Skin and Soft Tissue Infections: An Updated Network Meta-Analysis

Introduction

Skin and soft structure infections (SSTIs) caused by methicillin-resistant Staphylococcus aureus (MRSA) pose serious health risks and cause significant cost burdens, and a conclusive recommendation about antibiotics has not yet been generated. Therefore, we performed this updated network meta-analysis to determine the preferred drug for the treatment of MRSA-caused SSTIs.

Methods

We searched PubMed, Embase, and Cochrane Library to identify any potentially eligible randomized controlled trials (RCTs) investigating the comparative efficacy and safety of any two of vancomycin, linezolid, tedizolid, and daptomycin in MRSA-caused SSTIs. All statistical analyses were conducted with RevMan, ADDIS, and STATA software.

Results

Twenty eligible RCTs involving 7804 patients were included for the final analysis. Direct meta-analysis suggested that linezolid was superior to vancomycin in improving clinical (odds ratio [OR], 1.46; 95% confidence interval [CI], 1.07–1.99; P = 0.02) and microbiological (OR, 1.89; 95% CI, 1.24–2.86; P = 0.003) success, which were all confirmed by network meta-analyses. No statistical differences were identified regarding other comparisons. Meanwhile, there were no significant differences between any two antibiotics related to safety. Moreover, ranking probabilities indicated that linezolid had the highest probability of being ranked best in terms of clinical and microbiological success.

Conclusion

Based on the limited evidence, linezolid may be a preferred antibiotic for the treatment of MRSA-caused SSTIs because it showed superiority in clinical and microbiological success without difference regarding safety.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-021-00456-0.

Is coverage of S. aureus necessary in cellulitis/erysipelas? A literature review

BACKGROUND

Empirical treatment of patients with cellulitis/erysipelas usually targets both streptococci and methicillin-sensitive S. aureus (MSSA). However, the recommendation to empirically cover MSSA is weak and based on low-quality evidence.

METHODS AND OBJECTIVE

A systematic review was conducted in PubMed and clinical trial registries to assess the role of S. aureus in cellulitis/erysipelas and the need for empirical MSSA coverage.

RESULTS

Combined microbiological and serological data, and response to penicillin monotherapy suggest that streptococci are responsible for the vast majority of cases of cellulitis/erysipelas. However, most cases are non-culturable and the specificity of microbiological and serological studies is questionable based on recent studies using molecular techniques. According to epidemiological data and three randomized controlled trials, empirical coverage of methicillin-resistant S. aureus (MRSA) is not recommended for most patients, despite the high prevalence of MRSA in many areas. If MRSA is indeed not an important cause of uncomplicated cellulitis/erysipelas, then the same may apply to MSSA. Based on indirect comparison of data from clinical studies, cure rates with penicillin monotherapy (to which most MSSA are resistant) are comparable to the cure rates reported in many studies using wider-spectrum antibiotics.

CONCLUSION

Considering the limitations of microbiological studies in identifying the pathogens responsible for cellulitis/erysipelas, treatment needs to be guided by clinical trials. Trials comparing penicillin or amoxicillin monotherapy to MSSA-covering regimens are needed to definitively answer whether empirical coverage of MSSA is needed and to identify the subset of patients that can be safely treated with penicillin or amoxicillin monotherapy.

Efficacy and safety of daptomycin: systematic review and meta-analysis

Background:

The aim of this study was to assess whether daptomycin is safer and more efficacious than comparators for the treatment of serious infection caused by gram-positive microorganisms.

Methods:

Electronic databases (Medline, EMBASE, the Cochrane Central Register of Controlled Trials and clinical registered trials) were searched to identify randomized controlled trials (RCTs) that assessed the efficacy and safety of daptomycin versus therapy with any other antibiotic comparator. Two reviewers independently applied selection criteria, performed a quality assessment and extracted the data. Heterogeneity was assessed, and a random-effects or fixed-effects model, when appropriate, was used for estimates of risk ratio (RR). The primary outcome assessed was the risk of clinical treatment failure among the intention-to-treat population and the presence of any treatment related adverse event (AEs).

Results:

A total of seven trials fulfilled the inclusion criteria. Daptomycin treatment failure rates were no different to comparator regimens (RR = 0.96; CI 95% 0.86–1.06). No significantly different treatment related AEs were identified when comparing groups (RR = 0.91; CI 95% 0.83–1.01).

Conclusions:

No significant differences in treatment failure rates and safety were found using daptomycin or any of the comparators treatment.

Effect of Statin Coadministration on the Risk of Daptomycin-Associated Myopathy

Background

Daptomycin-associated myopathy has been identified in 2%-14% of patients, and rhabdomyolysis is a known adverse effect. Although risk factors for daptomycin-associated myopathy are poorly defined, creatine phosphokinase (CPK) monitoring and temporary discontinuation of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, or "statins," has been recommended.

Methods

We conducted a single-center, retrospective, matched case-control risk factor analysis in adult and pediatric patients from 2004 to 2015. Patients in whom myopathy (defined as CPK values above the upper limit of normal) developed during daptomycin treatment were matched 1:1 to no-myopathy controls with at least the same duration of therapy. Risk factors independently associated with myopathy were determined using multivariable conditional logistic regression. Secondary analysis was performed in patients with rhabdomyolysis, defined as CPK values ≥10 times the upper limit of normal.

Results

Of 3042 patients reviewed, 128 (4.2%) were identified as having daptomycin-associated myopathy, 25 (0.8%) of whom had rhabdomyolysis; 121 (95%) of the 128 were adults, and the mean duration of therapy before CPK elevation was 16.7 days (range, 1-58 days). In multivariate analysis, deep abscess treatment (odds ratio, 2.80; P = .03), antihistamine coadministration (3.50; P = .03), and statin coadministration (2.60; P = .03) were independent risk factors for myopathy. Obesity (odds ratio, 3.28; P = .03) and statin coadministration (4.67; P = .03) were found to be independent risk factors for rhabdomyolysis, and older age was associated with reduced risk (0.97; P = .05).

Conclusions

Statin coadministration with daptomycin was independently associated with myopathy and rhabdomyolysis. This is the first study to provide strong evidence supporting this association. During coadministration, we recommend twice-weekly CPK monitoring and consideration of withholding statins.

Quaternary ammonium-induced multidrug tolerant Streptococcus mutans persisters elevate cariogenic virulence in vitro

Dental caries are the most prevalent chronic infections in the oral cavity, and Streptococcus mutans acts as the main cariogenic bacterial species. Antibacterial quaternary ammonium compounds (QAs) have been developed to preveFnt or treat dental caries. However, there is no report on the tolerance of S. mutans to QAs. In this study, we investigated the development of S. mutans persistence induced by a novel dental caries defensive agent, dimethylaminododecyl methacrylate (DMADDM), for the first time. Typical biphasic killing kinetics for persisters were observed in both S. mutans planktonic and biofilm cultures challenged by DMADDM at concentrations of 20 and 200 μg·mL-1, respectively. The persisters tolerated six other antibiotics with different antibacterial mechanisms, while only daptomycin and vancomycin could slightly reduce the persister numbers in planktonic cultures. The distribution of persisters in DMADDM-treated biofilms was similar to that in the untreated control, except that the total biomass and biofilm height were significantly reduced. A higher exopolysaccharides (EPS):bacteria ratio was observed in DMADDM-treated biofilms. Persisters in biofilms significantly upregulated gtf gene expression, indicating an increase in the bacteria's ability to produce EPS and an elevated capability of cariogenic virulence. Carbon source metabolism was significantly reduced, as related metabolic genes were all downregulated in persisters. Concentrations of 0.1 mM, 1 mM and 10 mM of extra glucose significantly reduced the number of persisters both in planktonic and biofilm conditions. The formation of non-inheritable and multidrug tolerant persisters induced by DMADDM suggested that drug tolerance and new persistent eradication strategies should be considered for oral antibacterial agents.

A double-blind randomized controlled trial of ibuprofen compared to placebo for uncomplicated cellulitis of the upper or lower limb

OBJECTIVES

Cellulitis is a common skin infection resulting in inflammation that may take weeks to resolve despite appropriate antibiotics. It is unclear whether the adjunctive use of nonsteroidal anti-inflammatory drugs hastens the resolution of inflammation in patients with cellulitis.

METHODS

We conducted a double-blind, randomized controlled trial comparing ibuprofen 400 mg three times daily for 5 days with identical placebo in adults with uncomplicated cellulitis of the upper or lower limb who were treated with intravenous cefazolin via an outpatient parenteral antibiotic treatment service at one of two Australian hospitals. Participants were assessed twice daily by a study nurse. The primary outcome measure was the proportion of patients with regression of inflammation 48 hours after the first effective dose of parenteral antibiotics (trial registration ANZCTR 12611000515998).

RESULTS

Fifty-one patients were enrolled; 48 had sufficient data available to be included in the modified intention-to-treat analysis. Inflammation had begun to regress at 48 hours in 20 participants (80%) in the ibuprofen group compared to 15 (65%) in the placebo group (absolute risk difference +15%; 95% confidence interval -10 to +40; p >0.05). There was no significant difference in any secondary outcome. Ibuprofen appeared safe, with no patients developing renal impairment or necrotizing fasciitis.

CONCLUSIONS

This trial demonstrated no significant benefit of adjunctive ibuprofen in adults with uncomplicated cellulitis. The trial was powered to detect a large effect, and hence it is unclear whether the 15% absolute increase in the primary end point in the ibuprofen group was attributable to chance.

Systematic review and network meta-analysis of tedizolid for the treatment of acute bacterial skin and skin structure infections caused by MRSA

BACKGROUND

Tedizolid, the active moiety of tedizolid phosphate, is approved in the United States, the European Union, Canada and a number of other countries for the treatment of acute bacterial skin and skin structure infections (ABSSSI) caused by certain susceptible bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). This network meta-analysis (NMA) evaluates the comparative effectiveness of tedizolid and other antibacterials indicated for the treatment of ABSSSI caused by MRSA.

METHODS

Systematic review of 10 databases was undertaken to inform an NMA to estimate the relative effectiveness of tedizolid and established monotherapy comparators (ceftaroline, daptomycin, linezolid, teicoplanin, tigecycline, vancomycin) for treating MRSA-associated ABSSSI. Randomized controlled trials enrolling adults with ABSSSI or complicated skin and skin structure infections caused by suspected/documented MRSA were eligible for inclusion. Networks were developed based on similarity of study design, patient characteristics, outcome measures and available data. Outcomes of interest included clinical response at end of therapy (EOT), post-therapy evaluation (PTE) or test-of-cure assessment and treatment discontinuations resulting from adverse events (AEs). Bayesian NMA was conducted for each outcome using fixed-effects and random effects models.

RESULTS

Literature searches identified 3,618 records; 15 trials met the inclusion criteria and were considered suitable for NMA comparison. In fixed-effects models, tedizolid had higher odds of clinical response at EOT (odds ratio [OR], 1.7; credible interval, 1.0, 3.0) and PTE than vancomycin (OR, 1.6; credible interval, 1.1, 2.5). No differences in odds of clinical response at EOT or PTE were observed between tedizolid and other comparators. There was no evidence of a difference among treatments for discontinuation due to AEs. Results from random effects and fixed-effects models were generally consistent.

CONCLUSIONS

Tedizolid was superior to vancomycin for clinical response at EOT and PTE. There was no evidence of a difference between tedizolid and other comparators and no evidence of a difference between tedizolid and all comparators when evaluating discontinuation due to AEs. These findings suggest that tedizolid provides an alternative option for the management of serious skin infections caused by suspected or documented MRSA. This study is subject to the limitations inherent in all NMAs, and the results should be interpreted accordingly.

Efficacy and safety of daptomycin for skin and soft tissue infections: a systematic review with trial sequential analysis

Background

Skin and soft tissue infections (SSTIs) are significant indications for antibiotic treatment. Daptomycin, a novel antibiotic, has been registered and licensed to be used in the treatment of these infections. However, its efficacy and safety remain controversial.

Objective

The objective of this study was to conduct a systematic review with trial sequential analysis (TSA) to evaluate the efficacy and safety of daptomycin for the treatment of SSTIs and to analyze whether the available sample size has been large enough and is conclusive.

Methods

PubMed, the Cochrane Library, and EMBASE were searched for published randomized controlled trials (RCTs) that compared daptomycin with other antibiotics in adult patients with SSTIs up to February 2016.

Results

This meta-analysis included eight randomized controlled trials (n=2,002). There was no difference in either the clinical success rate (intention-to-treat population: relative risk [RR] =1.04, 95% confidence interval [CI] =0.99–1.10, P=0.12; clinically evaluable population: RR =1.00, 95% CI =0.97–1.04, P=0.82) or the microbiological success rate (RR =1.00, 95% CI =0.95–1.06, P=0.92) between the daptomycin and comparator groups for treating SSTIs, which was confirmed by TSA. Compared with vancomycin, daptomycin exhibited no advantage in increasing the clinical success rate (RR =1.03, 95% CI =0.95–1.13, P=0.47), and this was also confirmed by TSA. All-cause mortality, overall treatment-related adverse events, and creatine phosphokinase events were similar between these two groups.

Conclusion

Daptomycin and comparator drugs are equally efficacious with regard to clinical and microbiological success for patients with SSTIs, and TSA showed that no additional randomized controlled trials are required. Although daptomycin is a good alternative when other antibiotics are contraindicated for patients with SSTIs and it can serve as a first-line treatment for SSTIs, clinicians should be aware of potential adverse events, such as daptomycin-induced acute eosinophilic pneumonia and creatine phosphokinase, when treating patients with daptomycin.

Failure of antibiotics in cellulitis trials: a systematic review and meta-analysis

OBJECTIVES

The objectives of the study are to quantify trial-to-trial variability in antibiotic failure rates, in randomized clinical trials of cellulitis treatment and to provide a point estimate for the treatment failure rate across trials.

METHODS

We conducted a structured search for clinical trials evaluating antibiotic treatment of cellulitis, indexed in PubMed by August 2015. We included studies published in English and excluded studies conducted wholly outside of developed countries because the pathophysiology of cellulitis is likely to be different in such settings. Two authors reviewed all abstracts identified for possible inclusion. Of studies identified initially, 5% met the selection criteria. Two reviewers extracted data independently, and data were pooled using the Freeman-Tukey transformation under a random-effects model. Our primary outcome was the summary estimate of treatment failure across intent-to-treat and clinically evaluable participants.

RESULTS

We included 19 articles reporting data from 20 studies, for a total of 3935 patients. Treatment failure was reported in 6% to 37% of participants in the 9 trials reporting intent-to-treat results, with a summary point estimate of 18% failing treatment (95% confidence interval, 15%-21%). In the 15 articles evaluating clinically evaluable participants, treatment failure rates ranged from 3% to 42%, and overall, 12% (95% confidence interval, 10%-14%) were designated treatment failures.

CONCLUSIONS

Treatment failure rates vary widely across cellulitis trials, from 6% to 37%. This may be due to confusion of cellulitis with its mimics and perhaps problems with construct validity of the diagnosis of cellulitis. Such factors bias trials toward equivalence and, in routine clinical care, impair quality and antibiotic stewardship. Objective diagnostic tools are needed.

Daptomycin: an evidence-based review of its role in the treatment of Gram-positive infections

Infections caused by Gram-positive pathogens remain a major public health burden and are associated with high morbidity and mortality. Increasing rates of infection with Gram-positive bacteria and the emergence of resistance to commonly used antibiotics have led to the need for novel antibiotics. Daptomycin, a cyclic lipopeptide with rapid bactericidal activity against a wide range of Gram-positive bacteria including methicillin-resistant Staphylococcus aureus, has been shown to be effective and has a good safety profile for the approved indications of complicated skin and soft tissue infections (4 mg/kg/day), right-sided infective endocarditis caused by S. aureus, and bacteremia associated with complicated skin and soft tissue infections or right-sided infective endocarditis (6 mg/kg/day). Based on its pharmacokinetic profile and concentration-dependent bactericidal activity, high-dose (>6 mg/kg/day) daptomycin is considered an important treatment option in the management of various difficult-to-treat Gram-positive infections. Although daptomycin resistance has been documented, it remains uncommon despite the increasing use of daptomycin. To enhance activity and to minimize resistance, daptomycin in combination with other antibiotics has also been explored and found to be beneficial in certain severe infections. The availability of daptomycin via a 2-minute intravenous bolus facilitates its outpatient administration, providing an opportunity to reduce risk of health care-associated infections, improve patient satisfaction, and minimize health care costs. Daptomycin, not currently approved for use in the pediatric population, has been shown to be widely used for treating Gram-positive infections in children.

Randomized Controlled Noninferiority Trial Comparing Daptomycin to Vancomycin for the Treatment of Complicated Skin and Skin Structure Infections in an Observation Unit

BACKGROUND

Incidence of methicillin-resistant Staphylococcus aureus (MRSA) is increasing in complicated skin and skin structure infection (cSSSI) presenting to emergency departments (EDs). Treatment is heterogeneous and can require inpatient admission to an observation unit (OU). Vancomycin is commonly used in the OU for treatment, but increasing MRSA resistance to vancomycin suggests the need for alternatives. Daptomycin is an alternative but it is not known how it compares with vancomycin.

OBJECTIVE

This study tested the hypothesis that daptomycin is noninferior to vancomycin for the treatment of cSSSI in an OU, using a relative risk (RR) of 1.3 as the noninferiority limit.

METHODS

Subjects admitted to an ED-based OU with a diagnosis of cSSSI were eligible. Consenting subjects were randomized 1:1 to intravenous (i.v.) vancomycin at 15 mg/kg dosing every 12 h or i.v. daptomycin at 4 mg/kg once. Subjects were followed until they met objective criteria for discharge home or hospital admission. Discharged patients were prescribed 10-14 days of oral cephalexin and trimethoprim-sulfamethoxazole, or clindamycin if allergic to either of these medications. The primary endpoint was meeting objective discharge criteria with no change in antibiotic therapy or return to the ED for the same cellulitis within 30 days of OU discharge.

RESULTS

There were 100 patients enrolled. RR for satisfying the endpoint was 1.07 (95% confidence interval 0.58-1.98) for daptomycin compared with vancomycin. Hospital admission rates were 36% and 32% for daptomycin and vancomycin treatment, respectively.

CONCLUSION

Daptomycin was not inferior to vancomycin in the treatment of cSSSI in an OU.

Comparative efficacy of antibiotics for the treatment of acute bacterial skin and skin structure infections (ABSSSI): a systematic review and network meta-analysis

OBJECTIVE

The objective was to conduct a systematic review and network meta-analysis (NMA) of existing treatments for ABSSSI focusing on the novel lipoglycopeptide oritavancin.

METHODS

EMBASE, MEDLINE, MEDLINE in Process, CENTRAL (Cochrane), and select conferences were searched for randomized controlled trials investigating antimicrobial agents for the treatment of ABSSSI. NMA was used to estimate the odds ratios of the Test-Of-Cure (TOC) and Early Clinical Response (ECR) outcomes for treatments relative to vancomycin in the ITT populations. Sub-group analyses in MRSA and MSSA populations were conducted for TOC; sensitivity analyses investigated the use of the clinically evaluable (CE) populations and the restriction to trials following the recent FDA guidelines for clinical trials.

RESULTS

The systematic review identified 52 trials. The most commonly investigated treatments were vancomycin and linezolid; most trials reported TOC, but not ECR. The posterior mean and 95% credible intervals for odds ratios of TOC for antimicrobial agents relative to vancomycin were: linezolid (1.55; 0.91-2.57), daptomycin (2.18; 0.90-5.42), and oritavancin 1200 mg (1.06; 0.80-1.43). The odds ratio of ECR for oritavancin 1200 mg was 1.02 (0.23-4.33). In the MRSA sub-group the odds ratios relative to vancomycin for TOC were: linezolid (1.55; 0.96-2.46), daptomycin (0.74; 0.13-3.66), and oritavancin 1200 mg (0.94; 0.44-2.02). In the MSSA sub-group they were linezolid (1.36; 0.15-13.34) and oritavancin 1200 mg (0.82; 0.08-7.83). These results were robust to the sensitivity analyses.

CONCLUSIONS

This NMA provides a unified framework for the comparison of all available antimicrobial agents used in the treatment of ABSSSI and is the first to assess the ECR end-point. The results suggest equivalence of clinical efficacy between vancomycin, daptomycin, linezolid, and novel antimicrobial agents including oritavancin for the treatment of ABSSSI at TOC. The wide uncertainty margins indicate the heterogeneity of the available evidence and the need for further research.

Oral versus parenteral antimicrobials for the treatment of cellulitis: a randomized non-inferiority trial

OBJECTIVES

To determine whether outcomes for patients with cellulitis treated with oral antimicrobials are as good as for those who are treated with parenteral antimicrobials.

METHODS

A prospective randomized non-inferiority trial was conducted at a tertiary teaching hospital in Melbourne, Australia. Participants were patients referred by the emergency department for treatment of uncomplicated cellulitis with parenteral antimicrobials. Patients were randomized to receive either oral cefalexin or parenteral cefazolin. Parenteral antimicrobials were changed to oral after the area of cellulitis ceased progressing. The primary outcome was days until no advancement of the area of cellulitis. A non-inferiority margin of 15% was set for the oral arm compared with the parenteral arm. Secondary outcomes were failure of treatment, pain, complications and satisfaction with care. This trial is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12611000685910).

RESULTS

Twenty-four patients were randomized to oral antimicrobials and 23 to parenteral antimicrobials. Mean days to no advancement of cellulitis was 1.29 (SD 0.62) for the oral arm and 1.78 (SD 1.13) for the parenteral arm, with a mean difference of -0.49 (95% CI: -1.02 to +0.04). The upper limit of the 95% CI of the difference in means of +0.04 was below the 15% non-inferiority margin of +0.27 days, indicating non-inferiority. More patients failed treatment in the parenteral arm (5 of 23, 22%) compared with the oral arm (1 of 24, 4%), although this difference was not statistically significant (P=0.10). Pain, complications and satisfaction with care were similar for both groups.

CONCLUSIONS

Oral antimicrobials are as effective as parenteral antimicrobials for the treatment of uncomplicated cellulitis.

Ceftaroline fosamil for the treatment of acute bacterial skin and skin structure infections in obese patients

BACKGROUND

Ceftaroline fosamil is a broad-spectrum antibiotic approved by the US Food and Drug Administration (FDA) for the treatment of acute bacterial skin and skin structure infections (ABSSSIs) and community-acquired bacterial pneumonia. The Clinical Assessment Program and Teflaro Utilization Registry (CAPTURE) is a multicenter registry study of patients treated with ceftaroline fosamil in the United States for ABSSSI or community-acquired bacterial pneumonia.

OBJECTIVE

To describe the clinical effectiveness of ceftaroline fosamil in the treatment of ABSSSI in obese patients [body mass index (BMI) ≥ 30] compared with patients with a normal BMI (18.5 to ≤ 24.9).

METHODS

Data were collected at US study centers by randomly ordered chart review.

RESULTS

Data from 261 patients with a normal BMI and 690 patients with an obese BMI were collected. The percentage of males was higher in the normal BMI than in the obese category (58.2% and 49.0%, respectively). The mean and median ages at baseline were similar. Most patients (91%) were treated on a general hospital ward, and the mean and median lengths of stay were similar between the 2 groups (approximately 11 days and 7 days, respectively). A total of 73.2% of normal BMI patients and 77.5% of obese patients were discharged to home. Rates of diabetes mellitus were 26.4% in the normal BMI group and 55.1% in the obese group. Methicillin-resistant Staphylococcus aureus was isolated from 26.1% of normal BMI patients and 20.5% of obese patients (16.4% morbidly obese subset). Mean treatment duration for all patients was 5.9 days. Of patients with a normal BMI, 57.5% received ceftaroline fosamil as monotherapy as did 63.3% of obese patients. Clinical success was high in both the normal BMI (85.1%) and the obese (89.0%) groups.

CONCLUSION

Ceftaroline fosamil is an effective treatment option for obese patients with ABSSSI with a similar clinical success rate, mean and median length of stay, and discharge destination to home when compared with normal BMI patients.

The safety and efficacy of daptomycin versus other antibiotics for skin and soft-tissue infections: a meta-analysis of randomised controlled trials

OBJECTIVE

Daptomycin, a cyclic lipopeptide that exhibits rapid, concentration-dependent bactericidal activity in vitro against a broad spectrum of Gram-positive pathogens, has now, since 2003, been approved in more than 70 countries and regions to treat skin and soft-tissue infections (SSTIs). The purpose of this meta-analysis was to compare the safety and efficacy of daptomycin with other antibiotics, especially with vancomycin which has long been considered the standard therapy for complicated SSTIs.

DESIGN

Meta-analysis of randomised controlled trials (RCTs).

DATA SOURCES

We thoroughly searched PubMed, EMBASE, Cochrane Central to identify relevant RCTs. Six RCTs with a total of 1710 patients were included in this meta-analysis.

RESULTS

The results demonstrated that the efficacy of daptomycin was at par with or maybe better than other first-line antibiotics for treating SSTIs as shown by the OR for clinical success (OR=1.05, 95% CI 0.84 to 1.31, p=0.65, I(2)=0%); daptomycin versus vancomycin subgroup (OR=1.19, 95% CI 0.77 to 1.83, p=0.43, I(2)=0%); overall microbiological success (OR=1.05, 95% CI 0.61 to 1.79, p=0.86, I(2)=42%); microbiological success of daptomycin versus comparators for Staphylococcus aureus (SA, OR=1.05, 95% CI 0.61 to 2.60, p=0.53, I(2)=47%), for methicillin-resistant S. aureus (OR=0.90, 95% CI 0.77 to 1.06, p=0.20, I(2)=56%). However, daptomycin tended to have a similar treatment-related adverse events (AEs) incidence in comparison with other antibiotics (OR=1.06, 95% CI 0.71 to 1.59, p=0.76, I(2)=41%). The trend showed that daptomycin might cause less discontinuation due to AEs and death compared with other first-line antibiotics (OR=0.71, 95% CI 0.46 to 1.10, p=0.12, I(2)=11%). Significantly more patients in the daptomyicn group had creatine phosphokinase elevation than those in the control group; however, it could be reversed when the therapy ended (OR=1.95, 95% CI 1.04 to 3.65, p=0.04, I(2)=0).

CONCLUSIONS

This meta-analysis demonstrated that the safety and efficacy of daptomycin was not inferior to that of other first-line drugs, and daptomycin tended to exhibit superior efficacy when compared with vancomycin or with comparators for SA infections; nevertheless, more high-quality RCTs are needed to draw a more credible conclusion.

Medical management of diabetic foot infections

Diabetic foot infections (DFIs) are a commonly encountered medical problem. They are associated with an increased frequency and length of hospitalization and risk for lower-extremity amputation. Furthermore, they have substantial economic consequences. Patients with diabetes mellitus are particularly susceptible to foot infections because of neuropathy, vascular insufficiency, and diminished neutrophil function. The approach to managing DFIs starts with determining if an infection exists. If an infection exists, then the type, severity, extent of infection, and risk factors for resistant organisms should be determined through history, physical examination, and additional laboratory and radiological testing. Optimal management requires surgical debridement, pressure offloading, effective antibiotic therapy, wound care and moisture, maintaining good vascular supply, and correction of metabolic abnormalities, such as hyperglycemia, through a multidisciplinary team. Empiric antibiotics for DFIs vary based on the severity of the infection, but must include anti-staphylococcal coverage.

Meta-analysis of randomized controlled trials of vancomycin for the treatment of patients with gram-positive infections: focus on the study design

OBJECTIVE

To study the effectiveness and safety of vancomycin compared with that of other antibiotics for the treatment of gram-positive infections.

METHODS

Major electronic databases were searched. Data from published randomized controlled trials (January 1, 1950, to September 15, 2011) were pooled using a meta-analytic method.

RESULTS

Fifty-three trials comparing vancomycin with linezolid, daptomycin, quinupristin-dalfopristin, tigecycline, ceftaroline, ceftobiprole, telavancin, teicoplanin, iclaprim, and dalbavancin were included in the meta-analysis. Individual antibiotics were as effective as vancomycin, except for linezolid, which was more effective than vancomycin for the treatment of skin and soft tissue infections (odds ratio [OR], 1.61; 95% confidence interval [CI], 1.07-2.43). Comparators were as effective as vancomycin in the intent-to-treat population (OR, 1.08; 95% CI, 0.98-1.18) but were more effective in the clinically evaluable population (OR, 1.14; 95% CI, 1.02-1.27) when all infections were pooled. When available data from all trials were pooled, no differences were noted when patients with febrile neutropenia (OR, 1.07; 95% CI, 0.82-1.39), pneumonia (OR, 1.10; 95% CI, 0.87-1.37), bacteremia (OR, 1.05; 95% CI, 0.76-1.45), and skin and soft tissue infections (OR, 1.11; 95% CI, 0.89-1.39) were studied. Comparators were more effective in open-label (OR, 1.28; 95% CI, 1.08-1.50) but not in double-blind trials (OR, 1.04; 95% CI, 0.90-1.20). Total adverse events attributed to studied antibiotics (OR, 1.07; 95% CI, 0.90-1.28) and patients withdrawn from trials (OR, 0.86; 95% CI, 0.68-1.09) were similar in the compared groups. Mortality was not different between vancomycin and comparator antibiotics when all trials were included in the analysis (OR, 1.09; 95% CI, 0.96-1.23). Comparators were associated with higher mortality in open-label (OR, 1.27; 95% CI, 1.05-1.54) but not double-blind trials (OR, 0.96; 95% CI, 0.80-1.14).

CONCLUSION

On the basis mainly of data from open-label trials, vancomycin is a treatment choice that is as effective as other available antibiotics for patients with gram-positive infections. Study design seems to make a major contribution to the outcome.

Cutaneous infections and infestations: new therapies

Directed and preventive therapies for cutaneous infectious disease and infestation continue to evolve, providing physicians with new options for care. Common infectious diseases (e.g., genital herpes, herpes zoster, and head lice) occur in the outpatient and inpatient setting. This review of the literature highlights new therapies, including those still in development, such as novel drugs and vaccines, all of which should help to decrease the frequency and severity of common infectious diseases of the skin and subcutaneous tissues.

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.

Interventions for cellulitis and erysipelas

BACKGROUND

Cellulitis and erysipelas are now usually considered manifestations of the same condition, a skin infection associated with severe pain and systemic symptoms. A range of antibiotic treatments are suggested in guidelines.

OBJECTIVES

To assess the efficacy and safety of interventions for non-surgically-acquired cellulitis.

SEARCH STRATEGY

In May 2010 we searched for randomised controlled trials in the Cochrane Skin Group Specialised Register, the Cochrane Central Register of Controlled Trials in The Cochrane Library, MEDLINE, EMBASE, and the ongoing trials databases.

SELECTION CRITERIA

We selected randomised controlled trials comparing two or more different interventions for cellulitis.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data.

MAIN RESULTS

We included 25 studies with a total of 2488 participants. Our primary outcome 'symptoms rated by participant or medical practitioner or proportion symptom-free' was commonly reported. No two trials examined the same drugs, therefore we grouped similar types of drugs together.Macrolides/streptogramins were found to be more effective than penicillin antibiotics (Risk ratio (RR) 0.84, 95% CI 0.73 to 0.97). In 3 trials involving 419 people, 2 of these studies used oral macrolide against intravenous (iv) penicillin demonstrating that oral therapies can be more effective than iv therapies (RR 0.85, 95% CI 0.73 to 0.98).Three studies with a total of 88 people comparing a penicillin with a cephalosporin showed no difference in treatment effect (RR 0.99, 95% CI 0.68 to 1.43).Six trials which included 538 people that compared different generations of cephalosporin, showed no difference in treatment effect (RR 1.00, 95% CI 0.94 to1.06).We found only small single studies for duration of antibiotic treatment, intramuscular versus intravenous route, the addition of corticosteroid to antibiotic treatment compared with antibiotic alone, and vibration therapy, so there was insufficient evidence to form conclusions. Only two studies investigated treatments for severe cellulitis and these selected different antibiotics for their comparisons, so we cannot make firm conclusions.

AUTHORS' CONCLUSIONS

We cannot define the best treatment for cellulitis and most recommendations are made on single trials. There is a need for trials to evaluate the efficacy of oral antibiotics against intravenous antibiotics in the community setting as there are service implications for cost and comfort.

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.

Daptomycin Versus Other Antimicrobial Agents for the Treatment of Skin and Soft Tissue Infections: A Meta-Analysis

BACKGROUND

Skin and soft tissue infections (SSTIs) are common in everyday clinical practice. Daptomycin has been shown to achieve very good concentrations in skin and soft tissues.

OBJECTIVE

To compare the effectiveness and toxicity of daptomycin with that of other antimicrobials for the treatment of SSTIs.

METHODS

PubMed, Scopus, and the Cochrane Central Register of Controlled Trials were searched for articles published up to March 2009. Comparative studies in which daptomycin was used in the intervention group were included in this meta-analysis. The primary outcome of interest was clinical success; secondary outcomes were microbiologic success, clinical success in subsets with complicated SSTIs (cSSTIs) or infections due to methicillin-resistant Staphylococcus aureus; (MRSA), clinical success of daptomycin-versus vancomycin-treated patients, time to clinical cure, treatment-related adverse events, withdrawal from treatment due to toxicity, all-cause mortality, and development of resistance.

RESULTS

Four studies were included in the analysis (3 were randomized controlled trials [RCTs]). Vancomycin and semisynthetic penicillins were used in the comparator arm. Three studies reported on patients with cSSTIs. The intention-to-treat (ITT) population was 1557 patients. No statistically significant difference between daptomycin and comparators was found regarding clinical success in clinically evaluable (OR 0.89; 95% CI 0.63 to 1.25 in the 3 RCTs and OR 1.34; 95% CI 0.38 to 4.66 with all 4 studies included), ITT, MRSA-infected patients, and those with cSSTIs. Two studies reported that significantly fewer patients with cSSTIs required prolonged treatment in the daptomycin arm and that clinical cure was faster than with comparators. No difference between the compared regimens was found in other outcomes.

CONCLUSIONS

Daptomycin is effective and safe for the treatment of SSTIs. Studies evaluating the optimal duration of daptomycin therapy for cSSTIs, comparing daptomycin with new agents, and focusing on proven MRSA SSTIs will be helpful for the further evaluation of the drug.