Patterns of Care and Treatment Outcomes for Outpatient Daptomycin-Containing Regimens in Osteomyelitis.

BACKGROUND: Use of daptomycin at doses ≥ 6 mg/kg for treatment of osteomyelitis is increasing in clinical practice; unfortunately, limited data are available to guide optimal dosing and duration. The objective of this study was to assess daptomycin dosing and duration regimens for osteomyelitis treatment. METHODS: This was a retrospective, multi-site, cohort study conducted in an integrated healthcare delivery system. Nonpregnant patients ≥ 18 years of age with osteomyelitis diagnosed between November 1, 2003 and June 30, 2011, ≥ 2 weeks outpatient daptomycin therapy, and ≥ 1 month of follow-up were included. Daptomycin doses < 6 mg/kg and ≥ 6 mg/kg at durations of < 6 weeks and ≥ 6 weeks were examined with univariate and multivariate analyses to assess treatment success and all-cause mortality. RESULTS: A total of 247 patients were included, with 39 (15.8%), 37 (15.0%), 107 (43.3%), and 64 (25.9%) receiving < 6 mg/kg and ≥ 6 weeks, < 6 mg/kg and < 6 weeks, ≥ 6 mg/kg and ≥ 6 weeks, and ≥ 6 mg/kg and < 6 weeks of daptomycin therapy, respectively. Patients had a mean age of 58 years and had received prior vancomycin therapy (65.6%). Patients receiving < 6 weeks of therapy were less likely to experience treatment success compared with ≥ 6 weeks (41.5% vs 25.3%, adjusted odds ratio = 0.55; 95% confidence interval = 0.31-0.98) independent of duration. There were no differences across groups in mortality after adjustment. CONCLUSION: In a diverse clinical population, daptomycin for treatment of osteomyelitis of 6 weeks or longer duration was associated with success independent of dose. This finding supports longer treatment with daptomycin as a first-line agent in antimicrobial stewardship initiatives.

Antibiotic Exposure and Risk for Hospital-Associated Clostridioides difficile Infection.

Clostridioides difficile infection (CDI) is a health care-associated infection associated with significant morbidity and cost, with highly varied risk across populations. More effective, risk-based prevention strategies are needed. Here, we investigate risk factors for hospital-associated CDI in a large integrated health system. In a retrospective cohort of all adult admissions to 21 Intermountain Healthcare hospitals from 2006 to 2012, we identified all symptomatic (i) hospital-onset and (ii) health care-facility-associated, community-onset CDI. We then evaluated the risk associated with antibiotic exposure, including that of specific agents, using multivariable logistic regression. A total of 2,356 cases of CDI among 506,068 admissions were identified (incidence, 46.6 per 10,000). Prior antibiotic use was the dominant risk factor, where for every antibiotic day of therapy prior to the index admission, the odds of subsequent CDI increased by 12.8% (95% confidence interval [CI], 12.2 to 13.4%; P < 0.0001). This was a much stronger association than was inpatient antibiotic exposure (odds ratio [OR], 1.007 [95% CI, 1.005 to 1.009]; P < 0.0001). The highest-risk antibiotics included second-generation and later cephalosporins (especially oral), carbapenems, fluoroquinolones, and clindamycin, while doxycycline and daptomycin were associated with a lower CDI risk. We concluded that cumulative antibiotic exposure prior to admission is the greatest contributor to the risk of subsequent CDI. Most classes of antibiotics carry some risk, which varies by drug and route. This information may be useful for antimicrobial stewardship efforts.

A randomized phase 2B trial of vancomycin versus daptomycin for the treatment of methicillin-resistant Staphylococcus aureus bacteremia due to isolates with high vancomycin minimum inhibitory concentrations - results of a prematurely terminated study.

BACKGROUND: Studies have suggested the reduced effectiveness of vancomycin against methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections with high vancomycin minimum inhibitory concentrations. Alternative agents such as daptomycin may be considered. We conducted a randomized controlled study comparing daptomycin against vancomycin in the treatment of MRSA bloodstream infections with high vancomycin minimum inhibitory concentrations. METHODS: Patients were randomized to receive vancomycin or daptomycin for a minimum of 14 days. The primary end point was the rate of all-cause mortality at day 60. RESULTS: A total of 14 patients were randomized in this study, with 7 patients in each treatment arm. The study was terminated early due to slow patient accrual. At day 60, there was one death in the vancomycin arm and none in the daptomycin arm. The median time to microbiological clearance was 4 days in both arms (IQR 3-5 days in the vancomycin arm and 3-7 days in daptomycin arm). Only one patient in the vancomycin arm had recurrence of bacteremia. Rates of adverse events were similar in both arms. There was one case of musculoskeletal toxicity and one case of drug-related nephrotoxicity - both events occurred in the daptomycin arm. None of the patients in either treatment arm required cessation of study treatment or addition of a second anti-MRSA agent because of worsening infection. CONCLUSION: Based on the limited number of patients evaluated in this study, it remains unclear if alternative, more expensive agents such as daptomycin are superior to vancomycin in the treatment of high vancomycin minimum inhibitory concentration MRSA bloodstream infections. More studies are urgently needed but investigators may wish to consider employing novel, alternative trial methodologies to ensure a greater chance of success. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01975662 . Registered on 5 November 2013.

Randomized Multicenter Study Comparing Safety and Efficacy of Daptomycin Versus Standard-of-care in Pediatric Patients With Staphylococcal Bacteremia.

BACKGROUND: Staphylococcus aureus, including community-associated methicillin-resistant S. aureus, is an important cause of pediatric bacteremia. Daptomycin is a well-established treatment option for Gram-positive bacteremia in adults, but its safety and efficacy in children require confirmation. METHODS: This was a randomized (2:1), evaluator-blinded, multicenter, phase 4 clinical trial comparing intravenous daptomycin with standard-of-care (SOC) for treatment of S. aureus bacteremia in 1- to 17-year-old patients (Clinicaltrials.gov: NCT01728376). Total treatment duration (intravenous followed by oral step-down therapy) was 5-42 days. Daptomycin was dosed once daily by patient age: 12-17 years, 7 mg/kg; 7-11 years, 9 mg/kg and 1-6 years, 12 mg/kg. The primary objective was to evaluate daptomycin safety in children who received ≥1 dose; secondary objectives included comparing daptomycin efficacy with SOC (the trial was not designed to confirm noninferiority) and pharmacokinetic analysis. RESULTS: Fifty-five children were randomized to daptomycin and 27 to SOC (primarily vancomycin or cefazolin); 90% had S. aureus. In both groups, 15% of patients had drug-related adverse events, primarily diarrhea (4% daptomycin, 8% SOC) and increased creatine phosphokinase (4% daptomycin, 0% SOC). Clinical success (blinded evaluator-assessed complete/partial resolution of bacteremia signs and symptoms 7-14 days after end-of-treatment) rates were similar for daptomycin (88%) and SOC (77%; 95% confidence interval for difference: -9% to 31%). Daptomycin plasma levels across age groups were comparable with those in adults receiving daptomycin at 6 mg/kg. CONCLUSIONS: Once-daily, age-appropriate daptomycin was well tolerated in children with staphylococcal bacteremia; efficacy was comparable with SOC. Daptomycin in age-adjusted doses is a safe treatment alternative in this setting.

Comparative Effectiveness and Safety of Standard-, Medium-, and High-Dose Daptomycin Strategies for the Treatment of Vancomycin-Resistant Enterococcal Bacteremia Among Veterans Affairs Patients.

Background: Vancomycin-resistant Enterococcus bloodstream infections (VRE-BSIs) are associated with significant mortality. Daptomycin exhibits concentration-dependent activity vs VRE in vitro, yet the clinical impact of higher-dose strategies remains unclear. Methods: We performed a national retrospective cohort study of hospitalized Veterans Affairs patients treated with standard-dose (6 mg/kg total body weight), medium-dose (8 mg/kg total body weight), or high-dose (≥10 mg/kg total body weight) daptomycin for VRE-BSI. Patient-related, microbiological, and outcomes data were abstracted from clinical databases. The primary outcome was overall survival, evaluated by Cox regression. Secondary outcomes included 30-day mortality, time to microbiological clearance, and creatine phosphokinase (CPK) elevation. Results: A total of 911 patients were included (standard dose, n = 709; medium dose, n = 142; high dose, n = 60). Compared to high-dose daptomycin, both standard-dose (hazard ratio [HR], 2.68; 95% confidence interval; [CI], 1.33-3.06; P = .002) and medium-dose (HR, 2.66; 95% CI, 1.33-3.92; P = .003) daptomycin were associated with poorer survival. After adjusting for confounders, the relationship between poorer survival and standard-dose (adjusted HR [aHR], 2.58; 95% CI, 1.27-4.88; P = .004) and medium-dose (aHR, 2.52; 95% CI, 1.27-5.00; P = .008) daptomycin persisted. Thirty-day mortality was significantly lower among high-dose daptomycin-treated patients compared with other dosing strategies (risk ratio, 0.83; 95% CI, .74-.94; P = .015). Compared with standard-dose daptomycin, both medium-dose (HR, 0.78; 95% CI, .55-.90; P = .012) and high-dose daptomycin (HR, 0.70; 95% CI, .41-.84; P = .006) were associated with significantly improved microbiological clearance. No difference in the risk of CPK elevation was observed between the treatment groups (P = .504). Conclusions: High-dose daptomycin was associated with improved survival and microbiological clearance in VRE-BSI.

Daptomycin Improves Outcomes Regardless of Vancomycin MIC in a Propensity-Matched Analysis of Methicillin-Resistant Staphylococcus aureus Bloodstream Infections.

Vancomycin remains the mainstay treatment for methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections (BSIs) despite increased treatment failures. Daptomycin has been shown to improve clinical outcomes in patients with BSIs caused by MRSA isolates with vancomycin MICs of >1 mg/liter, but these studies relied on automated testing systems. We evaluated the outcomes of BSIs caused by MRSA isolates for which vancomycin MICs were determined by standard broth microdilution (BMD). A retrospective, matched cohort of patients with MRSA BSIs treated with vancomycin or daptomycin from January 2010 to March 2015 was completed. Patients were matched using propensity-adjusted logistic regression, which included age, Pitt bacteremia score, primary BSI source, and hospital of care. The primary endpoint was clinical failure, which was a composite endpoint of the following metrics: 30-day mortality, bacteremia with a duration of ≥7 days, or a change in anti-MRSA therapy due to persistent or worsening signs or symptoms. Secondary endpoints included MRSA-attributable mortality and the number of days of MRSA bacteremia. Independent predictors of failure were determined through conditional backwards-stepwise logistic regression with vancomycin BMD MIC forced into the model. A total of 262 patients were matched. Clinical failure was significantly higher in the vancomycin cohort than in the daptomycin cohort (45.0% versus 29.0%; P = 0.007). All-cause 30-day mortality was significantly higher in the vancomycin cohort (15.3% versus 6.1%; P = 0.024). These outcomes remained significant when stratified by vancomycin BMD MIC. There was no significant difference in the length of MRSA bacteremia. Variables independently associated with treatment failure included vancomycin therapy (adjusted odds ratio [aOR] = 2.16, 95% confidence interval [CI] = 1.24 to 3.76), intensive care unit admission (aOR = 2.46, 95% CI = 1.34 to 4.54), and infective endocarditis as the primary source (aOR = 2.33, 95% CI = 1.16 to 4.68). Treatment of MRSA BSIs with daptomycin was associated with reduced clinical failure and 30-day mortality; these findings were independent of vancomycin BMD MIC.

Comparative Effectiveness of Vancomycin Versus Daptomycin for MRSA Bacteremia With Vancomycin MIC >1 mg/L: A Multicenter Evaluation.

PURPOSE: Clinical studies comparing vancomycin with alternative therapy for methicillin-resistant Staphylococcus aureus (MRSA) bacteremia are limited. The objective of this study was to compare outcomes of early daptomycin versus vancomycin treatment for MRSA bacteremia with high vancomycin MICs in a geographically diverse multicenter evaluation. METHODS: This nationwide, retrospective, multicenter (N = 11), matched, cohort study compared outcomes of early daptomycin with vancomycin for MRSA bloodstream infection (BSI) with vancomycin MICs 1.5 to 2 µg/mL. Matching variables, based on propensity regression analysis, included age, intensive care unit (ICU), and type of BSI. Outcomes were as follows: (1) composite failure (60-day all-cause mortality, 7-day clinical or microbiologic failure, 30-day BSI relapse, or end-of-treatment failure (EOT; discontinue/change daptomycin or vancomycin because of treatment failure or adverse event]); (2) nephrotoxicity; and (2) day 4 BSI clearance. FINDINGS: A total of 170 patients were included. The median (interquartile range) age was 60 years (50-74); the median (range) Acute Physiology and Chronic Health Evaluation II score was 15 (10-18); 31% were in an ICU; and 92% had an infectious disease consultation. BSI types included endocarditis/endovascular (39%), extravascular (55%), and central catheter (6%). The median daptomycin dose was 6 mg/kg, and the vancomycin trough level was 17 mg/L. Overall composite failure was 35% (59 of 170): 15% due to 60-day all-cause mortality, 14% for lack of clinical or microbiologic response by 7 days, and 17% due to failure at end of therapy (discontinue/change because of treatment failure or adverse event). Predictors of composite failure according to multivariate analysis were age >60 years (odds ratio, 3.7; P < 0.01) and ICU stay (odds ratio, 2.64; P = 0.03). Notable differences between treatment groups were seen with: (1) end of therapy failure rates (11% vs 24% for daptomycin vs vancomycin; P = 0.025); (2) acute kidney injury rates (9% vs 23% for daptomycin vs vancomycin; P = 0.043); and (3) day 4 bacteremia clearance rates for immunocompromised patients (n = 26) (94% vs 56% for daptomycin vs vancomycin; P = 0.035). IMPLICATIONS: Results from this multicenter study provide, for the first time, a geographically diverse evaluation of daptomycin versus vancomycin for patients with vancomycin-susceptible MRSA bacteremia with vancomycin MIC values >1 µg/mL. Although the overall composite failure rates did not differ between the vancomycin and daptomycin groups when intensively matched according to risks for failure, the rates of acute kidney injury were significantly lower in the daptomycin group. These findings suggest that daptomycin is a useful therapy for clinicians treating patients who have MRSA bacteremia. Prospective, randomized trials should be conducted to better assess the potential significance of elevated vancomycin MIC.

Evaluation of Daptomycin Exposure and Efficacy and Safety Endpoints To Support Risk-versus-Benefit Considerations.

The choice of an antimicrobial agent must balance optimization of efficacy endpoints with the minimization of safety events. The risk versus benefit of daptomycin for patients with Staphylococcus aureus bacteremia with or without infective endocarditis receiving daptomycin at 6, 8, and 10 mg/kg of body weight/day was assessed. The relationships between the area under the concentration-time curve over 24 h (AUC)/MIC ratio and both clinical response and time to decreased susceptibility were evaluated using data from patients with such infections who received daptomycin at 6 mg/kg/day. Using these relationships, plus the previously identified relationship between the minimum concentration and an elevation in the creatine phosphokinase (CPK) concentration (CPK elevation) (S. M. Bhavnani, C. M. Rubino, P. G. Ambrose, and G. L. Drusano, Clin Infect Dis 50:1568-1574, 2010) and Monte Carlo simulation, the probability of each outcome by MIC for daptomycin at 6, 8, and 10 mg/kg/day was calculated. The function for exposure-response relationships for clinical response (P = 0.06) and time to decreased susceptibility (P = 0.01) resembled U and inverted U shapes, respectively. Multivariable analyses demonstrated AUC/MIC ratio, creatinine clearance, albumin concentration, and disease category to be predictors of clinical response. The results of simulations failed to demonstrate large improvements in the probabilities of clinical success among cohorts of simulated patients defined by the above-described predictive factors or the probability of decreased susceptibility at 30 days when the daptomycin dose was increased from 6 to 10 mg/kg/day. The probability of CPK elevation increased from 0.073 to 0.156 over this dose range. These data can be used to inform risk-versus-benefit decisions for daptomycin dose selection in patients with S. aureus bacteremia with or without infective endocarditis. The risk of CPK elevation, which is reversible, should be weighed in the context of the mortality and severe morbidity associated with these types of serious staphylococcal infections.

Impact of the combination of daptomycin and trimethoprim-sulfamethoxazole on clinical outcomes in methicillin-resistant Staphylococcus aureus infections.

Complicated Staphylococcus aureus infections, including bacteremia, are often associated with treatment failures, prolonged hospital stays, and the emergence of resistance to primary and even secondary therapies. Daptomycin is commonly used as salvage therapy after vancomycin failure for the treatment of methicillin-resistant S. aureus (MRSA) infections. Unfortunately, the emergence of daptomycin resistance, especially in deep-seated infections, has been reported, prompting the need for alternative or combination therapy. Numerous antibiotic combinations with daptomycin have been investigated clinically and in vitro. Of interest, the combination of daptomycin and trimethoprim-sulfamethoxazole (TMP-SMX) has proved to be rapidly bactericidal in vitro to strains that are both susceptible and nonsusceptible to daptomycin. However, to date, there is limited clinical evidence supporting the use of this combination. This was a multicenter, retrospective case series of patients treated with the combination of daptomycin and TMP-SMX for at least 72 h. The objective of this study was to describe the safety and effectiveness of this regimen in clinical practice. The most commonly stated reason that TMP-SMX was added to daptomycin was persistent bacteremia and/or progressive signs and symptoms of infection. After the initiation of combination therapy, the median time to clearance of bacteremia was 2.5 days. Microbiological eradication was demonstrated in 24 out of 28 patients, and in vitro synergy was demonstrated in 17 of the 17 recovered isolates. Further research with this combination is necessary to describe the optimal role and its impact on patient outcomes.

Daptomycin-induced hyperkalemia in a patient with normal renal function.

PURPOSE: A case of episodic hyperkalemia associated with daptomycin administration is reported. SUMMARY: A 46-year-old African-American woman was hospitalized for treatment of a shoulder abscess. Initially treated with i.v. vancomycin, the patient was switched to daptomycin 9 mg/kg i.v. (500 mg daily) after three days. On day 10 of daptomycin therapy, she was noted to have a serum potassium concentration of 5.4 meq/L, with an increase to 6.1 meq/L on day 11. Reversal of hyperkalemia was achieved with oral sodium polystyrene sulfonate and other agents, and daptomycin was withheld for one day, during which time the patient's serum potassium level normalized. One day after daptomycin therapy was resumed at a lower dose (7 mg/kg), the potassium concentration increased again (to 5.5 meq/L). With a further dosage reduction and continued administration of sodium polystyrene sulfonate, the patient completed the full course of daptomycin therapy. There was a close temporal relationship between daptomycin administrations and the serum potassium fluctuations; other potential causes of hyperkalemia were ruled out. Evaluation of this case using the algorithm of Naranjo et al. yielded a score of 6, indicating that the serum potassium elevations probably constituted an adverse reaction to daptomycin. A literature search identified no other reports of hyperkalemia associated with daptomycin use in a patient with normal renal function. CONCLUSION: A 46-year-old women with normal renal function developed hyperkalemia after receiving high-dose daptomycin therapy. The potassium levels normalized when daptomycin was withheld but increased again when the patient was rechallenged with the drug.

Vancomycin versus daptomycin for the treatment of methicillin-resistant Staphylococcus aureus bacteremia due to isolates with high vancomycin minimum inhibitory concentrations: study protocol for a phase IIB randomized controlled trial.

BACKGROUND: Vancomycin is the standard first-line treatment for methicillin-resistant Staphylococcus aureus bacteremia. However, recent consensus guidelines recommend that clinicians consider using alternative agents such as daptomycin when the vancomycin minimum inhibitory concentration is greater than 1 ug/ml. To date however, there have been no head-to-head randomized trials comparing the safety and efficacy of daptomycin and vancomycin in the treatment of such infections. The primary aim of our study is to compare the efficacy of daptomycin versus vancomycin in the treatment of bloodstream infections due to methicillin-resistant Staphylococcus aureus isolates with high vancomycin minimum inhibitory concentrations (greater than or equal to 1.5 ug/ml) in terms of reducing all-cause 60-day mortality. METHODS/DESIGN: The study is designed as a multicenter prospective open label phase IIB pilot randomized controlled trial. Eligible participants will be inpatients over 21-years-old with a positive blood culture for methicillin-resistant Staphylococcus aureus with vancomycin minimum inhibitory concentration of greater than or equal to 1.5 ug/ml. Randomization into intervention or active control arms will be performed with a 1:1 allocation ratio. We aim to recruit 50 participants over a period of two years. Participants randomized to the active control arm will receive vancomycin dose-while those randomized to the intervention arm will receive daptomycin. Participants will receive a minimum of 14 days study treatment.The primary analysis will be conducted on the intention-to-treat principle. The Fisher's exact test will be used to compare the 60-day mortality rate from index blood cultures (primary endpoint) between the two treatment arms, and the exact two-sided 95% confidence interval will be calculated using the Clopper and Pearson method. Primary analysis will be conducted using a two sided alpha of 0.05. DISCUSSION: If results from this pilot study suggest that daptomycin shows significant efficacy in the treatment of bloodstream infections due to methicillin-resistant Staphylococcus aureus isolates with high vancomycin minimum inhibitory concentrations, we aim to proceed with a larger scale confirmatory study. This would help guide clinicians and inform practice guidelines on the optimal treatment for such infections. TRIAL REGISTRATION: The trial is listed on clinicaltrials.gov (NCT01975662, date of registration: 29 October 2013).

Population pharmacokinetics of daptomycin in patients affected by severe Gram-positive infections.

A population pharmacokinetic analysis of daptomycin was performed based on therapeutic drug monitoring (TDM) data from 58 patients receiving doses of 4-12 mg/kg for the treatment of severe Gram-positive infections. At a daily dose of 8 mg/kg, daptomycin plasma concentrations (mean ± S.D.) were 76.9 ± 9.8 mg/L at the end of infusion and 52.7 ± 15.4 mg/L and 11.4 ± 5.4 mg/L at 0.5 h and 23 h after drug administration, respectively. The final model was a one-compartmental model with first-order elimination, with estimated clearance (CL) of 0.80 ± 0.14 L/h and a volume of distribution (V(d)) of 0.19 ± 0.05 L/kg. Creatinine clearance (CL(Cr)) was identified as having a significant influence on daptomycin CL, and a decrease in CL(Cr) of 30 mL/min from the median value (80 mL/min) was associated with a reduction of daptomycin CL from 0.80 L/h to 0.73 L/h. These results confirm that the presence of severe infection may be associated with an altered disposition of daptomycin, with an increased Vd. MICs were available in 41 patients and results showed that 38 and 31 subjects achieved AUC/MIC values associated with bacteriostatic (>400) and bactericidal effects (>800), respectively. Of note, 31 of these 41 subjects experienced a clinical improvement or were cured. Although daptomycin pharmacokinetics may be influenced by infections, effective AUC/MIC values were achieved in the majority of patients. The present model may be applied in clinical settings for a TDM routine on the basis of a sparse blood sampling protocol.

Efficacy and safety of intravenous daptomycin in Japanese patients with skin and soft tissue infections.

Daptomycin is a lipopeptide antibiotic active against gram-positive organisms and recently approved for marketing in Japan. This study investigates the efficacy and safety of daptomycin in Japanese patients with skin and soft tissue infections (SSTIs) caused by methicillin-resistant Staphylococcus aureus (MRSA) for regulatory filing in Japan. Overall, 111 Japanese patients with SSTI were randomized in this open-label, randomized, active-comparator controlled, parallel-group, multicenter, phase III study. Patients received intravenous daptomycin 4 mg/kg once daily or vancomycin 1 g twice daily for 7-14 days. Efficacy was determined by a blinded Efficacy Adjudication Committee. Among patients with SSTIs caused by MRSA, 81.8 % (95 % CI, 69.1-90.9) of daptomycin recipients and 84.2 % (95 % CI, 60.4-96.6) of vancomycin recipients achieved a successful clinical response at the test-of-cure (TOC) visit. The microbiological success rate against MRSA at the TOC visit was 56.4 % (95 % CI, 42.3-69.7) with daptomycin and 47.4 % (95 % CI, 24.4-71.1) with vancomycin. Daptomycin was generally well tolerated; most adverse events were of mild to moderate severity. The measurement of daptomycin concentration in plasma revealed that patients with mild or moderate impaired renal function showed similar pharmacokinetics profiles to patients with normal renal function. Clinical and microbiological responses, stratified by baseline MRSA susceptibility, suggested that patients infected with MRSA of higher daptomycin MIC showed a trend of lower clinical success with a P value of 0.052 by Cochran-Armitage test. Daptomycin was clinically and microbiologically effective for the treatment of MRSA-associated SSTIs in Japanese patients.

High-dose daptomycin plus fosfomycin is safe and effective in treating methicillin-susceptible and methicillin-resistant Staphylococcus aureus endocarditis.

We describe 3 patients with left-sided staphylococcal endocarditis (1 with methicillin-susceptible Staphylococcus aureus [MSSA] prosthetic aortic valve endocarditis and 2 with methicillin-resistant S. aureus [MRSA] native-valve endocarditis) who were successfully treated with high-dose intravenous daptomycin (10 mg/kg/day) plus fosfomycin (2 g every 6 h) for 6 weeks. This combination was tested in vitro against 7 MSSA, 5 MRSA, and 2 intermediately glycopeptide-resistant S. aureus isolates and proved to be synergistic against 11 (79%) strains and bactericidal against 8 (57%) strains. This combination deserves further clinical study.

Papel de la daptomicina en el tratamiento de las infecciones en el paciente oncohematológico / Role of daptomycin in the treatment of infections in patients with hematological malignancies

Introducción: Las infecciones bacterianas en pacientes con neoplasias hematológicas conllevan una alta morbimortalidad. Los microorganismos grampositivos pueden causar más de la mitad de los episodios infecciosos bacterianos del enfermo con neutropenia febril, especialmente cuando se trata de bacteriemias. Se precisa una cobertura eficaz frente a tales infecciones en estos huéspedes especialmente inmunodeprimidos. Pacientes y métodos: Se revisa la literatura científica reciente de la última década sobre infecciones en pacientes oncohematológicos, con o sin neutropenia febril, y se destacan las publicaciones que atienden los procesos causados por grampositivos y el manejo de estas infecciones, sean o no bacteriémicas, mediante los fármacos tradicionales (glucopéptidos) y los nuevos antibióticos (linezolid, tigeciclina y daptomicina). Resultados: Se evidencia una llamativa escasez de estudios sobre el tratamiento de estas infecciones por microorganismos grampositivos en pacientes con cáncer mediante los nuevos antimicrobianos; destaca especialmente la carencia de ensayos comparativos. En concreto, para el caso de la daptomicina no se dispone de estudios aleatorizados comparativos en pacientes con neutropenia febril, aunque sí de estudios observacionales retrospectivos y de registro de casos (EUCORE) con un amplio número de pacientes oncohematoló- gicos (en torno a 200). En cuanto a la eficacia, las tasas de respuesta global favorable se sitúan entre el 65 y el 90% en los tres estudios principales, con un porcentaje de éxito terapéutico del 85% en pacientes con neutropenia febril grave. Simultáneamente, el perfil de seguridad de la daptomicina se mostró muy apropiado, con una buena tolerancia y una baja tasa de efectos secundarios (< 10% para los directamente relacionados con el antibiótico) que, en muy pocas ocasiones, fueron graves u obligaron a la interrupción del tratamiento. La tasa de nefrotoxicidad fue mucho más baja respecto a la causada por vancomicina en grupos de control históricos comparativos, aunque no alcanzaron la significación estadística. Conclusiones: La daptomicina es una alternativa terapéutica eficaz y segura en el tratamiento de las infecciones bacterianas por microorganismos grampositivos en los pacientes con cáncer, con o sin neutropenia, si bien se precisan datos más sólidos y definitivos para apoyar su inclusión en el tratamiento empírico de la neutropenia febril (AU)

Introduction: Bacterial infections in patients with hematological neoplasms carry high morbidity and mortality. Gram-positive microorganisms can cause more than half of the bacterial infections in patients with febrile neutropenia, especially bacteremias. Effective coverage against these infections in these hosts, especially the immunodepressed, is required. Patients and methods: We reviewed the literature published in the last decade on infections in patients with hematological malignancies, with or without febrile neutropenia. Emphasis was placed on publications analyzing the processes caused by Gram-positive microorganisms and the management of these infections (whether bacteremic or otherwise) through traditional drugs (glycopeptides) and the new antibiotics (linezolid, tigecycline and daptomycin). Results: There was a notable scarcity of studies on the treatment of infections due to Gram-positive microorganisms in patients with cancer through treatment with the new antimicrobial drugs. Especially striking was the lack of comparative studies. Specifically, in the case of daptomycin, there were no randomized comparative trials in patients with febrile neutropenia, although there were observational retrospective studies or case studies [European Cubicin® Outcome Registry and Experience (EUCORE)] with a large number of patients (around 200) with oncological malignancies. In the three main studies, the overall favorable response rates were between 65% and 90%, with a therapeutic success rate of 85% in patients with severe febrile neutropenia. At the same time, the safety profile of daptomycin was shown to be highly favorable with good tolerability and a low rate of adverse effects (< 10% for those directly related to the antibiotic) which, on very few occasions, were severe or led to treatment withdrawal. The nephrotoxicity rate was much lower than that caused by vancomycin in historical control groups, although there were no statistically significant differences. Conclusions: Daptomycin is a safe and effective therapeutic alternative in the treatment of bacterial infections due to Gram-positive microorganisms in patients with cancer, with or without neutropenia. However, further studies are required to support the use of this drug in the empirical treatment of febrile neutropenia (AU)

[Role of daptomycin in the treatment of infections in patients with hematological malignancies]. / Papel de la daptomicina en el tratamiento de las infecciones en el paciente oncohematológico.

INTRODUCTION: Bacterial infections in patients with hematological neoplasms carry high morbidity and mortality. Gram-positive microorganisms can cause more than half of the bacterial infections in patients with febrile neutropenia, especially bacteremias. Effective coverage against these infections in these hosts, especially the immunodepressed, is required. PATIENTS AND METHODS: We reviewed the literature published in the last decade on infections in patients with hematological malignancies, with or without febrile neutropenia. Emphasis was placed on publications analyzing the processes caused by Gram-positive microorganisms and the management of these infections (whether bacteremic or otherwise) through traditional drugs (glycopeptides) and the new antibiotics (linezolid, tigecycline and daptomycin). RESULTS: There was a notable scarcity of studies on the treatment of infections due to Gram-positive microorganisms in patients with cancer through treatment with the new antimicrobial drugs. Especially striking was the lack of comparative studies. Specifically, in the case of daptomycin, there were no randomized comparative trials in patients with febrile neutropenia, although there were observational retrospective studies or case studies [European Cubicin(®) Outcome Registry and Experience (EUCORE)] with a large number of patients (around 200) with oncological malignancies. In the three main studies, the overall favorable response rates were between 65% and 90%, with a therapeutic success rate of 85% in patients with severe febrile neutropenia. At the same time, the safety profile of daptomycin was shown to be highly favorable with good tolerability and a low rate of adverse effects (< 10% for those directly related to the antibiotic) which, on very few occasions, were severe or led to treatment withdrawal. The nephrotoxicity rate was much lower than that caused by vancomycin in historical control groups, although there were no statistically significant differences. CONCLUSIONS: Daptomycin is a safe and effective therapeutic alternative in the treatment of bacterial infections due to Gram-positive microorganisms in patients with cancer, with or without neutropenia. However, further studies are required to support the use of this drug in the empirical treatment of febrile neutropenia.

[Daptomycin: revitalizing a former drug due to the need of new active agents against grampositive multiresistant bacterias]. / Daptomicina: revitalizando un antiguo fármaco ante la necesidad de nuevos agentes activos frente a bacterias grampositivas multirresistentes.

The development of mechanisms of resistance of many Gram-positive bacterial strains that cause complicated skin and soft tissue infections, as well as sepsis and bacteremia, has necessitated the search for new drugs that will improve treatment strategies. Daptomycin is a cyclic lipopeptide antibacterial that was launched for the treatment of complicated skin and soft tissue infections caused by Gram-positive organisms. The drug's mechanism of action is different from that of any other antibiotic. It binds to bacterial membranes and causes a rapid depolarization of membrane potential. This loss of membrane potential causes inhibition of protein, DNA and RNA synthesis, which results in bacterial cell death. The in vitro spectrum of activity of daptomycin encompasses most clinically relevant aerobic Gram-positive pathogenic bacteria. Compared to other antibiotics with a similar antibacterial spectrum, daptomycin does not cause nephrotoxicity. Taking these and other characteristics into consideration, daptomycin appears to be a good alternative to other drugs used in the treatment of complicated skin and soft tissue infections and in Gram-positive bacteremial infections.

Evaluation of high-dose daptomycin for therapy of experimental Staphylococcus aureus foreign body infection.

BACKGROUND: Daptomycin is a novel cyclic lipopeptide whose bactericidal activity is not affected by current antibiotic resistance mechanisms displayed by S. aureus clinical isolates. This study reports the therapeutic activity of high-dose daptomycin compared to standard regimens of oxacillin and vancomycin in a difficult-to-treat, rat tissue cage model of experimental therapy of chronic S. aureus foreign body infection. METHODS: The methicillin-susceptible S. aureus (MSSA) strain I20 is a clinical isolate from catheter-related sepsis. MICs, MBCs, and time-kill curves of each antibiotic were evaluated as recommended by NCCLS, including supplementation with physiological levels (50 mg/L) of Ca2+ for daptomycin. Two weeks after local infection of subcutaneously implanted tissue cages with MSSA I20, each animal received (i.p.) twice-daily doses of daptomycin, oxacillin, or vancomycin for 7 days, or was left untreated. The reductions of CFU counts in each treatment group were analysed by ANOVA and Newman-Keuls multiple comparisons procedures. RESULTS: The MICs and MBCs of daptomycin, oxacillin, or vancomycin for MSSA strain I20 were 0.5 and 1, 0.5 and 1, or 1 and 2 mg/L, respectively. In vitro elimination of strain I20 was more rapid with 8 mg/L of daptomycin compared to oxacillin or vancomycin. Twice-daily administered daptomycin (30 mg/kg), oxacillin (200 mg/kg), or vancomycin (50 mg/kg vancomycin) yielded bactericidal antibiotic levels in infected cage fluids throughout therapy. Before therapy, mean (+/- SEM) viable counts of strain I20 were 6.68 +/- 0.10 log10 CFU/mL of cage fluid (n = 74). After 7 days of therapy, the mean (+/- SEM) reduction in viable counts of MSSA I20 was 2.62 (+/- 0.30) log10 CFU/mL in cages (n = 18) of daptomycin-treated rats, exceeding by > 2-fold (P < 0.01) the viable count reductions of 0.92 (+/- 0.23; n = 19) and 0.96 (+/- 0.24; n = 18) log10 CFU/mL in cages of oxacillin-treated and vancomycin-treated rats, respectively. Viable counts in cage fluids of untreated animals increased by 0.48 (+/- 0.24; n = 19) log10 CFU/mL. CONCLUSION: The improved efficacy of the twice-daily regimen of daptomycin (30 mg/kg) compared to oxacillin (200 mg/kg) or vancomycin (50 mg/kg) may result from optimisation of its pharmacokinetic and bactericidal properties in infected cage fluids.

Daptomycin: a novel cyclic lipopeptide antimicrobial.

PURPOSE: The development, activity, pharmacokinetics, pharmacodynamics, clinical efficacy, adverse effects, and dosage and administration of daptomycin are reviewed. SUMMARY: Daptomycin, a novel cyclic lipopeptide antimicrobial, is bactericidal against a range of gram-positive bacteria, including many multiple-drug-resistant isolates. It has only minimal activity against anaerobic bacteria and no activity against gram-negative bacteria. Daptomycin exhibits linear pharmacokinetics, and the plasma concentration-versus-time relationship is best described by a two-compartment model with first-order elimination. The initial bactericidal activity is rapid, extensive, and concentration related. In clinical trials, daptomycin has shown efficacy in treating complicated skin and skin-structure infections (CSSSIs); the drug carries FDA-approved labeling for same. The adverse effects of daptomycin appear comparable to those of vancomycin and semisynthetic penicillins. The dosage for CSSSIs is 4 mg/kg by i.v. infusion every 24 hours. CONCLUSION: Daptomycin is bactericidal against gram-positive organisms and offers an option in the treatment of CSSSIs.