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

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

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

Association between age and onset of daptomycin-induced adverse events using the U.S. food and drug administration adverse event reporting system

BACKGROUND

Daptomycin is a lipopeptide antibiotic with a broad spectrum of activity against gram-positive bacteria. Although information on daptomycin-induced adverse events can be found in clinical trials, data regarding the impact of age on these events are insufficient. Therefore, we evaluated whether age affects the occurrence of daptomycin-induced adverse events using adverse drug event reports in post-marketing stages provided by the U.S. Food and Drug Administration (FDA).

METHODS

A total dataset of 7307 reports of patients treated with daptomycin in the FDA's Adverse Event Reporting System were analyzed. The patients were divided into seven age groups: 0-28 days, >28 days-23 months, 2-11 years, 12-17 years, 18-64 years, 65-80 years, and >80 years. A disproportionality analysis was conducted to calculate the reporting odds ratio, with a 95 % confidence interval. The univariate regression analysis was conducted using the percentage of each adverse event and age groups.

RESULTS

Compared with the number of reports aged 18-64 years, there were significantly increased reports of eosinophilic pneumonia in patients aged 65-80 years and >80 years, anaphylactic reaction and pseudomembranous colitis in patients aged 12-17 years, and acute renal failure in patients aged 65-80 years. The regression coefficient for the reporting proportion of eosinophilic pneumonia was significantly positive.

CONCLUSIONS

Our findings revealed age-related trends in daptomycin-induced adverse events, supporting the idea that implementing age-dependent follow-up and supportive care helps in the continuation of daptomycin therapy.

Daptomycin Dose Optimization in Pediatric Staphylococcus aureus Bacteremia: A Pharmacokinetic/Pharmacodynamic Investigation

Daptomycin is an antibiotic with Gram-positive activity, including methicillin-resistant Staphylococcus aureus, for which optimal pediatric dosing is unknown. This study aimed to evaluate daptomycin exposures achieved with package label dosing and to identify dosing regimens necessary to enhance efficacy and minimize toxicity in children with S. aureus bacteremia. Monte Carlo simulations were performed to determine probability of target attainment (PTA) for six pediatric age cohorts. Area under the curve to minimum inhibitory concentration ratio (AUC0-24:MIC) ≥666 was used to determine the PTA for efficacy (PTAE). Minimum concentration (Cmin) ≥24.3 mg/L determined the PTA for toxicity (PTAT). Acceptable dosing regimens were those which achieved the combined target of ≥90% PTAE and ≤5% PTAT. Package label dosing of daptomycin yielded insufficient efficacy with only 26.3% PTAE in children 13-24 months, 39.5% PTAE in children 2-6 years, 30.1% PTAE in children 7-11 years, and 50.1% PTAE in adolescents ≥12 years. To achieve the combined efficacy and safety target, doses of 18-24 mg/kg in children 3-12 months, 20-24 mg/kg in children 13-24 months, 19-24 mg/kg in children 2-6 years, 17-19 mg/kg in children 7-11 years, and 10-14 mg/kg in adolescents ≥12 years are necessary. Package label dosing resulted in suboptimal exposure for the majority of pediatric patients in all age groups evaluated. If targeting validated efficacy and safety endpoints, daily daptomycin doses of at least 20 mg/kg in children ≤6 years, 17 mg/kg in children 7-11 years, and 10 mg/kg in adolescents ≥12 years are necessary. Clinical studies evaluating these higher doses are needed.

Daptomycin Use for Persistent Coagulase-Negative Staphylococcal Bacteremia in a Neonatal Intensive Care Unit

During the last two decades, the incidence of late-onset sepsis (LOS) has increased due to improved survival of premature neonates. Persistent bacteremia (PB) in LOS is defined as more than two positive blood cultures obtained on different calendar days during the same infectious episode. Although rare, PB should be treated aggressively to prevent adverse outcomes. Daptomycin, a lipopeptide antibiotic, has been used in neonates with persistent coagulase-negative staphylococci (CoNS) bacteremia with promising results, but studies reporting on the efficacy and safety of the agent are scarce. The purpose of this study was to evaluate the efficacy and safety of daptomycin use for persistent CoNS bacteremia in a neonatal cohort. This is a retrospective, observational, single-center study of neonates treated with daptomycin during 2011-2022 in the Tertiary Neonatal Intensive Care Unit (NICU) of the University General Hospital of Patras, Greece. For the years 2011-2022, there were 3.413 admissions to the NICU. During the last 3 years (2020-2022)-the active epidemiological surveillance period-123 infants (out of 851 admissions, 14.4%) developed CoNS bacteremia (LOS). During the study period, twelve infants with PB were treated with daptomycin. They had a median gestational age of 32 weeks (IQR 31-34) and mean (SD) birth weight of 1.840 (867) grams. CoNS bacteremia isolates were s. epidermidis (50%), s. haemolyticus (20%), s. hominis (20%) and s. warneri (10%). The decision to start daptomycin (6 mg/kg/dose twice daily) was taken on median day 10 (ΙQR 7-15) of infection. None of the infants had focal complications or meningitis. Daptomycin therapy caused no renal, hepatic, muscular or gastrointestinal adverse events. One neonate developed seizures, and one death occurred due to multiple complications of prematurity. Most infants (11/12) were successfully treated and eventually had negative blood culture. Daptomycin monotherapy showed an adequate cure rate in premature neonates with persistent CoNS bacteremia in a tertiary NICU. In our study, daptomycin was effective and well tolerated; the safety profile, however, needs to be confirmed in larger studies and randomized controlled trials.

Pharmacokinetics of intravenous daptomycin in Japanese pediatric patients: Pharmacokinetic comparisons supporting dosing recommendations in Japanese pediatric patients

INTRODUCTION

The pharmacokinetics (PK) of daptomycin has not been previously characterized in Japanese pediatric patients with complicated skin and soft tissue infections (cSSTI) or bacteremia. An aim of the study includes evaluation of PK of daptomycin in Japanese pediatric patients and an appropriateness of the age-specific, weight-based dosing regimens in Japanese pediatric patients based on PK comparison with Japanese adult patients.

METHODS

The phase 2 trial enrolled Japanese pediatric patients (age 1-17 years) with cSSTI (n = 14) or bacteremia (n = 4) caused by gram-positive cocci in order to evaluate safety, efficacy and PK. The Phase 3 trial in Japanese adult patients (SSTI n = 65, septicemia/right-sided infective endocarditis (RIE) n = 7) was referred to for PK comparison between adult and pediatric. Daptomycin concentrations in plasma were analyzed by reverse-phase high-performance liquid chromatography (HPLC). PK parameters were determined using non-compartmental analysis in Japanese pediatric and Japanese adult patients. The exposures in Japanese pediatric patients were graphically compared with those in Japanese adult patients. The relationship between daptomycin exposures and creatine phosphokinase (CPK) elevation was explored visually.

RESULTS

Following administration of the age-specific, weight-based dosing regimens, daptomycin exposures were overlapping across age groups in pediatric patients with cSSTI with similar observations based on clearance. The distribution of individual exposure in Japanese pediatric patients was overlapping with that in Japanese adult patients. No apparent relationship between daptomycin exposures and CPK elevation in Japanese pediatric patients was observed.

CONCLUSIONS

The results suggested that the age-specific, weight-based dosing regimens are considered to be appropriate in Japanese pediatric patients.

Therapeutic Options and Outcomes for the Treatment of Children with Gram-Positive Bacteria with Resistances of Concern: A Systematic Review

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant coagulase-negative Staphylococci (MR-CoNS), and vancomycin-resistant Enterococci (VRE) are increasing worldwide and represent a threat for the limited treatment options in pediatric patients and neonates compared to adults. Recommendations in pediatrics are mainly extrapolated from adults' studies.

METHODS

A literature search for the treatment of these pathogens in children (<18 years old) was conducted in Embase, MEDLINE, and Cochrane Library. Studies reporting data on single-patient-level outcomes related to a specific antibiotic treatment for multidrug resistant (MDR) Gram-positive bacterial infection in children were included. Studies reporting data from adults and children were included if single-pediatric-level information could be identified (PROSPERO registration: CRD42022383867).

RESULTS

The search identified 11,740 studies (since January 2000), of which 48 fulfilled both the inclusion and the exclusion criteria and were included in the analysis: 29 for MRSA, 20 for VRE, and seven for MR-CoNS. Most studies were retrospective studies. Vancomycin was mainly used as a comparator, while linezolid and daptomycin were the most studied antimicrobials showing good efficacy.

CONCLUSIONS

Linezolid showed a safety and efficacy profile in a neonatal setting; daptomycin is increasingly used for MRSA, but the evidence is scarce for VRE.

Data mining for adverse drug reaction signals of daptomycin based on real-world data: a disproportionality analysis of the US Food and Drug Administration adverse event reporting system

BACKGROUND

Previous reports on daptomycin's adverse drug reactions (ADRs) have been insufficient, often because of limited data. Pharmacovigilance risk signal detection is innovative and has been applied to the safety monitoring and reevaluation of drugs post-marketing.

AIM

The study aimed to promote safe daptomycin prescribing by mining and evaluating the daptomycin ADR signals from the US Food and Drug Administration Adverse Event Reporting System (FAERS).

METHOD

A disproportionality analysis (reporting odds ratio ROR and proportional reporting ratio PRR) was utilized for FAERS data mining from the first quarter of 2004 to the second quarter of 2021 (the most recent quarterly data at the time of the study). Preferred Terms of ADR reports were categorized by System Organ Class (SOC) based on the Medical Dictionary for Regulatory Activities.

RESULTS

This study retrieved 12,221 cases within the reporting period. A total of 140 repetitive signals were obtained by ROR and PRR, of which 53 new ADR signals were not recorded in the drug labels/datasheets. The top three ADR reports were "blood creatine phosphokinase elevation" (ROR, 56.66, 95% confidence interval (CI) 51.07-62.87, PRR 51.94), "eosinophilic pneumonia" (ROR 696.71, 95%CI 603.21-804.70, PRR 657.57), and "rhabdomyolysis" (ROR 22.85, 95%CI 19.94-26.18, PRR 21.83). The highest ROR of "antimicrobial susceptibility test resistant" was found at 9808.14. Reports of rare adverse events, such as "necrotizing fasciitis and compartment syndrome," have emerged. The significant SOCs were "Infections and Infestations" and "Investigations."

CONCLUSION

New daptomycin ADR signals were detected. Clinicians should monitor these potential ADRs in patients receiving daptomycin.

Daptomycin-Associated Diarrhea: A Case Report and Review of the Literature

Antibiotic-associated diarrhea (AAD) describes any unexplained diarrhea associated with the use of antibiotics. AAD develops through diverse mechanisms, ranging from pharmacologic effects on gut motility to disturbance of the function and carbohydrate metabolism of the indigenous intestinal flora and overgrowth by pathogenic micro-organisms. Clostridioides difficile-associated diarrhea (CDAD) is a subset of AAD; however, it accounts only for a small percentage of diarrhea caused by antibiotics. Diarrhea has been reported as a side effect of daptomycin use, nevertheless, it's thought to be mild and carries significantly less risk of diarrhea than other alternative treatments of S. aureus bacteremia, i.e., vancomycin or cefazolin. The authors present an interesting case of daptomycin-associated diarrhea presenting with a protracted and severe course. Patient symptoms didn’t improve with empiric Clostridioides difficile therapy and CDAD testing was negative. Diarrhea promptly resolved after discontinuation of daptomycin. Furthermore, a thorough literature review was conducted and discussed in this article to raise awareness of this under-recognized complication. Clinicians should be mindful of daptomycin-associated diarrhea along with its presentation and treatment. Further studies are needed to identify the pathophysiology of daptomycin-associated diarrhea and other forms of AAD. Understanding their mechanism could help prevent, treat, and reduce the significant medical costs associated with antibiotic adverse events.

Thoracic Spinal Cord Compression Secondary to Metastatic Papillary Thyroid Carcinoma: An Unusual Oncological Phenomenon

Hematogenous spread is fairly an unusual feature for papillary thyroid carcinoma (PTC) in comparison to follicular thyroid carcinoma (FTC). Thoracic spinal metastasis with complicating cord compression is an even rarer manifestation of PTC that was reported in a limited number of cases in the literature. Herein we present a 65-year-old female with a history of PTC on current radiotherapy, status post attempted surgery due to significant tumor burden and intraoperative bleeding, presented with a one-week history of rapidly progressive bilateral lower extremities weakness. Physical examination revealed paraplegia of both lower extremities with areflexia and a sensory level equivalent to the upper thoracic vertebrae. Urgent imaging depicted destructive epidural lesions at T1-T3 vertebrae with thoracic cord compression. Emergent laminectomy and debulking of these lesions were undertaken. Histopathological examination confirmed metastatic PTC. The patient proceeded to further treatment with radiotherapy following her successful neurological recovery. Thoracic vertebral metastasis is an unusual oncological phenomenon of PTC. Metastatic PTC should be considered in patients with a current or remote history of PTC who present with thoracic cord compression. Our case demonstrates that multidisciplinary management is the key to achieving a better outcome for metastatic PTC with thoracic cord compression.

A case of acute focal bacterial nephritis caused by methicillin-resistant Staphylococcus saprophyticus in a 13-year-old adolescent girl treated with daptomycin

Staphylococcus saprophyticus is a gram-positive, coagulase-negative member of the Staphylococcus genus and is second only to Escherichia coli as a cause of urinary tract infections in the young female population. S. saprophyticus usually has good susceptibility to drugs commonly used to treat urinary tract infections, but it is often methicillin-resistant. Here we report a case of acute focal bacterial nephritis in a 13-year-old female patient caused by methicillin-resistant S. saprophyticus and treated with daptomycin (DAP). The patient had a history of unilateral hearing loss and presented to her previous physician with a 3-day history of fever, right-sided abdominal pain, and diarrhea. Cefotaxime antimicrobial chemotherapy was initiated as an empiric therapy targeting E. coli, the most frequent cause of community-onset pyelonephritis. Vancomycin (VCM) was started for acute focal bacterial nephritis caused by methicillin-resistant S. saprophyticus but was stopped due to allergy and replaced with DAP. After 13 days of treatment with DAP, the patient received 17 days of treatment with sulfamethoxazole-trimethoprim combination therapy. The patient experienced no adverse events and did not relapse. DAP is a relatively new anti-methicillin-resistant Staphylococcus aureus drug used to treat gram-positive cocci infections. It is primarily excreted by the kidneys, which may be desirable in treating urinary tract infections. For children who cannot receive VCM for any reason, DAP may be a viable alternative.

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S. saprophyticus is a common cause of urinary tract infections in young women.

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The use of daptomycin for urinary tract infections in children is rare.

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Vancomycin (VCM) is usually used to treat methicillin-resistant S. saprophyticus.

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If VCM is unavailable, daptomycin can used to treat urinary tract infections in such cases.

Efficacy and safety of daptomycin in Japanese pediatric participants with complicated skin and soft tissue infections or bacteremia caused by gram-positive cocci

INTRODUCTION

Complicated skin and soft tissue infections (cSSTIs) and bacteremia caused by Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA), are common causes of infection for children worldwide. Here, the safety and efficacy of daptomycin in Japanese pediatric participants are reported.

METHODS

This open-label, single-arm phase 2 study (NCT03643952) enrolled Japanese pediatric participants (age 1-17 years) with cSSTI or bacteremia caused by gram-positive cocci. Participants received age-adjusted doses of intravenous daptomycin for 5 to up to 14 days (cSSTI) or 5 to up to 42 days (bacteremia). The primary objective was safety and tolerability; efficacy among participants with infections caused by MRSA was a secondary objective.

RESULTS

A total of 18 participants (cSSTI, n = 14; bacteremia, n = 4) were enrolled across 12 study sites in Japan. The most common pathogen was S. aureus (15/18 [83.3%]), including methicillin-susceptible and -resistant isolates. Adverse events (AE) were reported in 42.9% (6/14) of participants with cSSTI and 100% (4/4) of participants with bacteremia. No deaths, serious AEs, discontinuations of study medication due to an AE, or events of clinical interest occurred in the study. In participants with infections caused by MRSA, 87.5% [7/8] achieved favorable clinical response at test of cure (TOC) visit (cSSTI, 85.7% [6/7]; bacteremia, 100% [1/1]). In this population, favorable microbiological response at TOC was achieved by 71.4% (5/7) of participants with cSSTI and 100% (1/1) of participants with bacteremia.

CONCLUSIONS

Daptomycin was well tolerated, exhibited a favorable safety profile, and was effective for the treatment of cSSTI or bacteremia in Japanese children.

Unremitting Pain and Fever in a 15-Year-Old Boy With Osteomyelitis

A previously healthy 15-year-old boy from a rural county in the southeastern United States was evaluated in the emergency department with fever and worsening toe pain in the absence of trauma. He initially presented to his primary care physician 4 weeks before with upper respiratory symptoms and was treated with corticosteroids for presumed reactive airway disease. His respiratory symptoms resolved. One week after this presentation, he developed fever and right great toe pain and presented to an outside hospital. Inflammatory markers were elevated. MRI confirmed a diagnosis of osteomyelitis with associated periosteal abscess. He was treated with intravenous antibiotics and drainage of the abscess. Ten days after his discharge from the outside hospital, he developed fever and had increasing drainage of the toe and pain refractory to oral pain medications. He presented to our facility for further evaluation. Repeat MRI and inflammatory markers corroborated his worsening disease, and he was admitted to the hospital for intravenous antibiotics and underwent serial surgical debridement. He developed painful subcutaneous nodules on his lower extremities and was found to have lung abnormalities on chest radiograph. A multispecialty team collaborated in the management of this patient and unveiled a surprising diagnosis.

Antimicrobial prescribing for treatment of serious infections caused by Staphylococcus aureus and methicillin-resistant Staphylococcus aureus in pediatrics: an expert review

Introduction: Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA), remains a significant pathogen in children. Despite evidence of decreasing prevalence, MRSA bacteremia has been closely associated with complications, including certain infections (i.e. musculoskeletal and endovascular) linked to increased treatment failures.Areas covered: This expert review summarized recent published literature on the role of treatment, dosing and administration of antibiotics used to combat serious S. aureus infections in children. The pertinent antibiotics presented were vancomycin, oxazolidinones, semi-synthetic glycopeptides, daptomycin, tigecycline, novel cephalosporins, fosfomycin and lefamulin. Vancomycin has been the most commonly used antibiotic in empiric therapy for serious MRSA infection, with new key recommendations emphasizing a different approach to dosing and therapeutic monitoring. For other antibiotics, data remain limited or clinical trials are underway.Expert opinion: MRSA remains a significant pathogen in the pediatric population. As numerous therapeutic agents are available, many agents have limited data on usage in pediatric patients. Future studies require pharmacokinetic, safety and efficacy studies in pediatric patients to ensure appropriate therapeutic treatment and outcomes. Phage therapy has been used to treat deep-seated MRSA infections and is an emerging investigational treatment option.

Safety and Efficacy of Daptomycin in Neonates with Coagulase-Negative Staphylococci: Case Series Analysis

There has been an increase in the prevalence of gram-positive bacteremia in neonates in the last two decades. However, as a consequence of better care, there has been an increase in the survival of premature neonates. Coagulase-negative staphylococci (CoNS) is the most prevalent bacteria, responsible for up to 60% of late-onset sepsis (LOS). Daptomycin, a lipopeptide antimicrobial agent, is active against CoNS. This was an observational, retrospective case series study carried out in the Pediatric Hospital of King Saud Medical City, Riyadh, Saudi Arabia. The medical records of 21 neonates, aged 0-28 days, who were treated in Neonatal Intensive Care Unit (NICU) with intravenous daptomycin as monotherapy or combination therapy for at least 4 days for proven gram-positive infection between June 2019 to July 2020, were included. The median gestational and chronological age were 27 weeks and 5 days, respectively. The most frequent diagnosis in neonates was infective endocarditis (42.9%). Of the 21 patients who received daptomycin therapy, 13 (62%) recovered and 8 died. The clinical cure rate was higher in Staphylococcus hominis (100%) and in patients who received 6 mg/kg/dose twice daily (62.5%). The mean of aspartate aminotransferase significantly elevated after starting daptomycin (p = 0.048). However, no muscular or neurological toxicity of daptomycin was documented in any of the cases. Overall, daptomycin was well tolerated, even with long-term treatment.

Clinical Pharmacokinetics of Daptomycin

Due to the low level of resistance observed with daptomycin, this antibiotic has an important place in the treatment of severe Gram-positive infections. It is the first-in-class of the group of calcium-dependent, membrane-binding lipopeptides, and is a cyclic peptide constituted of 13 amino acids and an n-decanoyl fatty acid chain. The antibacterial action of daptomycin requires its complexation with calcium. Daptomycin is not absorbed from the gastrointestinal tract and needs to be administered parenterally. The distribution of daptomycin is limited (volume of distribution of 0.1 L/kg in healthy volunteers) due to its negative charge at physiological pH and its high binding to plasma proteins (about 90%). Its elimination is mainly renal, with about 50% of the dose excreted unchanged in the urine, justifying dosage adjustment for patients with renal insufficiency. The pharmacokinetics of daptomycin are altered under certain pathophysiological conditions, resulting in high interindividual variability. As a result, therapeutic drug monitoring of daptomycin may be of interest for certain patients, such as intensive care unit patients, patients with renal or hepatic insufficiency, dialysis patients, obese patients, or children. A target for the ratio of the area under the curve to the minimum inhibitory concentration > 666 is usually recommended for clinical efficacy, whereas in order to limit the risk of undesirable muscular effects the residual concentration should not exceed 24.3 mg/L.

Daptomycin for Pediatric Gram-Positive Acute Hematogenous Osteomyelitis

BACKGROUND

We prospectively evaluated efficacy and safety of daptomycin versus active comparator in children with acute hematogenous osteomyelitis (AHO).

METHODS

Randomized, controlled, double-blind, global, multicenter, phase 3 trial. Patients 1-17 years of age with suspected/confirmed AHO requiring hospitalization and intravenous therapy were randomized 1:1 to intravenous daptomycin (once-daily, age-adjusted doses) or comparator (vancomycin, nafcillin or equivalent) ≥4 days, followed by oral therapy (14-42 days total). Primary endpoint: protocol-defined clinical improvement by Day 5 in the modified intention-to-treat (MITT) population (confirmed AHO, ≥1 dose of study treatment); differences between study arms were evaluated using a prespecified 15% noninferiority margin for daptomycin.

RESULTS

Seventy-three patients per arm received treatment. Pathogens were isolated from 62% of patients (83% methicillin-susceptible Staphylococcus aureus, 9% methicillin-resistant S. aureus [MRSA]). Clinical improvement by Day 5 was observed in 55/71 (78%) daptomycin- and 58/70 (83%) comparator-treated MITT patients (95% confidence interval [CI]: -19.4, 7.4). This difference was not statistically significant; however, daptomycin did not meet the prespecified 15% noninferiority margin, since the lower bound of the 95% CI extended below 15%. Overall, 82% of daptomycin and 87% of comparator patients achieved clinical cure at the test-of-cure visit (secondary endpoint). More comparator patients had treatment-emergent (63% vs. 46%) and treatment-related (18% vs. 7%) adverse events.

CONCLUSIONS

Differences between daptomycin and comparator for the primary endpoint were not statistically significant; however, prespecified noninferiority criteria for daptomycin were not met. With insufficient cases of confirmed MRSA, we could not evaluate daptomycin for MRSA AHO. Our nonvalidated protocol design yields valuable information for implementing future trials in AHO (ClinicalTrials.gov NCT01922011).

Effect of Vancomycin Loading Doses on the Attainment of Target Trough Concentrations in Hospitalized Children

OBJECTIVE

Subtherapeutic vancomycin trough concentrations are common in children and may be associated with suboptimal therapeutic response. Our objective was to determine if vancomycin loading doses safely increase the frequency of target trough attainment in hospitalized children.

METHODS

Patients (≥6 months and <18-years-old) who received a vancomycin loading dose between February 1, 2018, and January 30, 2019, were retrospectively enrolled. These patients were compared to a convenience cohort of patients hospitalized between January 1, 2015, and December 31, 2015, who received vancomycin without a loading dose. Target trough concentrations were defined as >15 mg/dL for invasive infections and >10 mg/dL for non-invasive infections.

RESULTS

A total of 151 patients were enrolled, with 77 in the control arm and 74 in the loading dose arm. There was no significant difference in the frequency of comorbidities or need for intensive care unit admission between the two arms. Those receiving a vancomycin loading dose were older (mean age 9.1 vs 5.2 years, p < 0.0001). Patients given a loading dose achieved higher mean initial trough values (13.0 mg/dL vs 9.2 mg/dL, p < 0.0001), were more likely to have an initial trough at or above target (37.0% vs 10.4%, p = 0.0001), were more likely to reach target trough values at any point during therapy (52.1% vs 32.9%, p = 0.0081), and attained a target trough concentration more quickly (mean 41.1 hours vs 58.8 hours, p = 0.0118). There were no significant differences in the frequency of serum creatinine elevation or oliguria at the end of therapy.

CONCLUSIONS

Vancomycin loading doses may improve the ability to safely obtain target trough values in hospitalized children.

Considerations and Caveats in Combating ESKAPE Pathogens against Nosocomial Infections

ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) are among the most common opportunistic pathogens in nosocomial infections. ESKAPE pathogens distinguish themselves from normal ones by developing a high level of antibiotic resistance that involves multiple mechanisms. Contemporary therapeutic strategies which are potential options in combating ESKAPE bacteria need further investigation. Herein, a broad overview of the antimicrobial research on ESKAPE pathogens over the past five years is provided with prospective clinical applications.

One Size Fits All? Application of Susceptible-Dose-Dependent Breakpoints to Pediatric Patients and Laboratory Reporting

The Clinical and Laboratory Standards Institute antimicrobial and antifungal standards define a susceptible-dose-dependent (SDD) category for certain organisms and drug combinations. Reporting MICs within the SDD category suggests that treatment success is likely with increased drug exposure. These breakpoints are based on pharmacokinetic, pharmacodynamic, and clinical outcome data from adults and not pediatric patients. This commentary aims to discuss the implications of reporting SDD interpretations for pediatric patients and recommends laboratory reporting comments.

CASSETTE-clindamycin adjunctive therapy for severe Staphylococcus aureus treatment evaluation: study protocol for a randomised controlled trial

BACKGROUND

Exotoxins are important virulence factors in Staphylococcus aureus. Clindamycin, a protein synthesis inhibitor antibiotic, is thought to limit exotoxin production and improve outcomes in severe S. aureus infections. However, randomised prospective data to support this are lacking.

METHODS

An open-label, multicentre, randomised controlled trial (RCT) will compare outcome differences in severe S. aureus infection between standard treatment (flucloxacillin/cefazolin in methicillin-susceptible S. aureus; and vancomycin/daptomycin in methicillin-resistant S. aureus) and standard treatment plus an additional clindamycin given for 7 days. We will include a minimum of 60 participants (both adult and children) in the pilot study. Participants will be enrolled within 72 h of an index culture. Severe infections will include septic shock, necrotising pneumonia, or multifocal and non-contiguous skin and soft tissue/osteoarticular infections. Individuals who are immunosuppressed, moribund, with current severe diarrhoea or Clostridiodes difficile infection, pregnant, and those with anaphylaxis to β-lactams or lincosamides will be excluded. The primary outcomes measure is the number of days alive and free (1 or 0) of systemic inflammatory response syndrome (SIRS) within the first 14 days post randomisation. The secondary outcomes measure will include all-cause mortality at 14, 42, and 90 days, time to resolution of SIRS, proportion with microbiological treatment failure, and rate of change of C-reactive protein over time. Impacts of inducible clindamycin resistance, strain types, methicillin susceptibility, and presence of various exotoxins will also be analysed.

DISCUSSION

This study will assess the effect of adjunctive clindamycin on patient-centred outcomes in severe, toxin-mediated S. aureus infections. The pilot study will provide feasibility for a much larger RCT.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry, ACTRN12617001416381p . Registered on 6 October 2017.

Ceftaroline Plus Daptomycin for Refractory Methicillin- Resistant Staphylococcus aureus Bacteremia in a Child

Persistent methicillin-resistant Staphylococcus aureus (MRSA) bacteremia can be difficult to treat, with growing adult literature supporting the combination of ceftaroline and daptomycin for these patients. Here, we report a pediatric patient with persistent MRSA bacteremia with associated cellulitis, fasciitis, myositis, and a deep venous thrombosis causing septic pulmonary emboli. After being unable to clear the bacteremia on vancomycin and then daptomycin monotherapy, the bacteremia cleared quickly with rapid clinical improvement after the addition of ceftaroline to daptomycin. In support of this case, we also review the adult literature supporting treatment with this combination of antibiotics.

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.