Liposomal amphotericin B treatment for neonatal fungal infections

Nephrotoxic medications and acute kidney injury risk factors in the neonatal intensive care unit: clinical challenges for neonatologists and nephrologists

Neonatal acute kidney injury (AKI) is common. Critically ill neonates are at risk for AKI for many reasons including the severity of their underlying illnesses, prematurity, and nephrotoxic medications. In this educational review, we highlight four clinical scenarios in which both the illness itself and the medications indicated for their treatment are risk factors for AKI: sepsis, perinatal asphyxia, patent ductus arteriosus, and necrotizing enterocolitis. We review the available evidence regarding medications commonly used in the neonatal period with known nephrotoxic potential, including gentamicin, acyclovir, indomethacin, vancomycin, piperacillin-tazobactam, and amphotericin. We aim to illustrate the complexity of decision-making involved for both neonatologists and pediatric nephrologists when managing infants with these conditions and advocate for ongoing multidisciplinary collaboration in the development of better AKI surveillance protocols and AKI mitigation strategies to improve care for these vulnerable patients.

Pharmacokinetic, efficacy, and safety considerations for the use of antifungal drugs in the neonatal population

INTRODUCTION

Invasive fungal infections are an important cause of morbidity and mortality in infants, particularly in extreme prematurity. Successful systemic treatment requires consideration of antifungal efficacy, safety, and pharmacokinetics, including optimization of dosing in this population.

AREAS COVERED

This review summarizes published pharmacokinetic data on four classes of antifungal agents used in the neonatal population. Alterations in absorption, distribution, drug metabolism and clearance in infants compared to adult populations are highlighted. Additionally, pharmacodynamics, safety, and therapeutic drug monitoring are discussed. Recent advancements in neonatal antifungal pharmacotherapies are examined, with emphasis on clinical application.

EXPERT OPINION

Over the last two decades, published studies have provided increased knowledge on pharmacokinetic considerations in the neonatal population. Future research should focus on filling in the knowledge gaps that remain regarding the benefits and risks of combination antifungal therapy, the rising use of micafungin for invasive candidiasis given its fungicidal activity against polyene and azole-resistant Candida species and its minimal adverse effect profile, and the need for pharmacokinetic and safety data of broad spectrum triazoles, like voriconazole and posaconazole, in infants. Furthermore, efforts should focus on well-designed trials, including population pharmacokinetic studies, to develop dosing recommendations with subsequent implementation into clinical practice.

Maternal and environmental risk factors for neonatal AKI and its long-term consequences

Acute kidney injury (AKI) is a common and life-threatening complication in critically ill neonates. Gestational risk factors for AKI include premature birth, intrauterine growth restriction and low birthweight, which are associated with poor nephron development and are often the consequence of pre-gestational and gestational factors, such as poor nutritional status. Our understanding of how to best optimize renal development and prevent AKI is in its infancy; however, the identification of pre-gestational and gestational factors that increase the risk of adverse neonatal outcomes and the implementation of interventions, such as improving nutritional status early in pregnancy, have the potential to optimize fetal growth and reduce the risk of preterm birth, thereby improving kidney health. The overall risk of AKI among critically ill and premature neonates is exacerbated postnatally as these infants are often exposed to dehydration, septic shock and potentially nephrotoxic medications. Strategies to improve outcomes - for example, through careful evaluation of nephrotoxic drugs - may reduce the incidence of AKI and its consequences among this population. Management strategies and updated technology that will support neonates with AKI are greatly needed. Extremely premature infants and those who survive an episode of AKI should be screened for chronic kidney disease until early adulthood. Here, we provide an overview of our current understanding of neonatal AKI, focusing on its relationship to preterm birth and growth restriction. We describe factors that prevent optimal nephrogenesis during pregnancy and provide a framework for future explorations designed to maximize outcomes in this vulnerable population.

ESCMID-ECMM guideline: diagnosis and management of invasive aspergillosis in neonates and children

SCOPE

Presenting symptoms, distributions and patterns of diseases and vulnerability to invasive aspergillosis (IA) are similar between children and adults. However, differences exist in the epidemiology and underlying conditions, the usefulness of newer diagnostic tools, the pharmacology of antifungal agents and in the evidence from interventional phase 3 clinical trials. Therefore, the European Society for Clinical Microbiology and Infectious Diseases (ESCMID) and the European Confederation of Medical Mycology (ECMM) have developed a paediatric-specific guideline for the diagnosis and management of IA in neonates and children.

METHODS

Review and discussion of the scientific literature and grading of the available quality of evidence was performed by the paediatric subgroup of the ESCMID-ECMM-European Respiratory Society (ERS) Aspergillus disease guideline working group, which was assigned the mandate for the development of neonatal- and paediatric-specific recommendations.

QUESTIONS

Questions addressed by the guideline included the epidemiology of IA in neonates and children; which paediatric patients may benefit from antifungal prophylaxis; how to diagnose IA in neonates and children; which antifungal agents are available for use in neonates and children; which antifungal agents are suitable for prophylaxis and treatment of IA in neonates and children; what is the role of therapeutic drug monitoring of azole antifungals; and which management strategies are suitable to be used in paediatric patients. This guideline provides recommendations for the diagnosis, prevention and treatment of IA in the paediatric population, including neonates. The aim of this guideline is to facilitate optimal management of neonates and children at risk for or diagnosed with IA.

Clinical Pharmacokinetics, Pharmacodynamics, Safety and Efficacy of Liposomal Amphotericin B

Since its introduction in the 1990s, liposomal amphotericin B (LAmB) continues to be an important agent for the treatment of invasive fungal diseases caused by a wide variety of yeasts and molds. This liposomal formulation was developed to improve the tolerability of intravenous amphotericin B, while optimizing its clinical efficacy. Since then, numerous clinical studies have been conducted, collecting a comprehensive body of evidence on its efficacy, safety, and tolerability in the preclinical and clinical setting. Nevertheless, insights into the pharmacokinetics and pharmacodynamics of LAmB continue to evolve and can be utilized to develop strategies that optimize efficacy while maintaining the compound's safety. In this article, we review the clinical pharmacokinetics, pharmacodynamics, safety, and efficacy of LAmB in a wide variety of patient populations and in different indications, and provide an assessment of areas with a need for further clinical research.

Advances in the Treatment of Mycoses in Pediatric Patients

The main indications for antifungal drug administration in pediatrics are reviewed as well as an update of the data of antifungal agents and antifungal policies performed. Specifically, antifungal therapy in three main areas is updated as follows: a) Prophylaxis of premature neonates against invasive candidiasis; b) management of candidemia and meningoencephalitis in neonates; and c) prophylaxis, empiric therapy, and targeted antifungal therapy in children with primary or secondary immunodeficiencies. Fluconazole remains the most frequent antifungal prophylactic agent given to high-risk neonates and children. However, the emergence of fluconazole resistance, particularly in non-albicans Candida species, should be considered during preventive or empiric therapy. In very-low birth-weight neonates, although fluconazole is used as antifungal prophylaxis in neonatal intensive care units (NICU's) with relatively high incidence of invasive candidiasis (IC), its role is under continuous debate. Amphotericin B, primarily in its liposomal formulation, remains the mainstay of therapy for treating neonatal and pediatric yeast and mold infections. Voriconazole is indicated for mold infections except for mucormycosis in children >2 years. Newer triazoles-such as posaconazole and isavuconazole-as well as echinocandins, are either licensed or under study for first-line or salvage therapy, whereas combination therapy is kept for refractory cases.

Diagnosis and management of Aspergillus diseases: executive summary of the 2017 ESCMID-ECMM-ERS guideline

The European Society for Clinical Microbiology and Infectious Diseases, the European Confederation of Medical Mycology and the European Respiratory Society Joint Clinical Guidelines focus on diagnosis and management of aspergillosis. Of the numerous recommendations, a few are summarized here. Chest computed tomography as well as bronchoscopy with bronchoalveolar lavage (BAL) in patients with suspicion of pulmonary invasive aspergillosis (IA) are strongly recommended. For diagnosis, direct microscopy, preferably using optical brighteners, histopathology and culture are strongly recommended. Serum and BAL galactomannan measures are recommended as markers for the diagnosis of IA. PCR should be considered in conjunction with other diagnostic tests. Pathogen identification to species complex level is strongly recommended for all clinically relevant Aspergillus isolates; antifungal susceptibility testing should be performed in patients with invasive disease in regions with resistance found in contemporary surveillance programmes. Isavuconazole and voriconazole are the preferred agents for first-line treatment of pulmonary IA, whereas liposomal amphotericin B is moderately supported. Combinations of antifungals as primary treatment options are not recommended. Therapeutic drug monitoring is strongly recommended for patients receiving posaconazole suspension or any form of voriconazole for IA treatment, and in refractory disease, where a personalized approach considering reversal of predisposing factors, switching drug class and surgical intervention is also strongly recommended. Primary prophylaxis with posaconazole is strongly recommended in patients with acute myelogenous leukaemia or myelodysplastic syndrome receiving induction chemotherapy. Secondary prophylaxis is strongly recommended in high-risk patients. We strongly recommend treatment duration based on clinical improvement, degree of immunosuppression and response on imaging.

Comprehensive drug utilization review in neonates: liposomal amphotericin B

Objectives

This drug utilization evaluation aims to review current evidence on safety and efficacy of using liposomal amphotericin B (LAMB) in newborns with candidiasis, and compare it to the conventional preparation. Conventional amphotericin B deoxycholate (DAMB) is more commonly used in newborns, but dose-limiting adverse effects may compromise its efficacy. This review will examine the advantages and disadvantages of liposomal amphotericin B and define its place in current practice.

Key Findings

The terms ‘AmBisome’ or ‘liposomal amphotericin B’ and ‘neonatal candidiasis’ were entered in both PubMed and Ovid; studies included focused on safety and efficacy of liposomal amphotericin B in newborns with candidiasis, as well as studies comparing the conventional and the liposomal formulations in newborns as monotherapy. Pertinent references obtained from this search were also included. Additionally, pharmacokinetic studies were reviewed to include available data on dosing. Single case reports were not included in the review due to the limited conclusions that can be drawn from such sample sizes and quality of data.

Summary

Although liposomal amphotericin B may be better tolerated and as efficacious as the conventional formulation based on the published literature, the weakness of the studies available on the subject cannot be overlooked. Additional randomized controlled trials are needed to determine the true benefits of this medication.

Invasive fungal infection in neonatal intensive care units: a multicenter survey

This study assesses the epidemiology of invasive fungal infection (IFI) in Portuguese Neonatal Intensive Care Units (NICUs) and compares the effectiveness and safety of antifungal therapies. A survey concerning the period 2005-2010 was carried out in NICUs of Greater Lisbon. Among 10 473 admitted neonates, 44 cases were identified, 29 among extreme low birth weight neonates (65.9%). Cumulative incidence rate was 0.42% (95%CI 0.309-0.559). A central vascular catheter was present before IFI in all cases. Candida albicans and Candida parapsilosis were the most frequent isolates. The initial antifungic was fluconazole in 22 cases and liposomal amphotericin B (L-AmB) in 18. Therapy was switched in 10 patients on fluconazole and 3 on L-AmB. Case fatality rate was 11.4% (95%CI 4.39-23.91). No serious adverse drugs reactions (SADRs) or clinical side effects were observed. The knowledge of the local epidemiology helps to identify adequate prophylactic and treatment strategies.

CNS infections in patients with hematological disorders (including allogeneic stem-cell transplantation)-Guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO)

Diagnosis of CNS infections remains a great challenge in patients with hematological disorders since symptoms might both be masked and be mimicked by other conditions such as metabolic disturbances or consequences from antineoplastic treatment. Thus, awareness of this complication is crucial and any suspicion of a CNS infection should lead to timely and adequate diagnostics and treatment to improve the outcome in this population.

Infections of the central nervous system (CNS) are infrequently diagnosed in immunocompetent patients, but they do occur in a significant proportion of patients with hematological disorders. In particular, patients undergoing allogeneic hematopoietic stem-cell transplantation carry a high risk for CNS infections of up to 15%. Fungi and Toxoplasma gondii are the predominant causative agents. The diagnosis of CNS infections is based on neuroimaging, cerebrospinal fluid examination and biopsy of suspicious lesions in selected patients. However, identification of CNS infections in immunocompromised patients could represent a major challenge since metabolic disturbances, side-effects of antineoplastic or immunosuppressive drugs and CNS involvement of the underlying hematological disorder may mimic symptoms of a CNS infection. The prognosis of CNS infections is generally poor in these patients, albeit the introduction of novel substances (e.g. voriconazole) has improved the outcome in distinct patient subgroups. This guideline has been developed by the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO) with the contribution of a panel of 14 experts certified in internal medicine, hematology/oncology, infectious diseases, intensive care, neurology and neuroradiology. Grades of recommendation and levels of evidence were categorized by using novel criteria, as recently published by the European Society of Clinical Microbiology and Infectious Diseases.

Drug-induced acute kidney injury in neonates

PURPOSE OF REVIEW

Acute kidney injury (AKI) is an independent risk factor for morbidity and mortality in critically ill neonates. Nephrotoxic medication exposure is common in neonates. Nephrotoxicity represents the most potentially avoidable cause of AKI in this population.

RECENT FINDINGS

Recent studies in critically ill children revealed the importance of recognizing AKI and potentially modifiable risk factors for the development of AKI such as nephrotoxic medication exposures. Data from critically ill children who have AKI suggest that survivors are at risk for the development of chronic kidney disease. Premature infants are born with incomplete nephrogenesis and are at risk for chronic kidney disease. The use of nephrotoxic medications in the neonatal intensive care unit is very common; yet the effects of medication nephrotoxicity on the short and long-term outcomes remains highly understudied.

SUMMARY

The neonatal kidney is predisposed to nephrotoxic AKI. Our ability to improve outcomes for this vulnerable group depends on a heightened awareness of this issue. It is important for clinicians to develop methods to minimize and prevent nephrotoxic AKI in neonates through a multidisciplinary approach aiming at earlier recognition and close monitoring of nephrotoxin-induced AKI.

Advances in the treatment of invasive neonatal candidiasis

INTRODUCTION

Invasive candidiasis is responsible for ∼ 10% of nosocomial sepsis in very-low-birth-weight infants and is associated with substantial morbidity and mortality. Over the last two decades, the antifungal armamentarium against Candida spp. has increased; however, efficacy and safety studies in this population are lacking.

AREAS COVERED

We reviewed the medical literature and extracted information on clinical and observational studies evaluating the use of antifungal agents in neonates with invasive candidiasis.

EXPERT OPINION

Efficacy and safety data for antifungals in neonates are lacking, and the majority of studies conducted to date have concentrated on pharmacokinetic/pharmacodynamic evaluations. Unlike other anti-infective agents, efficacy data in the setting of neonatal candidiasis cannot be extrapolated from adult studies due to differences in the pathophysiology of the disease in this population relative to older children and adults. Data for amphotericin B deoxycholate, fluconazole, and micafungin suggest that these are the current agents of choice for this disease in neonates until data for newer antifungal agents become available. For prophylaxis, data from fluconazole randomized controlled trials will be submitted to the regulatory agencies for labeling. Ultimately, the field of therapeutics for neonatal candidiasis will require multidisciplinary collaboration given the numerous challenges associated with conducting clinical trials in neonates.

New antifungal and antiviral dosing

Neonatal fungal and viral infections are associated with mortality and neurologic impairment among survivors. Advances in pharmacokinetics (PK) and pharmacodynamics (PD) of antimicrobial medications have led to improved dosing guidance for neonates. This article discusses the basic PK/PD properties and dosing of the most common antifungal and antiviral medications used in neonates.

Pharmacokinetics and pharmacodynamics of antifungals in children: clinical implications

Invasive fungal disease (IFD) remains life threatening in premature infants and immunocompromised children despite the recent development of new antifungal agents. Optimal dosing of antifungals is one of the few factors clinicians can control to improve outcomes of IFD. However, dosing in children cannot be extrapolated from adult data because IFD pathophysiology, immune response, and drug disposition differ from adults. We critically examined the literature on pharmacokinetics (PK) and pharmacodynamics (PD) of antifungal agents and highlight recent developments in treating pediatric IFD. To match adult exposure in pediatric patients, dosing adjustment is necessary for almost all antifungals. In young infants, the maturation of renal and metabolic functions occurs rapidly and can significantly influence drug exposure. Fluconazole clearance doubles from birth to 28 days of life and, beyond the neonatal period, agents such as fluconazole, voriconazole, and micafungin require higher dosing than in adults because of faster clearance in children. As a result, dosing recommendations are specific to bracketed ranges of age. PD principles of antifungals mostly rely on in vitro and in vivo models but very few PD studies specifically address IFD in children. The exposure-response relationship may differ in younger children compared with adults, especially in infants with invasive candidiasis who are at higher risk of disseminated disease and meningoencephalitis, and by extension severe neurodevelopmental impairment. Micafungin is the only antifungal agent for which a specific target of exposure was proposed based on a neonatal hematogenous Candida meningoencephalitis animal model. In this review, we found that pediatric data on drug disposition of newer triazoles and echinocandins are lacking, dosing of older antifungals such as fluconazole and amphotericin B products still need optimization in young infants, and that target PK/PD indices need to be clinically validated for almost all antifungals in children. A better understanding of age-specific PK and PD of new antifungals in infants and children will help improve clinical outcomes of IFD by informing dosing and identifying future research areas.

Antifungal agents and therapy for infants and children with invasive fungal infections: a pharmacological perspective

Invasive fungal infections, although relatively rare, are life-threatening diseases in premature infants and immunocompromised children. While many advances have been made in antifungal therapeutics in the last two decades, knowledge of the pharmacokinetics and pharmacodynamics of antifungal agents for infants and children remains incomplete. This review summarizes the pharmacology and clinical utility of currently available antifungal agents and discusses the opportunities and challenges for future research.

Diagnosis and treatment of invasive fungal infections focus on liposomal amphotericin B

Invasive fungal infections (IFIs) are responsible for significant morbidity and mortality, especially in immunocompromised patients and in those requiring admission to an intensive care unit. The epidemiology of IFI is changing, and an increment in non-Aspergillus filamentous fungi and non-Candida albicans species has been observed. The present paper reviews the epidemiology and diagnosis of IFIs. Regarding the treatment of IFIs, it focuses primarily on the role of liposomal amphotericin B in this setting. The main recommendations put forth by expert societies and groups are discussed.

Treatment of invasive fungal infections in cancer patients-updated recommendations of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO)

The Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO) here presents its updated recommendations for the treatment of documented fungal infections. Invasive fungal infections are a main cause of morbidity and mortality in cancer patients undergoing intensive chemotherapy regimens. In recent years, new antifungal agents have been licensed, and agents already approved have been studied in new indications. The choice of the most appropriate antifungal treatment depends on the fungal species suspected or identified, the patient's risk factors (e.g., length and depth of neutropenia), and the expected side effects. This guideline reviews the clinical studies that served as a basis for the following recommendations. All recommendations including the levels of evidence are summarized in tables to give the reader rapid access to the information.

Canadian clinical practice guidelines for invasive candidiasis in adults

Candidemia and invasive candidiasis (C/IC) are life-threatening opportunistic infections that add excess morbidity, mortality and cost to the management of patients with a range of potentially curable underlying conditions. The Association of Medical Microbiology and Infectious Disease Canada developed evidence-based guidelines for the approach to the diagnosis and management of these infections in the ever-increasing population of at-risk adult patients in the health care system. Over the past few years, a new and broader understanding of the epidemiology and pathogenesis of C/IC has emerged and has been coupled with the availability of new antifungal agents and defined strategies for targeting groups at risk including, but not limited to, acute leukemia patients, hematopoietic stem cell transplants and solid organ transplants, and critical care unit patients. Accordingly, these guidelines have focused on patients at risk for C/IC, and on approaches of prevention, early therapy for suspected but unproven infection, and targeted therapy for probable and proven infection.

Antifungal agents for the treatment of systemic fungal infections in children

Traditionally, the mainstay of systemic antifungal therapy has been amphotericin B deoxycholate (conventional amphotericin B). Newer agents have been developed to fulfill special niches and to compete with conventional amphotericin B by virtue of having more favourable toxicity profiles. Some agents have displaced conventional amphotericin B for the treatment of specific fungal diseases. For example, voriconazole has emerged as the preferred treatment for invasive pulmonary aspergillosis. This notwithstanding, conventional amphotericin B remains a useful agent for the treatment of paediatric fungal infections. Knowledge of the characteristics of the newer agents is important, given the increasing numbers of patients who are being treated with these drugs. Efforts need to be directed at research aimed at generating paediatric data where these are lacking. The antifungal agents herein described are most often used as monotherapy regimens because there is no uniform consensus on the value of combination therapy, except for specific scenarios.

Antifungal therapy and outcomes in infants with invasive Candida infections

BACKGROUND

Invasive candidiasis is a leading cause of mortality and morbidity in neonatal intensive care units. Treatment recommendations are limited by a lack of comparative outcomes data.

METHODS

We identified all infants ≤ 120 days of age with positive blood, urine, or cerebrospinal fluid cultures for Candida species who received amphotericin B deoxycholate, fluconazole, amphotericin B lipid products, or combination therapy admitted to one of 192 neonatal intensive care units in the United States between 1997 and 2003. Primary outcome measures included overall mortality and therapeutic failure (combined outcome of duration of infection >7 days, need for additional antifungal therapy, or death before discharge). We compared outcomes by antifungal therapy using logistic regression, controlling for gestational age, day of life at start of antifungal therapy, delay in therapy, and site of infection.

RESULTS

Overall, 138 of 730 (19%) infants died. On multivariable logistic regression, we observed higher overall mortality for infants receiving amphotericin B lipid products compared with infants receiving amphotericin B deoxycholate (odds ratio 1.96 [95% confidence intervals: 1.16, 3.33]; P = 0.01) or fluconazole (odds ratio 2.39 [1.18, 4.83]; P = 0.02).

CONCLUSIONS

Infants treated with amphotericin B lipid products had higher mortality than infants treated with either amphotericin B deoxycholate or fluconazole. This finding may be related to inadequate penetration of amphotericin B lipid products into the kidneys, inappropriate dosing in premature infants, or unknown differences in acuity of illness in infants treated with amphotericin B lipid products.

Liposomal amphotericin B does not induce nephrotoxicity or renal function impairment in premature neonates

BACKGROUND

Liposomal amphotericin B (LAMB) is frequently administered in NICU to preterm infants <1500 g at birth (VLBW) for treatment of systemic fungal infections (SFI). Concerns exist on safety and tolerability of such drug in patients who are at risk for renal function impairment due to their prematurity.

AIM

To assess the occurrence of renal function impairment related to LAMB in a 10-year cohort of VLBW neonates treated with this drug.

METHODS

Through database search of clinical charts, all VLBW neonates admitted to a 3(rd) level NICU in the years 1998-2007 and undergoing treatment with LAMB were identified. The occurrence of LAMB-attributable renal toxicity was investigated; infants withdrawn from treatment for development of adverse effects or toxicity were identified.

RESULTS

In the study period, 71 of 792 admitted VLBW neonates (8.9%) underwent antifungal treatment with LAMB administered at the recommended dosages (3-to-5 mg/kg/day). Mean duration of treatment was 14 (±9) days, mean cumulative dose given was 58 (±25) mg/kg per infant. Renal compromise, defined as hypokalaemia, and/or elevated creatinine serum levels, and/or decreased urine output, occurred in 2 of 71 (2.8%) treated patients, by 5 (±3) mean days after treatment initiation. In both patients LAMB was withdrawn; renal function impairment was only mild and transient, and normal renal function was restored at discharge. No other significant adverse effects were recorded in any treated neonate.

CONCLUSIONS

LAMB is generally safe and well tolerated in VLBW neonates. The occurrence of LAMB-related nephrotoxicity appears to be uncommon, mild and transient.

The use of antifungal therapy in neonatal intensive care

Invasive fungal infections remain a significant cause of infection-related mortality and morbidity in preterm infants. Central nervous system involvement is the hallmark of neonatal candidiasis, differentiating the disease's impact on young infants from that among all other patient populations. Over the past decade, the number of antifungal agents in development has grown, but most are not labeled for use in newborns. We summarize the findings of several antifungal studies that have been completed to date, emphasizing those including infant populations. We conclude that more studies are required for antifungals to be used safely and effectively in infants.

Liposomal amphotericin B in critically ill paediatric patients

WHAT IS KNOWN AND OBJECTIVE

Literature provides much evidence regarding liposomal amphotericin B treatment for fungal infections in neonates and infants. Relevant data regarding critically ill paediatric patients of older age are scarce. We aimed to present our experience regarding liposomal amphotericin B use in critically ill paediatric patients from a tertiary-care paediatric hospital in Athens, Greece.

METHODS

We prospectively identified all paediatric patients who received treatment with liposomal amphotericin B in the intensive care unit of a tertiary-care paediatric hospital during a 3-year period (2005-2008). Data were retrieved from the evaluation of the available medical records.

RESULTS AND DISCUSSION

Twenty-three (nine females, mean age: 26·4 months, range: 5-39 months) critically ill paediatric patients were included; 12 had malignancy. In 16 of the 23 included children, liposomal amphotericin B was administered for the treatment of confirmed fungal infections (all but one were invasive), whereas in seven patients, it was used as pre-emptive treatment. One patient received voriconazole concomitantly. Eleven of the 16 children with documented infections were cured; five improved. Six of the seven children who received pre-emptive treatment also showed clinical improvement. Nine deaths were noted, all attributed to underlying diseases. Two cases of hepatotoxicity and one case of nephrotoxicity (all leading to drug-discontinuation) occurred. Seven and five cases of mild reversible hypokalaemia and hyponatraemia, respectively, were also noted.

WHAT IS NEW AND CONCLUSION

According to the findings of our small case series, liposomal amphotericin B may provide a useful treatment option for fungal infections of vulnerable critically ill paediatric patients with considerable comorbidity.

[Guidelines for the treatment of Invasive Candidiasis and other yeasts. Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC). 2010 Update]

These guidelines are an update of the recommendations of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) that were issued in 2004 (Enferm Infecc Microbiol Clin. 2004, 22:32-9) on the treatment of Invasive Candidiasis and infections produced by other yeasts. This 2010 update includes a comprehensive review of the new drugs that have appeared in recent years, as well as the levels of evidence for recommending them. These guidelines have been developed following the rules of the SEIMC by a working group composed of specialists in infectious diseases, clinical microbiology, critical care medicine, paediatrics and oncology-haematology. It provides a series of general recommendations regarding the management of invasive candidiasis and other yeast infections, as well as specific guidelines for prophylaxis and treatment, which have been divided into four sections: oncology-haematology, solid organ transplantation recipients, critical patients, and paediatric patients.

Role of echinocandins in the management of fungal infections in neonates

As the incidence rates of neonatal systemic fungal infections (SFI) have been increasing over the last years, research efforts have been addressed towards identifying both effective preventative strategies, and efficacious and well-tolerated antifungal drugs. Historically, the first options in treatment of neonatal SFI have been &#x2013; and currently are &#x2013; fluconazole and amphotericin B. However, these two drugs carry limitations both in efficacy and in putative toxicity. Recently, new therapeutic alternatives have drawn the neonatologists' attention. Echinocandins are a new class of antifungal drugs with characteristics that might better meet the needs of this particular population of patients. Caspofungin (CSP), micafungin (MICA), and anidulafungin have inherent good activities both against biofilms, and against natively fluconazole-resistant strains of Candida spp, thus overcoming two of the major weaknesses of the commonly used antifungal drugs in nurseries. CSP and MICA have been recently studied in neonatal populations. The kinetics and appropriate dosing of this agent in premature and term infants have been described, but ongoing further studies are needed to better address this area. Case-report series show clinical efficacy and tolerability in critical neonatal patients given CSP and MICA. In addition, extrapolation of data from randomized trials conducted in pediatric and adult patients showed through a subgroup analysis that both CSP and MICA are effective and well tolerated also in neonates. Further studies properly designed for neonatal populations will better address long-term safety and ecological issues related to echinocandin use in neonates.

Safety of micafungin in infants: insights into optimal dosing

INTRODUCTION

Invasive Candida infections are a leading cause of mortality and morbidity in neonatal intensive care units (NICUs). Micafungin is a promising therapeutic option for treatment of invasive fungal infections in infants given its safety profile in older children and adults. Understanding micafungin safety in infants is particularly important because antifungals are most often used in premature infants with multiple underlying medical conditions in a critical care setting.

AREAS COVERED

This article reviews the literature evaluating the safety profile of micafungin in infants and offers recommendations for optimal dosing for treatment of invasive candidiasis in the NICU setting. The review has been performed using a Medline search in September 2010 for related articles from 1990 to the present with the Mesh related terms 'micafungin' and 'safety' in combination with the free words 'antifungal', 'candidiasis', 'drug toxicity', 'infant, premature' and 'infant, newborn'.

EXPERT OPINION

Despite the limitations of the existing literature, we believe micafungin dosing of 10 mg/kg/day for all term and preterm infants is a viable treatment option in the NICU setting for management of invasive candidiasis. Although the number of infants for whom safety data are reported is small, higher doses of micafungin appear safe and well tolerated in this population.

Once-weekly liposomal amphotericin B as Candida prophylaxis in very low birth weight premature infants: a prospective, randomized, open-label, placebo-controlled pilot study

OBJECTIVE

This study was conducted to evaluate once-weekly liposomal amphotericin B (L-AmB) for Candida prophylaxis in very low birth weight (VLBW) neonates.

METHODS

This prospective, randomized, open-label, placebo-controlled study included neonates who were <32 weeks' gestational age, <7 days old, and weighing <1500 g at birth. Subjects were randomized to receive L-AmB 5 mg/kg per week or placebo (dextrose water) and were followed until 6 weeks of age. Surveillance cultures were obtained at baseline, at 72 hours, and weekly thereafter. Study drug was continued until 6 weeks after birth or the discontinuation of high-risk treatments and invasive devices, whichever occurred first. Blood cultures were obtained as clinically indicated. The primary end point was development of Candida colonization by 6 weeks' postnatal age; secondary end points included development of invasive candidiasis and occurrence of treatment-related adverse events. Safety variables included renal and hepatic function tests, incidence of grade III-IV intraventricular hemorrhage (IVH) and necrotizing enterocolitis (NEC), and mortality.

RESULTS

Forty subjects were enrolled and randomized to receive L-AmB (12 males, 8 females; 50% white) or placebo (12 males, 8 females; 35% white). Subjects were evenly distributed by gestational age, age at enrollment, birth weight, race, and sex. Consent was withdrawn after completion of study treatment in 1 subject (L-AmB); 1 subject in each study arm died during the study; and 3 subjects were transferred back to their referring institutions (1 L-AmB, 2 placebo). Thus, 17 subjects in each arm completed all study procedures, although all 40 subjects were evaluable. Colonization before administration of study drug was noted in 4 L-AmB subjects (20%) and 1 placebo subject (5%); 1 (5%) and 3 (15%) subjects in the respective groups developed colonization while receiving study drug. No L-AmB subjects and 1 placebo subject developed candidiasis. One subject in each group died; these deaths were not considered related to study drug or fungal infection. There were no clinical differences between groups in the incidence of grade III-IV IVH, NEC, hypokalemia, nephrotoxicity, need for platelet or packed red blood cell transfusion, or mortality.

CONCLUSIONS

L-AmB 5 mg/kg once weekly was generally well tolerated in these VLBW infants. The data did not allow evaluation of efficacy. A larger, multicenter, randomized clinical trial of L-AmB for Candida prophylaxis that is appropriately powered is warranted.

Pharmacokinetics of an elevated dosage of micafungin in premature neonates

BACKGROUND

Determining the safety and pharmacokinetics of antifungal agents in neonates is important. A previous single-dose pharmacokinetic study of micafungin in neonates demonstrated that doses of 0.75 to 3 mg/kg produced lower plasma micafungin concentrations than in older patients because of increased apparent plasma clearance of micafungin in neonates. The primary objective of this study was to assess the safety and pharmacokinetics of an increased (15 mg/kg/d) dose of micafungin.

METHODS

A repeated dose, open-label pharmacokinetic, and safety trial of intravenous micafungin in 12 preterm neonates >48 hours of life with suspected systemic infections. Neonates received 15 mg/kg/d of micafungin for 5 days. Blood samples were drawn relative to either the fourth or fifth dose. Systemic exposure was assessed by examination of the plasma area under the curve.

RESULTS

The median birth weight and gestational age of the neonates were 775 g and 27 weeks, respectively. No adverse events related to micafungin were detected. The mean area under the curve and clearance for the cohort was 437.5 microg'h/mL and 0.575 mL/min/kg, respectively. The calculated clearance and volume of distribution for neonates was greater than that observed in older children and adults.

CONCLUSIONS

These data suggest that 15 mg/kg dosing in premature neonates corresponds to an exposure of approximately 5 mg/kg in adults. No adverse events related to micafungin were observed.

Central nervous system infections in immunocompromised patients: update on diagnostics and therapy

Infections of the central nervous system (CNS) are increasingly reported in patients with malignancies. Heavily immunocompromised patients like those after allogeneic stem cell transplantation (SCT) or previous T cell depleting treatment regimens (e.g. with fludarabine or alemtuzumab) are at highest risk for cerebral infections. The spectrum of causative organisms may vary greatly, depending on the underlying malignancy, its treatment and various other factors. Toxoplasma gondii and fungi are the leading causative organisms in patients after allogeneic SCT, but also viruses such as herpes simplex virus or JC virus may be detected in these patients. Definitive diagnosis of cerebral infection still remains a high challenge, although diagnostics have improved by the wide availability of imaging techniques and polymerase chain reaction in recent years. Novel therapeutic options are arising, particularly for fungal CNS infections. Here, we summarise aspects on epidemiology, clinical symptoms and prognosis of CNS infections in patients with malignancies. Additionally, we give an overview on the diagnostics and management of cerebral infections in these patients including evidence evaluation of efficacy of treatment.

Clinical practice guidelines for the management of candidiasis: 2009 update by the Infectious Diseases Society of America

Guidelines for the management of patients with invasive candidiasis and mucosal candidiasis were prepared by an Expert Panel of the Infectious Diseases Society of America. These updated guidelines replace the previous guidelines published in the 15 January 2004 issue of Clinical Infectious Diseases and are intended for use by health care providers who care for patients who either have or are at risk of these infections. Since 2004, several new antifungal agents have become available, and several new studies have been published relating to the treatment of candidemia, other forms of invasive candidiasis, and mucosal disease, including oropharyngeal and esophageal candidiasis. There are also recent prospective data on the prevention of invasive candidiasis in high-risk neonates and adults and on the empiric treatment of suspected invasive candidiasis in adults. This new information is incorporated into this revised document.

Influence of sodium intake on Amphotericin B-induced nephrotoxicity among extremely premature infants

Amphotericin B (AmphoB) remains the preferred therapy for invasive fungal infections despite many side effects, such as nephrotoxicity and electrolyte imbalance. Our previous study suggested that high sodium (Na) intake >4 mEq/kg per day may be associated with lower nephrotoxicity in extremely premature infants treated with AmphoB. Subsequently, it became a standard of care in our unit to administer Na >4 mEq/kg per day to extremely premature infants treated with AmphoB. The purpose of this study was to evaluate the effect of high Na intake > 4 mEq/kg per day on the incidence of AmphoB-induced nephrotoxicity among extremely premature infants with birth weight <1250 gm. All extremely premature infants with birth weight <1250 gm born between 1992 and 2004 and treated with AmphoB for systemic fungal infections were included in the study. The study infants were divided into two groups: a control (CL) group (1/1992-12/1999, n = 21) consisting of extremely premature infants given a maintenance Na intake during AmphoB therapy, and a high sodium intake (High Na) group (1/2000-12/2004, n = 16) consisting of extremely premature infants given a high Na intake >4 mEq/kg per day during AmphoB therapy. Nephrotoxicity was defined as serum creatinine levels >1 mg/dl, urinary output (UOP) < 1 ml/kg per hour or a decrease in UOP of 50%, compared with the previous 2 days, and persisting for at least 2 days. Invasive fungal infection was diagnosed in 5.7% of the infants (44/763 infants). Thirty-seven infants were eligible for the study and seven were excluded. There were no differences between the two groups in gestational age, birth weight, age at fungal infection diagnosis, length of AmphoB therapy, daily fluid intake or hyponatremia. Nephrotoxicity was significantly higher in the CL group than in the High Na group (13/21 vs. 3/16; P = 0.02). In the CL group, nephrotoxicity occurred at (mean +/- SD) 1.9 +/- 3.2 days after the initiation of AmphoB treatment and lasted for 5.5 +/- 4.7 days. In this group, nephrotoxicity occurred in two of the 13 infants before the initiation of AmphoB therapy. In the High Na group, nephrotoxicity occurred before the start of AmphoB therapy in two of the three infants. In the third infant, nephrotoxicity lasted for 1 day. Mean Na intake was not different between the two groups during the 4-day period prior to AmphoB therapy. Mean Na intake during the first 10-day period of AmphoB therapy was significantly lower in the CL group (3.7 vs 6.2; P < 0.001).

CONCLUSION

High Na intake was associated with a reduction in the incidence of AmphoB-induced nephrotoxicity in extremely premature infants with birth weight <1250 gm. We recommend the use of a high Na intake of >4 mEq/kg per day for extremely premature infants during Amphotericin B therapy.

Effect of amphotericin B lipid complex (ABLC) in very low birth weight infants

The aim of this retrospective, case-control study was to determine the effect of the amphotericin B lipid complex (ABLC) on serum creatinine (SCr), blood urea nitrogen (BUN), sodium (Na), and potassium (K) in very low birth weight (VLBW) infants. Medical records of all VLBW infants who were admitted to our Neonatal Intensive Care Unit between May 1998 and May 2006 and had received ABLC for at least 2 weeks were reviewed for patient demographics, use of medications (ABLC, diuretics, xanthines, indomethacin, vancomycin, gentamicin, pressors, and inotropes), fluid intake, urinary output, and serum electrolytes. Thirty-five patients who received ABLC were identified and matched by gestational age (GA) to 35 patients who served as controls. Infants who received ABLC had an average GA of 25.7 +/- 2.1 weeks and a birth weight of 764 +/- 196 g. Between day 1 and 14 of ABLC treatment, the BUN decreased from 17.5 +/- 11.5 to 10.5 +/- 6.8 mg/dl (p = 0.01), the SCr varied between 0.78 +/- 0.32 and 0.69 +/- 0.32 mg/dl, Na varied between 136.6 +/- 5.8 and 137.8 +/- 3.6 mEq/l, and K varied between 4.8 +/- 0.9 and 4.9 +/- 0.6 mEq/l, respectively. Based on these results, we conclude that treatment with ABLC for 2 weeks did not increase BUN or SCr, nor decrease Na or K in VLBW infants.

Neonatal Candida spp. infections: an update

Candida-related morbidity and mortality have increased in neonatal intensive care units (NICUs) in the last 20 years. Invasive fungal infections (IFIs) in preterm infants are associated with high severity, high attributable mortality, substantial morbidity and poor outcomes owing to the frequent association with late neurodevelopmental impairment and retinopathy of prematurity in the survivors. Preterm very-low birth weight infants in NICUs have a specific, increased risk for IFIs, mainly because up to 60% of them may become colonized during their first month of life. Prevention of Candida colonization and infection is the key in these settings of unique patients, and solid data have recently been added to the very first promising results obtained in the early 2000’s with administation of fluconazole. In a multicenter randomized trial, this azole caused a striking reduction in the incidences of Candida spp. colonization (from 33 to 9%) and infection (from 13.2 to 3.2%), with no occurrence of significant side-effects and no signs of selective resistance during the 15-month study period. New guidelines incorporating the recent multicenter results are urgently needed.

Antifungal agents in neonates: issues and recommendations

Fungal infections are responsible for considerable morbidity and mortality in the neonatal period, particularly among premature neonates. Four classes of antifungal agents are commonly used in the treatment of fungal infections in pediatric patients: polyene macrolides, fluorinated pyrimidines, triazoles, and echinocandins. Due to the paucity of pediatric data, many recommendations for the use of antifungal agents in this population are derived from the experience in adults. The purpose of this article was to review the published data on fungal infections and antifungal agents, with a focus on neonatal patients, and to provide an overview of the differences in antifungal pharmacology in neonates compared with adults. Pharmacokinetic data suggest dosing differences in children versus adult patients with some antifungals, but not all agents have been fully evaluated. The available pharmacokinetic data on the amphotericin B deoxycholate formulation in neonates exhibit considerable variability; nevertheless, the dosage regimen suggested in the neonatal population is similar to that used in adults. More pharmacokinetic information is available on the liposomal and lipid complex preparations of amphotericin B and fluconazole, and it supports their use in neonates; however, the optimal dosage and duration of therapy is difficult to establish. All amphotericin-B formulations, frequently used in combination with flucytosine, are useful for treating disseminated fungal infections and Candida meningitis in neonates. Fluconazole, with potent in vitro activity against Cryptococcus neoformans and almost all Candida spp., has been used in neonates with invasive candidiasis at dosages of 6 mg/kg/day, and for antifungal prophylaxis in high-risk neonates. There are limited data on itraconazole, voriconazole, and posaconazole use in neonates. Caspofungin, which is active against Candida spp. and Aspergillus spp., requires higher doses in children relative to adults, and dosing is best accomplished based on body surface area. Micafungin shows a clear trend toward lower levels in the smallest patients. There are no data on the use of other new antifungal drugs (ravuconazole and anidulafungin) in neonates. In summary, the initial data suggest dosage differences in neonates for some antifungal agents, although the newer agents have not been fully tested for optimal administration in these patients.

A comparison of AmBisome to amphotericin B for treatment of systemic candidiasis in very low birth weight infants

PURPOSE

Amphotericin B is considered the treatment of choice for systemic candidiasis, but adverse effects may limit its use. An alternative option for the treatment of candidiasis includes lipid preparations of amphotericin B. This study investigated the safety and efficacy of AmBisome, a lipid formulation of amphotericin B containing liposomal structures, for the treatment of systemic candidiasis in very low birth weight infants (VLBWI).

MATERIALS AND METHODS

Data from 26 VLBWI treated with AmBisome in the study group (AmBisome group) from October 2003 to July 2006 were compared with data from 20 VLBWI treated with amphotericin B as a historical control (Amphotericin group). This study was a prospective, historical control, multi-center trial.

RESULTS

Candida spp. was isolated in 73% (19/26) of the cases for the AmBisome group and 90% (18/20) of the cases for the Amphotericin group. The fungal eradication rate and the time to eradication was 84% (16/19) and 9+/-8 days in the AmBisome group, and 89% (16/18) and 10+/-9 days in the Amphotericin group, respectively (p=0.680 vs p=0.712). The major adverse effects were lower in the AmBisome group (renal toxicity, 21% vs 55%, p=0.029; hepatotoxity, 25% vs 65%, p=0.014, AmBisome group vs Amphotericin group, respectively). There was no significant difference in mortality attributed to systemic candidiasis (12% in the AmBisome group, 10% in the Amphotericin group, p=0.868).

CONCLUSION

AmBisome is effective and safe for treating systemic fungal infections in VLBWI.

Antifungal therapy in children with invasive fungal infections: a systematic review

Invasive fungal infections are associated with significant morbidity and mortality. Differences between children and adults are reported, yet few trials of antifungal agents have been performed in pediatric populations. We performed a systematic review of the literature to guide appropriate pediatric treatment recommendations. From available trials that compared antifungal agents in either prolonged febrile neutropenia or invasive candidal or Aspergillus infection, no clear difference in treatment efficacy was demonstrated, although few trials were adequately powered. Differing antifungal pharmacokinetics between children and adults were demonstrated, requiring dose modification. Significant differences in toxicity, particularly nephrotoxicity, were identified between classes of antifungal agents. Therapy needs to be guided by the pathogen or suspected pathogens, the degree of immunosuppression, comorbidities (particularly renal dysfunction), concurrent nephrotoxins, and the expected length of therapy.

Prevention and treatment of Candida infections in neonates

Invasive Candia infections have become the third most common cause of late-onset infection among very low birth weight infants in most neonatal intensive care units. Significant risk factors include birth weight less than 1000 g, exposure to more than two antibiotics, third generation cephalosporin exposure, parenteral nutrition including lipid emulsion, central venous catheter, and abdominal surgery. The majority of neonatal Candida infections are caused by C. albicans and C. parapsilosis, although other nonalbicans species are being reported more frequently. Standard therapy has been amphotericin B; however, successful use of fluconazole as a single agent has also been reported and a small comparison trial demonstrated similar efficacy. The addition of new antifungal agents, including voriconazole and the echinocandins may further improve our ability to effectively treat these infections and possibly reduce the development of complications. Antifungal chemoprophylaxis has been studied in single-center and cohort studies, primarily using fluconazole. Although it is clear that fluconazole prophylaxis decreases the risk of fungal colonization and infection, identification of potential harm, particularly the development of or selection for resistant strains, requires further investigation with multicenter trials before widespread use is recommended outside of the clinical trial setting.

The pharmacokinetics and safety of micafungin, a novel echinocandin, in premature infants

BACKGROUND

: Candidal fungal infection rates in neonates are increasing and are a significant cause of mortality, especially in low birth weight infants. Micafungin is an echinocandin that works by inhibiting 1,3-beta-D-glucan synthase, an enzyme responsible for fungal cell wall synthesis. The objective of this study was to determine the safety and pharmacokinetics of micafungin in premature infants.

METHODS

: This was a phase I, single-dose, multicenter, open-label, sequential-dose trial of intravenous micafungin investigating 3 doses (0.75 mg/kg, 1.5 mg/kg and 3.0 mg/kg) in 18 premature infants weighing >1000 g (n = 6 in each dosage group). A further 5 infants (500-1000 g) were enrolled in the 0.75 mg/kg dosage group only.

RESULTS

: The mean +/- standard deviation gestational age in the >1000 g dosage group was 26.4 +/- 2.4 weeks and, on entry, patients had one or more of a variety of underlying conditions, including sepsis, pneumonia and other infections caused by Candida or other species. Micafungin pharmacokinetics in preterm infants appears linear. However, premature infants >1000 g on average displayed a shorter half-life (8 hours) and a more rapid rate of clearance (approximately 39 mL/h per kg) compared with published data in older children and adults. All doses of micafungin were well tolerated and no serious drug-related adverse events were observed.

CONCLUSIONS

: Single doses of micafungin, ranging up to 3.0 mg/kg, appear well tolerated in premature infants weighing >1000 g. The drug's elimination half-life and total plasma clearance in preterm infants appear dissimilar to published values for these parameters in older children and adults. The reason(s) for this apparent difference remain to be investigated.

Invasive aspergillosis in children with hematologic malignancies

The respiratory tract is the most common system affected by aspergillosis in children with hematologic malignancies. However, Aspergillus spp. tend to invade blood vessels, resulting in systemic dissemination to multiple organs including, but not limited to, the brain, bones, liver, kidneys, and skin. Because early diagnosis and treatment are critical to the patient's outcome, a high index of suspicion should be maintained in children with hematologic malignancies who are neutropenic and have prolonged fever that is unresponsive to systemic antibacterials. Several diagnostic modalities should be used simultaneously in order to establish the diagnosis in an expeditious manner. Detailed radiographic evaluations with plain radiographs, and CT scans of the chest, sinuses, brain, and other organs should be performed as soon as clinical suspicion is raised. Detection of circulating antigens, such as galactomannan and 1,3-beta-glucan, and polymerase chain reaction appear promising in aiding in the diagnosis. A definitive diagnosis requires both a positive culture from a sterile site and evidence of tissue damage demonstrated by imaging studies or microscopic evaluations of sites of infection. Because the mortality rate is very high, empiric systemic antifungal therapy with amphotericin B, or one of its lipid formulations, should be initiated while laboratory investigations to substantiate or refute the diagnosis are continued. Surgical intervention is associated with a high mortality rate but may be of benefit in children with localized disease.

Mycoses in Pediatric Patients

For more than 40 years, there has been limited progress in the treatment of invasive fungal infections. There are now numerous nuances to choosing the appropriate antifungal agent. Important advantages have been achieved in understanding the safety, tolerability, and pharmacokinetics of these agents. One of the most important aspects for successful management of pediatric invasive fungal infections is an understanding of the differences in the pharmacokinetics of the drugs in children and adults to offer optimal dosing strategies. Unfortunately there have been few antifungal studies conducted in children. Consequently most information for the pediatrician has been extrapolated from adult data. The breadth of antifungal data in children is expanding, however, with newer studies underway. Through the efforts of dedicated clinicians and collaboration, pediatric indications and dosing strategies will eventually be discovered that directly benefit pediatric patients.

Pharmacocinétique des antifongiques en fonction du terrain

Antifungal drugs for treating systemic mycoses are flucytosine, amphotéricin B, azoles and caspofungin. Their pharmacokinetics and pharmacodynamics are reviewed in order to determine the optimal modalities of their administration and the best dosing regimen for several populations: neonates, infants, patients with renal or liver disease, patients with hemodialysis or hemofiltration.