Antifungal agents in neonates: issues and recommendations

Cryptococcus liquefaciens isolated from the hand of a healthcare professional in a neonatal intensive care unit

Fungal infections are responsible for high morbidity and mortality in neonatal patients, especially in premature newborns. Infections in neonates caused by Cryptococcus spp. are rare, but it has occurred in an immunocompromised population. This study aims to describe the isolation of Cryptococcus liquefaciens from the hands of a health professional in a neonatal intensive care unit, and to evaluate the production of biofilm and virulence factors and susceptibility to antifungals. Antifungal susceptibility tests were performed according to Clinical and Laboratory Standard Institute document M27-A3. Thermotolerance virulence factors and DNase, phospholipase, proteinase, and hemolytic activities were verified through phenotypic tests; biofilm was evaluated by determining the metabolic activity and biomass. The isolate did not produce any of the tested enzymes and was susceptible to all antifungals (amphotericin B, fluconazole, and micafungin). The growth at 37 °C was very weak; however, the isolate showed a strong biomass production and low metabolic activity. This is the first report of C. liquefaciens isolated from the hands of a health professional. The isolate did not express any of the studied virulence factors in vitro, except for the low growth at 37 °C in the first 48 h, and the strong production of biofilm biomass. Cryptococcus liquefaciens can remain in the environment for a long time and is a human pathogen because it tolerates temperature variations. This report draws attention to the circulation of rare species in critical locations, information that may help in a fast and correct diagnosis and, consequently, implementation of an appropriate treatment.

Efficacy of LAMB against Emerging Azole- and Multidrug-Resistant Candida parapsilosis Isolates in the Galleria mellonella Model

While being the third leading cause of candidemia worldwide, numerous studies have shown severe clonal outbreaks due to fluconazole-resistant (FLCR) Candida parapsilosis isolates associated with fluconazole therapeutic failure (FTF) with enhanced mortality. More recently, multidrug resistant (MDR) C. parapsilosis blood isolates have also been identified that are resistant to both azole and echinocandin drugs. Amphotericin B (AMB) resistance is rarely reported among C. parapsilosis isolates and proper management of bloodstream infections due to FLZR and MDR isolates requires prompt action at the time of outbreak. Therefore, using a well-established Galleria mellonella model, we assessed whether (a) laboratory-based findings on azole or echinocandin (micafungin) resistance in C. parapsilosis lead to therapeutic failure, (b) LAMB could serve as an efficient salvage treatment option, and (c) distinct mutations in ERG11 impact mortality. Our in vivo data confirm fluconazole inefficacy against FLCR C. parapsilosis isolates carrying Y132F, Y132F + K143R, Y132F + G307A, and G307A + G458S in Erg11p, while LAMB proved to be an efficacious accessible option against both FLCR and MDR C. parapsilosis isolates. Moreover, positive correlation of in vitro and in vivo data further highlights the utility of G. melonella as a reliable model to investigate azole and polyene drug efficacy.

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.

A Phase 3 Study of Micafungin Versus Amphotericin B Deoxycholate in Infants With Invasive Candidiasis

BACKGROUND

Amphotericin B deoxycholate (AmB-D) is standard of care treatment for neonatal invasive candidiasis (IC). Micafungin (MCA) has broad-spectrum fungicidal activity against Candida spp. We compared the efficacy and safety of intravenous MCA with intravenous AmB-D and assessed the pharmacokinetics of MCA in infants >2-120 days of age with proven IC in a phase 3, randomized, double-blind, multicenter, parallel-group, noninferiority study (NCT00815516).

METHODS

Infants were randomized 2:1 to MCA (10 mg/kg/d) or AmB-D (1 mg/kg/d) for ≥21 days. Primary efficacy endpoint was fungal-free survival (FFS) 1 week after last study drug dose. MCA population pharmacokinetics included simulated area under the curve (AUC) at steady state and maximum plasma concentration after 2-hour infusion. AUC pharmacodynamic target exposure was 170 µg·h/mL.

RESULTS

Thirty infants received MCA (n = 20) or AmB-D (n = 10). The trial was terminated early because of slow recruitment. FFS was observed in 12 of 20 [60%; 95% confidence interval (CI): 36%-81%] MCA-group infants and in 7 of 10 (70%; 95% CI: 35%-93%) AmB-D-group infants. The most common treatment-emergent adverse events were anemia [MCA: n = 9 (45%); AmB-D: n = 3 (30%)] and thrombocytopenia [n = 2 (10%) and n = 3 (30%), respectively]. Model-derived mean AUC at steady state for MCA was 399.3 ± 163.9 µg·h/mL (95% prediction interval: 190.3-742.3 µg/mL); steady state and maximum plasma concentration after 2-hour infusion was 31.1 ± 10.5 µg/mL (95% prediction interval: 17.0-49.7 µg/mL). MCA exposures were above the AUC pharmacodynamic target exposure.

CONCLUSIONS

Within the study limitations, infants with IC treated with MCA achieved similar FFS compared with AmB-D. Both agents were safe and well tolerated.

Pharmacokinetics and safety of fluconazole and micafungin in neonates with systemic candidiasis: a randomized, open-label clinical trial

AIMS

The pharmacokinetics (PK) of fluconazole and micafungin differ in neonates compared with children and adults. Dosing instructions in product labels appear to be inconsistent with the emerging scientific evidence. Limited information is available on the safety profile of these agents in neonates. Our objective was to study the population PK and safety of both drugs, randomly administered in neonates with suspected or confirmed systemic candidiasis.

METHODS

Neonates were randomized 1:1 to fluconazole (loading dose 25 mg kg^-1 ; maintenance dose 12 mg kg^-1 day^-1 or 20 mg kg^-1 day^-1 , respectively, for infants <30 weeks or ≥30 weeks' corrected gestational age) or micafungin (loading dose 15 mg kg^-1 day^-1 ; maintenance dose 10 mg kg^-1 day^-1 ). PK samples were taken on treatment days 1 and 5. Population parameters were determined using NONMEM and Monte Carlo simulations performed to reach predefined targets. Clinical and laboratory data, and adverse events were collected up to 36 weeks' corrected gestational age or hospital discharge.

RESULTS

Thirty-six neonates were enrolled. The median (range) gestational age was 28.2 (24.1-40.1) and 26.8 (23.5-40.0) weeks for fluconazole and micafungin, respectively. Based on 163 PK samples, the median population clearance (l h^-1 kg^-1 ) and volume of distribution (l kg^-1 ) for fluconazole were: 0.015 [95% confidence interval (CI) 0.008, 0.039] and 0.913, and for micafungin were: 0.020 (95% CI 0.010, 0.023) and 0.354 (95% CI 0.225, 0.482), respectively. The loading dose was well tolerated. No adverse events associated with micafungin or fluconazole were reported.

CONCLUSION

Based on Monte Carlo simulations, a loading dose for fluconazole and dosing higher than recommended for both drugs are required to increase the area under the plasma drug concentration-time curve target attainment rate in neonates.

Pharmacokinetic evaluation of oral itraconazole for antifungal prophylaxis in children

Itraconazole is a first-generation triazole agent with an extended spectrum of activity; it is licensed in adults for superficial and systemic fungal infections; no recommendation has been yet established for use in children patients. Its variable and unpredictable oral bioavailability make it difficult to determine the optimal dosing regimen. Hence, therapeutic drug monitoring, highly available in clinical practice, may improve itraconazole treatment success and safety. The aim of the study was to describe in paediatrics the oral itraconazole pharmacokinetics, used for prophylaxis. Moreover, we evaluated the utility of its therapeutic drug monitoring in this cohort. A fully validated chromatographic method was used to quantify itraconazole concentration in plasma collected from paediatric patients, at the end of dosing interval. Associations between variables were tested using the Pearson test. Mann-Whitney U test has been used to probe the influence of categorical variables on continuous ones. Any predictive power of the considered variables was finally evaluated through univariate and multivariate linear and logistic regression analyses. A high inter-individual variability was shown; ethnicity (beta coefficient, β -0.161 and interval of confidence at 95%, IC -395.035; -62.383) and gender (β 0.123 and IC 9.590; 349.395) remained in the final linear regression model with P value of .007 and .038, respectively. This study highlights that therapeutic drug monitoring is required to achieve an adequate target itraconazole serum exposure.

Efficacy and safety of itraconazole use in infants

BACKGROUND

Itraconazole has been used to treat fungal infections, in particular invasive fungal infections in infants or neonates in many countries.

DATA SOURCES

Literature search was conducted through Ovid EMBASE, PubMed, ISI Web of Science, CNKI and Google scholarship using the following key words: "pediatric" or "infant" or "neonate" and "fungal infection" in combination with "itraconazole". Based on the literature and our clinical experience, we outline the administration of itraconazole in infants in order to develop evidence-based pharmacotherapy.

RESULTS

Of 45 articles on the use of itraconazole in infancy, 13 are related to superficial fungal infections including tinea capitis, sporotrichosis, mucosal fungal infections and opportunistic infections. The other 32 articles are related to systemic fungal infections including candidiasis, aspergillosis, histoplasmosis, zygomycosis, trichosporonosis and opportunistic infections as caused by Myceliophthora thermophila.

CONCLUSION

Itraconazole is safe and effective at a dose of 5 mg/kg per day in a short duration of therapy for superficial fungal infections and 10 mg/kg per day for systemic fungal infections in infants. With a good compliance, it is cost-effective in treating infantile fungal infections. The profiles of adverse events induced by itraconazole in infants are similar to those in adults and children.

Pharmacokinetic/pharmacodynamic analysis of voriconazole against Candida spp. and Aspergillus spp. in children, adolescents and adults by Monte Carlo simulation

The objective of this study was to investigate the cumulative fraction of response of various voriconazole dosing regimens against six Candida and six Aspergillus spp. in immunocompromised children, immunocompromised adolescents, and adults. Using pharmacokinetic parameters and pharmacodynamic data, 5000-subject Monte Carlo simulations (MCSs) were conducted to evaluate the ability of simulated dosing strategies in terms of fAUC/MIC targets of voriconazole. According to the results of the MCSs, current voriconazole dosage regimens were all effective for children, adolescents and adults against Candida albicans, Candida parapsilosis and Candida orthopsilosis. For adults, dosing regimens of 4 mg/kg intravenous every 12 h (q12h) and 300 mg orally q12h were sufficient to treat fungal infections by six Candida spp. (C. albicans, C. parapsilosis, Candida tropicalis, Candida glabrata, Candida krusei and C. orthopsilosis) and five Aspergillus spp. (Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus, Aspergillus niger and Aspergillus nidulans). However, high doses should be recommended for children and adolescents in order to achieve better clinical efficacy against A. fumigatus and A. nidulans. The current voriconazole dosage regimens were all ineffective against A. niger for children and adolescents. All voriconazole dosage regimens were not optimal against Aspergillus versicolor. This is the first study to evaluate clinical therapy of various voriconazole dosing regimens against Candida and Aspergillus spp. infections in children, adolescents and adults using MCS. The pharmacokinetic/pharmacodynamic-based dosing strategy provided a theoretical rationale for identifying optimal voriconazole dosage regimens in children, adolescents and adults in order to maximise clinical response and minimise the probability of exposure-related toxicity.

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.

Therapeutic strategies for invasive fungal infections in neonatal and pediatric patients: an update

INTRODUCTION

Invasive fungal infections (IFIs) in neonatal and pediatric patients are still associated with high morbidity and mortality, increased length of hospital stay and high healthcare cost. Two key components are prerequisite to combat pediatric IFIs; first, definition of the 'at-risk' populations that could benefit the most from prophylactic treatment and second, prompt initiation of effective antifungal therapy.

AREAS COVERED

In this article, updated prevention and targeted therapeutic approaches for IFIs in neonates and immunocompromised children are reviewed. Furthermore, European and American guidelines concerning IFI treatment in neonates and children are compared.

EXPERT OPINION

IFIs in neonates and children present substantial differences from adults in respect to their epidemiology, pharmacokinetics of antifungal agents and dosing as well as absence of interventional Phase III and IV clinical trials for guidance of evidence-based decisions. In the therapeutic armamentarium of these age groups, although amphotericin B formulations remain widely indicated, azoles with broader spectrum activity as well as echinocandins have been added in the updated antifungal treatment algorithm. Recent European guidelines (ESCMID and ECIL) contain specific recommendations for pediatric patients with IFIs. In both age groups, definitive updated guidance for prophylaxis and more importantly targeted treatment need to be further evaluated by large, multicenter, randomized controlled trials.

Oral colonization: a possible source for candidemia in low-weight neonates

OBJECTIVE

To check the oral colonization in neonates at high-risk and to associate these cases with candidemia.

SUBJECTS AND METHODS

This study was conducted in the NICU. For six months, 125 high-risk neonates were investigated for oral colonization and septicemia by yeasts. From this total, 19 neonates had yeasts on the oral mucosae and 12 neonates developed fungemia. All of the 12 neonates with fungemia were included in the amount of 19 who have presented oral colonization by yeasts.

RESULTS

There was a species concordance between the yeasts of the oral mucosae and the blood in 6 neonates (50%) among the 12 neonates with oral colonization and septicemia at the same time. The yeasts isolated in these 6 cases regarding the species concordance were Candida albicans (5 cases, 83.4%) and Candida parapsilosis (1 case, 16.6%). All of the cases involving an association were confirmed by PFGE. All of the strains of yeasts involved in oral colonization and also blood presented the same karyotype. A total of 66.6% of the patients with strains in agreement progressed to death.

CONCLUSION

The results indicate the relevance of monitoring the oral microbiota, as a possible source of fungal infection, and assisting to develop appropriate therapeutic strategy.

Micafungin versus fluconazole for prophylaxis against fungal infections in premature infants

BACKGROUND

We conducted a comparative clinical study to evaluate the prophylactic effects of micafungin (MCFG) and fluconazole (FLCZ) on the incidence of fungal infections in extremely low-birthweight infants who were born at a gestational age of less than 26 weeks and weighed less than 1000 g.

METHODS

With a combination of enteral administration of miconazole (6 mg/kg/day), FLCZ and MCFG were administered intravenously at a dose of 5 mg/kg/day and 3 mg/kg/day, respectively. The prophylaxis was classified as a failure when fungal infections were identified within the first 21 days after birth.

RESULTS

The prophylaxis was successful in seven of 18 cases (39%) in the FLCZ group and 15 of 21 cases (71%) in the MCFG group, indicating that the success rate was significantly higher in the latter group.

CONCLUSION

MCFG was superior to FLCZ as prophylaxis against fungal infections in extremely low-birthweight infants.

Recommendations for the management of candidemia in neonates in Latin America. Latin America Invasive Mycosis Network

Candidemia is one of the most frequent opportunistic mycoses worldwide. Limited epidemiological studies in Latin America indicate that incidence rates are higher in this region than in the Northern Hemisphere. Diagnosis is often made late in the infection, affecting the initiation of antifungal therapy. A more scientific approach, based on specific parameters, for diagnosis and management of candidemia in Latin America is warranted. 'Recommendations for the diagnosis and management of candidemia' are a series of manuscripts that have been developed by members of the Latin America Invasive Mycosis Network. They aim to provide a set of best-evidence recommendations for the diagnosis and management of candidemia. This publication, 'Recommendations for the management of candidemia in neonates in Latin America', was written to provide guidance to healthcare professionals on the management of neonates who have, or who are at risk of, candidemia. Computerized searches of existing literature were performed by PubMed. The data were extensively reviewed and analyzed by members of the group. The group also met on two occasions to pose questions, discuss conflicting views, and deliberate on a series of management recommendations. 'Recommendations for the management of candidemia in neonates in Latin America' includes prophylaxis, empirical therapy, therapy for proven candidemia, patient work-up following diagnosis of candidemia, central venous catheter management, and management of complications. This manuscript is the fourth of this series that deals with diagnosis and treatment of invasive candidiasis. Other publications in this series include: 'Recommendations for the diagnosis of candidemia in Latin America', 'Recommendations for the management of candidemia in adults in Latin America', and 'Recommendations for the management of candidemia in children in Latin America'.

[Recommendations for the management of candidemia in neonates in Latin America. Grupo Proyecto Épico]

Candidemia is one of the most frequent opportunistic mycoses worldwide. Limited epidemiological studies in Latin America indicate that incidence rates are higher in this region than in the Northern Hemisphere. Diagnosis is often made late in the infection, affecting the initiation of antifungal therapy. A more scientific approach, based on specific parameters, for diagnosis and management of candidemia in Latin America is warranted. 'Recommendations for the diagnosis and management of candidemia' are a series of manuscripts that have been developed by members of the Latin America Invasive Mycosis Network. They aim to provide a set of best-evidence recommendations for the diagnosis and management of candidemia. This publication, 'Recommendations for the management of candidemia in neonates in Latin America', was written to provide guidance to healthcare professionals on the management of neonates who have, or who are at risk of, candidemia. Computerized searches of existing literature were performed by PubMed. The data were extensively reviewed and analyzed by members of the group. The group also met on two occasions to pose questions, discuss conflicting views, and deliberate on a series of management recommendations. 'Recommendations for the management of candidemia in neonates in Latin America' includes prophylaxis, empirical therapy, therapy for proven candidemia, patient work-up following diagnosis of candidemia, central venous catheter management, and management of complications. This manuscript is the fourth of this series that deals with diagnosis and treatment of invasive candidiasis. Other publications in this series include: 'Recommendations for the diagnosis of candidemia in Latin America', 'Recommendations for the management of candidemia in adults in Latin America', and 'Recommendations for the management of candidemia in children in Latin America'.

Invasive fungal infections in infants-focus on anidulafungin

Introduction:

Invasive fungal infection in pediatric intensive care units (PICU) is a rising challenge. Candida species are the most common microorganisms in these infections. Due to growing resistance against fluconazole, echinocandins are being used for the appropriate therapy. However, the recent IDSA guidelines recommend them only in cases where fluconazole or Amphotericin B cause treatment failure or are contraindicated. In a literature review, the importance of invasive fungal infections in PICU settings and the role of anidulafungin shall be examined.

Materials and Methods:

Articles were retrieved form PubMed covering the years 2000–2012. Various search terms were used. Then the articles were clustered in different types like ‘review,’ ‘pharmacokinetics,’ ‘case reports’ and others.

Results:

From 67 search results, 14 articles were selected. Of these, 7 were related to anidulafungin, while 7 were related to echinocandins or fungal infections in the PICU. Anidulafungin was examined in 4 PK/PD studies where a good safety profile was found. No serious adverse events occurred. The articles reporting risk factors show that central venous catheters, receipt of antibiotics, receipt of parenteral nutrition, and neutropenia are the most important independent risk factors for invasive fungal infections in PICU. Three reviews of antifungal agents show that echinocandins may be useful due to their safety profile; micafungin is the best examined one and further trials are needed.

Discussion:

The published literature on invasive fungal infections in PICU settings has grown over the years. There are only a few articles, however, which are directly related to the use of anidulafungin in this setting. A most recent publication showed good PK/PD dynamics and a good safety profile for anidulafungin. So far, no RCT in the area of invasive candidiasis in infants and neonates has been published. A review of currently registered trials at ClinicalTrials.gov has shown one more trial related to PK/PD and two trials that investigate the use of anidulafungin or anidulafungin in combination with Voriconazole in pediatrics.

Conclusion:

The small body of existing literature on anidulafungin in infants shows success in treatment, no drug-related adverse events, and good pharmacodynamics. A dosing of 0.75 mg/kg/day or 1.5 mg/kg/day is as effective as 50 mg/day or 100 mg/day in adults. More trials on the use in clinical reality of PICU or NICU should follow.

A quality improvement approach to optimizing medication use in the neonatal intensive care unit

Despite many years of heavy use in premature and critically ill newborns, surprisingly few medications have been rigorously tested in neonatal multicenter randomized clinical trials. Little is known about the pharmacology of these drugs at various birth weights, gestational ages, and chronologic ages. This article describes a quality improvement approach to evaluating and improving neonatal intensive care unit (NICU) medication use, with an emphasis on adaptation of drug use to the specific clinical NICU context and use of system-based changes to minimize harm and maximize clinical benefit.

A randomized, double-blind, prospective study of caspofungin vs. amphotericin B for the treatment of invasive candidiasis in newborn infants

BACKGROUND

Caspofungin is an echinocandin agent with fungicidal activity against Candida species.

OBJECTIVE

To assess the efficacy, safety and tolerability of caspofungin relative to amphotericin B in neonates with invasive candidiasis.

PATIENTS AND METHODS

Thirty-two neonates with invasive candidiasis were randomly assigned to receive either caspofungin (n = 15) or amphotericin B (n = 17). Efficacy was evaluated, with a successful outcome defined as fulfilling all the components of a prespecified five-part composite endpoint. Evaluation of safety was done by monitoring drug-related adverse events.

RESULTS

At the end of intravenous therapy, evaluation showed that caspofungin was superior, with a favorable response in 86.7% of patients as compared with 41.7% of those who received amphotericin B (p = 0.04). There were significantly fewer adverse events in the caspofungin group than in the amphotericin B group.

CONCLUSION

Caspofungin is more effective, safer and alternative to amphotericin B for the treatment of invasive candidiasis in newborn infants.

Efficacy of CG(3)R(6)TAT nanoparticles self-assembled from a novel antimicrobial peptide for the treatment of Candida albicans meningitis in rabbits

BACKGROUND

Candidal meningitis is a common clinical manifestation of invasive candidiasis in neonates. The aim of this study was to evaluate the in vivo antifungal efficacy of CG(3)R(6)TAT nanoparticles, novel core-shell structures self-assembled from cationic antimicrobial peptides, in a rabbit model of candidal meningitis.

METHODS

In vitro activity of CG(3)R(6)TAT nanoparticles against Candida albicans was assessed by determining the minimum inhibitory concentration and kill-time curves. In vivo, intravenous treatment with CG(3)R(6)TAT nanoparticles (n = 6; 0.25 mg/kg/day) or fluconazole (n = 6; 100 mg/kg/day) began 3 days after infection and continued for 11 consecutive days; the efficacy was assessed following 11 days of treatment by yeast counting in cerebrospinal fluid (CSF), the leukocyte concentrations in CSF and the histopathology of brain parenchyma.

RESULTS

At a concentration three times higher than the minimum inhibitory concentration (8.1 μmol/l), the nanoparticles complete- ly sterilized C. albicans after 5 h of incubation. In addition, there was a significant reduction in fungal counts and leukocyte concentrations in the CSF from rabbits treated with CG(3)R(6)TAT nanoparticles or fluconazole versus those from untreated control rabbits (p < 0.05, ANCOVA). The median number of days of treatment required to sterilize CSF cultures was 8.5 days for CG(3)R(6)TAT nanoparticle therapy (p = 0.022, vs. control) and 9.7 days for fluconazole therapy (p > 0.05, vs. control). The histopathologic severity of rabbits was significantly attenuated after CG(3)R(6)TAT treatment (p = 0.001, vs. control).

CONCLUSION

This study suggests that CG(3)R(6)TAT nanoparticles may be a promising therapeutic agent for candidal meningitis.

[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.

A rapid and sensitive LC-MS/MS method for determination of fluconazole in human plasma and its application in infants with Candida infections

A rapid and sensitive LC-MS/MS method was developed to quantify fluconazole in human plasma. Seventy microliters of plasma were treated with protein precipitation procedures. Chromatographic separation was achieved on a C18 column using a gradient mobile phase of acetonitrile and water in 0.1% formic acid. Fluconazole and its deuterium-labeled internal standard were monitored in positive mode using electrospray ionization source. The method was fully validated over the range of 0.01 to 10 microg/mL. Intraday and interday precision ranged from 2.84% to 10.8% and 5.27% to 11.5%, respectively. The process recovery efficiency for fluconazole ranged from 98.6% to 104.4%. No carryover and minimal matrix effects were observed. Acceptable stability of fluconazole in blood at room temperature for up to 72 hours guaranteed that fluconazole concentrations in scavenged blood specimens were usable for infant PK analysis and model development. This method has been utilized for a fluconazole pharmacokinetic trial with 55 preterm and term infants younger than 90 days of age. The fast sample preparation cycle and lower limit of quantitation make this method a potential tool for therapeutic drug monitoring of fluconazole to optimize pediatric antifungal therapy. Optimal dose regimen of fluconazole in neonates and young infants might be achieved with application of TDM and pharmacometric approach designed to achieve AUC/MIC >50 for most Candida species with a MIC90 less than 8 microg/mL.

Micafungin: a review of its use in the prophylaxis and treatment of invasive Candida infections in pediatric patients

Intravenous micafungin (Mycamine; Funguard) is an echinocandin indicated in Japan and the EU for the treatment of pediatric patients (including neonates) with invasive candidiasis and as prophylaxis against Candida infection in pediatric patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). In the EU, micafungin is also indicated in pediatric patients who are expected to have neutropenia for >/=10 days. In Japan, children may also receive micafungin for the treatment of, or as prophylaxis against, invasive Aspergillus infection. Micafungin is not currently approved for use in pediatric patients in the US. Micafungin has very good antifungal activity against a wide range of Candida spp. in vitro. It has a favorable pharmacokinetic profile allowing for once-daily administration, has few drug-drug interactions, and reports of resistance are rare. The results of pediatric substudies indicate that intravenous micafungin is effective in a majority of patients for the treatment of candidemia and other types of invasive candidiasis, and provides effective prophylaxis against invasive fungal infections in pediatric patients undergoing HSCT. The tolerability profile of micafungin in pediatric patients was generally acceptable. In the EU, micafungin is indicated for use when other antifungal medications are not appropriate. Therefore, micafungin provides an alternative to other antifungal agents used in the management of candidemia and invasive candidiasis in pediatric patients, or as prophylaxis against fungal infections in pediatric patients undergoing HSCT.

Liposomal amphotericin B: a review of its use as empirical therapy in febrile neutropenia and in the treatment of invasive fungal infections

Liposomal amphotericin B (AmBisome) is a lipid-associated formulation of the broad-spectrum polyene antifungal agent amphotericin B. It is active against clinically relevant yeasts and moulds, including Candida spp., Aspergillus spp. and filamentous moulds such as Zygomycetes, and is approved for the treatment of invasive fungal infections in many countries worldwide. It was developed to improve the tolerability profile of amphotericin B deoxycholate, which was for many decades considered the gold standard of antifungal treatment, despite being associated with infusion-related events and nephrotoxicity. In well controlled trials, liposomal amphotericin B had similar efficacy to amphotericin B deoxycholate and amphotericin B lipid complex as empirical therapy in adult and paediatric patients with febrile neutropenia. In addition, caspofungin was noninferior to liposomal amphotericin B as empirical therapy in adult patients with febrile neutropenia. For the treatment of confirmed invasive fungal infections, liposomal amphotericin B was more effective than amphotericin B deoxycholate treatment in patients with disseminated histoplasmosis and AIDS, and was noninferior to amphotericin B deoxycholate in patients with acute cryptococcal meningitis and AIDS. In adults, micafungin was shown to be noninferior to liposomal amphotericin B for the treatment of candidaemia and invasive candidiasis. Data from animal studies suggested that higher dosages of liposomal amphotericin B might improve efficacy; however, in the AmBiLoad trial in patients with invasive mould infection, there was no statistical difference in efficacy between the standard dosage of liposomal amphotericin B 3 mg/kg/day and a higher 10 mg/kg/day dosage, although the standard dosage was better tolerated. Despite being associated with fewer infusion-related adverse events and less nephrotoxicity than amphotericin B deoxycholate and amphotericin B lipid complex, liposomal amphotericin B use is still limited to some extent by these adverse events. Both echinocandins were better tolerated than liposomal amphotericin B. The cost of liposomal amphotericin B therapy may also restrict its use, but further pharmacoeconomic studies are required to fully define its cost effectiveness compared with other antifungal agents. Based on comparative data from well controlled trials, extensive clinical experience and its broad spectrum of activity, liposomal amphotericin B remains a first-line option for empirical therapy in patients with febrile neutropenia and in those with disseminated histoplasmosis, and is an option for the treatment of AIDS-associated cryptococcal meningitis, and for invasive Candida spp. or Aspergillus spp. infections. Amphotericin B, a macrocyclic, polyene antifungal agent, is thought to act by binding to ergosterol, the principal sterol in fungal cell membranes and Leishmania cells. This results in a change in membrane permeability, causing metabolic disturbance, leakage of small molecules and, as a consequence, cell death. In vitro and in vivo studies have shown that liposomal amphotericin B remains closely associated with the liposomes in the circulation, thereby reducing the potential for nephrotoxicity and infusion-related toxicity associated with conventional amphotericin B. Amphotericin B shows very good in vitro activity against a broad spectrum of clinically relevant fungal isolates, including most strains of Candida spp. and Aspergillus spp., and other filamentous fungi such as Zygomycetes. Liposomal amphotericin B has proven effective in various animal models of fungal infections, including those for candidiasis, aspergillosis, fusariosis and zygomycosis. Liposomal amphotericin B also shows immunomodulatory effects, although the mechanisms involved are not fully understood, and differ from those of amphotericin B deoxycholate and amphotericin B colloidal dispersion. In adult patients with febrile neutropenia, intravenous liposomal amphotericin B has nonlinear pharmacokinetics, with higher than dose-proportional increases in exposure being consistent with reticuloendothelial saturation and redistribution of amphotericin B in the plasma compartment. Liposomal amphotericin B is rapidly and extensively distributed after single and multiple doses, with steady-state concentrations of amphotericin B attained within 4 days and no clinically relevant accumulation of the drug following multiple doses of 1-7.5 mg/kg/day. In autopsy tissue, the highest concentrations of the drug were found in the liver and spleen, followed by the kidney, lung, myocardium and brain tissue. Elimination of liposomal amphotericin B, like that of amphotericin B deoxycholate, is poorly understood; its route of metabolism is not known and its excretion has not been studied. The terminal elimination half-life is about 7 hours. No dosage adjustment is required based on age or renal impairment. In several randomized, double-blind trials (n = 73-1095) in adult and/or paediatric patients, liposomal amphotericin B was effective as empirical therapy or as treatment for confirmed invasive fungal infections, including invasive candidiasis, candidaemia, invasive mould infection (mainly aspergillosis), histoplasmosis and cryptococcal meningitis. All agents were administered as an intravenous infusion; the typical dosage for liposomal amphotericin B was 3 mg/kg/day. Treatment was generally given for 1-2 weeks. Participants in trials evaluating empirical therapy had neutropenia and a persistent fever despite antibacterial treatment and had received chemotherapy or undergone haematopoietic stem cell transplantation. As empirical therapy in adult and paediatric patients, liposomal amphotericin B appeared to be as effective as amphotericin B deoxycholate (approximately 50% of patients in each group achieved treatment success) or amphotericin B lipid complex (approximately 40% of liposomal amphotericin B recipients experienced treatment success). Of note, in the first trial, results of the statistical test to determine equivalence between treatments were not reported. In the second trial, efficacy was assessed as an 'other' endpoint. In another trial, caspofungin was shown to be noninferior to liposomal amphotericin B, with approximately one-third of patients in each group experiencing treatment success. Liposomal amphotericin B was significantly more effective than amphotericin B deoxycholate for the treatment of moderate to severe disseminated histoplasmosis in patients with AIDS, with 88% and 64% of patients, respectively, having a successful response. Liposomal amphotericin B was noninferior to amphotericin B deoxycholate for the treatment of cryptococcal meningitis in terms of mycological success. Micafungin therapy was shown to be noninferior to liposomal amphotericin B for the treatment of adult patients with candidaemia or invasive candidiasis. In a substudy in paediatric patients, which was not powered to determine noninferiority, liposomal amphotericin B was as effective as micafungin for the treatment of candidaemia or invasive candidiasis. In this patient population, within each trial, 90% of adult patients and approximately three-quarters of paediatric patients in both treatment groups experienced a successful response. In patients with invasive mould infection (mainly aspergillosis), there was no difference in efficacy between a higher dosage of liposomal amphotericin B (10 mg/kg/day) and the standard dosage (3 mg/kg/day), with 46% and 50% of patients experiencing a favourable overall response. In well designed clinical trials, liposomal amphotericin B was generally at least as well tolerated as other lipid-associated formulations of amphotericin B and better tolerated than amphotericin B deoxycholate in adult and paediatric patients. Compared with other amphotericin B formulations, liposomal amphotericin B treatment was associated with a lower incidence of infusion-related adverse events and nephrotoxicity. A higher than recommended dosage of liposomal amphotericin B (10 mg/kg/day) was associated with an increased incidence of nephrotoxicity compared with the standard dosage (3 mg/kg/day), although the incidence of infusion-related reactions did not differ between treatment groups. In general, liposomal amphotericin B treatment was not as well tolerated as echinocandin therapy in well designed clinical trials. As empirical therapy or for the treatment of confirmed invasive fungal infections in adult patients, liposomal amphotericin B recipients experienced more infusion-related events and nephrotoxicity than caspofungin or micafungin recipients. There was no difference in the incidence of these adverse events between the liposomal amphotericin B and micafungin groups in a study in paediatric patients.

[Future role of micafungin in the treatment of invasive mycoses caused by filamentous fungi]

BACKGROUND

Micafungin is a echinocandin. It inhibits beta-1,3-D-glucan synthesis, thus achieving fungicidal activity against virtually all Candida spp., including those resistant to fluconazole, and fungistatic activity against Aspergillus spp., as well as several but not all pathogenic molds. Results from in vitro studies, animal models, small clinical trials, hint at possible future indications such as invasive aspergillosis and empirical viantifungal therapy, although currently there is little information published.

AIMS

To describe published data of micafungin as treatment against invasive mold infections, specially analysing its role in the inmunodepressed host and critical care setting.

METHODS

A systematic review of literature using the principal medical search engines was performed. Terms such as micafungin, aspergillosis, zygomycosis, invasive fungal infections, emerging fungal infections, antifungal treatment or therapy, antifungal prophylaxis, empiric or pre-emptive therapy were crossed. Febrile neutropenia patients were excluded.

RESULTS

Several studies in these setting were identified and were described in this review. Although there were no blinded randomized clinical trials published, treatment or prophylaxis of invasive aspergillosis and other invasive mould infections with micafungin described in open clinical studies were analyzed.

CONCLUSIONS

Micafungin could play a future important role as a primary or rescue therapy, alone or in combination, in the treatment or prophylaxis of invasive fungal infections caused by moulds. New randomized clinical trials are needed to confirm their efficacy.