Treatment of candidemia and invasive candidiasis in the intensive care unit: post hoc analysis of a randomized, controlled trial comparing micafungin and liposomal amphotericin B

Amphotericin B in the Era of New Antifungals: Where Will It Stand?

Amphotericin B (AmB) has long stood as a cornerstone in the treatment of invasive fungal infections (IFIs), especially among immunocompromised patients. However, the landscape of antifungal therapy is evolving. New antifungal agents, boasting novel mechanisms of action and better safety profiles, are entering the scene, presenting alternatives to AmB's traditional dominance. This shift, prompted by an increase in the incidence of IFIs, the growing demographic of immunocompromised individuals, and changing patterns of fungal resistance, underscores the continuous need for effective treatments. Despite these challenges, AmB's broad efficacy and low resistance rates maintain its essential status in antifungal therapy. Innovations in AmB formulations, such as lipid complexes and liposomal delivery systems, have significantly mitigated its notorious nephrotoxicity and infusion-related reactions, thereby enhancing its clinical utility. Moreover, AmB's efficacy in treating severe and rare fungal infections and its pivotal role as prophylaxis in high-risk settings highlight its value and ongoing relevance. This review examines AmB's standing amidst the ever-changing antifungal landscape, focusing on its enduring significance in current clinical practice and exploring its potential future therapeutic adaptations.

Population Pharmacokinetic Model and Optimal Sampling Strategies for Micafungin in Critically Ill Patients Diagnosed with Invasive Candidiasis

Candida bloodstream infections are associated with high attributable mortality, where early initiation of adequate antifungal therapy is important to increase survival in critically ill patients. The exposure variability of micafungin, a first-line agent used for the treatment of invasive candidiasis, in critically ill patients is significant, potentially resulting in underexposure in a substantial portion of these patients. The objective of this study was to develop a population pharmacokinetic model including appropriate sampling strategies for assessing micafungin drug exposure in critically ill patients to support adequate area under the concentration-time curve (AUC) determination. A two-compartment pharmacokinetic model was developed using data from intensive care unit (ICU) patients (n = 19), with the following parameters: total body clearance (CL), volume of distribution of the central compartment (V1), inter-compartmental clearance (CL12), and volume of distribution of the peripheral compartment (V2). The final model was evaluated with bootstrap analysis and the goodness-of-fit plots for the population and individual predicted micafungin plasma concentrations. Optimal sampling strategies (with sampling every hour, 24 h per day) were developed with 1- and 2-point sampling schemes. Final model parameters (±SD) were: CL = 1.03 (0.37) (L/h/1.85 m²), V1 = 0.17 (0.07) (L/kg LBMc), CL12 = 1.80 (4.07) (L/h/1.85 m²), and V2 = 0.12 (0.06) (L/kg LBMc). Sampling strategies with acceptable accuracy and precision were developed to determine the micafungin AUC. The developed model with optimal sampling procedures provides the opportunity to achieve quick optimization of the micafungin exposure from a single blood sample using Bayesian software and may be helpful in guiding early dose decision-making.

Comparative efficacy and safety of systemic antifungal agents for candidemia: a systematic review with network meta-analysis and multicriteria acceptability analyses

AIM

Invasive candidiasis is the most common fungal infection in patients attending health services and is associated with high mortality rates and prolonged hospital stay. The aim of this review was to evaluate and compare efficacy and safety of antifungal agents for the treatment of candidemia.

METHODS

A systematic review with network meta-analysis (NMA), surface under the cumulative ranking analysis (SUCRA) and stochastic multicriteria acceptability analyses (SMAA) was performed (PROSPERO-CRD42020149264). Searches were conducted in PubMed and Scopus (Nov-2021). Randomised controlled trials evaluating the effect of oral antifungals (any dose or regimen) on mycological cure, discontinuation rates and adverse events were included.

RESULTS

Overall, 13 trials (n=3632) were analysed. There were no significant differences between therapies for the efficacy outcomes; however, caspofungin (50-150 mg), rezafungin (200-400 mg) and micafungin (100-150 mg) had higher rates of clinical and mycological responses (SUCRA overall response >60%) and were considered the most promising therapies. Fluconazole (400 mg) rated worst for overall response (17%). Rezafungin (200-400 mg) and micafungin (100 mg) were associated with lower discontinuation rates (<40%). Conventional amphotericin B (0.6-0.7 mg/kg) was more likely to be discontinued (odds ratio [OR] 0.08; 95% credibility interval [CrI] 0.00-0.95 vs. caspofungin 150 mg) and may impair liver function (87%).

CONCLUSION

Echinocandins are recommended as first-line treatments for invasive candidiasis following a priority order of caspofungin then micafungin. Rezafungin, an echinocandin under development, represents a potential option that should be further investigated. Azoles and liposomal amphotericin B can be used as second-line treatments in cases of fungal resistance or hypersensitivity.

New strategies for combating fungal infections: Inhibiting inositol lipid signaling by targeting Sec14 phosphatidylinositol transfer proteins

Virulent fungi represent a particularly difficult problem in the infectious disease arena as these organisms are eukaryotes that share many orthologous activities with their human hosts. The fact that these activities are often catalyzed by conserved proteins places additional demands on development of pharmacological strategies for specifically inhibiting target fungal activities without imposing undesirable secondary effects on the host. While deployment of a limited set of anti-mycotics has to date satisfied the clinical needs for treatment of fungal infections, the recent emergence of multi-drug resistant fungal 'superbugs' now poses a serious global health threat with rapidly diminishing options for treatment. This escalating infectious disease problem emphasizes the urgent need for development of new classes of anti-mycotics. In that regard, Sec14 phosphatidylinositol transfer proteins offer interesting possibilities for interfering with fungal phosphoinositide signaling with exquisite specificity and without targeting the highly conserved lipid kinases responsible for phosphoinositide production. Herein, we review the establishment of proof-of-principle that demonstrates the feasibility of such an approach. We also describe the lead compounds of four chemotypes that directly target fungal Sec14 proteins. The rules that pertain to the mechanism(s) of Sec14 inhibition by validated small molecule inhibitors, and the open questions that remain, are discussed - as are the challenges that face development of next generation Sec14-directed inhibitors.

Role of Antifungal Combinations in Difficult to Treat Candida Infections

Candida infections are varied and, depending on the immune status of the patient, a life-threatening form may develop. C. albicans is the most prevalent species isolated, however, a significant shift towards other Candida species has been noted. Monotherapy is frequently indicated, but the patient's evolution is not always favorable. Drug combinations are a suitable option in specific situations. The aim of this review is to address this problem and to discuss the role of drug combinations in difficult to treat Candida infections. A search for eligible studies in PubMed and Google Scholar databases was performed. An analysis of the data was carried out to define in which cases a combination therapy is the most appropriate. Combination therapy may be used for refractory candidiasis, endocarditis, meningitis, eye infections and osteomyelitis, among others. The role of the drug combination would be to increase efficacy, reduce toxicity and improve the prognosis of the patient in infections that are difficult to treat. More clinical studies and reporting of cases in which drug combinations are used are needed in order to have more data that support the use of this therapeutic strategy.

Emerging Prospects for Combating Fungal Infections by Targeting Phosphatidylinositol Transfer Proteins

The emergence of fungal “superbugs” resistant to the limited cohort of anti-fungal agents available to clinicians is eroding our ability to effectively treat infections by these virulent pathogens. As the threat of fungal infection is escalating worldwide, this dwindling response capacity is fueling concerns of impending global health emergencies. These developments underscore the urgent need for new classes of anti-fungal drugs and, therefore, the identification of new targets. Phosphoinositide signaling does not immediately appear to offer attractive targets due to its evolutionary conservation across the Eukaryota. However, recent evidence argues otherwise. Herein, we discuss the evidence identifying Sec14-like phosphatidylinositol transfer proteins (PITPs) as unexplored portals through which phosphoinositide signaling in virulent fungi can be chemically disrupted with exquisite selectivity. Recent identification of lead compounds that target fungal Sec14 proteins, derived from several distinct chemical scaffolds, reveals exciting inroads into the rational design of next generation Sec14 inhibitors. Development of appropriately refined next generation Sec14-directed inhibitors promises to expand the chemical weaponry available for deployment in the shifting field of engagement between fungal pathogens and their human hosts.

In vitro synergy of azole antifungals and methotrexate against Candida albicans

OBJECTIVE

This study aims to evaluate the effective of azoles and MTX for patients with invasive candidiasis.

METHODS

We used the disk diffusion assay and the checkerboard assay to evaluate the in vitro interactions between MTX and antifungals. In addition, we used the transmission electron microscopy to observe the ultrastructure of the effect of MTX and fluconazole on Candida albicans.

RESULTS

The rates of synergy for the combination of MTX with fluconazole (FLC), itraconazole (ITC), and voriconazole (VRZ) were 91.3%, 65.2%, and 87% in checkerboard testing. No antagonism was found between methotrexate and azole antifungals in any of the strains. Furthermore, MTX treated C. albicans showed extensive cell wall vacuolations and the inhibition of blastospores growth, as observed using transmission electron microscopy. There was an apparent destruction of the cell membrane and cell wall resulting in the destruction of cytoplasm, a phenomenon observed when MTX was combined with azoles.

CONCLUSION

This study provides evidence that the combination of azoles and MTX is effective for patients with invasive candidiasis, which on the other hand, will reduce the side effects of the drugs.

Efficacy and Safety of Echinocandins for the Treatment of Invasive Candidiasis in Children: A Meta-analysis

BACKGROUND

Echinocandins are recommended for the treatment of suspected or confirmed invasive candidiasis (IC) in adults. Less is known about the use of echinocandins for the management of IC in children. The aim of this study was to investigate the overall efficacy and safety of echinocandin class in neonatal and pediatric patients with IC.

METHODS

PubMed, Cochrane Central, Scopus and Clinical trial registries were searched up to July 27, 2017. Eligible studies were randomized controlled trials that evaluated the efficacy and safety of any echinocandin versus agents of other antifungal classes for the treatment of IC in pediatric patients. The primary outcome was treatment success with resolution of symptoms and signs, and absence of IC. In the meta-analysis a random effects model was used, and the odds ratio (OR) and 95% confidence intervals (CIs) were calculated.

RESULTS

Four randomized clinical trials (324 patients), 2 confirmed IC (micafungin vs. liposomal amphotericin B (L-AmB) and caspofungin vs. L-AmB) and 2 empirical therapy trials (caspofungin vs. deoxycholate amphotericin B and caspofungin vs. L-AmB) were included. There was no significant difference between echinocandins and comparator in terms of treatment success (OR = 1.61, 95% CI: 0.74-3.50) and incidence of treatment-related adverse events (OR = 0.70, 95% CI: 0.39-1.26). However, fewer children treated with echinocandins discontinued treatment because of adverse events than amphotericin B formulations (OR = 0.26, 95% CI: 0.08-0.82, P = 0.02).

CONCLUSIONS

In the treatment of IC in children, echinocandins show non-inferior efficacy compared with amphotericin B formulations with fewer discontinuations than in comparator arm.

Systematic review on the first line treatment of amphotericin B in critically ill adults with candidemia or invasive candidiasis

INTRODUCTION

Invasive candidiasis is the most common fungal infection affecting critically ill adults. International guidelines provide differing recommendations for first-line antifungal therapy, with echinocandins considered first-line in the majority. Amphotericin B has broad activity and low minimum inhibitory concentration resistance patterns across most Candida species and guidance away from its use should be supported by the available evidence. Areas Covered: A systematic literature review was conducted from August to September 2017 to determine whether treatment with echinocandins or other available drugs, namely voriconazole, confers a therapeutic or survival benefit over amphotericin B in critically ill adults with invasive candidiasis. Inclusion criteria were: (1) studies describing critically ill adults with invasive candidiasis, (2) studies describing therapeutic benefit or survival as an outcome, and (3) studies comparing amphotericin B, deoxycholate or lipid preparations, with any newer antifungal agent. Eight studies were included in the final review, incorporating 2352 unique patients. No difference in treatment efficacy or mortality outcomes in critically ill patients with invasive candidiasis receiving an amphotericin B formulation compared with those receiving an echinocandin or voriconazole was shown. Expert Commentary: We conclude that in the existing literature, there is no evidence that choice between echinocandins, voriconazole, or amphotericin B formulations as first-line therapy for critically ill adults with invasive candidiasis is associated with a therapeutic or survival benefit. Clinicians must therefore consider other factors in the selection of first-line therapy.

"De-escalation" strategy using micafungin for the treatment of systemic Candida infections: budget impact in France and Germany

Background

The incidence of azole-resistant Candida infections is increasing. Consequently, guidelines for treating systemic Candida infection (SCI) recommend a “de-escalation” strategy: initial broad-spectrum antifungal agents (e.g., echinocandins), followed by switching to fluconazole if isolates are fluconazole sensitive, rather than “escalation” with initial fluconazole treatment and then switching to echinocandins if isolates are fluconazole resistant. However, fluconazole may continue to be used as first-line treatment in view of its low acquisition costs. The aim of this study was, therefore, to evaluate the budget impact of the de-escalation strategy using micafungin compared with the escalation strategy in France and Germany.

Methods

A budget impact model was used to compare de-escalation to escalation strategies. As well as survival, clinical success (resolution/reduction of symptoms and radiographic abnormalities associated with fungal infection), was considered, as was mycological success (eradication of Candida from the bloodstream). Health economic outcomes included cost per health state according to clinical success and mycological success, and budget impact. A 42-day time horizon was used.

Results

For all patients with SCI, the budget impact of using de-escalation rather than escalation was greater, but improved rates of survival, clinical success and mycological success were apparent with de-escalation. In patients with fluconazole-resistant isolates, clinical success rates and survival were improved by ~72% with de-escalation versus escalation, producing cost savings of €6,374 and €356 per patient in France and Germany, respectively; improvements of ~72% in mycological success rates with de-escalation versus escalation did not translate into cost savings.

Conclusion

Modeling provides evidence that when treating SCI in individuals at risk of azole-resistant infections, de-escalation from micafungin has potential cost savings associated with improved clinical success rates.

Pharmacokinetic Properties of Micafungin in Critically Ill Patients Diagnosed with Invasive Candidiasis

The estimated attributable mortality rate for invasive candidiasis (IC) in the intensive care unit (ICU) setting varies from 30 to 40%. Physiological changes in critically ill patients may affect the distribution and elimination of micafungin, and therefore, dosing adjustments might be mandatory. The objective of this study was to determine the pharmacokinetic parameters of micafungin in critically ill patients and assess the probability of target attainment. Micafungin plasma concentrations were measured to estimate the pharmacokinetic properties of micafungin. MIC values for Candida isolates were determined to assess the probability of target attainment for patients. Data from 19 patients with suspected or proven invasive candidiasis were available for analysis. The median area under the concentration-time curve from 0 to 24 h at steady state (AUC_0-24) was 89.6 mg · h/liter (interquartile range [IQR], 75.4 to 113.6 mg · h/liter); this was significantly lower than the median micafungin AUC_0-24 values of 152.0 mg · h/liter (IQR, 136.0 to 162.0 mg · h/liter) and 134.0 mg · h/liter (IQR, 118.0 to 148.6 mg · h/liter) in healthy volunteers (P = <0.0001 and P = <0.001, respectively). All Candida isolates were susceptible to micafungin, with a median MIC of 0.016 mg/liter (IQR, 0.012 to 0.023 mg/liter). The median AUC_0-24/MIC ratio was 5,684 (IQR, 4,325 to 7,578), and 3 of the 17 evaluable patients (17.6%) diagnosed with proven invasive candidiasis did not meet the AUC/MIC ratio target of 5,000. Micafungin exposure was lower in critically ill patients than in healthy volunteers. The variability in micafungin exposure in this ICU population could be explained by the patients' body weight. Our findings suggest that healthier patients (sequential organ failure assessment [SOFA] score of <10) weighing more than 100 kg and receiving 100 mg micafungin daily are at risk for inappropriate micafungin exposure and potentially inadequate antifungal treatment. (This study has been registered at ClinicalTrials.gov under identifier NCT01716988.).

Clinical hepatotoxicity associated with antifungal agents

INTRODUCTION

Invasive fungal diseases (IFDs) are a leading cause of morbidity and mortality among immunocompromised patients with bone marrow failure syndromes, hematological malignancies, hematopoietic stem cell transplantation (HSCT), those admitted in intensive care units (ICUs) and those with prolonged febrile neutropenia. IFDs occur in a setting of multiple morbidities and are associated with case fatality rates between 30 and 70%. Along with the development of classes and compounds, the last two decades have seen substantial improvements in the prevention and management of these infections and an overall increased use of antifungal agents. Areas covered: All antifungal agents, including amphotericin B formulations, echinocandins and the triazoles, may cause hepatic toxicity that ranges from mild and asymptomatic abnormalities in liver function tests to substantial liver injury and fulminant hepatic failure. Expert opinion: The present article reviews incidence and severity of hepatotoxicity associated with different classes and agents to provide a better understanding of this specific end organ toxicity and safer use of antifungal agents A thorough understanding of the distribution, metabolism, elimination and drug-drug interactions of antifungal agents used for management of IFDs in combination with safety data from clinical trials, pharmacokinetic and pharmacodynamic studies may guide the use of antifungal treatment in patients at high risk for the development of hepatic dysfunction and in those with underlying liver damage due to cytotoxic therapy.

[Strategies for antifungal treatment failure in intensive care units]

Recent epidemiologic studies reveal both an increasing incidence and an escalation in resistance of invasive fungal infections in intensive care units. Primary therapy fails in 70 % of cases, depending on the underlying pathogens and diseases. The purpose of this review is to raise awareness for the topic of antifungal therapy failure, describe the clinical conditions in which it occurs, and suggest a possible algorithm for handling the situation of suspected primary therapy failure.

Clinical Practice Guideline for the Management of Candidiasis: 2016 Update by the Infectious Diseases Society of America

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

Cost-Effectiveness Analysis of Multiplex PCR with Magnetic Resonance Detection versus Empiric or Blood Culture-Directed Therapy for Management of Suspected Candidemia

Candida bloodstream infections (BSI) are associated with significant morbidity, mortality, and increased health care costs. Early treatment is essential, because delayed therapy detrimentally impacts clinical outcomes. The FDA recently approved the first culture-independent direct molecular detection method for Candida BSIs (T2Candida). The speed and sensitivity of this assay give it the potential to improve patient care, but the reagents and instrumentation are expensive. We used an analytic decision tree model to compare the cost-effectiveness of T2Candida-directed antifungal therapy (T2DT) to that of either empirical therapy (ET) or blood culture-directed therapy (BCDT). The costs included those of T2Candida testing, antifungal treatment, and hospital length of stay. The effectiveness measure was survival status at hospital discharge. T2DT was less costly and more effective than BCDT but was less costly and less effective than ET with an echinocandin (incremental cost-effectiveness ratio, $111,084 per additional survivor). One-way sensitivity analyses demonstrated that the cost-effectiveness of T2DT was highly dependent on Candida BSI prevalence and the cost of antifungal therapy and T2Candida test reagents. The use of T2DT reduced the number of unnecessarily treated patients by 98% relative to that with ET. Reduced drug exposure might lessen the possibility of drug-related adverse events and may also prevent the development of antifungal resistance or emergence of drug-resistant Candida species. The greatest benefit of T2Candida appears to be the ability to confidently withhold or stop empirical antifungal therapy in low-to-moderate-risk patients who are unlikely to benefit from treatment.

Cost-effectiveness of three echinocandins and fluconazole in the treatment of candidemia and/or invasive candidiasis in nonneutropenic adult patients

OBJECTIVE

To estimate the cost-effectiveness of three echinocandins (anidulafungin, caspofungin, and micafungin) and generic fluconazole in the treatment of nonneutropenic adult patients with candidemia and/or invasive candidiasis in intensive care units in Spain.

MATERIALS AND METHODS

A decision-tree model was applied. The success and safety (hepatic and renal adverse effects) of first-line treatments were obtained from meta-analyses and systematic reviews of clinical trials. In the case of failure, a second-line treatment (liposomal amphotericin B after the echinocandins, or one of the echinocandins after fluconazole) was administered. The duration of the treatments (14 days total) was established by a panel of clinical experts using the Delphi method and according to Infectious Diseases Society of America guidelines. The cost of the medications and renal toxicity were considered. Deterministic and probabilistic sensitivity analysis using Monte Carlo simulations were carried out.

RESULTS

The total cost of the treatment of candidemia and/or invasive candidiasis with anidulafungin, caspofungin, micafungin, and fluconazole was €5,483, €5,968, €6,231, and €2,088, respectively. Anidulafungin was the dominant treatment (more effective, less expensive) compared to micafungin and caspofungin. The cost of achieving one more patient successfully treated with anidulafungin, caspofungin, and micafungin compared to fluconazole was €17,199, €23,962, and €27,339, respectively. The result remained stable, despite modification of the duration of the first-line and second-line treatments, as well as most of the dosing regimens. The probabilistic analysis also remained stable.

CONCLUSION

In accordance with this economic study, anidulafungin would produce savings and would be the dominant treatment compared with micafungin and caspofungin in nonneutropenic adult patients with candidemia and/or invasive candidiasis in intensive care units in Spain.

[Patients treated with micafungin during their stay in intensive care unit]

OBJECTIVES

To determine the reasons of prescription, the characteristics of patients and factors that affected the outcome of critically ill patients treated with micafungin (MCF) during their stay in Spanish ICUs.

MATERIAL AND METHODS

Observational, retrospective and multicenter study. Patients admitted to the ICU between March 2011 and October 2012 (20-month period) treated with MCF for any reason were included in the study. Severity of patients at the beginning of treatment was measured with the APACHE II, SOFA, Child-Pugh and MELD scores. Reasons for the use of MCF were classified as prophylaxis, preemptive treatment, empirical treatment and directed treatment. Continuous variables are expressed as mean and standard deviation or median, and categorical variables as percentages. A multivariate analysis was performed to identify variables related to intra-ICU mortality.

RESULTS

The study population included 139 patients admitted to 19 Spanish ICUs, with a mean age of 57.3 (17.1) years, 89 (64%) men, with surgical (53.2%) and/or medical (44.6%) conditions, APACHE II score of 20.6 (7.7) and SOFA score of 8.4 (4.3), with 84.2% of patients requiring mechanical ventilation, 59% parenteral nutrition, 37.4% extrarenal depuration procedures and 37.4% treatment with steroids. MCF was indicated as empirical treatment of a proven infection in 51 (36.7%) cases, pre-emptive treatment in 50 (36%) especially as a result of the application of the Candida score (32 cases), directed treatment of fungal infection in 23 (16.5%) and as prophylactic treatment in 15 (10.8%) cases. In 108 (77%) cases, a daily dose of 100mg was administered, with a loading dose in only 9 cases (6.5%). The mean duration of treatment was 13.1 (13) days. A total of 59 (42.4%) patients died during their stay in the ICU and 16 after ICU discharge (hospital mortality 53.9%). Independent risk factors for intra-ICU mortality were the Child-Pugh score (OR 1.45, 95% CI 1.162-1.813; P=.001) and the MELD score (OR 1.05, 95% CI 1.011-1.099; P=.014).

CONCLUSIONS

MCF is usually administered at a dose of 100mg/day, without loading dose and in 72.7% of cases as pre-emptive or empirical treatment. Factors that better predicted mortality were indicators of liver insufficiency at the time of starting treatment.

Novel strategies to fight Candida species infection

In recent years, there has been a significant increase in the incidence of human fungal infections. The increase in cases of infection caused by Candida species, and the consequent excessive use of antimicrobials, has favored the emergence of resistance to conventional antifungal agents over the past decades. Consequently, Candida infections morbidity and mortality are also increasing. Therefore, new approaches are needed to improve the outcome of patients suffering from Candida infections, because it seems unlikely that the established standard treatments will drastically lower the morbidity of mucocutaneous Candida infections and the high mortality associated with invasive candidiasis. This review aims to present the last advances in the traditional antifungal therapy, and present an overview of novel strategies that are being explored for the treatment of Candida infections, with a special focus on combined antifungal agents, antifungal therapies with alternative compounds (plant extracts and essential oils), adjuvant immunotherapy, photodynamic therapy and laser therapy.

How to select an antifungal agent in critically ill patients

Fungal infections are common in critically ill patients and are associated with increased morbidity and mortality. Candida spp are the most commonly isolated fungal pathogens. The last 2 decades have seen an increased incidence of fungal infections in critical illness and the emergence of new pathogenic fungal species and also the development of more effective (better bioavailability) and safer (less toxicity, fewer drug interactions) drugs. The distinction between colonization and infection can be difficult, and problems diagnosing infection may delay initiation of antifungal treatment. A number of factors have been identified that can help to distinguish patients at high risk for fungal infection. The antifungal agents that are most frequently used in the intensive care unit are the first- and second-generation azoles and the echinocandins; amphotericin B derivatives (mainly the liposomal agents) are less widely used because of adverse effects. The choice of antifungal agent in critically ill patients will depend on the aim of therapy (prophylaxis, pre-emptive, empiric, definitive), as well as on local epidemiology and specific properties of the drug (antifungal spectrum, efficacy, toxicity, pharmacokinetic/pharmacodynamic properties, cost). In this article we will review all these aspects and propose an algorithm to guide selection of antifungal agents in critically ill patients.

Micafungin: an evidence-based review of its place in therapy

Invasive fungal infections have increased throughout the world. Many of these infections occur in patients with multiple comorbidities who are receiving medications with the potential for interactions with antifungal therapy that could lead to renal and hepatic dysfunction. The second marketed echinocandin, micafungin, was approved in 2005 for the treatment of esophageal candidiasis and prophylaxis of invasive Candida infections in patients undergoing hematopoietic stem cell transplantation. The indication for use was later expanded to include candidemia, acute disseminated candidiasis, Candida abscesses, and peritonitis. Like other echinocandins it is fungicidal against Candida species, including those that are polyene- and azole-resistant and fungistatic against Aspergillus species. Its formulation is by the intravenous route only and it is dosed once daily without a loading dose as 85% of the steady state concentration is achieved after three daily doses. It has a favorable tolerability profile with no significant drug interactions and does not need adjustment for renal or hepatic insufficiency.

An Italian consensus for invasive candidiasis management (ITALIC)

INTRODUCTION

Invasive candidiasis (IC) has primarily been studied in intensive care unit (ICU) patients, although, in reality, a vast majority of these infections occur outside of the ICU. The recent publication of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) guidelines also deal with the non-ICU population, but many uncertainties remain on the management of IC, particularly in non-critically ill patients.

METHODS

The Italian Society of Antimicrobial Therapy, Società Italiana di Terapia Antimicrobica (SITA), produced practical, hospital-wide recommendations on the management of Candida infection in non-immunocompromised patients in the hospital ward.

RESULTS AND DISCUSSION

Our focus is on patient stratification in terms of risk factors for IC and of clinical severity, emphasising a high index of suspicion to ensure early diagnosis, early treatment and de-escalation when a patient is clinically stable, in order to optimise resource allocation.

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.

[Antifungal treatment options in the critically ill patient]

Invasive fungal infections, especially in the critical care setting, have become an excellent target for prophylactic, empiric, and pre-emptive therapy interventions due to their associated high morbidity, mortality rate, increased incidence, and healthcare costs. For these reasons, new studies and laboratory tests have been developed over the last few years in order to formulate an early therapeutic intervention strategy in an attempt to reduce the high mortality rate associated with these infections. In recent years, evidence-based studies have shown the roles that the new antifungal drugs play in the treatment of invasive mycosis in seriously ill and complex patients, although data from critically ill patients are more limited. New antifungal agents have been analyzed in different clinical situations in critical care units, and the increasing number of non-Candida albicans species suggest that the application of early echinocandin therapy in critically ill patients with invasive candidiasis is a good option. Voriconazole should be recommended for invasive aspergillosis as a first line option.

Invasive candidiasis: update on current pharmacotherapy options and future perspectives

INTRODUCTION

Invasive candidiasis (IC), mainly candidemia, is a leading cause of morbidity and mortality among immunocompromised patients and those admitted to intensive care units. Despite the recognition of risk factors and advances in disease prevention, Candida-related hospitalizations and mortality continue to rise. For treatment, four classes of older and newer antifungal agents are currently available. Adjunctive immunotherapies and a monoclonal antibody against heat shock protein 90 (efungumab) are promising novel therapeutic approaches.

AREAS COVERED

In this article, approaches and therapeutic agents for candidemia and other forms of IC are reviewed.

EXPERT OPINION

The thorough understanding of the available antifungal agents in combination with the increasing knowledge of the mechanisms that underlie the pathogenesis of Candida infections and the development of newer approaches such as efungumab and immunotherapy with adjunctive cytokines may improve the prognosis of patients with life-threatening invasive Candida infections.

ESCMID* guideline for the diagnosis and management of Candida diseases 2012: adults with haematological malignancies and after haematopoietic stem cell transplantation (HCT)

Fungal diseases still play a major role in morbidity and mortality in patients with haematological malignancies, including those undergoing haematopoietic stem cell transplantation. Although Aspergillus and other filamentous fungal diseases remain a major concern, Candida infections are still a major cause of mortality. This part of the ESCMID guidelines focuses on this patient population and reviews pertaining to prophylaxis, empirical/pre-emptive and targeted therapy of Candida diseases. Anti-Candida prophylaxis is only recommended for patients receiving allogeneic stem cell transplantation. The authors recognize that the recommendations would have most likely been different if the purpose would have been prevention of all fungal infections (e.g. aspergillosis). In targeted treatment of candidaemia, recommendations for treatment are available for all echinocandins, that is anidulafungin (AI), caspofungin (AI) and micafungin (AI), although a warning for resistance is expressed. Liposomal amphotericin B received a BI recommendation due to higher number of reported adverse events in the trials. Amphotericin B deoxycholate should not be used (DII); and fluconazole was rated CI because of a change in epidemiology in some areas in Europe. Removal of central venous catheters is recommended during candidaemia but if catheter retention is a clinical necessity, treatment with an echinocandin is an option (CII(t) ). In chronic disseminated candidiasis therapy, recommendations are liposomal amphotericin B for 8 weeks (AIII), fluconazole for >3 months or other azoles (BIII). Granulocyte transfusions are only an option in desperate cases of patients with Candida disease and neutropenia (CIII).

ESCMID* guideline for the diagnosis and management of Candida diseases 2012: non-neutropenic adult patients

This part of the EFISG guidelines focuses on non-neutropenic adult patients. Only a few of the numerous recommendations can be summarized in the abstract. Prophylactic usage of fluconazole is supported in patients with recent abdominal surgery and recurrent gastrointestinal perforations or anastomotic leakages. Candida isolation from respiratory secretions alone should never prompt treatment. For the targeted initial treatment of candidaemia, echinocandins are strongly recommended while liposomal amphotericin B and voriconazole are supported with moderate, and fluconazole with marginal strength. Treatment duration for candidaemia should be a minimum of 14 days after the end of candidaemia, which can be determined by one blood culture per day until negativity. Switching to oral treatment after 10 days of intravenous therapy has been safe in stable patients with susceptible Candida species. In candidaemia, removal of indwelling catheters is strongly recommended. If catheters cannot be removed, lipid-based amphotericin B or echinocandins should be preferred over azoles. Transoesophageal echocardiography and fundoscopy should be performed to detect organ involvement. Native valve endocarditis requires surgery within a week, while in prosthetic valve endocarditis, earlier surgery may be beneficial. The antifungal regimen of choice is liposomal amphotericin B +/- flucytosine. In ocular candidiasis, liposomal amphotericin B +/- flucytosine is recommended when the susceptibility of the isolate is unknown, and in susceptible isolates, fluconazole and voriconazole are alternatives. Amphotericin B deoxycholate is not recommended for any indication due to severe side effects.

Pharmacokinetics of anidulafungin in critically ill patients with candidemia/invasive candidiasis

The pharmacokinetics of intravenous anidulafungin in adult intensive care unit (ICU) patients were assessed in this study and compared with historical data from a general patient population and healthy subjects. Intensive plasma sampling was performed over a dosing interval at steady state from 21 ICU patients with candidemia/invasive candidiasis. All patients received the recommended dosing regimen (a 200-mg loading dose on day 1, followed by a daily 100-mg maintenance dose), except for a 54-year-old 240-kg female patient (who received a daily 150-mg maintenance dose instead). Plasma samples were assayed for anidulafungin using a validated liquid chromatography-tandem mass spectrometry method. Pharmacokinetic parameters in ICU patients were calculated by a noncompartmental method. With the exclusion of the 240-kg patient, the median (minimum, maximum) age, weight, and body mass index (BMI) of 20 ICU patients were 57 (39, 78) years, 65 (48, 106) kg, and 23.3 (16.2, 33.8) kg/m(2), respectively. The average anidulafungin area under the curve over the 24-hour dosing interval (AUC(0-24)), maximum concentration (C(max)), and clearance (CL) in 20 ICU patients were 92.7 mg · h/liter, 7.7 mg/liter, and 1.3 liters/h, respectively. The exposure in the 240-kg patient at a daily 150-mg dose was within the range observed in ICU patients overall. The average AUC(0-24) and Cmax in the general patient population and healthy subjects were 110.3 and 105.9 mg · h/liter and 7.2 and 7.0 mg/liter, respectively. The pharmacokinetics of anidulafungin in ICU patients appeared to be comparable to those in the general patient population and healthy subjects at the same dosing regimen.

Comparison of micafungin and voriconazole in the treatment of invasive fungal infections in kidney transplant recipients

WHAT IS KNOWN AND OBJECTIVE

Invasive fungal infections are a major threat to renal transplant recipients. Micafungin and voriconazole are two useful antifungal agents for treating such infections. Our objective is to evaluate the comparative efficacy and safety of micafungin and voriconazole in the initial treatment of such infections.

METHODS

In this prospective, multicentre, open-labelled, randomized, controlled trial, renal transplant recipients with invasive fungal infections were assigned to receive either micafungin or voriconazole. The enrolled subjects received a kidney transplant between March 2008 and March 2010 at one of the two transplant centres in Henan Province, China. The efficacy and adverse effects of the two treatments were compared.

RESULTS AND DISCUSSION

The clinical trial enrolled 65 patients, of whom 31 were treated with micafungin, and 34 with voriconazole. The rates of microbiological evidence of infection in the micafungin and voriconazole groups were 64.5% and 70.5%, respectively, whereas the rates of Candida as the major cultured fungus were 80.0% and 75.0%, respectively. Complicated bacterial infection rates in the two treatment groups were 38.7% and 32.4%, respectively, whereas complicated CMV viral infection occurred at a rate of 19.2% and 23.5%, respectively. Fungal infection within one to 3 months after transplant was 83.6% (26/31) and 85.3% (29/34) in the micafungin and voriconazole groups, respectively. There was no significant difference between the two groups in terms of efficacy, survival beyond 10 days and discontinuation of treatment because of lack of efficacy (P > 0.05). Mortality rates in the micafungin and voriconazole groups were 9.7% (3/31) and 12.1% (4/33), respectively. Rates of adverse effects in the two groups were 41.9% and 51.6% (P > 0.05), respectively.

WHAT IS NEW AND CONCLUSIONS

This is the first comparison of micafungin and voriconazole in renal transplant patients. Our study shows that the effectiveness of micafungin was similar to that of voriconazole in such patients.

The utility of acute physiology and chronic health evaluation II scores for prediction of mortality among intensive care unit (ICU) and non-ICU patients with methicillin-resistant Staphylococcus aureus bacteremia

OBJECTIVE

Bloodstream infections due to methicillin-resistant Staphylococcus aureus (MRSA) have been associated with significant risk of in-hospital mortality. The acute physiology and chronic health evaluation (APACHE) II score was developed and validated for use among intensive care unit (ICU) patients, but its utility among non-ICU patients is unknown. The aim of this study was to determine the ability of APACHE II to predict death at multiple time points among ICU and non-ICU patients with MRSA bacteremia.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Secondary analysis of data from 200 patients with MRSA bacteremia at 2 hospitals.

METHODS

Logistic regression models were constructed to predict overall in-hospital mortality and mortality at 48 hours, 7 days, 14 days, and 30 days using APACHE II scores separately in ICU and non-ICU patients. The performance of APACHE II scores was compared with age adjustment alone among all patients. Discriminatory ability was assessed using the c-statistic and was compared at each time point using χ(2) tests. Model calibration was assessed using the Hosmer-Lemeshow goodness-of-fit test.

RESULTS

APACHE II was a significant predictor of death at all time points in both ICU and non-ICU patients. Discrimination was high in all models, with c-statistics ranging from 0.72 to 0.84, and was similar between ICU and non-ICU patients at all time points. APACHE II scores significantly improved the prediction of overall and 48-hour mortality compared with age adjustment alone.

CONCLUSIONS

The APACHE II score may be a valid tool to control for confounding or for the prediction of death among ICU and non-ICU patients with MRSA bacteremia.

[Invasive fungal infection in critically ill patients]

The most common organism implicated in fungal infections in the critically ill patients is Candida spp. C. albicans continues to be the species that causes the largest number of invasive candidiasis. In critically ill patients, Candida spp. are frequently isolated in non-sterile sites. Candida colonization is documented in nearly 60% of non-neutropenic critically ill patients staying more than one week in the ICU. However, only 5% of colonized patients will develop invasive candidiasis. The diagnosis of invasive non-candidemic candidiasis remains elusive in the majority of the patients. Candida in a blood culture should never be viewed as a contaminant and should always prompt treatment initiation. Patients with multifocal colonization with a Candida score >3 should also receive antifungal therapy. Fluconazole is reserved for non-severely ill patients without recent exposure to azoles. The use of an echinocandin is recommended for hemodynamically unstable patients or with a history of recent fluconazole exposure.

Anidulafungin for the treatment of candidaemia/invasive candidiasis in selected critically ill patients

A prospective, multicentre, phase IIIb study with an exploratory, open-label design was conducted to evaluate efficacy and safety of anidulafungin for the treatment of candidaemia/invasive candidiasis (C/IC) in specific ICU patient populations. Adult ICU patients with confirmed C/IC meeting ≥1 of the following criteria were enrolled: post-abdominal surgery, solid tumour, renal/hepatic insufficiency, solid organ transplant, neutropaenia, and age ≥65 years. Patients received anidulafungin (200 mg on day 1, 100 mg/day thereafter) for 10–42 days, optionally followed by oral voriconazole/fluconazole. The primary efficacy endpoint was global (clinical and microbiological) response at the end of all therapy (EOT). Secondary endpoints included global response at the end of intravenous therapy (EOIVT) and at 2 and 6 weeks post-EOT, survival at day 90, and incidence of adverse events (AEs). The primary efficacy analysis was performed in the modified intent-to-treat (MITT) population, excluding unknown/missing responses. The safety and MITT populations consisted of 216 and 170 patients, respectively. The most common pathogens were Candida albicans (55.9%), C. glabrata (14.7%) and C. parapsilosis (10.0%). Global success was 69.5% (107/154; 95% CI, 61.6–76.6) at EOT, 70.7% (111/157) at EOIVT, 60.2% (77/128) at 2 weeks post-EOT, and 50.5% (55/109) at 6 weeks post-EOT. When unknown/missing responses were included as failures, the respective success rates were 62.9%, 65.3%, 45.3% and 32.4%. Survival at day 90 was 53.8%. Treatment-related AEs occurred in 33/216 (15.3%) patients, four (1.9%) of whom had serious AEs. Anidulafungin was effective, safe and well tolerated for the treatment of C/IC in selected groups of ICU patients.

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.

When and how to cover for fungal infections in patients with severe sepsis and septic shock

Candida species remain the most frequently isolated fungi in intensive care unit (ICU) patients with severe sepsis or septic shock. Delayed antifungal therapy in these patients is a recognized risk factor for mortality. However, the diagnosis of invasive candidiasis remains difficult and is frequently delayed. Clinical scores have been proposed to assess the risk of development of invasive candidiasis or candidemia. Laboratory tools for early diagnosis are disappointing or still under development. Triazoles, polyenes, and echinocandins are the key drugs used to treat invasive candidiasis in ICU patients with similar efficacy, but very variable tolerability. The increasing incidence of fluconazole-resistant and susceptible-dose dependent strains and the safety profile of antifungal agents must be taken into account when selecting empiric therapy, frequently leading to the initial use of echinocandins in ICU patients with severe sepsis or septic shock.

Anidulafungin compared with fluconazole in severely ill patients with candidemia and other forms of invasive candidiasis: support for the 2009 IDSA treatment guidelines for candidiasis

Introduction

During the past decade, the incidence of Candida infections in hospitalized patients has increased, with fluconazole being the most commonly prescribed systemic antifungal agent for these infections. However, the 2009 Infectious Diseases Society of America (IDSA) candidiasis guidelines recommend an echinocandin for the treatment of candidemia/invasive candidiasis in patients who are considered to be "moderately severe or severely" ill. To validate these guidelines, clinical trial data were reviewed.

Methods

A secondary analysis of data from a previously published prospective, randomized, double-blind clinical trial was performed; it compared anidulafungin with fluconazole for the treatment of invasive candidiasis and candidemia. Patients with critical illness were identified at study entry by using the following criteria: Acute Physiology and Chronic Health Evaluation (APACHE) II score of ≥ 15, evidence of severe sepsis (sepsis and one or more end-organ dysfunctions) present, and/or patient was in intensive care. Global response rates were compared at the end of intravenous study treatment (the primary end point of the original study) and all-cause mortality at 14 and 28 days from study entry in this group.

Results

The patients (163 (66.5%) of 245) fulfilled at least one criterion for critical illness (anidulafungin, n = 89; fluconazole, n = 74). No significant differences were found in baseline characteristics between the two treatment groups. The global response rate was 70.8% for anidulafungin and 54.1% for fluconazole (P = 0.03; 95% confidence interval (CI): 2.0 to 31.5); all-cause mortality was 10.1% versus 20.3% at 14 days (P = 0.08; 95% CI, -0.9 to 21.3) and was 20.2% versus 24.3% at 28 days (P = 0.57; 95% CI, -8.8 to 17.0) for anidulafungin and fluconazole, respectively.

Conclusions

In this post hoc analysis, anidulafungin was more effective than fluconazole for treatment of severely ill patients with candidemia, thus supporting the 2009 IDSA guidelines.

Trial registration

Clinicaltrials.gov NCT00058682.

Anidulafungin for the treatment of invasive candidiasis

Candidaemia/invasive candidiasis (C/IC) is the most frequently occurring invasive fungal infection worldwide, with a particularly strong impact and high incidence in the intensive-care unit, where there is a need for new treatment options and strategies. The echinocandin anidulafungin has broad in vitro activity against a wide range of Candida species, along with favourable pharmacokinetics that allow administration in hepatic and renal impairment and with any comedication without the need for dose adjustments. The efficacy and safety of anidulafungin for the treatment of C/IC were demonstrated in a number of clinical studies and by some limited data from clinical practice. In a randomized comparative trial for the treatment of C/IC in adults, 76% of patients receiving anidulafungin and 60% of those given fluconazole were treated successfully (95% CI for difference: 4-27; p 0.01). Post hoc analyses suggest that anidulafungin is significantly more effective than standard-dose fluconazole for the treatment of candidaemia in critically ill patients. Anidulafungin is generally well tolerated, with commonly reported side effects including headache, hypokalaemia, gastrointestinal symptoms, abnormal liver function test results, and rash. In pharmaco-economic analyses, anidulafungin compared favourably with fluconazole (in terms of overall costs and hospital resource use) as well as with other echinocandins. Echinocandins, including anidulafungin, are now generally recommended as first-line therapy in moderately to severely ill patients, those with prior azole exposure, and patients with C/IC caused by Candida glabrata or Candida krusei.

Overview of treatment options for invasive fungal infections

The introduction of several new antifungals has significantly expanded both prophylaxis and treatment options for invasive fungal infections (IFIs). Relative to amphotericin B deoxycholate, lipid-based formulations of amphotericin B have significantly reduced the incidence of nephrotoxicity, but at a significant increase in drug acquisition cost. Newer, broad-spectrum triazoles (notably voriconazole and posaconazole) have added significantly to both the prevention and treatment of IFIs, most notably Aspergillus spp. (with voriconazole) and the treatment of some emerging fungal pathogens. Finally, a new class of parenteral antifungals, the echinocandins, is employed most frequently against invasive candidal infections. While the role of these newer agents continues to evolve, this review summarizes the activity, safety and clinical applications of agents most commonly employed in the treatment of IFIs.