Antifungal agents for preventing fungal infections in non-neutropenic critically ill and surgical patients: systematic review and meta-analysis of randomized clinical trials

Effect of the CYP3A inhibitors, diltiazem and ketoconazole, on ticagrelor pharmacokinetics in healthy volunteers

OBJECTIVES

Two open-label, two-period, crossover studies in healthy volunteers were designed to determine the pharmacokinetic interactions between ticagrelor, a P2Y12 receptor antagonist, and a moderate (diltiazem) and a strong (ketoconazole) cytochrome P450 (CYP) 3A inhibitor.

METHODS

Seventeen volunteers received diltiazem (240 mg once daily) for 14 days. In the second study, ketoconazole (n = 14) 200 mg twice daily was given for 10 days. A single oral 90-mg ticagrelor dose was administered on day 8 (diltiazem) or day 4 (ketoconazole). In each study, volunteers received a single 90-mg oral dose of ticagrelor before or after washout (≥14 days). Pharmacokinetic parameters for ticagrelor, AR-C124910XX (primary metabolite), diltiazem, and ketoconazole were assessed.

RESULTS

Compared with ticagrelor alone, diltiazem co-administration significantly increased the mean maximum concentration (C max) and mean area under the plasma concentration-time curve (AUC) for ticagrelor by 69% and 174%, respectively. Diltiazem co-administration reduced C max by 38% but had no significant effect on AUC for AR-C124910XX. C max and AUC for ticagrelor were increased by 135% and 632%, respectively, by ketoconazole co-administration, whereas these parameters were reduced by 89% and 56%, respectively, for AR-C124910XX. Diltiazem and ketoconazole pharmacokinetic parameters were not significantly affected by the presence of ticagrelor.

CONCLUSIONS

These results suggest that ticagrelor can be co-administered with moderate CYP3A inhibitors. However, co-administration of strong CYP3A inhibitors with ticagrelor is not recommended.

Treatment and prophylaxis of invasive candidiasis

Invasive candidiasis (IC) is a leading cause of morbidity and mortality in preterm infants. Even if successfully treated, IC can cause significant neurodevelopmental impairment. Preterm infants are at increased risk for hematogenous Candida meningoencephalitis owing to increased permeability of the blood-brain barrier, so antifungal treatment should have adequate central nervous system penetration. Amphotericin B deoxycholate, lipid preparations of amphotericin B, fluconazole, and micafungin are first-line treatments of IC. Fluconazole prophylaxis reduces the incidence of IC in extremely premature infants, but its safety has not been established for this indication, and as yet, the product has not been shown to reduce mortality in neonates. Targeted prophylaxis may have a role in reducing the burden of disease in this vulnerable population.

Canadian clinical practice guidelines for invasive candidiasis in adults

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

β-D-glucan surveillance with preemptive anidulafungin for invasive candidiasis in intensive care unit patients: a randomized pilot study

BACKGROUND

Invasive candidiasis (IC) is a devastating disease. While prompt antifungal therapy improves outcomes, empiric treatment based on the presence of fever has little clinical impact. Β-D-Glucan (BDG) is a fungal cell wall component detectable in the serum of patients with early invasive fungal infection (IFI). We evaluated the utility of BDG surveillance as a guide for preemptive antifungal therapy in at-risk intensive care unit (ICU) patients.

METHODS

Patients admitted to the ICU for ≥ 3 days and expected to require at least 2 additional days of intensive care were enrolled. Subjects were randomized in 3:1 fashion to receive twice weekly BDG surveillance with preemptive anidulafungin in response to a positive test or empiric antifungal treatment based on physician preference.

RESULTS

Sixty-four subjects were enrolled, with 1 proven and 5 probable cases of IC identified over a 2.5 year period. BDG levels were higher in subjects with proven/probable IC as compared to those without an IFI (117 pg/ml vs. 28 pg/ml; p<0.001). Optimal assay performance required 2 sequential BDG determinations of ≥ 80 pg/ml to define a positive test (sensitivity 100%, specificity 75%, positive predictive value 30%, negative predictive value 100%). In all, 21 preemptive and 5 empiric subjects received systemic antifungal therapy. Receipt of preemptive antifungal treatment had a significant effect on BDG concentrations (p< 0.001). Preemptive anidulafungin was safe and generally well tolerated with excellent outcome.

CONCLUSIONS

BDG monitoring may be useful for identifying ICU patients at highest risk to develop an IFI as well as for monitoring treatment response. Preemptive strategies based on fungal biomarkers warrant further study.

TRIAL REGISTRATION

Clinical Trials.gov NCT00672841.

[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.

Risk factors for invasive fungal disease in critically ill adult patients: a systematic review

Introduction

Over 5,000 cases of invasive Candida species infections occur in the United Kingdom each year, and around 40% of these cases occur in critical care units. Invasive fungal disease (IFD) in critically ill patients is associated with increased morbidity and mortality at a cost to both the individual and the National Health Service. In this paper, we report the results of a systematic review performed to identify and summarise the important risk factors derived from published multivariable analyses, risk prediction models and clinical decision rules for IFD in critically ill adult patients to inform the primary data collection for the Fungal Infection Risk Evaluation Study.

Methods

An internet search was performed to identify articles which investigated risk factors, risk prediction models or clinical decisions rules for IFD in critically ill adult patients. Eligible articles were identified in a staged process and were assessed by two investigators independently. The methodological quality of the reporting of the eligible articles was assessed using a set of questions addressing both general and statistical methodologies.

Results

Thirteen articles met the inclusion criteria, of which eight articles examined risk factors, four developed a risk prediction model or clinical decision rule and one evaluated a clinical decision rule. Studies varied in terms of objectives, risk factors, definitions and outcomes. The following risk factors were found in multiple studies to be significantly associated with IFD: surgery, total parenteral nutrition, fungal colonisation, renal replacement therapy, infection and/or sepsis, mechanical ventilation, diabetes, and Acute Physiology and Chronic Health Evaluation II (APACHE II) or APACHE III score. Several other risk factors were also found to be statistically significant in single studies only. Risk factor selection process and modelling strategy also varied across studies, and sample sizes were inadequate for obtaining reliable estimates.

Conclusions

This review shows a number of risk factors to be significantly associated with the development of IFD in critically ill adults. Methodological limitations were identified in the design and conduct of studies in this area, and caution should be used in their interpretation.

Multidisciplinary approach to the treatment of invasive fungal infections in adult patients. Prophylaxis, empirical, preemptive or targeted therapy, which is the best in the different hosts?

The high morbidity, mortality, and health care costs associated with invasive fungal infections, especially in the critical care setting and immunocompromised host, have made it an excellent target for prophylactic, empiric, and preemptive therapy interventions principally based on early identification of risk factors. Early diagnosis and treatment are associated with a better prognosis. In the last years there have been important developments in antifungal pharmacotherapy. An approach to the new diagnosis tools in the clinical mycology laboratory and an analysis of the use new antifungal agents and its application in different clinical situations has been made. Furthermore, an attempt of developing a state of the art in each clinical scenario (critically ill, hematological, and solid organ transplant patients) has been performed, trying to choose the best strategy for each clinical situation (prophylaxis, pre-emptive, empirical, or targeted therapy). The high mortality rates in these settings make mandatory the application of early de-escalation therapy in critically ill patients with fungal infection. In addition, the possibility of antifungal combination therapy might be considered in solid organ transplant and hematological patients.

Diagnosis and therapy of Candida infections: joint recommendations of the German Speaking Mycological Society and the Paul-Ehrlich-Society for Chemotherapy

Invasive Candida infections are important causes of morbidity and mortality in immunocompromised and hospitalised patients. This article provides the joint recommendations of the German-speaking Mycological Society (Deutschsprachige Mykologische Gesellschaft, DMyKG) and the Paul-Ehrlich-Society for Chemotherapy (PEG) for diagnosis and treatment of invasive and superficial Candida infections. The recommendations are based on published results of clinical trials, case-series and expert opinion using the evidence criteria set forth by the Infectious Diseases Society of America (IDSA). Key recommendations are summarised here: The cornerstone of diagnosis remains the detection of the organism by culture with identification of the isolate at the species level; in vitro susceptibility testing is mandatory for invasive isolates. Options for initial therapy of candidaemia and other invasive Candida infections in non-granulocytopenic patients include fluconazole or one of the three approved echinocandin compounds; liposomal amphotericin B and voriconazole are secondary alternatives because of their less favourable pharmacological properties. In granulocytopenic patients, an echinocandin or liposomal amphotericin B is recommended as initial therapy based on the fungicidal mode of action. Indwelling central venous catheters serve as a main source of infection independent of the pathogenesis of candidaemia in the individual patients and should be removed whenever feasible. Pre-existing immunosuppressive treatment, particularly by glucocorticosteroids, ought to be discontinued, if feasible, or reduced. The duration of treatment for uncomplicated candidaemia is 14 days following the first negative blood culture and resolution of all associated symptoms and findings. Ophthalmoscopy is recommended prior to the discontinuation of antifungal chemotherapy to rule out endophthalmitis or chorioretinitis. Beyond these key recommendations, this article provides detailed recommendations for specific disease entities, for antifungal treatment in paediatric patients as well as a comprehensive discussion of epidemiology, clinical presentation and emerging diagnostic options of invasive and superficial Candida infections.

Pharmacokinetic evaluation of fluconazole in critically ill patients

INTRODUCTION

Invasive candidiasis has emerged over the last few decades as an increasingly important nosocomial problem for the critically ill, affecting around 2% of intensive care unit patients. Although poor outcomes associated with invasive candidiasis among critically ill patients may relate to severe underlying disease processes and delayed institution of antifungal therapy, inadequate dosing of antifungal agents may also contribute.

AREAS COVERED

This drug evaluation provides a critical appraisal of the published literature pertaining to the pharmacokinetics of fluconazole in critically ill, obese or severely burned patients, including those receiving acute renal replacement therapy. The pharmacodynamics of fluconazole is also covered, as well as the likely clinical implications for optimal dosing and the toxicity of fluconazole. Last, variations in fluconazole susceptibility patterns of Candida spp. are also discussed.

EXPERT OPINION

Recently, there has been an increased but geographically variable prevalence of non-albicans Candida spp., causing invasive candidiasis and an overall trend towards reduced fluconazole susceptibility. The pathophysiological changes of critical illness, coupled with a lack of dose finding studies, support the use of local susceptibility patterns to guide fluconazole dosing until such time as pharmacokinetic-pharmacodynamic information to guide optimal fluconazole dosing strategies and pharmacodynamic targets becomes available.

Validation and comparison of clinical prediction rules for invasive candidiasis in intensive care unit patients: a matched case-control study

Introduction

Due to the increasing prevalence and severity of invasive candidiasis, investigators have developed clinical prediction rules to identify patients who may benefit from antifungal prophylaxis or early empiric therapy. The aims of this study were to validate and compare the Paphitou and Ostrosky-Zeichner clinical prediction rules in ICU patients in a 689-bed academic medical center.

Methods

We conducted a retrospective matched case-control study from May 2003 to June 2008 to evaluate the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of each rule. Cases included adults with ICU stays of at least four days and invasive candidiasis matched to three controls by age, gender and ICU admission date. The clinical prediction rules were applied to cases and controls via retrospective chart review to evaluate the success of the rules in predicting invasive candidiasis. Paphitou's rule included diabetes, total parenteral nutrition (TPN) and dialysis with or without antibiotics. Ostrosky-Zeichner's rule included antibiotics or central venous catheter plus at least two of the following: surgery, immunosuppression, TPN, dialysis, corticosteroids and pancreatitis. Conditional logistic regression was performed to evaluate the rules. Discriminative power was evaluated by area under the receiver operating characteristic curve (AUC ROC).

Results

A total of 352 patients were included (88 cases and 264 controls). The incidence of invasive candidiasis among adults with an ICU stay of at least four days was 2.3%. The prediction rules performed similarly, exhibiting low PPVs (0.041 to 0.054), high NPVs (0.983 to 0.990) and AUC ROCs (0.649 to 0.705). A new prediction rule (Nebraska Medical Center rule) was developed with PPVs, NPVs and AUC ROCs of 0.047, 0.994 and 0.770, respectively.

Conclusions

Based on low PPVs and high NPVs, the rules are most useful for identifying patients who are not likely to develop invasive candidiasis, potentially preventing unnecessary antifungal use, optimizing patient ICU care and facilitating the design of forthcoming antifungal clinical trials.

[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.

Invasive candidiasis in non-hematological patients

Candida is one of the most frequent pathogens isolated in bloodstream infections, and is associated with significant morbidity and mortality. In addition to haematological patients, there are several other populations with a substantial risk of developing invasive candidiasis (IC). These include patients undergoing prolonged hospitalisation with the use of broad-spectrum antibiotics, those fitted with intravascular catheters, admitted to both adult and neonate intensive care units (ICU) or gastrointestinal surgery wards and subjects with solid tumours undergoing cytotoxic chemotherapy. As a general rule, every immunocompromised patient might be at risk of Candida infection, including, for example, diabetic patients.

The epidemiology of species responsible for IC has been changing, both at local and worldwide level, shifting from C. albicans to non-albicans species, that can be intrinsically resistant to fluconazole (C. krusei and, to some extent, C. glabrata), difficult to eradicate because of biofilm production (C. parapsilosis) or than might acquire resistance to azole during therapy.

Delaying the specific therapy has been shown to increase morbidity and mortality, but traditional microbiological diagnosis is poorly sensitive and slow. Thus, culture-based treatment may result in therapy started too late. In order to reduce the mortality in IC, several management strategies have been developed: prophylaxis, empirical and pre-emptive therapy. Compared to prophylaxis, the latter approaches allow to reduce the use of antifungals by targeting only patients at very high risk of IC. Non-invasive serological markers and scores based on clinical prediction rules such as the presence of risk factors or Candida colonisation, have been developed with the aim of allowing prompt initiation of treatment. Although the use of these diagnostic tools in pre-emptive strategies is promising, the performance and cost-effectiveness should be tested in large trials.

Agents recommended for initial treatment of candidemia in severely ill patients include echinocandins and lipid formulations of amphotericin B, while stable patients without risk factors for azole-resistance might be treated with fluconazole.

Prophylaxis, empirical and preemptive treatment of invasive candidiasis

PURPOSE OF REVIEW

Invasive candidiasis remains an important infection for ICU patients, associated with poor clinical outcomes. It has been increasingly recognized that the traditional paradigm of culture-directed antifungal treatment is unsatisfactory, and that earlier antifungal intervention strategies, such as prophylaxis, preemptive therapy, and empiric therapy, are required to improve patient outcomes. The purpose of this review is to summarize the recent supportive evidence for such strategies and to highlight the current challenges in their implementation.

RECENT FINDINGS

Despite new antifungal agents and classes, the mortality from invasive candidiasis remains high. Antifungal prophylaxis remains the best-studied early antifungal intervention strategy; however, unless targeted to patients at highest risk, is inefficient. Recent data suggests that although risk predictive models, using a combination of clinical risk factors and Candida colonization parameters, may be a relatively simple and practical approach to guide prophylaxis or preemptive therapy, further validation of these models is required. A single trial has demonstrated that empiric antifungal therapy is not of benefit when instituted to patients with antibiotic-refractory fever alone.

SUMMARY

On the basis of current knowledge, it is difficult to universally recommend antifungal prophylaxis, apart from patient groups with a known very high risk, such as those with necrotising pancreatitis or recurrent gastrointestinal perforations. Antifungal prophylaxis may also be reasonable where local incidence rates and epidemiology are compelling. Among stable patients with multifocal Candida colonization and/or a multitude of clinical-risk factors, preemptive therapy is currently not indicated, although the development of better risk predictive models may assist with such patients. Among patients with refractory fever despite broad-spectrum antibacterial therapy, empiric antifungal therapy may be reasonable where local incidence rates are high (e.g. >10%); however, a thorough search for alternate causes must be instituted.

Economic considerations of antifungal prophylaxis in patients undergoing surgical procedures

Fungi are a frequent cause of nosocomial infections, with an incidence that has increased significantly in recent years, especially among critically ill patients who require intensive care unit (ICU) admission. Among ICU patients, postsurgical patients have a higher risk of Candida infections in the bloodstream. In consideration of the high incidence of fungal infections in these patients, their strong impact on mortality rate, and of the difficulties in Candida diagnosis, some experts suggest the use of antifungal prophylaxis in critically ill surgical patients. A clinical benefit from this strategy has been demonstrated, but the economic impact of the use of antifungal prophylaxis in surgical patients has not been systematically evaluated, and its cost-benefit ratio has not been defined. Whereas the costs associated with treating fungal infections are very high, the cost of antifungal drugs varies from affordable (ie, the older azoles) to expensive (ie, echinocandins, polyenes, and the newer azoles). Adverse drug-related effects and the possibly increased incidence of fluconazole resistance and of isolates other than Candida albicans must also be taken into account. From the published studies of antifungal prophylaxis in surgical patients, a likely economic benefit of this strategy could be inferred, but its usefulness and cost-benefits should be evaluated in light of local data, because the available evidence does not permit general recommendations.

Bench-to-bedside review: therapeutic management of invasive candidiasis in the intensive care unit

Candida is one of the most frequent pathogens in bloodstream infections, and is associated with significant morbidity and mortality. The epidemiology of species responsible for invasive candidiasis, both at local and worldwide levels, has been changing - shifting from Candida albicans to non-albicans species, which can be resistant to fluconazole (Candida krusei and Candida glabrata) or difficult to eradicate because of biofilm production (Candida parapsilosis). Numerous intensive care unit patients have multiple risk factors for developing this infection, which include prolonged hospitalisation, use of broad-spectrum antibiotics, presence of intravascular catheters, parenteral nutrition, high Acute Physiology and Chronic Health Evaluation score, and so forth. Moreover, delaying the specific therapy was shown to further increase morbidity and mortality. To minimise the impact of this infection, several management strategies have been developed - prophylaxis, empirical therapy, pre-emptive therapy and culture-based treatment. Compared with prophylaxis, empirical and pre-emptive approaches allow one to reduce the exposure to antifungals by targeting only the patients at high risk of candidemia, without delaying therapy until the moment blood Candida is identified in blood cultures. The agents recommended for initial treatment of candidemia in critically ill patients include echinocandins and lipid formulation of amphotericin B.

Recognition and prevention of nosocomial invasive fungal infections in the intensive care unit

Despite recent advances in antifungal treatments, the morbidity and mortality of fungal infections, especially invasive candidiasis, in patients in the intensive care unit setting remain high. Because of this, there has been a great interest in improving the evaluation, risk assessment, and prevention of fungal infections in the intensive care unit. Some important advances in the diagnosis of invasive candidiasis include rapid species identification and improvements in antigen testing. The introduction of several prediction rules has helped to guide clinicians in the use of prophylaxis or preemptive antifungal therapy in high-risk patients. However, the most immediate benefit has been realized with the introduction of new antifungal agents that have proved to be safer than those available in the past.

Invasive candidiasis in the intensive care unit

Invasive fungal disease by Candida spp. is on the rise in the modem era of prolonged patient survival by virtue of improved critical care measures, novel chemotherapy regimens, and increasing immunosuppression following organ transplants. Invasive candidiasis (IC) in the setting of an intensive care unit results in prolonged hospital stay and increased morbidity. Clinical suspicion plays a major role in the diagnosis of IC, as current laboratory methods are not very sensitive. Various serum markers and molecular techniques are under development to improve diagnostic strategies. Treatment options involve an expanding spectrum of antifungals. Knowledge of local epidemiology and the risk factors that predispose patients to this disease are essential for effective patient care in an intensive care setting.

Current aspects of invasive candidiasis and aspergillosis in adult intensive care patients

Sepsis is a leading cause of death in the intensive care unit (ICU), with Candida spp. in the forefront among the important pathogens. As recent studies have shown, survival outcome is strongly influenced by adequate antifungal therapy at an early stage that is often delayed by the time lag associated with microbiological diagnosis. Risk factor-based prediction models have a high negative predictive value, but positive prediction of candidaemia in the individual patient remains elusive. New antigen- or DNA-based methods for early diagnosis still await clinical validation. Their routine use is hampered by methodological issues. Species distribution of invasive Candida isolates in the ICU appears to be influenced primarily by age, previous hospitalisation and colonising species. In the context of the importance of adequate first-line treatment, recent guidelines favour the use of echinocandins in critically ill patients with symptoms evoking high suspicion of invasive candidiasis. This is supported by robust clinical trial data, a few interactions and low toxicity. Fluconazole is characterised by reduced activity against some important Candida species, elevated rates of persistent infection seen in comparative trials. Amphotericin B deoxycholate should be considered obsolete in ICU patients because of its high toxicity. Invasive aspergillosis (IA) is a rare devastating infection in the general ICU population, but some centres have reported elevated incidences and underdiagnosis as determined in autopsy-controlled studies. Treatment with mould-active agents such as voriconazole must be initiated early in patients with suspected IA.

Candidemia and invasive candidiasis: a review of the literature for the burns surgeon

Advances in critical care, operative techniques, early fluid resuscitation, antimicrobials to control bacterial infections, nutritional support to manage the hypermetabolic response and early wound excision and coverage has improved survival rates in major burns patients. These advances in management have been associated with increased recognition of invasive infections caused by Candida species in critically ill burns patients. Candida albicans is the most common species to cause invasive Candida infections, however, non-albicans Candida species appear to becoming more frequent. These later species may be less fluconazole susceptible than Candida albicans. High crude and attributable mortality rates from invasive Candida sepsis are multi-factorial. Diagnosis of invasive candidiasis and candidemia remains difficult. Prophylactic and pre-emptive therapies appear promising strategies, but there is no specific approach which is well-studied and clearly efficacious in high-risk burns patients. Treatment options for invasive candidiasis include several amphotericin B formulations and newer less toxic antifungal agents, such as azoles and echinocandins. We review the currently available data on diagnostic and management strategies for invasive candidiasis and candidemia; whenever possible providing reference to the high-risk burn patients. We also present an algorithm for the management of candidemia and invasive candidiasis in burn patients.

Issues in the design and interpretation of antifungal drug trials in the critically ill

PURPOSE OF REVIEW

Invasive fungal infections, such as invasive candidiasis and aspergillosis, are increasingly important in the critical care setting. This review will focus on clinical trials of antifungals in this setting and the methodological issues surrounding them.

RECENT FINDINGS

Critically ill patients have traditionally only comprised a fraction of the patients enrolled in clinical trials exploring antifungal use, but recently a few clinical trials with specific therapeutic approaches have focused on this subpopulation. Increased mortality and problems with diagnosis have fostered the development of new management strategies, such as prophylaxis, pre-emptive treatment, and empirical antifungal therapy.

SUMMARY

Although there are limited data supporting preventive and early therapeutic strategies, their use is recommended in highly selected patients and settings. Although critically ill patients are under-represented in clinical trials of antifungals conducted for the purpose of licensing, most experts agree that it is reasonable to extrapolate from these data until specific trials are conducted.

Effect of antifungal therapy timing on mortality in cancer patients with candidemia

Prior studies have shown that delays in treatment are associated with increased mortality in patients with candidemia. The purpose of this study was to measure three separate time periods comprising the diagnosis and treatment of candidemia and to determine which one(s) is associated with hospital mortality. Patients with blood cultures positive for Candida spp. were identified. Subjects were excluded if no antifungal therapy was given or if there was preexisting antifungal therapy. Collected data included the time from blood culture collection to positivity (incubation period), the time from blood culture positivity to provider notification (provider notification period), and the time from provider notification to the first dose of antifungal given (antifungal initiation period). These times were assessed as predictors of inpatient mortality. A repeat analysis was done with adjustments for age, sex, race, underlying cancer, catheter removal, APACHE III score, acute renal failure, neutropenia, and non-Candida albicans species. A total of 106 episodes of candidemia were analyzed. The median incubation time was 32.1 h and was associated with mortality (univariate hazard ratio per hour, 1.025; P = 0.001). The median provider notification and antifungal initiation periods were 0.3 and 7.5 h, respectively, and were not associated with mortality. Adjusted analysis yielded similar results. For cancer patients with candidemia, the incubation period accounts for a significant amount of time, compared with the provider notification and antifungal initiation times, and is associated with in-hospital mortality. Strategies to shorten the incubation time, such as utilizing rapid molecularly based diagnostic methods, may help reduce in-hospital mortality.

Value of anti-infective chemoprophylaxis in primary systemic vasculitis: what is the evidence?

Although infections are a major concern in patients with primary systemic vasculitis, actual knowledge about risk factors and evidence concerning the use of anti-infective prophylaxis from clinical trials are scarce. The use of high dose glucocorticoids and cyclophosphamide pose a definite risk for infections. Bacterial infections are among the most frequent causes of death, with Staphylococcus aureus being the most common isolate. Concerning viral infections, cytomegalovirus and varicella-zoster virus reactivation represent the most frequent complications. The only prophylactic measure that is widely accepted is trimethoprim/sulfamethoxazole to avoid Pneumocystis jiroveci pneumonia in small vessel vasculitis patients with generalised disease receiving therapy for induction of remission.

Invasive candidiasis and candidemia: from current opinions to future perspectives

Candida spp. are the fourth most common cause of nosocomial bloodstream infections in the United States, as well as the single most important cause of opportunistic fungal infections worldwide. A delayed diagnosis of invasive candidiasis and/or inadequate treatment choice is associated with high mortality rates and prolonged hospital stays. Even though the antifungal armamentarium has been broadened significantly over the last years, the best options for diagnosing and treating invasive candidiasis still remain a matter of discussion. In this article we present and analyze current evidence on the epidemiology, diagnostic methods and treatment options of invasive candidiasis, with a focus on results from randomized clinical trials. Finally, the reader is provided with a brief overview on promising clinical trial designs and antifungals that might shape the treatment of invasive candidiasis in the years to come.

Antifungal treatment strategies in high risk patients

We discuss different strategies for the treatment of invasive fungal infections (IFI) in high risk patients with a focus on patients experiencing profound and prolonged neutropenia, comprising those with acute myelogenous leukaemia (AML) or myelodysplastic syndrome (MDS) during remission induction chemotherapy and on patients undergoing allogeneic haematopoietic stem cell transplantation (SCT). Among these patients, invasive aspergillosis (IA) is the most frequently observed form of IFI, as opposed to high risk intensive care unit (ICU) patients in whom an increased incidence of invasive candidiasis (IC) can be observed. In both groups, initiation of early treatment has a profound impact on mortality rates, but adequate diagnostic tools are lacking. These circumstances have led to the parallel use of different treatment strategies, e.g. prophylaxis, empiric, pre-emptive and targeted treatment of IFI. The optimum treatment strategies for these severe infections are a matter of extensive research and discussion. A review of major clinical trials on the issue reveals that comparisons between different treatment strategies cannot be made. Considering the complexity of the issue, we advocate an eclectic treatment approach that reduces morbidity and mortality from IFI without compromising tolerability. In allogeneic HSCT recipients, patients receiving induction chemotherapy for AML or MDS and those under immunosuppressive medication for graft vs. host disease after allogeneic HSCT, we recommend prophylaxis with posaconazole. For empiric treatment of persistently febrile neutropenic patients, we opt for caspofungin as first and liposomal amphotericin B deoxycholate (L-AmB) as second line choice. If the diagnosis of IA can be established, voriconazole should be favoured over the alternative, liposomal amphotericin B (L-AmB). While high risk ICU patients benefit from fluconazole prophylaxis for IC, the choice of an optimal agent for targeted therapy depends largely on the neutrophil count. In non-neutropenic patients, we recommend an echinocandin as the first line treatment option. Patients with susceptible Candida spp. may be switched to fluconazole. Caspofungin or micafungin might be preferred to anidulafungin in the neutropenic patient. L-AmB is a valuable second line treatment option for both groups of patients.

Assessment of clinical risk predictive rules for invasive candidiasis in a prospective multicentre cohort of ICU patients

PURPOSE

To assess the generalisability of published clinical risk predictive models for invasive candidiasis in ICU patients.

METHODS

The performance characteristics of published clinical risk factor-only and Candida colonisation-only predictive models for invasive candidiasis were assessed in a multicentre cohort of Australian ICU patients. Clinical risk factors and Candida colonisation parameters were collected prospectively from patients.

RESULTS

The two clinical risk factor-only predictive models applied to an Australian patient cohort (n = 615) performed less well than in published studies involving derivation populations. Model performance characteristics improved when Candida colonisation parameters were added post-hoc.

CONCLUSIONS

Risk predictive models should factor in both clinical risk factors and Candida colonisation parameters. Integrating these models into therapeutic algorithms first requires external validation in different patient populations and settings.

Overview of the changing epidemiology of candidemia

Candida spp. are currently the fourth most common cause of bloodstream infections in US hospitals, and the third most common cause of bloodstream infections in the intensive care unit. Over the last 2 decades there has been a shift towards a greater involvement of non-Candida albicans spp. as the cause of candidemia. Several of these non-albicans spp. (e.g., C. glabrata and C. krusei ) exhibit resistance to traditional triazole antifungals like fluconazole, and cross-resistance with newer triazoles, focusing attention on the first-line use of antifungals such as the echinocandins, which possess improved activity against fluconazole-resistant strains. Recent treatment guidelines from the Infectious Diseases Society of America (IDSA) recommend an echinocandin as primary therapy for nonneutropenic or neutropenic patients with moderately severe to severe candidiasis and for patients at risk for infection with a triazole-resistant strain. However, further improvement in candidemia-associated mortality will only be attainable with the development and validation of new diagnostic tools that will allow earlier detection, discrimination, and treatment of invasive candidiasis. Clinicians should remain vigilant to wider emergence of Candida spp. with echinocandin resistance.

Dose tolerability of chronically inhaled voriconazole solution in rodents

Invasive pulmonary aspergillosis (IPA) is a fungal disease of the lung associated with high mortality rates in immunosuppressed patients despite treatment. Targeted drug delivery of aqueous voriconazole solutions has been shown in previous studies to produce high tissue and plasma drug concentrations as well as improved survival in a murine model of IPA. In the present study, rats were exposed to 20 min nebulizations of normal saline (control group) or aerosolized aqueous solutions of voriconazole at 15.625 mg (low dose group) or 31.25mg (high dose group). Peak voriconazole concentrations in rat lung tissue and plasma after 3 days of twice daily dosing in the high dose group were 0.85+/-0.63 microg/g wet lung weight and 0.58+/-0.30 microg/mL, with low dose group lung and plasma concentrations of 0.38+/-0.01 microg/g wet lung weight and 0.09+/-0.06 microg/mL, respectively. Trough plasma concentrations were low but demonstrated some drug accumulation over 21 days of inhaled voriconazole administered twice daily. Following multiple inhaled doses, statistically significant but clinically irrelevant abnormalities in laboratory values were observed. Histopathology also revealed an increase in the number of alveolar macrophages but without inflammation or ulceration of the airway, interstitial changes, or edema. Inhaled voriconazole was well tolerated in a rat model of drug inhalation.

[Clinical use of micafungin for the treatment of invasive candidiasis in critical ill patients]

BACKGROUND

Over the last 30 years a significant increase of Candida spp. invasive disease has been observed in non-neutropenic critical ill patients. Both fluconazole and amphotericin B have been considered first line treatment for invasive (proven and probable) Candida spp. disease, although the mortality rate is still high.

OBJECTIVES

To review the current data on the use of micafungin for the treatment of Candida invasive disease in critical ill patients.

METHODS

The pharmacologic, mycological and clinical properties of micafungin are reviewed based on current published data. The use and efficacy of micafungin for the treatment of Candida invasive disease in critical ill patients is discussed.

RESULTS AND CONCLUSIONS

To reduce the rate of mortality more effective antifungals and pre-emptive treatment strategies are currently warranted. Candins achieve better results for the treatment of invasive Candida disease in non-neutropenic critical ill patients. Micafungin has a good safety profile (similar to fluconazole). Micafungin is a first line drug for the treatment of invasive Candida disease and may be used as a pre- emptive approach followed by a de-escalating strategy with azoles.

Consensus statement on the management of invasive candidiasis in Intensive Care Units in the Asia-Pacific Region

Invasive candidiasis has emerged as an important nosocomial infection, especially in critically ill patients. The incidence of candidaemia in Intensive Care Units (ICUs) is 5- to 10-fold higher than in the entire hospital and the crude mortality rate of patients with candidaemia is between 35% and 60%. Candida albicans remains the predominant cause of invasive candidiasis in ICUs, followed by Candida tropicalis, Candida glabrata and Candida parapsilosis. Invasive isolates of Candida spp. remain highly susceptible to fluconazole (>90% susceptible), although among Asia-Pacific countries the susceptibility rate of C. glabrata to fluconazole varies widely from 22% to 72%. Early diagnosis and prompt initiation of antifungal therapy are crucial for the effective treatment of invasive candidiasis. However, invasive candidiasis is difficult to diagnose owing to its non-specific clinical features, and delayed therapy is a major contributor to poor outcomes. Combining clinical risk factors with Candida colonisation parameters appears promising for guiding early interventions. Because of considerable regional variability, local epidemiological knowledge is critical in the effective management of invasive candidiasis among ICU patients in Asia-Pacific.

Evolving role of early antifungals in the adult intensive care unit

BACKGROUND

Invasive candidiasis (IC) is associated with significant morbidity and mortality in critically ill patients. This, in conjunction with difficulties in diagnosis, underscores the need for novel treatment strategies based on the identification of significant risk factors for IC.

OBJECTIVE

To review the evidence surrounding the use of early antifungals in critically ill adult patients and to present concise and specific recommendations for different early treatment strategies for IC.

DATA SOURCES AND DATA EXTRACTION

Pubmed search from 1966 to July 2008 using the search terms "antifungals, critical care, prophylaxis, preemptive therapy, and empiric therapy." Examined all relevant peer-reviewed original articles, meta-analyses, guidelines, consensus statements, and review articles.

CONCLUSION

The use of early antifungal therapy should be reserved for patients with a high risk (10% to 15%) of developing IC. Despite a large number of articles published on this topic, there is no single predictive rule that can adequately forecast IC in critically ill patients. Until further prospective validation of existing data is completed, clinicians should assess patients on a case-by-case basis and determine the need for early antifungal treatment strategies based on frequent evaluations of risk factors and clinical status.

The epidemiology of Candida colonization and invasive candidiasis in a surgical intensive care unit where fluconazole prophylaxis is utilized: follow-up to a randomized clinical trial

OBJECTIVE

To determine whether Candida glabrata colonization and invasive candidiasis (IC) increased among critically ill surgical patients 3 years after the introduction of fluconazole prophylaxis to a surgical intensive care unit (SICU).

SUMMARY BACKGROUND DATA

Fluconazole prophylaxis has been shown in randomized clinical trials to reduce the occurrence of candidiasis in some patient populations, including high-risk SICU patients. One such trial was performed in The Johns Hopkins Hospital SICU in 1998. Whether the epidemiology of Candida colonization and IC has changed in SICUs where fluconazole prophylaxis is routinely utilized has not been adequately studied.

METHODS

We conducted a prospective, observational study of subjects admitted for > or = 3 days to the SICU of a large, urban, academic medical center, where fluconazole prophylaxis had been utilized for approximately 3 years. Surveillance fungal cultures of rectal/fecal swabs, urine, and endotracheal aspirates were performed on admission to the SICU, once weekly, and upon discharge from the SICU. Demographic and clinical data were collected. C. glabrata colonization and IC prevalence among patients in the prospective cohort were compared with the prevalence among SICU patients enrolled in the 1998 clinical trial of fluconazole for the prevention of candidiasis that was performed at the same institution.

RESULTS

C. glabrata colonization was not significantly more common among patients in the 2003 cohort as compared with patients in the 1998 trial (adjusted odds ratio [OR]: 0.90, 95% confidence interval [CI]: 0.57-1.41). Patients with IC in the 2003 cohort were not more likely than those in the 1998 trial to have IC due to C. glabrata (adjusted OR: 1.93, 95% CI: 0.20-18.98), while patients with IC in the 2003 cohort were less likely than patients in the 1998 trial to have acquired IC in the ICU (adjusted OR: 0.08, 95% CI: 0.009-0.82).

CONCLUSIONS

There was no increase in C. glabrata colonization or in the proportion of IC due to C. glabrata after a 3-year period of routine fluconazole prophylaxis for selected SICU patients.

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

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

Management of invasive Candida infections in non-neutropenic critically ill patients: from prophylaxis to early therapy

Echinocandins are the treatment of choice for patients with severe forms of candidaemia, including neutropenic patients and those episodes presenting with shock. There is little distinction between the three available echinocandins (caspofungin, anidulafungin and micafungin), but there is more clinical experience with caspofungin. Identifying patients who will benefit from early antifungal therapy using clinical tools such as the 'Candida Score' is an interesting strategy that may reduce the high mortality in critically ill patients with invasive fungal infections.

Caspofungin for prevention of intra-abdominal candidiasis in high-risk surgical patients

PURPOSE

Thirty to forty percent of patients with recurrent gastrointestinal perforation/anastomotic leakage or acute necrotizing pancreatitis develop intra-abdominal invasive candidiasis (IC). A corrected Candida colonization index (CCI) > or =0.4 is a powerful predictor of IC. Fluconazole prevents intra-abdominal IC in this setting, but azole-resistant Candida species are emerging. The aim of this study was to explore the efficacy and safety of caspofungin for prevention of intra-abdominal IC in high-risk surgical patients.

METHODS

Prospective non-comparative single-center study in consecutive adult surgical patients with recurrent gastrointestinal perforation/anastomotic leakage or acute necrotizing pancreatitis. Preventive caspofungin therapy (70 mg, then 50 mg/day) was given until resolution of the surgical condition. Candida colonization index and CCI, occurrence of intra-abdominal IC and adverse events were monitored.

RESULTS

Nineteen patients were studied: 16 (84%) had recurrent gastrointestinal perforation/anastomotic leakage and 3 (16%) acute necrotizing pancreatitis. The median duration of preventive caspofungin therapy was 16 days (range 4-46). The colonization index decreased significantly during study therapy, and the CCI remained <0.4 in all patients. Caspofungin was successful for prevention of intra-abdominal IC in 18/19 patients (95%, 1 breakthrough IC 5 days after inclusion). No drug-related adverse event requiring caspofungin discontinuation occurred.

CONCLUSION

Caspofungin may be efficacious and safe for prevention of intra-abdominal candidiasis in high-risk surgical patients. This needs to be further investigated in randomized trials.

Antifungals in the ICU

PURPOSE OF REVIEW

Invasive fungal infections remain a serious complication for critically ill ICU patients. The aim of this article is to review recent efficacy data of newer antifungal agents for the treatment of invasive candidiasis. The influence that recent epidemiological trends, advances in diagnostic testing, and risk prediction methods exert on the optimization of antifungal therapy for critically ill ICU patients will also be reviewed.

RECENT FINDINGS

Recent clinical trials have documented the clinical efficacy of the echinocandins and the newer triazoles for the management of invasive candidiasis. Thus far, resistance to echinocandins remains rare. Changes in the epidemiology of Candida spp. causing invasive candidiasis, such as an increasing relative proportion of non-albicans Candida spp., have not been universally reported, although they have important implications for the use of fluconazole as first-line therapy for invasive candidiasis. Efforts to improve the timeliness and accuracy of laboratory diagnostic techniques and clinical prediction models to allow early and accurately targeted antifungal intervention strategies continue.

SUMMARY

Echinocandins, given their clinical efficacy, spectrum of activity, and favourable pharmacological properties, are likely to replace fluconazole as initial antifungal agents of choice among critically ill ICU patients. The optimization of patient outcomes will require more accurately targeted early antifungal intervention strategies based upon sensitive and specific biological and clinical markers of risk.

Treatment of invasive candidal infections: systematic review and meta-analysis

OBJECTIVE

To compare available antifungal treatments for invasive candidiasis, a leading cause of nosocomial bloodstream infections.

METHODS

We performed a systematic review and meta-analysis of randomized controlled trials that compared different antifungal agents for the treatment of candidemia and other forms of invasive candidiasis. Two reviewers independently appraised the quality of trials and extracted data. The primary outcome was all-cause mortality, and secondary outcomes were microbiological failure, treatment failure, and adverse events. Relative risks (RRs) with 95% confidence intervals (CIs) were pooled.

RESULTS

Of the 15 included trials, 9 compared fluconazole with other drugs (amphotericin B, itraconazole, or a combination of fluconazole and amphotericin B), 4 compared echinocandins with other drugs (fluconazole, amphotericin B, liposomal amphotericin B), 1 compared micafungin and caspofungin, and 1 compared amphotericin B plus fluconazole and voriconazole. No difference in mortality was observed with fluconazole vs amphotericin B (RR, 0.92; 95% CI, 0.72-1.17); however, the rate of microbiological failure increased in the fluconazole arm (RR, 1.52; 95% CI, 1.12-2.07). Anidulafungin decreased the rate of microbiological failure compared with fluconazole (RR, 0.50; 95% CI, 0.29-0.86) with fewer adverse events. Caspofungin was comparable to amphotericin B in mortality and efficacy, with fewer adverse events requiring discontinuation (RR, 0.11; 95% CI, 0.04-0.36). Micafungin was comparable to liposomal amphotericin B in mortality.

CONCLUSION

All assessed antifungal agents showed similar efficacy, but the rate of microbiological failure increased with fluconazole vs amphotericin B or anidulafungin. Amphotericin B is associated with a higher rate of adverse events than fluconazole and echinocandins.

Routine use of fluconazole prophylaxis in a neonatal intensive care unit does not select natively fluconazole-resistant Candida subspecies

BACKGROUND

We have previously demonstrated efficacy against fungal colonization and infection of fluconazole prophylaxis that was routinely administered since 2001 in our ICU for preterm infants <1500 g at birth (VLBW). With prolonged use, concerns exist for the emergence of acquired fungal resistance and of Candida subspecies that are natively fluconazole-resistant (NFR), mostly Candida glabrata and Candida krusei.

METHODS

We evaluated retrospectively all clinical and surveillance fungal isolates obtained from VLBW infants in our NICU during a 10-year period (1997-2006). Each fungal isolate was speciated, infants colonized or infected with NFR-Candida spp were identified and the incidence rates of colonization and infection by these fungal species were calculated. A comparison was made of the 6-year (2001-2006) prophylaxis period with the 4-year (1997-2000) preprophylaxis period.

RESULTS

Overall, colonization by NFR-Candida spp ranged between 2.8% and 6.6% of VLBW infants yearly admitted, without any increasing trend during the study period. There were 18 of 434 (4.1%) neonates colonized by these species. Five episodes of systemic fungal infections caused by NFR-Candida spp occurred (incidence rate, 1.1%). No significant differences were detected when compared with the preprophylaxis period, when 11 of 295 infants (3.7%) were colonized by NFR-Candida spp and 4 episodes of infection occurred (1.4%) (P = 0.84 and 0.76, respectively).

CONCLUSIONS

Fluconazole prophylaxis administered to VLBW neonates in 4- to 6-week courses after birth does not lead to the emergence of natively fluconazole-resistant Candida spp.