A randomized and blinded multicenter trial of high-dose fluconazole plus placebo versus fluconazole plus amphotericin B as therapy for candidemia and its consequences in nonneutropenic subjects

Impact of real-time fungal susceptibility on clinical practices

PURPOSE OF REVIEW

In the past two decades standardized in-vitro antifungal susceptibility tests have been developed in response to increasing invasive fungal infections. Our purpose is to review the utility of real-time Candida antifungal susceptibility testing and its effects on clinical outcomes in the context of the new antifungal agents, existing antifungal susceptibility testing methods, and the changing epidemiology and susceptibilities of Candida spp.

RECENT FINDINGS

New antifungal agents active against Candida spp. are now available. Caspofungin is approved for the treatment of invasive candidiasis but standardized antifungal susceptibility testing has not been developed. The newer triazoles, such as voriconazole, posaconazole and ravuconazole, are not yet approved for invasive candidiasis. As infections caused by non-albicans Candida spp. with growing resistance to fluconazole increase, antifungal susceptibility testing may be important to guide therapy. Unfortunately, few studies exist describing the impact of real-time antifungal susceptibility testing on the treatment of invasive fungal infections.

SUMMARY

Newer antifungal agents with broader anti-Candida activity, fewer adverse events and minimal resistance are currently available. The challenge clinicians face is choosing when to use these agents appropriately, while considering the changing Candida epidemiology and susceptibility trends without over-treating fluconazole-sensitive pathogens. Unfortunately, the correlation of antifungal susceptibility testing results by any method and clinical outcome is mostly lacking. We suggest that a concerted examination of the utility of real-time antifungal susceptibility testing and its effect on clinical outcomes by guiding appropriate antifungal therapy for high-risk patients with invasive candidiasis is warranted.

Management of opportunistic infections in solid-organ transplantation

Solid-organ transplantation is often the last alternative in many patients with end-stage organ disease. Although advances in immunosuppressive regimens, surgical techniques, organ preservation, and overall management of transplant recipients have improved graft and patient survival, infectious complications remain problematic. Bacterial, fungal, viral, and parasitic infections are implicated after transplantation depending on numerous factors, such as degree of immunosuppression, type of organ transplant, host factors, and period after transplantation. Proper prophylactic and treatment strategies are imperative in the face of chronic immunosuppression, nosocomial and community pathogens, emerging drug resistance, drug-drug interactions, and medication toxicities. This review summarizes the pathophysiology, incidence, prevention, and treatment strategies of common posttransplant infections.

In vitro activities of voriconazole in combination with three other antifungal agents against Candida glabrata

Candida glabrata has recently emerged as a significant pathogen involved in both superficial and deep-seated infections. In the present study, a checkerboard broth microdilution method was performed to investigate the in vitro activities of voriconazole (VOR) in combination with terbinafine (TRB), amphotericin B (AMB), and flucytosine (5FC) against 20 clinical isolates of C. glabrata. Synergy, defined as a fractional inhibitory concentration (FIC) index of < or = 0.50, was observed in 75% of VOR-TRB, 10% of VOR-AMB, and 5% of VOR-5FC interactions. None of these combinations yielded antagonistic interactions (FIC index > 4). When synergy was not achieved, there was still a decrease in the MIC of one or both drugs used in the combination. In particular, the MICs were reduced to < or = 1.0 microg/ml as a result of the combination for all isolates for which the AMB MIC at the baseline was > or = 2.0 microg/ml. By a disk diffusion assay, the halo diameters produced by antifungal agents in combination were greater that those produced by each drug alone. Finally, killing curves showed that VOR-AMB exhibited synergistic interactions, while VOR-5FC sustained fungicidal activities against C. glabrata. These studies demonstrate that the in vitro activity of VOR against this important yeast pathogen can be enhanced upon combination with other drugs that have different modes of action or that target a different step in the ergosterol pathway. Further studies are warranted to elucidate the potential beneficial effects of such combination regimens in vivo.

Posaconazole and amphotericin B combination therapy against Cryptococcus neoformans infection

To investigate the effects of posaconazole (POS) and amphotericin B (AMB) combination therapy in cryptococcal infection, we established an experimental model of systemic cryptococcosis in CD1 mice by intravenous injection of three distinct clinical isolates of Cryptococcus neoformans. Therapy was started 24 h after the infection and continued for 10 consecutive days. POS was given at 3 and 10 mg/kg of body weight/day, while AMB was given at 0.3 mg/kg/day. Combination therapy consisted of POS given at a low (combo 3) or at a high (combo 10) dose plus AMB. Survival studies showed that combo 3 was significantly more effective than POS at 3 mg/kg for two isolates tested (P value, < or = 0.001), while combo 10 was significantly more effective than POS at 10 mg/kg for all three isolates (P values ranging from <0.001 to 0.005). However, neither combination regimen was more effective than AMB alone. For two isolates, combination therapy was significantly more effective than each single drug at reducing the fungal burden in the brain (P values ranging from 0.001 to 0.015) but not in the lungs. This study demonstrates that the major impact of POS and AMB combination therapy is on brain fungal burden rather than on survival.

Considerations in Clinical Trials of Combination Antifungal Therapy

The cure rate for serious fungal diseases with currently available agents used as monotherapy is not optimal. The introduction of new classes of antifungal drugs in the last few years naturally leads to the hypothesis that antifungal drugs used in combination may be more effective than the same drugs used alone. The design and interpretation of combination therapy studies raise challenges beyond those encountered when drugs are studied as monotherapy in the treatment of a disease. The definition of combination therapy, the study design, the selection of appropriate patient populations, and the selection of end points, as well as practical considerations, are all important in the design and interpretation of clinical trials of combination therapies. Although combination therapies hold the promise of improved efficacy, it is important to prove this hypothesis, because they also may be associated with increased toxicity and increased drug costs. A careful consideration of study design factors before the initiation of a trial will help obtain the most useful information for patients in this important area.

Design of Efficacy Trials of Cytokines in Combination with Antifungal Drugs

Resolution of invasive fungal infections is often dependent on recovery from an immunocompromised state, which indicates that host defense mechanisms are extremely important in the clearance of fungal pathogens. Immunotherapy aimed at enhancement of host defense mechanisms may improve clinical outcome of invasive mycoses. The design of trials of immunotherapy against fungal pathogens requires profound knowledge of the host defense mechanisms that are involved in invasive fungal infections. Prospective phase II studies with recombinant granulocyte colony-stimulating factor and interferon-gamma have been done. Recombinant interferon-gamma is a candidate for phase III trials of adjunctive immunotherapy for cryptococcal meningitis, invasive aspergillosis, and candidemia, but the proper design of future trials will be crucial to establish whether immunotherapy is of clinical value in the treatment of invasive fungal infections.

The Design of Clinical Trials That Evaluate Antifungal Prophylaxis and Combination Therapy: Introduction and Overview

On 8 February 2003, the second in a series of meetings in honor of John E. Bennett, M.D., was convened in New York City. A report from the previous meeting was published in 2003. The goal of this second meeting was to discuss the design of clinical trials in prophylaxis and combination therapy. This supplement presents 12 articles by leading clinicians who are currently active in trials in this area and presents a current view of the unmet needs and challenges.

A new era of antifungal therapy

Invasive fungal infections pose major management problems for clinicians caring for hematopoietic cell transplant patients. Two major fungal genera, Candida and Aspergillus, account for most fungal infections. Rates of systemic Candida infection range from 15% to 25%, mostly in the pre-engraftment period. Prophylaxis by fluconazole has dramatically reduced the frequency of early Candida infections. Caspofungin has recently been shown to offer an excellent alternative to amphotericin B (with less toxicity) or fluconazole (with a broader spectrum) for therapy of systemic Candida infections. Aspergillus infections occur in 15% to 20% of allogeneic hematopoietic cell transplant patients, most frequently in the post-engraftment period; they are associated with a severe diminution of cell-mediated immune responses by graft-versus-host disease and prolonged corticosteroid use. Voriconazole, a recently introduced broad-spectrum azole, has excellent activity against Aspergillus and is generally well tolerated. Voriconazole currently offers the best prospect for success and tolerance as a first-line treatment for aspergillosis. Second-line therapies include lipid formulations of amphotericin B, caspofungin, or intravenous itraconazole. Unfortunately, early initiation of therapy for aspergillosis is frequently not possible because of inaccurate diagnostics. One new diagnostic, the galactomannan assay, has recently been approved, and others are in development; these offer promise for earlier diagnosis without the need for invasive procedures. It is hoped that these new therapies and new diagnostics will usher in a new era of antifungal therapy.

Combinations of antifungal agents in therapy--what value are they?

Concurrent or sequential antifungal treatment for invasive mycoses has been typically considered as an option to improve results of monotherapy. However, data on the efficacy of combination therapy are sparse and consist largely of results from studies in vitro and experimental animal models. These studies have yielded controversial results depending on the criteria used to evaluate the antifungal interaction. Several combinations that showed synergy in vitro failed to do so in animal models. Overall, apart from cryptococcal infections, combined antifungal therapy is not significantly better than monotherapy in terms of clinical efficacy. It is questionable whether combination therapy should be used in most cases as there is a lack of evidence from well-designed clinical trials. However, combination therapy could be an alternative to monotherapy for patients with invasive infections that are difficult to treat, such as those due to multi-resistant species and for those who fail to respond to standard treatment.

Prophylaxis and treatment of invasive candidiasis in the intensive care setting

The term "invasive candidiasis" encompasses a group of infections of increasing relevance in the intensive care setting. Prophylaxis is an attractive strategy when dealing with diseases of high prevalence, morbidity, and mortality. The success of prophylaxis is determined by the selection of a population at high risk and the use of the safest and most effective drug. Although risk factors for this disease are known, risk assessment strategies need to be developed to predict a high likelihood of disease so that targeted prophylaxis can be offered. Recent advances in antifungal therapy, such as development of the azoles and echinocandins, have resulted in excellent prophylactic and therapeutic choices for the management of this problem.

Update on antifungal treatment of invasive Candida and Aspergillus infections. Derzeitiger Kenntnisstand in der antimykotischen Behandlung invasiver Candida- und Aspergillus-Infektionen

Invasive Candida and Aspergillus infections are among the most common serious complications occurring in chronically immunosuppressed patients, in particular those with hematological malignancies and transplant recipients. A rational, early systemic antifungal treatment can be based upon imaging diagnostic techniques as well as upon conventional mycological and non-culture-based procedures. The availability of well tolerable and highly efficacious systemic antifungals has improved the spectrum of therapeutic options and the success rates of antifungal treatment. However, with respect to high treatment costs associated with these new agents, it is mandatory to specify indications and limitations for the use of these substances. Voriconazole may well become the new standard primary treatment of invasive aspergillosis. The role of the new echinocandins such as caspofungin, which has recently been approved for salvage treatment of resistant and refractory Aspergillus infections, in primary or combination treatment of invasive aspergillosis must be further studied. Caspofungin is at least as effective as, yet significantly better tolerated than amphotericin B for primary treatment of invasive candidosis in non-neutropenic patients, and has been approved for this indication. The selection of systemic antifungals in patients with invasive Candida infection critically depends upon the identification of Candida species involved, because some non-albicans Candida spp. are resistant to azole antifungals.

Phase 2, randomized, dose-ranging study evaluating the safety and efficacy of anidulafungin in invasive candidiasis and candidemia

This study evaluated the safety and efficacy of anidulafungin, a novel echinocandin, in patients with invasive candidiasis, including candidemia. A total of 123 eligible patients were randomized to one of three intravenous regimens, 50, 75, or 100 mg once daily. Treatment continued for 2 weeks beyond resolution or improvement of signs and symptoms. The primary efficacy criterion was a successful global response rate (i.e., clinical and microbiological success) in the evaluable population at the follow-up (FU) visit, 2 weeks after end of therapy (EOT). One hundred twenty (120) patients received at least one dose of anidulafungin; 68 were evaluable. Review of adverse events and laboratory data indicated no dose response for safety parameters. Non-albicans Candida species accounted for approximately one-half of all isolates. Success rates at EOT were 84, 90, and 89% in the 50-, 75-, and 100-mg groups, respectively. At FU, the success rates were 72, 85, and 83%. Phase 3 studies of anidulafungin for the treatment of invasive candidiasis and candidemia are warranted.

Toward more effective antifungal therapy: the prospects of combination therapy

The availability of new antifungal agents with unique mechanisms of action and improved tolerability has widened the possibilities for the use of combination antifungal therapy for difficult-to-treat opportunistic mycoses. However, the use of this therapy is largely governed by empiricism, especially in patients with invasive mould infections, for whom there is a tremendous need to improve outcomes. Because of the difficulties associated with the design and conduct of clinical trials of combination antifungal therapy for opportunistic mycoses, the majority of the studies evaluating antifungal combinations are still performed in the laboratory or using animal models of infection. However, the methods used to assess combined antifungal effects in vitro and in animals are poorly standardized, and there is little evidence that data generated from these studies can be translated in treating human mycotic infections. Despite the empiricism of combination antifungal therapy, certain principles help guide the use and study of these regimens.

Resolution of orbitocerebral aspergillosis during combination treatment with voriconazole and amphotericin plus adjunctive cytokine therapy

Orbitocerebral aspergillosis has a very high fatality rate and cure is unusual. We describe the successful management of a child with cereberal aspergillosis who had a dramatic response to therapy with a combination of liposomal amphotericin and voriconazole with adjunctive cytokine therapy during immunosuppresive chemotherapy for acute lymphoblastic leukaemia.

In vitro evaluation of double and triple combinations of antifungal drugs against Aspergillus fumigatus and Aspergillus terreus

Microdilution broth checkerboard techniques based on the National Committee for Clinical Laboratory Standards methodology were used to study double and triple antifungal combinations against clinical isolates of Aspergillus fumigatus and A. terreus. The influences of the end-point definition (partial or complete inhibition) and the mode of reading (visually or spectrophotometrically) were determined. Interactions between antifungal drugs were also evaluated by agar diffusion tests. Combinations of caspofungin with either amphotericin B or voriconazole were additive for all the isolates, and antagonism was not observed. The interaction between caspofungin and flucytosine was synergistic for 62% of the isolates. In contrast, the interaction between voriconazole and flucytosine was never synergistic and antagonism was noted for 93% of the isolates. The triple combination of caspofungin with flucytosine and amphotericin B was synergistic for all the isolates tested. The triple combination of caspofungin with flucytosine and voriconazole was also mostly synergistic; but complex interactions were obtained for some isolates, with synergy or antagonism depending on the concentrations of caspofungin and voriconazole. Analysis of the influence of the reading technique on the results showed that spectrophotometric reading was a good alternative to the recommended visual reading. The results of these in vitro tests suggest that the activity of flucytosine as part of a double combination with caspofungin and as part of a triple combination with caspofungin and amphotericin B against Aspergillus spp. warrants further investigations. Animal studies are needed to evaluate the in vivo efficacies of these combinations.

New developments in antifungal strategy

The increasing importance of invasive fungal infection as a cause of severe morbidity and mortality in immunocompromised patients has fuelled the development of new antifungal agents, including new triazole agents and echinocandins. Failure to diagnose fungal infection adequately has hampered the evaluation of these drugs in clinical trials. Consequently, the evidence base behind many prophylactic and empirical treatment strategies has been poor. Recent advances have improved diagnostic criteria and opened the way for more rational usage of these expensive preparations. The proven efficacy and improved safety profile of newer agents is a major advantage. Furthermore, better understanding of the immune response may allow novel strategies of adjunctive therapy and immunomodulation.

Antifungal susceptibility survey of 2,000 bloodstream Candida isolates in the United States

Candida bloodstream isolates (n = 2,000) from two multicenter clinical trials carried out by the National Institute of Allergy and Infectious Diseases Mycoses Study Group between 1995 and 1999 were tested against amphotericin B (AMB), flucytosine (5FC), fluconazole (FLU), itraconazole (ITR), voriconazole (VOR), posaconazole (POS), caspofungin (CFG), micafungin (MFG), and anidulafungin (AFG) using the NCCLS M27-A2 microdilution method. All drugs were tested in the NCCLS-specified RPMI 1640 medium except for AMB, which was tested in antibiotic medium 3. A sample of isolates was also tested in RPMI 1640 supplemented to 2% glucose and by using the diluent polyethylene glycol (PEG) in lieu of dimethyl sulfoxide for those drugs insoluble in water. Glucose supplementation tended to elevate the MIC, whereas using PEG tended to decrease the MIC. Trailing growth occurred frequently with azoles. Isolates were generally susceptible to AMB, 5FC, and FLU. Rates of resistance to ITR approached 20%. Although no established interpretative breakpoints are available for the candins (CFG, MFG, and AFG) and the new azoles (VOR and POS), they all exhibited excellent antifungal activity, even for those strains resistant to the other aforementioned agents.

High-dose fluconazole therapy for cancer patients with solid tumors and candidemia: an observational, noncomparative retrospective study

BACKGROUND

Response rates for candidemia treated with standard-dose fluconazole (400 mg/day) are approximately 70%. Higher doses of fluconazole have been recommended for susceptible dose-dependent Candida isolates. Herein, we describe the outcome of 20 patients with solid tumors and candidemia treated with high-dose fluconazole (HDF) at The University of Texas M.D. Anderson Cancer Center (1998-2002).

PATIENTS AND METHODS

Patients were identified either by searching the microbiology laboratory database or through direct referral from primary oncology services to the Infectious Diseases Consultative Services. A retrospective review of cases was performed. HDF was defined as > or =600 mg/day.

RESULTS

Five patients were treated with 600 mg/day, whereas 15 patients received 800 mg/day. Only one patient was neutropenic. The median APACHE II score at the onset of candidemia was 12 (range 6-24). The most common species identified were Candida albicans (eight patients, 40%) and Candida parapsilosis (seven patients, 35%). Of 19 patients whose quantitative data were available, eight (42%) had high-grade candidemia [> or =200 colony forming units (CFU)/ml]. Fifteen (83%) of 18 isolates were fluconazole susceptible, and two (both Candida glabrata) were fluconazole resistant (MIC 64 each) in vitro. Nineteen patients (95%) responded to HDF therapy. The only HDF failure occurred in a patient with C. glabrata (MIC 64.0) infection. The other patient with C. glabrata (MIC 64.0) infection responded to HDF. Central venous catheters were removed from all patients with > or =10 CFU/ml candidemias. All patients with high-grade candidemias responded to HDF. The median duration of HDF therapy was 16 (range 6-42) days. No significant toxicity occurred.

CONCLUSIONS

Although our data are limited, HDF appears to be well tolerated and may be associated with higher response rates than standard-dose fluconazole in a selected group of patients with solid tumors and candidemia caused by species that are susceptible to this triazole.

Supportive care

To optimize treatment outcomes for hematologic malignancies, minimizing the consequences of treatment complications requires as much skill as the choice of the treatment itself. Myelosuppression and immunosuppression are frequent complications and have potentially serious infectious consequences. Invasive fungal infections and infections from respiratory viruses are increasing in frequency and have life-threatening potential. Damage to vital organs, especially the liver, is another important concern. In this chapter, the scope of invasive fungal and respiratory viral infections, recent insights into the pathogenesis of hepatic sinusoidal injury, and recent developments that impact prevention and treatment approaches for these complications are described. In Section I, Dr. John Wingard describes the advantages and disadvantages of various treatment options for invasive infections by the two chief fungal pathogens, Candida and Aspergillus. Adjunctive therapies and practical considerations that clinicians should weigh in choosing one or another of the various agents are discussed. The studies that have evaluated antifungal prophylaxis and empirical treatment strategies are reviewed. Finally, new approaches such as combination therapy, new diagnostics, and efforts to bolster host immunity are considered. In Section II, Dr. W. Garrett Nichols describes the epidemiology of community-acquired respiratory viruses (CRV) in patients with hematologic malignancies. Risk factors, clinical syndromes, and possible indirect effects of CRV infections are discussed. Treatment and prevention options are reviewed. In Section III, Dr. George McDonald describes sinusoidal obstruction syndrome (once known as hepatic veno-occlusive disease). Recent insights into pathogenesis are described. Diagnostic criteria and the advantages and disadvantages of various diagnostic methods are reviewed and prognosis is considered. Prevention and treatment options are discussed.

Status of combination therapy for refractory mycoses

PURPOSE OF REVIEW

Invasive fungal infections remain a leading cause of infectious morbidity and mortality in heavily immunosuppressed patients. As the efficacy of current antifungal agents is suboptimal, combinations of antifungal agents, administered concomitantly or sequentially, are increasingly used (mostly empirically) as a strategy to improve the treatment outcomes for refractory mycoses. Here we review recent developments in the area of antifungal combinations based on both laboratory (in vitro and in animal models) and clinical studies.

RECENT FINDINGS

With the exception of cryptococcal meningitis, the benefits of combination antifungal therapy have been more difficult to prove for other life-threatening mycoses such as invasive candidiasis or invasive aspergillosis. The recent introduction of a new class of antifungal agents (the echinocandins) and of extended spectrum triazoles has renewed interest in studying antifungal combinations that may result in additive or synergistic effects in difficult-to-treat mycoses. The combination of an echinocandin plus amphotericin B or a newer triazole seems to be the most promising in vitro and in animal model studies, whereas reliable clinical information especially for invasive mould infections is still lacking.

SUMMARY

Antifungal combinations are conceptually appealing as a strategy to overcome the frequent failures of antifungal monotherapy in immunosuppressed patients with invasive mycoses. Results of in-vitro studies cannot yet be translated into measurable clinical results because of methodological problems and the complexity of designing relevant prospective clinical trials, but important findings are expected in the near future in this rapidly expanding investigational area.

Management of candidiasis Management of Candida species infections in critically ill patients

Invasive candidiasis is a feared infection with mortality similar to that of septic shock (40-60%). Improved knowledge of its pathophysiology and the availability of new compounds for antifungal therapy and prophylaxis have contributed to improving the prognosis of severe candidal infections among immunosuppressed patients at the possible cost of the emergence of non-albicans strains of candida with lower susceptibility to azoles. This review focuses on the management of invasive deep-seated candidiasis in critically ill, non-immunocompromised patients. We discuss antifungal use, indications, potential benefit, and main secondary effects. Prevention strategies include pre-emptive antifungal therapy and azole-based prophylaxis. For patients at lower initial risk, pre-emptive therapy should be based on a management strategy that takes into account the presence of definite risk factors and the dynamics of candida colonisation. Among critically ill patients, azole prophylaxis is effective and is not associated with acquisition of resistance; it must be restricted to highly selected groups of patients at high risk only.

Epidemiology of Candida species infections in critically ill non-immunosuppressed patients

A substantial proportion of patients become colonised with Candida spp during hospital stay, but only few subsequently develop severe infection. Clinical signs of severe infection manifest early but lack specificity until late in the course of the disease, thus representing a particular challenge for diagnosis. Mostly nosocomial, invasive candidiasis occurs in only 1-8% of patients admitted to hospitals, but in around 10% of patients housed in intensive care units where it can represent up to 15% of all nosocomial infections. We review the epidemiology of invasive candidiasis in non-immunocompromised, critically ill patients with special emphasis on disease trends over time, pathophysiology, diagnostic approach, risk factors, and impact. Recent epidemiological data suggesting that the emergence of non-albicans candida strains with reduced susceptibility to azoles, previously linked to the use of new antifungals for empiric and prophylactic therapy in immunocompromised patients, may not have occurred in the critically ill. Management of invasive candidiasis in these patients will be addressed in the December issue of The Lancet Infectious Diseases.

Systemic Antifungal Therapy: New Options, New Challenges

The frequency of invasive fungal infections has increased dramatically in recent decades because of an expanding population at risk. Until now, treatment options for invasive mycoses have been primarily amphotericin B and the azoles, fluconazole and itraconazole. Traditional agents are limited by an inadequate spectrum of activity, drug resistance, toxicities, and drug-drug interactions. The recent approval of caspofungin and voriconazole clearly has expanded the number of existing antifungal drugs available. However, the enthusiasm that accompanies their availability is counterbalanced by limited clinical experience, high drug acquisition costs, and distinctive toxicities. The pharmacologic characteristics, extent of clinical experience (efficacy and toxicity), and drug acquisition costs among available systemic antifungal agents are compared, with emphasis on the new agents. Also, recommendations on the role of each agent are provided according to the most common indications for systemic antifungal therapy: invasive candidiasis, invasive aspergillosis, and febrile neutropenia.

New approaches to invasive fungal infections

Invasive fungal infections are typically difficult to prevent, diagnose, and treat; consequently, fungal infection-related mortality has become high, particularly among patients with prolonged neutropenia and severe graft-versus-host disease. However, much recent progress has been made in understanding the immune response to fungi and the epidemiology of infection, and new diagnostic tests and antifungal drugs have become available. This review will describe these most recent developments with the goal of evaluating new approaches to prevent, diagnose, and treat invasive fungal infections.

Combination chemotherapy for invasive fungal infections: what laboratory and clinical studies tell us so far

Despite potential benefits, few objective clinical data (with the exception of cryptococcocal meningitis) are available supporting the routine use of combination antifungal regimens in patients with invasive mycoses, importantly aspergillosis or candidiasis. There is considerable debate on what constitutes synergy or antagonism in vitro and whether these laboratory findings are translated to beneficial interactions in patients. Given the lack of rigorous clinical data, a better understanding of the important concepts for the justification of the clinical and pharmacoeconomic threshold of antifungal therapy is needed. Such concepts include standardized methods for screening antifungal combinations in culture or in animals and collaborative efforts to collect clinical data on the efficacy and safety of combination regimens.

Treatment of fungal infections in hematology and oncology--guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO)

The Infectious Diseases Working Party of the German Society of Haematology and Oncology presents their guidelines for the treatment of fungal infections in patients with hematological and oncological malignancies. These guidelines are evidence-based, considering study results, case reports and expert opinions, using the evidence criteria of the Infectious Diseases Society of America (IDSA). The recommendations for major fungal complications in this setting are summarized here. The primary choice of therapy for chronic candidiasis should be fluconazole, reserving caspofungin or amphotericin B (AmB) for use in case of progression of the Candida infection. Patients with candidemia (except C. krusei or C. glabrata) who are in a clinically stable condition without previous azole prophylaxis should receive fluconazole, otherwise AmB or caspofungin. Voriconazole is recommended for the first-line treatment of invasive aspergillosis. The benefit of a combination of AmB and 5-flucytosine has not been demonstrated except in patients with cryptococcal meningitis. Mucormycosis is relatively rare. The drug therapy of choice consists of AmB, desoxycholate or liposomal formulation, in the highest tolerable dosage. Additional surgical intervention has been shown to achieve a lower fatality rate than with antifungal therapy alone. The role of interventional strategies, cytokines/G-CSF, and granulocyte transfusions in invasive fungal infections are further reviewed. These guidelines offer actual standards and discussions on the treatment of oropharyngeal and esophageal candidiasis, invasive candidiasis, cryptococcosis and mould infections.

A prospective observational study of candidemia: epidemiology, therapy, and influences on mortality in hospitalized adult and pediatric patients

We conducted a prospective, multicenter observational study of adults (n=1447) and children (n=144) with candidemia at tertiary care centers in the United States in parallel with a candidemia treatment trial that included nonneutropenic adults. Candida albicans was the most common bloodstream isolate recovered from adults and children (45% vs. 49%) and was associated with high mortality (47% among adults vs. 29% among children). Three-month survival was better among children than among adults (76% vs. 54%; P<.001). Most children received amphotericin B as initial therapy, whereas most adults received fluconazole. In adults, Candida parapsilosis fungemia was associated with lower mortality than was non-parapsilosis candidemia (24% vs. 46%; P<.001). Mortality was similar among subjects with Candida glabrata or non-glabrata candidemia; mortality was also similar among subjects with C. glabrata candidemia who received fluconazole rather than other antifungal therapy. Subjects in the observational cohort had higher Acute Physiology and Chronic Health Evaluation II scores than did participants in the clinical trial (18.6 vs. 16.1), which suggests that the former subjects are more often excluded from therapeutic trials.

Combination antifungal therapy againstCandidaspecies: the new frontier-are we there yet?

In the past decade, we have seen a significant increase in the incidence of invasive fungal infections. In addition, opportunistic fungal infections resistant to antifungal agents have become increasingly common and their frequency will more than likely continue to increase. The antifungal armamentarium for the treatment of serious fungal infections remains limited. A possible approach to overcoming antifungal drug resistance and high mortality rates seen in severe fungal infections is to combine two or three classes of antifungals, especially if the drugs have different mechanisms of action. The unique properties of newer antifungals now provide us with the opportunity to investigate antifungal combinations that may become the standard of care for serious fungal infections. Combinations of new agents along with more traditional antifungals have now been shown to possess some synergistic or at least additive activity against Candida in clinical trials. On the other hand, caution is still needed since other antifungal combinations have demonstrated antagonistic activity in vitro. Well-controlled clinical trials are needed to define the most efficacious antifungal regimen. Furthermore, these trials should also evaluate the side effect potential of combination regimens and the pharmacoeconomic impact these regimens may have. Thus, while much optimism exists for combination therapy, there is much yet to be done.