Liposomal amphotericin (AmBisome) in the prophylaxis of fungal infections in neutropenic patients: a randomised, double-blind, placebo-controlled study

Primary prophylaxis of invasive fungal infections in patients with hematologic malignancies. Recommendations of the Infectious Diseases Working Party of the German Society for Haematology and Oncology

There is no widely accepted standard for antifungal prophylaxis in patients with hematologic malignancies. The Infectious Diseases Working Party of the German Society for Haematology and Oncology assigned a committee of hematologists and infectious disease specialists to develop recommendations. Literature data bases were systematically searched for clinical trials on antifungal prophylaxis. The studies identified were shared within the committee. Data were extracted by two of the authors (OAC and MSi). The consensus process was conducted by email communication. Finally, a review committee discussed the proposed recommendations. After consensus was established the recommendations were finalized. A total of 86 trials were identified including 16,922 patients. Only a few trials yielded significant differences in efficacy. Fluconazole 400 mg/d improved the incidence rates of invasive fungal infections and attributable mortality in allogeneic stem cell recipients. Posaconazole 600 mg/d reduced the incidence of IFI and attributable mortality in allogeneic stem cell recipients with severe graft versus host disease, and in patients with acute myelogenous leukemia or myelodysplastic syndrome additionally reduced overall mortality. Aerosolized liposomal amphotericin B reduced the incidence rate of invasive pulmonary aspergillosis. Posaconazole 600 mg/d is recommended in patients with acute myelogenous leukemia/myelodysplastic syndrome or undergoing allogeneic stem cell recipients with graft versus host disease for the prevention of invasive fungal infections and attributable mortality (Level A I). Fluconazole 400 mg/d is recommended in allogeneic stem cell recipients until development of graft versus host disease only (Level A I). Aerosolized liposomal amphotericin B is recommended during prolonged neutropenia (Level B II).

Antifungal therapy strategies in hematopoietic stem-cell transplant recipients: early treatment options for improving outcomes

Changes in clinical practice permit more patients to undergo hematopoietic stem-cell transplantation but also have increased the risk for invasive fungal infection (IFI) in this population. Given the difficulties in the diagnosis of fungal infection and the correlation between delays in therapy and poor outcome, earlier treatment, and prophylactic strategies are attractive options for the management of IFIs in high-risk patients. The selection of the most effective antifungal treatment strategy requires a thorough knowledge of IFI risk factors, potential causative organisms, and the safety and efficacy of appropriate antifungal agents.

Management of fungal infections following allogeneic stem cell transplantation

Fungal infection remains an important complication in allogeneic stem cell transplantation (allo-SCT). Since the prognosis of fungal infection is poor, prophylaxis is critical for its management; owing to recent progression in allo-SCT management and widespread use of reduced-intensity regimens, the strategy of infectious prophylaxis has also changed. Various antifungals have recently been developed and applied to clinical use. A major change in antifungal management will probably occur in the next few years.

Evolving strategies in the management of aspergillosis

Aspergillus spp. remain the most common causes of invasive mould infections among patients with hematologic malignancies and recipients of solid-organ and hematopoietic stem-cell transplants. Despite advances in prevention and treatment, invasive aspergillosis continues to be a deadly disease. This paper reviews current approaches to treatment of aspergillosis in adults, including surgical and immune-based strategies, and developments in prophylaxis for aspergillosis in high-risk patient populations.

Liposomal amphotericin B prophylaxis of invasive mold infections in children post allogeneic stem cell transplantation

BACKGROUND

Invasive mold infections (IMI) are a leading cause of infectious mortality in allogeneic stem cell transplant (AlloSCT) recipients. Fluconazole, the current standard for fungal prophylaxis, is ineffective against molds. We initiated a pilot study to determine the safety and activity of prophylactic liposomal amphotericin B (AMB) in preventing IMI in pediatric and adolescent AlloSCT recipients during the first 100 days.

PROCEDURE

Fifty-one patients (57 AlloSCT) were given AMB (3 mg/kg/day) intravenously, day 0-100. Median age 6 years, 32 males, 19 females. Donors: 33 unrelated and 2 related cord blood, 13 related and 1 unrelated peripheral blood stem cell and 8 related bone marrow (BM); 30 received myeloablative and 27 reduced intensity conditioning. Graft-versus-host disease (GVHD) prophylaxis comprised tacrolimus and mycophenolate mofetil.

RESULTS

Median follow-up is 557 days. AMB was generally well tolerated. The probability of developing >/=grade II acute GVHD and extensive chronic GVHD was 45% and 7%, respectively. Estimated 1-year OS is 62.4% for all patients with 78.8% and 26.7% for average-risk and poor-risk, respectively. The incidence of IMI was 0%.

CONCLUSIONS

These results suggest prophylactic AMB is tolerable and may prevent IMI, especially Aspergillus, during the first 100 days post AlloSCT in pediatric and adolescent patients. A randomized study is needed to determine the efficacy of this approach.

Antifungal Prophylaxis in Cancer Patients After Chemotherapy or Hematopoietic Stem-Cell Transplantation: Systematic Review and Meta-Analysis

Purpose

To evaluate the effect of antifungal prophylaxis on all-cause mortality as primary outcome, invasive fungal infections (IFIs), and adverse events. Many studies have evaluated the role of antifungal prophylaxis in cancer patients, with inconsistent conclusions.

Methods

We performed a systematic review and meta-analysis of randomized, controlled trials comparing systemic antifungals with placebo, no intervention, or other antifungal agents for prophylaxis in cancer patients after chemotherapy. The Cochrane Library, MEDLINE, conference proceedings, and references were searched. Two reviewers independently appraised the quality of trials and extracted data.

Results

Sixty-four trials met inclusion criteria. Antifungal prophylaxis decreased all-cause mortality significantly at end of follow-up compared with placebo, no treatment, or nonsystemic antifungals (relative risk [RR], 0.84; 95% CI, 0.74 to 0.95). In allogeneic hematopoietic stem-cell transplantation (HSCT) recipients, prophylaxis reduced all-cause mortality (RR, 0.62; 95% CI, 0.45 to 0.85), fungal-related mortality, and documented IFI. In acute leukemia patients, there was a significant reduction in fungal-related mortality and documented IFI, whereas the difference in mortality was only borderline significant (RR, 0.88; 95% CI, 0.74 to 1.06). Prophylaxis with itraconazole suspension reduced documented IFI when compared with fluconazole, with no difference in survival, and at the cost of more adverse events. On the basis of two studies, posaconazole prophylaxis reduced all-cause mortality (RR, 0.74; 95% CI, 0.56 to 0.98), fungal-related mortality, and IFI when compared with fluconazole.

Conclusion

Antifungal prophylaxis decreases all-cause mortality significantly in patients after chemotherapy. Antifungal prophylaxis should be administered to patients undergoing allogeneic HSCT, and should probably be administered to high-risk acute leukemia patients.

Invasive aspergillosis: epidemiology, diagnosis and management in immunocompromised patients

Morbidity and mortality caused by invasive Aspergillus infections are increasing. This is because of the higher number of patients with malignancies treated with intensive immunosuppressive therapy regimens as well as their improved survival from formerly fatal bacterial infections, and the rising number of patients undergoing allogeneic haematopoietic stem cell or organ transplantation. Early initiation of effective systemic antifungal treatment is essential for a successful clinical outcome in these patients; however, clinical clues for diagnosis are sparse and early microbiological proof of invasive aspergillosis (IA) is rare. Clinical diagnosis is based on pulmonary CT scan findings and non-culture based diagnostic techniques such as galactomannan or DNA detection in blood or bronchoalveolar lavage samples. Most promising outcomes can be expected in patients at high risk for aspergillosis in whom antifungal treatment has been started pre-emptively, backed up by laboratory and imaging findings. The gold standard of systemic antifungal treatment is voriconazole, which has been proven to be significantly superior to conventional amphotericin B and has led to a profound improvement of survival rates in patients with cerebral aspergillosis. Liposomal amphotericin B at standard dosages appears to be a suitable alternative for primary treatment, while caspofungin, amphotericin B lipid complex or posaconazole have shown partial or complete response in patients who had been refractory to or intolerant of primary antifungal therapy. Combination therapy with two antifungal compounds may be a promising future strategy for first-line treatment. Lung resection helps to prevent fatal haemorrhage in single patients with pulmonary lesions located in close proximity to larger blood vessels, but is primarily considered for reducing the risk of relapse during subsequent periods of severe immunosuppression. Strict reverse isolation appears to reduce the incidence of aspergillosis in allogeneic stem cell transplant recipients and patients with acute myeloid leukaemia undergoing aggressive anticancer therapy. Well designed, prospective randomised studies on infection control measures effective to prevent aspergillosis are lacking. Prophylactic systemic antifungal treatment with posaconazole significantly improves survival and reduces IA in acute myeloid leukaemia patients and reduces aspergillosis incidence rates in patients with intermediate-to-severe graft-versus-host reaction emerging after allogeneic haematopoietic stem cell transplantation. Voriconazole prophylaxis may be suitable for prevention of IA as well; however, the results of large clinical trials are still awaited.

Effects of dosing regimen on accumulation, retention and prophylactic efficacy of liposomal amphotericin B

OBJECTIVES

We hypothesized that effective prophylactic treatment of fungal infections would require adequate drug penetration and retention at potential infection sites. Using a mouse model, we examined liposomal amphotericin B (L-AmB) biodistribution, cell localization and retention in kidneys, lungs, liver and spleen to evaluate effective dosing regimens for prophylaxis of Candida glabrata and Candida albicans infections.

METHODS

Following treatment of mice with cumulative doses of L-AmB (60-225 mg/kg), a bioassay was done to determine tissue drug concentrations 12 h to 6 weeks post-treatment. Immunohistochemical staining with anti-amphotericin B antibodies was used for cellular drug localization. Mice were treated prophylactically with 15-90 mg/kg L-AmB and challenged intravenously 1-7 days later with C. glabrata or they were given a total of 60 mg/kg as daily or intermittent dosing followed by intravenous challenge with C. albicans 3 or 6 weeks later.

RESULTS

On the basis of microg/g tissue, the relative amount of drug was in the order spleen > liver > kidneys > lungs. Amphotericin B levels were maintained above the MIC for many fungi for 1 week in lungs and for as long as 6 weeks in kidneys and spleen. Drug localized in kidney tubular epithelial cells and in macrophages of liver and spleen. In prophylactic models, fungal burden was reduced by several 1000-fold or was undetectable within target tissues (kidneys, spleen).

CONCLUSIONS

These observations underscore the importance of including drug tissue levels to obtain a better understanding of L-AmB efficacy. The sustained concentrations of bioactive AmB in many tissues provide a further rationale for investigating L-AmB prophylactic regimens.

Interventions for preventing oral candidiasis for patients with cancer receiving treatment

BACKGROUND

Treatment of cancer is increasingly more effective but is associated with short and long term side effects. Oral side effects remain a major source of illness despite the use of a variety of agents to prevent and treat them. One of these side effects is oral candidiasis.

OBJECTIVES

To assess the effectiveness of interventions (which may include placebo or no treatment) for the prevention of oral candidiasis for patients with cancer receiving chemotherapy or radiotherapy or both.

SEARCH STRATEGY

Computerised searches of Cochrane Oral Health Group and PAPAS Trials Registers, CENTRAL, MEDLINE, EMBASE, CINAHL, CANCERLIT, SIGLE and LILACS were undertaken. Reference lists from relevant articles were searched and the authors of eligible trials were contacted to identify trials and obtain additional information. Date of the most recent searches: June 2006: CENTRAL (The Cochrane Library 2006, Issue 2).

SELECTION CRITERIA

Trials were selected if they met the following criteria: design - random allocation of participants; participants - anyone receiving chemotherapy or radiotherapy treatment for cancer; interventions - agents prescribed to prevent oral candidiasis; primary outcome - prevention of oral candidiasis.

DATA COLLECTION AND ANALYSIS

Data were recorded on the following secondary outcomes if present: relief of pain, amount of analgesia, relief of dysphagia, incidence of systemic infection, duration of stay in hospital (days), cost of oral care, patient quality of life, death, use of empirical antifungal treatment, toxicity and compliance. Information regarding methods, participants, interventions, outcome measures and results were independently extracted, in duplicate, by two review authors. The Cochrane Oral Health Group statistical guidelines were followed and risk ratios (RR) calculated using random-effects models. Potential sources of heterogeneity were examined in random-effects metaregression analyses.

MAIN RESULTS

Twenty-eight trials involving 4226 patients satisfied the inclusion criteria. Drugs absorbed and partially absorbed from the gastrointestinal (GI) tract were found to prevent oral candidiasis when compared to a placebo, or a no treatment control group, with RR for absorbed drugs = 0.47 (95% confidence interval (CI) 0.29 to 0.78). For absorbed drugs in populations with an incidence of 20% (mid range of results in control groups), this implies a NNT of 9 (95% CI 7 to 13) patients need to be treated to avoid one patient getting oral candidiasis. There was no significant benefit shown for drugs not absorbed from the GI tract.

AUTHORS' CONCLUSIONS

There is strong evidence, from randomised controlled trials, that drugs absorbed or partially absorbed from the GI tract prevent oral candidiasis in patients receiving treatment for cancer. There is also evidence that these drugs are significantly better at preventing oral candidiasis than drugs not absorbed from the GI.

High-dose weekly AmBisome antifungal prophylaxis in pediatric patients undergoing hematopoietic stem cell transplantation: a pharmacokinetic study

Disseminated fungal infection causes significant morbidity and mortality in children undergoing hematopoietic stem cell transplantation (HSCT). The widespread use of prophylactic oral triazoles has limitations of poor absorption, interindividual variability in metabolism, and hepatic toxicity. AmBisome (amphotericin B liposomal complex) has a better safety profile than the parent drug amphotericin B and produces higher plasma and tissue concentrations. We hypothesized that once-weekly high-dose AmBisome therapy could provide adequate fungal prophylaxis for immunocompromised children undergoing HSCT. We performed a pharmacokinetic pilot study to determine whether once-weekly high-dose AmBisome administration would result in effective concentrations throughout the dosing interval. A total of 14 children (median age, 3 years, 1 month; range, 4.5 months-9 years, 9 months) undergoing HSCT received once-weekly intravenous AmBisome prophylaxis (10 mg/kg as a 2-hour infusion). Blood samples for pharmacokinetic measurements were drawn around the first and the fourth weekly doses. The concentration of non-lipid-complexed amphotericin in plasma was determined by a validated bioassay. Pharmacokinetic parameters after single doses and during steady state were calculated using standard noncompartmental methods. AmBisome was well tolerated at this dose. Complete pharmacokinetic profiles for weeks 1 and 4 were obtained in 12 patients. The half-life calculated in this pediatric population was shorter on average than reported in adults (45 hours vs 152 hours). The volume of distribution correlated best with body weight (R(2) = .55), and clearance was best predicted by initial serum creatinine level (R(2) = .19). Mean (+/- standard deviation) individual plasma trough concentrations were 0.23 (0.13) mg/L after single doses and 0.47 (0.41) mg/L after multiple doses. Mean steady-state area under the curve was higher at week 4 than after a single dose (P < .05). Single-dose and steady-state pharmacokinetic profiles were similar in 8 patients, whereas in 4 patients the week 4 profile showed nonlinear elimination. However, plasma concentrations at 7 days (Cmin) were not significantly different after the first and fourth doses, suggesting no significant accumulation over the course of therapy. Our data show measurable amphotericin B plasma concentrations 7 days after high-dose infusion of AmBisome. This suggests that once-weekly dosing, as described in this study, may provide useful protection against fungal infections.

Antifungal prophylaxis following reduced-intensity stem cell transplantation

Reduced-intensity stem cell transplantation (RIST) has been developed to be a novel curative option for advanced hematologic diseases. Its minimal toxicity allows for transplantation in patients with advanced age or with organ dysfunction. Young patients without comorbidity can undergo RIST as outpatients. However, fungal infection remains an important complication in RIST. Given the poor prognosis of fungal infection, prophylaxis is critical in its management. The prophylactic strategy is recently changing with the development of RIST. Hospital equipment is important for fungal prophylaxis; however, the median day for the development of fungal infection is day 100, when most RIST patients are followed as outpatients. The focus of fungal management after RIST needs to shift from in-hospital equipment to oral antifungals. Various antifungals have recently been developed and introduced for clinical use. A major change in antifungal management will probably occur within several years.

New strategies of antifungal therapy in hematopoietic stem cell transplant recipients and patients with hematological malignancies

Invasive fungal infections (IFIs) are associated with considerable morbidity and mortality among high-risk individuals. Outcomes for IFI historically have been suboptimal and associated with a high mortality rate, hence global prophylaxis strategies have been applied to at-risk populations. Among certain populations, fluconazole prophylaxis has reduced systemic and superficial infections caused by Candida species. Newer azoles are currently being evaluated as prophylaxis and have the potential to provide protection against mould pathogens that are more troublesome to treat once they occur. Global prophylaxis strategies have the shortcoming of subjecting patients to therapy that ultimately will not need it. Targeted prophylaxis has the advantage of treating only patients at highest risk using some parameter of greater host susceptibility. Prophylaxis strategies are most suitable in patients at the highest risk for IFI. For patient groups whose risk is somewhat lower or when suspicion of IFI occurs in patients receiving prophylaxis, empirical antifungal therapy is often employed following a predefined period of fever. Again this approach subjects many non-infected patients to unnecessary and toxic therapy. A more refined approach such as presumptive or pre-emptive therapy whereby treatment is only initiated upon positive identification of a surrogate marker of infection in combination with clinical and radiological signs will subject fewer patients to toxic and expensive treatments.

Fungal infection-related mortality versus total mortality as an outcome in trials of antifungal agents

BACKGROUND

Disease specific mortality is often used as outcome rather than total mortality in clinical trials. This approach assumes that the classification of cause of death is unbiased. We explored whether use of fungal infection-related mortality as outcome rather than total mortality leads to bias in trials of antifungal agents in cancer patients.

METHODS

As an estimate of bias we used relative risk of death in those patients the authors considered had not died from fungal infection. Our sample consisted of 69 trials included in four systematic reviews of prophylactic or empirical antifungal treatment in patients with cancer and neutropenia we have published previously.

RESULTS

Thirty trials met the inclusion criteria. The trials comprised 6130 patients and 869 deaths, 220 (25%) of which were ascribed to fungal infection. The relative risk of death was 0.85 (95% CI 0.75-0.96) for total mortality, 0.57 (95% CI 0.44-0.74) for fungal mortality, and 0.95 (95% CI 0.82-1.09) for mortality among those who did not die from fungal infection.

CONCLUSION

We could not support the hypothesis that use of disease specific mortality introduces bias in antifungal trials on cancer patients as our estimate of the relative risk for mortality in those who survived the fungal infection was not increased. We conclude that it seems to be reliable to use fungal mortality as the primary outcome in trials of antifungal agents. Data on total mortality should be reported as well, however, to guard against the possible introduction of harmful treatments.

Low-dose liposomal amphotericin B in the prevention of invasive fungal infections in patients with prolonged neutropenia: results from a randomized, single-center trial

BACKGROUND

We performed a prospective, randomized, open-label trial to evaluate the efficacy of low-dose liposomal amphotericin B (L-AmB) to reduce the incidence of invasive fungal infections (IFI) in patients with hematological malignancies and prolonged neutropenia (>10 days) following intensive chemotherapy.

PATIENTS AND METHODS

In 219 neutropenic episodes (NE) of 132 patients randomization was performed. Patients received either 50 mg L-AmB every other day (arm A) or no systemic antifungal prophylaxis (arm B).

RESULTS

In the first NE of each patient the incidence of proven or probable IFI (primary end point) was five of 75 patients (6.7%) in arm A and 20 of 57 patients (35%) in arm B (P=0.001). Invasive aspergillosis occurred less frequently in patients receiving L-AmB-prophylaxis (P=0.0057), whereas the reduction of invasive candidiasis did not reach statistical significance (P=0.0655). In all NE the incidence of IFI was five of 110 NE (4.6%) in arm A versus 22 of 109 NE (20.2%) in arm B (P<0.01). Adverse events, possibly related to L-AmB, were observed in five NE (4.6%) and L-AmB was discontinued in three NE (2.8%). No grade 3 or 4 toxicities were observed.

CONCLUSIONS

Antifungal prophylaxis with low-dose L-AmB proved to be feasible and effective in our trial.

A prospective randomized trial of itraconazole vs fluconazole for the prevention of fungal infections in patients with acute leukemia and hematopoietic stem cell transplant recipients

Fluconazole antifungal prophylaxis is standard care in allogeneic hematopoietic stem cell transplant (HSCT) recipients, but this drug lacks anti-Aspergillus activity, the primary cause of invasive fungal infection (IFI) in many transplantation centers. We performed a randomized trial to compare itraconazole vs fluconazole, for prevention of IFIs in patients with acute leukemia (AL) and HSCT recipients. One hundred and ninety-five patients were randomly assigned to either fluconazole or itraconazole antifungal prophylaxis, after stratification into high-risk and low-risk groups. Antifungal prophylaxis was started at the beginning of chemotherapy and continued until resolution of neutropenia, or until amphotericin B treatment was started. IFI occurred in 11 (11%) of itraconazole, and in 12 (12%) fluconazole recipients. Invasive candidiasis (IC) developed in two (2%) itraconazole and one (1%) fluconazole recipients, while invasive aspergillosis (IA) developed in nine (9%) itraconazole and 11(11%) fluconazole recipients. There was no difference in the incidence of total IFI, IC and IA between the two study arms. However, there was a nonsignificant trend towards reduced mortality among patients who developed IA while receiving itraconazole prophylaxis (3/9=33% vs 8/11=73%, P=0.095).

Liposomal amphotericin B: clinical experience and perspectives

While amphotericin B deoxycholate (Fungizone, Apothecon Pharmaceuticals) has been considered by many to be the gold standard for the treatment for numerous invasive fungal infections for over 45 years, toxicities associated with its use often necessitate treatment modification or discontinuation. Lipid-based formulations, including liposomal amphotericin B (AmBisome, Fujisawa Healthcare, Inc.), were developed to decrease many of these toxicities while retaining broad antifungal spectrum and potency of amphotericin B. In clinical trials, liposomal amphotericin B has demonstrated efficacy comparable to that of amphotericin B deoxycholate while reducing the incidence of treatment-related nephrotoxicity, electrolyte-wasting, and infusion-related reactions. In addition, recent clinical trials have also compared liposomal amphotericin B with other antifungal classes. Acquisition costs of liposomal amphotericin B are substantially higher than those of amphotericin B deoxycholate and other antifungals. While pharmacoeconomic analyses consider outcomes and other treatment-related costs, they have yet to clearly demonstrate the cost-effectiveness of liposomal amphotericin B when compared with amphotericin B deoxycholate or other antifungal agents. This review will focus primarily on recent liposomal amphotericin B experience and attempt to put its use into perspective considering other available antifungal agents.

Aspergillus pulmonary infections in transplant recipients

Aspergillus infections are increasing in frequency in those undergoing solid organ and hematopoietic stem cell transplantation. The ongoing impact of Aspergillus infection on morbidity and mortality after transplantation makes this subject an area of intense clinical and research interest. This article discusses the evolving epidemiologic features of the infection and its management and diagnosis.

Invasive Candidiasis in Immunocompromised Hospitalized Patients

The frequency of infections by Candida species is increasing worldwide, with candidemia representing the fourth most common bloodstream infection in the U.S. The risk of infection is especially high in the immunocompromised, hospitalized patient. The treatment of and prophylaxis for Candida infection have led to the emergence of resistant species and the acquisition of resistance in previously susceptible species. Current therapeutic options include amphotericin B and its lipid compounds, fluconazole, itraconazole, voriconazole, and caspofungin. Research is focusing on better diagnostics and the evaluation of strategies such as prophylaxis in high-risk hosts and pre-emptive therapy.

Aspergillus infections in transplant recipients

Aspergillus infections are occurring with an increasing frequency in transplant recipients. Notable changes in the epidemiologic characteristics of this infection have occurred; these include a change in risk factors and later onset of infection. Management of invasive aspergillosis continues to be challenging, and the mortality rate, despite the use of newer antifungal agents, remains unacceptably high. Performing molecular studies to discern new targets for antifungal activity, identifying signaling pathways that may be amenable to immunologic interventions, assessing combination regimens of antifungal agents or combining antifungal agents with modulation of the host defense mechanisms, and devising diagnostic assays that can rapidly and reliably diagnose infections represent areas for future investigations that may lead to further improvement in outcomes.

Long-term antifungal prophylaxis in high-risk hematopoietic stem cell transplant recipients

The risks for invasive fungal infections, particularly mould infections such as invasive aspergillosis, among hematopoietic stem cell transplant (HSCT) recipients are linked to the duration and severity of myelosuppression and immunosuppression. Strategies to prevent invasive fungal infections have focused primarily on the use of orally administered azole antifungal agents during the neutropenic period rather than on the more prolonged post-engraftment period. The major limitations of these studies included the heterogeneity among the subjects studied for fungal infection risk factors, the agents administered, the dosing, and duration of prophylaxis. More recent studies have attempted to examine the efficacy of antifungal prophylaxis strategies among allogeneic HSCT recipients to day 100 and beyond. It is clear that a variety of products have efficacy in preventing invasive candidiasis, including imidazole and triazole antifungals, low-dose amphotericin B, and the echinocandin, micafungin; however, only the extended spectrum azole, itraconazole, has been shown to impact the incidence of proven invasive aspergillosis. Other extended spectrum azole antifungal agents, voriconazole and posaconazole, are being studied as long-term prophylaxis in high-risk HSCT recipients. While clinical trials have suggested that a duration of prophylaxis against moulds of six months or more may be required, it remains unclear if this is required in all cases. The prophylactic efficacy over time may be linked to the degree of immunosuppression as measured by markers such as the numbers of circulating CD4 T lymphocytes. Concerns about selection for resistant moulds among long-term recipients of these drugs are emerging. The cumulative experience to date suggests that long-term antifungal chemoprophylaxis is feasible and effective when applied in defined circumstances. The concerns about treatment-related toxicities, resistance, and costs are valid.

Interventions for preventing oral candidiasis for patients with cancer receiving treatment

BACKGROUND

Treatment of cancer is increasingly more effective but is associated with short and long term side effects. Oral side effects remain a major source of illness despite the use of a variety of agents to prevent and treat them. One of these side effects is oral candidiasis.

OBJECTIVES

To assess the effectiveness of interventions (which may include placebo or no treatment) for the prevention of oral candidiasis for patients with cancer receiving chemotherapy and/or radiotherapy.

SEARCH STRATEGY

Electronic databases: Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE, MEDLINE Pre-indexed, EMBASE, CINAHL, CANCERLIT, SIGLE and LILACS were searched. Date of the most recent searches April 2004 (CENTRAL Issue 2, 2004).

SELECTION CRITERIA

Trials were selected if they met the following criteria: design - random allocation of participants; participants - anyone receiving chemotherapy or radiotherapy treatment for cancer; interventions - agents prescribed to prevent oral candidiasis; primary outcome - prevention of oral candidiasis.

DATA COLLECTION AND ANALYSIS

Data were recorded on the following secondary outcomes if present: relief of pain, amount of analgesia, relief of dysphagia, incidence of systemic infection, duration of stay in hospital (days), cost of oral care, patient quality of life, death, use of empirical antifungal treatment, toxicity and compliance. Information regarding methods, participants, interventions, outcome measures and results were independently extracted, in duplicate, by two reviewers (HW & JC). The Cochrane Oral Health Group statistical guidelines were followed and relative risk values calculated using random effects models. Potential sources of heterogeneity were examined in random effects metaregression analyses.

MAIN RESULTS

Twenty-eight trials involving 4226 patients satisfied the inclusion criteria. Drugs absorbed and partially absorbed from the gastrointestinal (GI) tract were found to prevent oral candidiasis when compared to a placebo, or a no treatment control group, with RR for absorbed drugs = 0.47 (95% CI 0.29 to 0.78). For absorbed drugs in populations with an incidence of 20% (mid range of results in control groups), this implies a NNT of 9 (95% CI 7 to 13) patients need to be treated to avoid one patient getting oral candidiasis. There was no significant benefit shown for drugs not absorbed from the GI tract.

REVIEWERS' CONCLUSIONS

There is strong evidence, from randomised controlled trials, that drugs absorbed or partially absorbed from the GI tract prevent oral candidiasis in patients receiving treatment for cancer. There is also evidence that these drugs are significantly better at preventing oral candidiasis than drugs not absorbed from the GI.

Antimicrobial prophylaxis in hematopoietic stem cell transplant recipients: heterogeneity of current clinical practice

Antimicrobial agents are commonly used after hematopoietic stem cell transplant (HSCT) to prevent bacterial, viral and fungal infections. A pharmacy practice survey was undertaken to evaluate prevailing practices. The 31 centers evaluated transplanted over 3400 patients in 2001. Over half used bacterial prophylaxis; all with fluoroquinolones. A significantly higher proportion (90-100%) used fungal and viral prophylaxis. Most centers used fluconazole for fungal prophylaxis, but the dose used varied from 400 mg (the recommended dose) to 100 mg. Itraconazole and amphotericin preparations were used by some centers for allograft recipients because of their activity against aspergillosis. Most centers used brief viral prophylaxis for autograft recipients aimed at preventing HSV reactivation. Viral prophylaxis for allograft recipients was usually much more prolonged, reflecting concern over cytomegalovirus infections. Overall, there was significant deviation from recommended guidelines in many of the practices. Our survey suggests that substantial variation exists among transplant centers in their approach to antimicrobial prophylaxis after HSCT. This probably stems from the lack of definitive studies and strong recommendations in several areas, availability of newer agents that have not been adequately studied in the HSCT setting, and a desire to improve outcome before definitive studies are available for newer agents, a process that could take several years.

Choices aplenty: antifungal prophylaxis in hematopoietic stem cell transplant recipients

The incidence of invasive fungal infection (IFIs) in hematopoietic stem cell transplantation (HSCT) recipients ranges from 10 to 25% with an overall case fatality rate of up to 70-90%. Candida and Aspergillus genera remain the two most common pathogens. Although fluconazole prophylaxis in this population has been moderately effective in reducing mortality due to invasive candidiasis, this agent does not have activity against invasive aspergillosis (IA) and other mould. Several new agents such as voriconazole and caspofungin have enhanced potency and broad-spectrum antifungal activity and show promising results against yeasts and filamentous fungi when given as therapy and as chemoprophylaxis. Further, new diagnostic tools to detect circulating fungal antigens in biological fluids and PCR-based methods to detect species or genus-specific DNA or RNA have been developed. Incorporating these techniques along with clinical criteria appear to improve the accuracy of preclinical diagnosis of IFIs. Such approaches may alter the current treatment strategy from prophylaxis to pre-emptive therapy, thereby potentially decreasing cost and toxicity in high-risk patients.

Improved survival in steroid-refractory acute graft versus host disease after non-myeloablative allogeneic transplantation using a daclizumab-based strategy with comprehensive infection prophylaxis

Approximately 15% of patients undergoing non-myeloablative allogeneic haematopoietical cell transplantation (NMHCT) develop steroid-refractory acute-graft versus host disease (aGVHD), a usually fatal complication. We encountered 18 cases of steroid-refractory aGVHD in 146 patients, undergoing NMHCT from a related human leucocyte antigen-compatible donor following cyclophosphamide/fludarabine-based conditioning. Our initial cohort of steroid-refractory aGVHD patients treated with antithymocyte globulin (ATG) and mycophenolate mofetil (regimen-1: n = 6) had high GVHD-related mortality. Therefore, we investigated an alternative strategy for subsequent patients developing this complication (regimen-2: n = 12), consisting of daclizumab (alone or combined with infliximab/ATG) and targeted broad spectrum antibacterial and aspergillus prophylaxis in conjunction with rapid tapering of steroids to minimize opportunistic infections. In a retrospective analysis, patients receiving regimen-2 were significantly more likely to have complete resolution of GVHD compared with those receiving regimen-1 [12/12 (100%) vs. 1/6 (17%); P < 0.001]. When compared with those receiving regimen-1, regimen-2 patients also had a higher probability of survival at day 100 (100% vs. 50%) and day 200 (73% vs. 17%) post-transplant, and improved overall survival (median 453 d vs. 42 d from aGVHD onset; P < 0.0001). GVHD-related mortality was 89% for regimen-1 patients vs. 17% for regimen-2 patients (P < 0.0001). These data suggest that a co-ordinated approach using immunoregulatory monoclonal antibodies, pre-emptive antimicrobial therapy and judicious steroid withdrawal can dramatically improve outcome in steroid-refractory aGVHD.

Amphotericin B lipid complex as prophylaxis of invasive fungal infections in patients with acute myelogenous leukemia and myelodysplastic syndrome undergoing induction chemotherapy

BACKGROUND

The optimal antifungal prophylactic regimen for patients with acute myelogenous leukemia (AML) or high-risk myelodysplastic syndrome (MDS) undergoing induction chemotherapy has yet to be identified. A prospective historical control study evaluated the efficacy and safety of amphotericin B lipid complex (ABLC) in this patient population.

METHODS

Newly diagnosed patients with AML or high-risk MDS who were undergoing induction chemotherapy received prophylactic ABLC 2.5 mg/kg intravenously 3 times weekly. This treatment group was compared with a historical control group that had similar baseline characteristics and received prophylactic liposomal amphotericin B (L-AmB) 3 mg/kg 3 times weekly. The primary endpoint was the incidence of documented or suspected fungal infections during and up to 4 weeks after cessation of prophylaxis. Reported adverse events were used to assess tolerability.

RESULTS

The overall efficacy of antifungal prophylaxis was similar in patients who received ABLC and patients who received L-AmB (P=0.95). Among 131 ABLC-treated patients and 70 L-AmB-treated patients who were assessed for efficacy and safety, 49% of patients in each group completed therapy without developing a documented or suspected fungal infection. Documented fungal infections occurred in 5% of ABLC-treated patients and in 4% of L-AmB-treated patients. Alternative antifungal strategies were required because of persistent fever or pneumonia of unknown pathogen in 28% and 32% of ABLC-treated and L-AmB-treated patients, respectively. Grade 3 and 4 adverse events, therapy discontinuations due to adverse events, and survival rates also were similar between treatment groups.

CONCLUSIONS

ABLC and L-AmB appeared to have similar efficacy and were tolerated well as antifungal prophylaxis in patients with AML and high-risk MDS who were undergoing induction chemotherapy.

The lipid formulations of amphotericin B

Amphotericin B spectrum covers most of the fungal pathogens involved in human diseases. Its use is limited by infusion-related effects and nephrotoxicity. As a result of strong lipophilic properties, encapsulation in liposomes or binding to lipid complexes led to the development of lipid formulations in an attempt to increase both efficacy and safety. Three lipid formulations of amphotericin B are commercially available: a liposomal preparation, a lipid complex and a colloidal dispersion. They differ in their lipid composition, shape, pharmacokinetic behaviour and clinical effects. The nephrotoxicity of these formulations is significantly decreased compared to their parent compound. Infusion-related events are lowest with liposomal amphotericin B. Increased efficacy of the lipid formulations over conventional amphotericin B, however, still has to be demonstrated. These formulations are mainly indicated for the treatment of documented fungal infections in patients failing conventional amphotericin B or with renal impairment. Liposomal amphotericin B is also indicated for empirical therapy of suspected fungal infections in febrile neutropenic patients giving this compound an advantage over the two other formulations. Lipid formulations of amphotericin B are extremely expensive. Whether the increase in cost translates into a long-term benefit for the patient is still unknown.

A systematic review of the antifungal effectiveness and tolerability of amphotericin B formulations

OBJECTIVE

A systematic review was performed to compare the effectiveness and tolerability of lipid-based amphotericin B (AmB) formulations and conventional AmB in the treatment of systemic fungal infections.

METHODS

The literature and unpublished studies were searched using MEDLINE, EMBASE, Biological Abstracts, AIDSLINE, CANCERLIT, CRD database, Cochrane Controlled Trials Register, and other databases. Search terms included: amphotericin, liposom*, lipid*, colloid*, antifungal agents, and mycoses. Studies were selected according to predetermined criteria. The outcome measures reviewed were efficacy, mortality, renal toxicity, and infusion-related reactions. Meta-analyses and number-needed-to-treat (NNT) analyses were performed.

RESULTS

Seven studies (8 publications) met the entry criteria. Meta-analysis showed that lipid-based formulations significantly reduced all-cause mortality risk by an estimated 28% compared with conventional AmB (odds ratio [OR], 0.72; 95% CI, 0.54 to 0.97). There was no significant difference in efficacy between the lipid-based formulations and conventional AmB (OR, 1.21; 95% CI, 0.98 to 1.49). AmB lipid complex (ABLC) and liposomal AmB (L-AmB) significantly reduced the risk of doubling serum creatinine by an estimated 58% (OR, 0.42; 95% CI, 0.33 to 0.54). There was no significant reduction in risk of infusion-related reactions with lipid-based formulations, although this was difficult to interpret given the lack of consistent control of confounding factors. Comparing the lipid-based formulations with conventional AmB, the overall NNT to prevent 1 death was 31. The NNT to prevent a doubling of serum creatinine for both ABLC and L-AmB compared with conventional AmB was 6.

CONCLUSIONS

This study demonstrates advantages with lipid-based formulations over conventional AmB in terms of reduced risk of mortality and renal toxicity. Future trials in patients with proven fungal infection should control for factors such as premedication, infusion rates, fluid preloading, sodium/potassium supplementation, and concomitant medication.

Evidence-based assessment of primary antifungal prophylaxis in patients with hematologic malignancies

Invasive fungal infection is an increasing source of morbidity and mortality in patients with hematologic malignancies, particularly those with prolonged and severe neutropenia (absolute white blood cell count < 100/microL). Early diagnosis of invasive fungal infection is difficult, suggesting that antifungal prophylaxis could be the best approach for neutropenic patients undergoing intensive myelosuppressive chemotherapy. Consequently, antifungal prophylaxis has been extensively studied for more than 20 years. Nonabsorbable polyenes reduce superficial mycoses but are not effective in preventing or treating invasive fungal infections. Intravenous amphotericin B and the newer azoles were used in numerous clinical trials, but the value of antifungal prophylaxis in defined risk groups with cancer is still open to discussion. Recipients of allogeneic stem cell transplants and patients with a relapsed leukemia are high-risk patient populations. In addition, certain risk factors are well defined, for example, neutropenia more than 10 days, corticosteroid therapy, sustained immunosuppression, and graft-versus-host disease. In contrast to study efforts, evidence-based recommendations on the clinical use of antifungal prophylaxis according to risk groups are rare. The objective of this review of 50 studies accumulating more than 9000 patients is to assess evidence-based criteria with regard to the efficacy of antifungal prophylaxis in neutropenic cancer patients.

Liposomal amphotericin B versus the combination of fluconazole and itraconazole as prophylaxis for invasive fungal infections during induction chemotherapy for patients with acute myelogenous leukemia and myelodysplastic syndrome

BACKGROUND

Fungal infections are a major cause of morbidity and mortality in patients undergoing induction chemotherapy for acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS). The authors evaluated the efficacy and toxicity of liposomal amphotericin B (L-AmB) compared with a combination of fluconazole plus itraconazole (F+I) as prophylaxis in this setting.

METHODS

Patients with newly diagnosed AML or high-risk MDS who were undergoing initial induction chemotherapy were randomized to receive either F+I (fluconazole 200 mg orally every 12 hours plus itraconazole tablets 200 mg orally every 12 hours) or L-AmB (3 mg/kg intravenously 3 times per week) in this prospective, open-label study.

RESULTS

Seventy-two L-AmB-treated patients and 67 F+I-treated patients were enrolled in the study. Of these, 47% of patients completed antifungal prophylaxis without a change in therapy for proven or suspected fungal infection. Three patients in each arm developed a proven fungal infection. Twenty-three percent of the L-AmB-treated patients and 24% of the F+I-treated patients were changed to alternative antifungal therapy because of persistent fever (P value not significant). Nine percent of the L-AmB-treated patients developed pneumonia of unknown etiology compared with 16% of the F+I-treated patients (P value not significant). Increases in serum creatinine levels to > 2 mg/dL (20% for the L-AmB arm vs. 6% for the F+I arm; P = 0.012) and increases in serum bilirubin levels to > 2 mg/dL (43% vs. 22%, respectively; P = 0.021) were more common with L-AmB. Infusion-related reactions were noted in five L-AmB-treated patients. Responses to chemotherapy and induction mortality rates were similar for the two arms.

CONCLUSIONS

L-AmB and F+I appear similar in their efficacy as antifungal prophylaxis during induction chemotherapy for patients with AML and MDS. L-AmB was associated with higher rates of increased serum bilirubin and creatinine levels.

High rate of invasive fungal infections following nonmyeloablative allogeneic transplantation

Nonmyeloablative allogeneic transplantation is an emerging therapy for hematologic and solid malignancies and potentially offers patients reduced transplant-related toxicity. Data regarding infectious complications of these protocols are limited, but early studies have demonstrated little infectious morbidity, particularly low rates of invasive fungal infections (IFIs). In the present study, 31 consecutive cases of nonmyeloablative transplantation were reviewed over a 2.5-year period, with a specific focus on infectious complications. Twenty-six patients (84%) had at least 1 significant infection during the year after transplantation, and infection-related mortality was 37%. Cytomegalovirus end-organ disease was diagnosed in 3 patients (10%). Ten patients (32%) were given the diagnosis of IFI; 7 (23%) met criteria for proven IFI. Fungal-related mortality was 80% within the group of patients with IFI and accounted for a significant portion of the overall mortality in the study. Severe graft-versus-host disease, high-dose corticosteroid use, recurrent neutropenia, and relapsed or refractory disease were factors associated with development of IFI.

Amphotericin B and liver function

Amphotericin B is well established as a highly efficacious agent against systemic fungal infections in humans. The therapeutic potential of amphotericin B is limited due to its side effects. Although in clinical use for more than 35 years, impairment of liver function is not considered to be a typical adverse effect of amphotericin B. Experimental data suggest that the drug may interfere with the hepatic cytochrome P450 and may thus influence the metabolic capacity of the liver. A confirmation of such a finding in patients treated with amphotericin B would be of value. The incidence of severe acute or subacute hepatotoxicity in response to amphotericin B is very low. Frequently, in critically ill patients, it is not always clear whether liver abnormalities are caused by an antifungal agent or whether they are due to the critical condition of these patients. Nevertheless, there are experimental data suggesting that amphotericin B may influence the metabolic capacity of the liver. Accordingly, drug interactions during prolonged amphotericin B treatment seem possible. Careful monitoring of liver function in those patients receiving amphotericin B in combination with other drugs, which undergo hepatic metabolism or are potentially hepatotoxic, is recommended. In this review, the current understanding and knowledge of the clinical significance, detection, and possible pathogenesis of amphotericin-B-induced liver damage are presented. With respect to the current experimental data, the influence of the drug on the hepatic microsomal cytochrome P450 are also presented and discussed, as is the impact of several clinical studies using different amphotericin B formulas in humans.

Antifungal prophylaxis for severely neutropenic chemotherapy recipients: a meta analysis of randomized-controlled clinical trials

BACKGROUND

The overall clinical efficacy of the azoles antifungal agents and low-dose intravenous amphotericin B for antifungal chemoprophylaxis in patients with malignant disease who have severe neutropenia remains unclear.

METHODS

Randomized-controlled trials of azoles (fluconazole, itraconazole, ketoconazole, and miconazole) or intravenous amphotericin B formulations compared with placebo/no treatment or polyene-based controls in severely neutropenic chemotherapy recipients were evaluated using meta-analytical techniques.

RESULTS

Thirty-eight trials that included 7014 patients (study agents, 3515 patients; control patients, 3499 patients) were analyzed. Overall, there were reductions in the use of parenteral antifungal therapy (prophylaxis success: odds ratio [OR], 0.57; 95% confidence interval [95% CI], 0.48-0.68; relative risk reduction [RRR], 19%; number requiring treatment for this outcome [NNT], 10 patients), superficial fungal infection (OR, 0.29; 95% CI, 0.20-0.43; RRR, 61%; NNT, 12 patients), invasive fungal infection (OR, 0.44; 95% CI, 0.35-0.55; RRR, 56%; NNT, 22 patients), and fungal infection-related mortality (OR, 0.58; 95% CI, 0.41-0.82; RRR, 47%; NNT, 52 patients). Invasive aspergillosis was unaffected (OR, 1.03; 95% CI, 0.62-1.44). Although overall mortality was not reduced (OR, 0.87; 95% CI, 0.74-1.03), subgroup analyses showed reduced mortality in studies of patients who had prolonged neutropenia (OR, 0.72; 95% CI, 0.55-0.95) or who underwent hematopoietic stem cell transplantation (HSCT) (OR, 0.77; 95% CI, 0.59-0.99). The multivariate metaregression analyses identified HSCT, prolonged neutropenia, acute leukemia with prolonged neutropenia, and higher azole dose as predictors of treatment effect.

CONCLUSIONS

Antifungal prophylaxis reduced morbidity, as evidenced by reductions in the use of parenteral antifungal therapy, superficial fungal infection, and invasive fungal infection, as well as reducing fungal infection-related mortality. These effects were most pronounced in patients with malignant disease who had prolonged neutropenia and HSCT recipients.

Antifungal chemoprophylaxis after blood and marrow transplantation

Invasive fungal infections are common and deadly in recipients of blood and marrow transplants. Current diagnostic techniques do not allow accurate early diagnosis, especially of infection with mould pathogens, and delays in diagnosis are associated with treatment failure. This lack of early diagnosis has provided the impetus for the development of antifungal prophylaxis. Fluconazole prophylaxis is highly effective for the control of invasive yeast infections and associated with few breakthrough infections. The development of antimould prophylaxis in this patient population is a high priority.

Management of Candidiasis in Critically Ill Patients

Fungal infections have been increasing at an alarming rate in critically ill patients. Candida is now the fourth most common pathogen isolated from the bloodstream and is associated with significant morbidity, mortality, and economic consequences. Novel antifungals have been developed in recent years to provide alternatives to amphotericin B, which continues to be the standard therapy for most invasive fungal infections. These alternatives include lipid-based amphotericin B, ketoconazole, fluconazole, itraconazole, caspofungin, and potentially voriconazole. Optimal therapy for the various forms of candidiasis remains controversial. A standardized antifungal susceptibility testing method for Candida isolates has been developed to assist drug selection, but its clinical relevance remains to be determined. The relative susceptibility of Candida isolates can be estimated by the species. Specifically, C krusei is resistant to azoles, C glabrata may be resistant to azoles, and C lusitaniae may be resistant to amphotericin B Candida infections can affect any organ system, and the diagnosis of such infections remains difficult. The Infectious Diseases Society of America recently developed guidelines for the management of candidiasis. This review includes a brief discussion of systemically administered antifungal agents and provides a synopsis of the practice guidelines for the management of candidiasis.

Routine versus selective antifungal administration for control of fungal infections in patients with cancer

BACKGROUND

Systemic fungal infection is considered to be an important cause of morbidity and mortality in cancer patients, particularly those with neutropenia. Antifungal drugs are often given prophylactically, or to patients with persistent fever.

OBJECTIVES

The objective of this review was to assess the effect of antifungal drugs in cancer patients with neutropenia.

SEARCH STRATEGY

We searched the Cochrane Controlled Trials Register and MEDLINE (November 2001) and the reference lists of articles. We searched the proceedings of the ICAAC (from 1990 to 2001, General Meeting of the ASM (from 1990 to 2001), and the European Congress of Clinical Microbiology and Infectious Diseases (1995 to 2001) and contacted researchers in the field.

SELECTION CRITERIA

Randomised trials of amphotericin B, fluconazole, ketoconazole, miconazole, or itraconazole compared with placebo or no treatment in cancer patients with neutropenia.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial eligibility, methodological quality and abstracted data.

MAIN RESULTS

Thirty trials involving 4094 patients were included. Prophylactic or empirical treatment with antifungals as a group had no statistically significant effect on mortality (relative risk 0.95, 95% confidence interval 0.82 to 1.11). The relative risk was smallest for amphotericin B, 0.73 (0.52 to 1.03) (P=0.08). In another review, three trials compared intravenous lipid soluble amphotericin B (AmBisome) with smaller doses of standard intravenous amphotericin B; the relative risk was 0.74 (0.52 to 1.07). Taken together, these results indicate that intravenous amphotericin B might decrease mortality. In contrast, trials with fluconazole, ketoconazole, miconazole and itraconazole failed to find an effect on mortality. The incidence of invasive fungal infection decreased significantly with administration of amphotericin B (relative risk 0.39, 95% CI 0.20 to 0.76), fluconazole (0.39, 0.27 to 0.57) and itraconazole (0.51, 0.27 to 0.96), but not with miconazole or ketoconazole.

REVIEWER'S CONCLUSIONS

Intravenous amphotericin B is the only antifungal agent for which there is evidence suggesting that it might reduce mortality. It should therefore be preferred when prophylactic or empirical antifungal therapy in cancer patients with neutropenia is considered indicated.

Liposomal amphotericin B for prophylaxis of invasive fungal infections in high-risk paediatric patients with chemotherapy-related neutropenia: interim analysis of a prospective study

Invasive fungal infections (IFI) are a major cause of morbidity and mortality in patients with cancer. A retrospective analysis of children with cancer at high risk for IFI treated at Münster University Hospital showed that the incidence (7.4% vs. 1.8%) and lethality (28.1% vs. 0) of documented IFI were lower in patients receiving systemic antifungal prophylaxis with liposomal amphotericin B (l-AmB) in comparison to a historical control group. To determine whether this decline in incidence and lethality was due to antifungal prophylaxis or was produced by advances in diagnostic procedures and early empirical antifungal therapy, a prospective study was initiated. Patients in the prophylaxis arm received thrice-weekly 1 mg kg(-1) body weight l-AmB, whilst patients in the early intervention arm received no prophylaxis. Diagnostic procedures and antifungal therapy for suspected or proven IFI were initiated as clinically indicated for all patients. The primary endpoint of the study was the incidence of IFI. Secondary endpoints were the use of therapeutic doses of l-AmB, the safety of prophylactic l-AmB, and the total consumption of l-AmB for antifungal therapy. The interim analysis after 1 year showed no differences between the two approaches with respect to the incidence of IFI and to safety issues.

Antifungal prophylaxis in hematopoietic stem cell transplant recipients

Infections remain a major complication of hematopoietic stem cell transplantation, with recent trends indicating that fungal pathogens have become one of the most common causes of death. Attention has turned to the use of prophylactic antifungal medications to prevent infection with both Candida and Aspergillus species. Recent studies, which are reviewed within, indicate success in preventing infections caused by azole-susceptible Candida species, accompanied by improved transplant-related mortality rates in high-risk patients. Further studies are necessary to develop strategies to prevent infection with Aspergillus species.

The interactions of amphotericin B with various sterols in relation to its possible use in anticancer therapy

Amphotericin B (AmB) is still the most common anti-fungal agent used to treat systemic fungal infections. It is known that this antibiotic acts by forming pores with the ergosterol contained in the membranes of fungi, but it also interacts with the cholesterol contained in the membranes of eukaryotic cells, hence its toxicity. AmB may also interact with the most common oxidation products of cholesterol found in vivo, together with interacting with biosynthetic precursors of cholesterol, namely, lanosterol and 7-dehydrocholesterol (7-DHC). The purpose of the present work was to study the interactions in solution between AmB and these various sterols, the techniques used being UV-Vis spectroscopy and differential scanning calorimetry. The results are globally interpreted in terms of the structural differences between the sterols. We show that AmB selectively interacts with 7-DHC which, according to a recent hypothesis proposed in the literature, has been identified in connexion with a therapeutic strategy against hepatocellular carcinomas. We find that the affinity of AmB towards 7-DHC is even greater than the affinity of the antibiotic towards ergosterol. We also find that AmB selectively interacts with the principal oxidation product of cholesterol, 7-ketocholesterol, a situation that has to be taken into account when AmB is administered.