Preventing fungal infection in neutropenic patients with acute leukemia: fluconazole compared with oral amphotericin B

8th European Conference on Infections in Leukaemia: 2020 guidelines for the diagnosis, prevention, and treatment of invasive fungal diseases in paediatric patients with cancer or post-haematopoietic cell transplantation

Paediatric patients with cancer and those undergoing allogeneic haematopoietic cell transplantation have an increased susceptibility to invasive fungal diseases. In addition to differences in underlying conditions and comorbidities relative to adults, invasive fungal diseases in infants, children, and adolescents are unique in terms of their epidemiology, the validity of current diagnostic methods, the pharmacology and dosing of antifungal agents, and the absence of phase 3 clinical trials to provide data to guide evidence-based interventions. To re-examine the state of knowledge and to further improve invasive fungal disease diagnosis, prevention, and management, the 8th European Conference on Infections in Leukaemia (ECIL-8) reconvened a Paediatric Group to review the literature and to formulate updated recommendations according to the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) and European Confederation of Medical Mycology (ECMM) grading system, which are summarised in this Review.

Management of fever and neutropenia in the adult patient with acute myeloid leukemia

INTRODUCTION

Febrile neutropenia represents one of the most common treatment-associated complications in the management of acute myeloid leukemia (AML) and is considered an oncologic emergency. Rapid and detailed workup as well as the initiation of empiric broad-spectrum antibiotic therapy are critical to avoid sepsis and to reduce mortality. Although a definitive source of infection is frequently not identified, the severely immunosuppressed status of the AML patient undergoing cytotoxic therapy results in a high risk for a wide array of bacterial, fungal, and viral etiologies.

AREAS COVERED

The authors herein review the diagnostic and therapeutic approach to the neutropenic leukemia patient based on the current knowledge. Special consideration is given to the rapidly changing therapeutic landscape in AML, creating new challenges in the management of infectious complications.

EXPERT OPINION

Multidrug-resistant organisms pose a major challenge in the management of neutropenic fever patients with hematologic malignancies - including AML. Future directions to improve outcomes demand innovative treatment approaches as well as advances in biomarker research to facilitate diagnosis and disease monitoring. Recent achievements in AML-targeted therapy led to an increased incidence of differentiation syndrome, a potentially life-threatening side effect that frequently resembles clinical infection and requires prompt recognition and aggressive intervention.

Antifungal agents in preventing oral candidiasis in clinical oncology: A network meta-analysis

OBJECTIVE

This review examined the comparative efficacy and safety of antifungal agents in preventing oral candidiasis among patients on cancer treatment.

METHODS

We performed a systematic review and network meta-analysis based on randomised controlled trials that compared antifungal agents to placebo or other antifungal agents used in patients undergoing cancer treatment. Relative ranking of antifungal agents was evaluated with surface under the cumulative ranking (SUCRA) probability score. A total of 20 randomised controlled trials (3,215 participants) comparing 11 interventions were included.

RESULTS

Compared with placebo, clotrimazole was ranked the best agent for preventing the incidence of oral candidiasis (risk ratio (RR), 0.21 [95% CI 0.08 to 0.55]; SUCRA = 0.89). Fluconazole was ranked the safest among other antifungal agents (SUCRA = 0.80), whereas clotrimazole (SUCRA = 0.36) and amphotericin B (SUCRA = 0.18) were ranked low for safety. Amphotericin B was associated with highest risk of adverse events (RR, 3.52 [95% CI 1.27 to 9.75]).

CONCLUSION

Clotrimazole is the most effective in preventing oral candidiasis, whereas fluconazole has the most favourable risk-benefit profile in patients undergoing cancer treatment. However, we are unable to recommend clotrimazole as the best choice to prevent oral candidiasis due to unavailability of studies comparing clotrimazole with other antifungal agents.

Voriconazole is a safe and effective anti-fungal prophylactic agent during induction therapy of acute myeloid leukemia

Background:

Antifungal prophylaxis (AFP) reduces the incidence of invasive fungal infections (IFIs) during induction therapy of acute myeloid leukemia (AML). Posaconazole is considered the standard of care. Voriconazole, a generic cheaper alternative is a newer generation azole with broad anti-fungal activity. There is limited data on the use of voriconazole as a prophylactic drug.

Materials and Methods:

A single-center, prospective study was performed during which patients with AML undergoing induction chemotherapy received voriconazole as AFP (April 2012 to February 2014). Outcomes were compared with historical patients who received fluconazole as AFP (January 2011-March 2012, n = 66).

Results:

Seventy-five patients with AML (median age: 17 years [range: 1-75]; male:female 1.6:1) received voriconazole as AFP. The incidence of proven/probable/possible (ppp) IFI was 6.6% (5/75). Voriconazole and fluconazole cohorts were well-matched with respect to baseline characteristics. Voriconazole (when compared to fluconazole) reduced the incidence of pppIFI (5/75, 6.6% vs. 19/66, 29%; P < 0.001), need to start therapeutic (empiric + pppIFI) antifungals (26/75, 34% vs. 51/66, 48%; P < 0.001) and delayed the start of therapeutic antifungals in those who needed it (day 16 vs. day 10; P < 0.001). Mortality due to IFI was also reduced with the use of voriconazole (1/75, 1.3% vs. 6/66, 9%; P = 0.0507), but this was not significant. Three patients discontinued voriconazole due to side-effects.

Conclusion:

Voriconazole is an effective and safe oral agent for IFI prophylaxis during induction therapy of AML. Availability of generic equivalents makes this a more economical alternative to posaconazole.

Anti-infective prophylaxis in pediatric patients with acute myeloid leukemia

Pediatric patients undergoing treatment for acute myeloid leukemia (AML) are at high risk for infectious complications, predominantly due to Gram-negative bacteria, viridans group streptococci and fungal pathogens. In order to prevent infections in these patients, most institutions have implemented a number of non-pharmacological approaches to supportive care. In addition, antibiotic prophylaxis reduces bacterial infection, but may increase the emergence of resistance. Antifungal prophylaxis is generally recommended for children with AML. Whereas the use of hematopoietic growth factors has not resulted in improved survival, the efficacy of prophylactic granulocyte transfusions has to be determined.

Amphotericin B versus fluconazole for controlling fungal infections in neutropenic cancer patients

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 empirically to patients with persistent fever.

OBJECTIVES

To compare the effect of fluconazole and amphotericin B on morbidity and mortality in patients with cancer complicated by neutropenia.

SEARCH METHODS

We searched PubMed from 1966 to 7 July 2014 and the reference lists of identified articles.

SELECTION CRITERIA

Randomised clinical trials comparing fluconazole with amphotericin B.

DATA COLLECTION AND ANALYSIS

The two review authors independently assessed trial eligibility and risk of bias, and abstracted data.

MAIN RESULTS

Seventeen trials (3798 patients, 381 deaths) were included. In two large three-armed trials, results for amphotericin B were combined with results for nystatin in a 'polyene' group. Because nystatin is an ineffective drug in these circumstances, this approach creates a bias in favour of fluconazole. Furthermore, most patients were randomised to oral amphotericin B, which is poorly absorbed and poorly documented. There was overlap among the 'polyene' trials but we were unable to obtain any information from the trial authors or from Pfizer, the manufacturer of fluconazole, to clarify these issues. There were no significant differences in effect between fluconazole and amphotericin B, but the confidence intervals were wide. More patients dropped out of the study when they received amphotericin B, but as none of the trials were blinded decisions on premature interruption of therapy could have been biased. Furthermore, amphotericin B was not given under optimal circumstances, with premedication to reduce infusion-related toxicity, slow infusion, and with fluid, potassium and magnesium supplements to prevent nephrotoxicity. The major harms were hepatic impairment and gastrointestinal adverse effects with fluconazole and infusion-related toxicity, renal impairment and gastrointestinal adverse effects with amphotericin B. For the 2011 and 2014 updates no additional trials were identified for inclusion.

AUTHORS' CONCLUSIONS

Amphotericin B has been disfavoured in several of the trials through their design or analysis, or both. Since intravenous amphotericin B is the only antifungal agent for which an effect on mortality has been shown, and since it is considerably cheaper than fluconazole, it should be the preferred agent.

Early implementation of antifungal therapy in the management of febrile neutropenia is associated with favourable outcome during induction chemotherapy for acute leukaemias

BACKGROUND

Mortality related to induction chemotherapy during the treatment of acute leukaemias (AL) has been estimated at 5-20%, and this increases with age. Fungal infection remains one of the major causes of morbidity and mortality and is considered an obstacle to the successful management of acute leukaemias.

METHODS

We retrospectively analysed all patients treated for acute leukaemias at a single institution between July 2006 and January 2009, to assess the impact of early antifungal therapy on outcome during induction chemotherapy. There were 44 episodes of induction chemotherapy, with a median age of patients of 61 years (range 18-81), including 29 patients with acute myeloid leukaemia, 9 with acute lymphoblastic leukaemia and 6 with relapsed AL. The median age was 61 years (range 18-81), and 20 patients were over the age of 60 years.

RESULTS

All patients who developed febrile neutropenia received broad-spectrum antibiotics. Early empirical antifungal treatment was commenced with voriconazole (15 patients) or caspofungin (12 patients) if the febrile neutropenia did not resolve after 72 h of antibiotic therapy, in conjunction with radiological changes consistent with possible fungal infection. None of the patients succumbed during induction chemotherapy. The 120-day mortality rate after the induction therapy was 2.2%, without any incidence of invasive fungal disease.

CONCLUSION

Our analysis shows that early empirical treatment for fungal infection with voriconazole or caspofungin is associated with a favourable outcome of induction therapy for acute leukaemias. Further studies to confirm this finding are warranted.

Evidence-based guidelines for empirical therapy of neutropenic fever in Korea

Neutrophils play an important role in immunological function. Neutropenic patients are vulnerable to infection, and except fever is present, inflammatory reactions are scarce in many cases. Additionally, because infections can worsen rapidly, early evaluation and treatments are especially important in febrile neutropenic patients. In cases in which febrile neutropenia is anticipated due to anticancer chemotherapy, antibiotic prophylaxis can be used, based on the risk of infection. Antifungal prophylaxis may also be considered if long-term neutropenia or mucosal damage is expected. When fever is observed in patients suspected to have neutropenia, an adequate physical examination and blood and sputum cultures should be performed. Initial antibiotics should be chosen by considering the risk of complications following the infection; if the risk is low, oral antibiotics can be used. For initial intravenous antibiotics, monotherapy with a broad-spectrum antibiotic or combination therapy with two antibiotics is recommended. At 3-5 days after beginning the initial antibiotic therapy, the condition of the patient is assessed again to determine whether the fever has subsided or symptoms have worsened. If the patient's condition has improved, intravenous antibiotics can be replaced with oral antibiotics; if the condition has deteriorated, a change of antibiotics or addition of antifungal agents should be considered. If the causative microorganism is identified, initial antimicrobial or antifungal agents should be changed accordingly. When the cause is not detected, the initial agents should continue to be used until the neutrophil count recovers.

Antifungal prophylaxis during treatment for haematological malignancies: are we there yet?

Antifungal prophylaxis during treatment for haematological malignancies has been studied for 50 years, yet it has not been wholly effective even when using antifungal drugs that exhibit potent activity in vitro against a broad range of fungal pathogens. Trials have demonstrated that it can reduce the incidence of invasive fungal diseases (IFD) and fungal deaths, but only two studies have had an impact on overall mortality. Furthermore, it has not significantly reduced the need for empirical antifungal therapy. Posaconazole was effective in preventing invasive aspergillosis in two studies of high-risk patients, and consensus guidelines grade it as a suitable choice for antifungal prophylaxis of invasive mould disease; however, its bioavailability was compromised by vomiting or diarrhoea so that an alternative parenteral antifungal drug was required. A recent trial of voriconazole prophylaxis after allogeneic stem cell transplantation failed to show superiority over fluconazole. With more accurate definitions of IFD, that utilize fungal biomarkers, such as galactomannan, together with computerized tomographic imaging, there is growing interest in a diagnostic-driven strategy, which could prove to be a more efficacious approach.

A systematic review of oral fungal infections in patients receiving cancer therapy

PURPOSE

The aims of this systematic review were to determine, in patients receiving cancer therapy, the prevalence of clinical oral fungal infection and fungal colonization, to determine the impact on quality of life and cost of care, and to review current management strategies for oral fungal infections.

METHODS

Thirty-nine articles that met the inclusion/exclusion criteria were independently reviewed by two calibrated reviewers, each using a standard form. Information was extracted on a number of variables, including study design, study population, sample size, interventions, blinding, outcome measures, methods, results, and conclusions for each article. Areas of discrepancy between the two reviews were resolved by consensus. Studies were weighted as to the quality of the study design, and recommendations were based on the relative strength of each paper. Statistical analyses were performed to determine the weighted prevalence of clinical oral fungal infection and fungal colonization.

RESULTS

For all cancer treatments, the weighted prevalence of clinical oral fungal infection was found to be 7.5% pre-treatment, 39.1% during treatment, and 32.6% after the end of cancer therapy. Head and neck radiotherapy and chemotherapy were each independently associated with a significantly increased risk for oral fungal infection. For all cancer treatments, the prevalence of oral colonization with fungal organisms was 48.2% before treatment, 72.2% during treatment, and 70.1% after treatment. The prophylactic use of fluconazole during cancer therapy resulted in a prevalence of clinical fungal infection of 1.9%. No information specific to oral fungal infections was found on quality of life or cost of care.

CONCLUSIONS

There is an increased risk of clinically significant oral fungal infection during cancer therapy. Systemic antifungals are effective in the prevention of clinical oral fungal infection in patients receiving cancer therapy. Currently available topical antifungal agents are less efficacious, suggesting a need for better topical agents.

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).

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.

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.

Use of prophylactic antifungals in the immunocompromised host

Oral candidiasis is a significant infection in patients being treated with chemotherapy and radiotherapy for cancer, and in patients who are immunocompromised because of HIV infection and AIDS. Candida albicans is the most common fungal pathogen and has developed an extensive array of putative virulent mechanisms that allows successful colonization and infection of the host under suitable predisposing conditions. The purpose of this review of the literature was to assess the effectiveness of interventions for the prevention of oral candidiasis in immunocompromised patients and in patients treated for cancer with radiotherapy and/or chemotherapy. These patient categories were selected because they have been the topic of published randomized controlled clinical trials. The studies reviewed provide strong evidence that oral candidiasis is associated with greater morbidity and mortality in these populations, which substantiates the aggressive treatment and prophylaxis of this infection. The literature supports the recommendation that systemically applied antifungal drugs have the greatest efficacy for the treatment of oral candidiasis in cancer and immunocompromised patients; however, these therapies must be prescribed with a thorough assessment for the risk for developing drug-induced toxicities. Guidelines on the prevention of drug-resistant oral candidiasis in these patients are not available and require elucidation. Further studies are required to expand the knowledge base of evidence-based antifungal therapies in a wider variety of immunocompromised patients and conditions, such as Sjögren's syndrome, diabetes, and denture wearers. Additional exploration is needed to determine which antifungal drug formulation, dose, and method of delivery is preferable for the type of fungal infection and the underlying etiology.

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.

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.

Oral amphotericin B for the prevention of Candida bloodstream infection in critically ill children

OBJECTIVES

To determine the efficacy of oral amphotericin B for the prevention of Candida bloodstream infection in the pediatric intensive care unit.

DESIGN

Retrospective, nonrandomized, historic-control study.

SETTING

Multidisciplinary pediatric intensive care unit at a university-affiliated children's medical center.

PATIENTS

Study group included all patients admitted to the pediatric intensive care unit from January 1, 1998, to December 31, 1999, who required mechanical ventilation and who were admitted for >7 days. The control group included all patients admitted for >7 days who needed mechanical ventilation from January 1, 1994, to December 31, 1997.

INTERVENTIONS

Oral amphotericin B suspension, 50 mg every 8 hrs, administered to all study group patients soon after initiation of mechanical ventilation and terminating after weaning.

MEASUREMENTS

The rates of Candida bloodstream infection were compared between the study and control groups.

MAIN RESULTS

Candida species were isolated from blood cultures in 5 of 185 (2.1%) and 21 of 196 (10.7%) patients in the study and control groups, respectively (p= .0038). There was also a statistically significant (p= .017) decrease in Candida bloodstream infection rate in all patients admitted to the pediatric intensive care unit for >7 days during the study period compared with the Candida bloodstream infection rate during the control period.

CONCLUSION

Prophylactic administration of oral amphotericin B may lead to a significant decrease in the rate of Candida bloodstream infection in ventilated pediatric intensive care unit patients.

Cost-effectiveness analysis of antifungal treatment for patients on chemotherapy

Invasive fungal infections are fatal complications for patients on chemotherapy, and antifungal prophylactic treatment has been commonly recommended. Because its clinical and economic impact is not well known, we evaluated cost-effectiveness of anti-fungal treatment for patients who were neutropoenic as a result of chemotherapy. We constructed a hypothetical cohort of 40-year-old patients with acute myelogenic leukemia to evaluate years of life survived (YLS), costs (US$), and incremental cost-effectiveness ratio (US$/YLS). The following treatment strategies for fungal infections were compared: (1) prophylactic fluconazole strategy: oral fluconazole administration concurrently with chemotherapy; (2) empirical amphotericin B strategy: empirical intravenous amphotericin B administration at the point where fever is detected; and (3) no prophylaxis strategy: intravenous micafangin administration at the point where fungal infections is diagnosed. Baseline analyses showed that prophylactic fluconazole strategy involved higher costs but also longer YLSs (25,900 US$ and 24.08 YLS). The incremental cost-effectiveness ratio of prophylactic fluconazole strategy was 625 US$/YLS compared to no prophylaxis strategy, and 652 US$/YLS compared to empirical amphotericin B strategy. Baseline result was found to be robust through sensitivity analyses. Our study showed that concurrent administration of oral fluconazole during induction chemotherapy appears to ensure clinical benefits together with acceptable cost-effectiveness.

Fluconazole for the management of invasive candidiasis: where do we stand after 15 years?

Candida spp. are responsible for most of the fungal infections in humans. Available since 1990, fluconazole is well established as a leading drug in the setting of prevention and treatment of mucosal and invasive candidiasis. Fluconazole displays predictable pharmacokinetics and an excellent tolerance profile in all groups, including the elderly and children. Fluconazole is a fungistatic drug against yeasts and lacks activity against moulds. Candida krusei is intrinsically resistant to fluconazole, and other species, notably Candida glabrata, often manifest reduced susceptibility. Emergence of azole-resistant strains as well as discovery of new antifungal drugs (new triazoles and echinocandins) have raised important questions about its use as a first line drug. The aim of this review is to summarize the main available data on the position of fluconazole in the prophylaxis or curative treatment of invasive Candida spp. infections. Fluconazole is still a major drug for antifungal prophylaxis in the setting of transplantation (solid organ and bone marrow), intensive care unit, and in neutropenic patients. Prophylactic fluconazole still has a place in HIV-positive patients in viro-immunological failure with recurrent mucosal candidiasis. Fluconazole can be used in adult neutropenic patients with systemic candidiasis, as long as the species identified is a priori susceptible. Among non-neutropenic patients with candidaemia fluconazole is one of the first line drugs for susceptible species. Cases reports and uncontrolled studies have also reported its efficacy in the setting of osteoarthritis, endophthalmitis, meningitis, endocarditis and peritonitis caused by Candida spp. among immunocompetent adults. In paediatrics, fluconazole is a well tolerated and major prophylactic drug for high-risk neonates, as well as an alternative treatment for neonatal candidiasis. Importantly 15 years after its introduction in the antifungal armamentarium, fluconazole is still a first line treatment option in several cases of invasive candidiasis. Its prophylactic use should however be limited to selected high-risk patients to limit the risk of emergence of azole-resistant strains.

Profilaxis de las infecciones en el paciente neutropénico

Infections are the main cause of death in neutropenic patients and are related to the degree and duration of neutropenia, the underlying disease, and the treatments received. To reduce the number of these infections, prophylactic strategies have been proposed. These strategies aim to prevent adquisition through contact, inhalation, or the gastrointestinal tract. Intestinal decontamination through fluoroquinolones has reduced Gram-negative infections but this strategy should not be used indiscriminately and should be reserved for high risk patients. Fluconazole as antifungal prophylaxis reduces mortality but does not modify the incidence of invasive aspergillosis. Cytomegalovirus infection should be prevented in patients with negative serology; in high risk patients with positive serology, monitoring and preemptive treatment with ganciclovir or foscarnet is recommended. Hematopoietic growth factors reduce the duration of neutropenia and could reduce mortality from infection.

Economic Evaluation of Intravenous Itraconazole for Presumed Systemic Fungal Infections in Neutropenic Patients in Korea

Systemic fungal infections remain a major clinical problem in immunocompromised patients. Presumed systemic fungal infections (PSFI) are treated empirically with an intravenous antifungal agent to reduce the occurrence of documented infections and associated mortality. The objective of this study was to compare the cost-effectiveness of intravenous itraconazole (IVitra) treatment with the current first-line empirical treatment of PSFI with conventional amphotericin B (CAB) in cases of neutropenic cancer and bone marrow transplantation (BMT). Cost-effectiveness was expressed as cost per additional "responder" (defined as a patient without fever or major toxicity). We developed a medical decision analytical tree that included probabilities of toxicity, response and pathogen documentation, and second-line treatments. Clinical data were obtained from randomized clinical trials, and resource use data were obtained from a panel of clinical experts. The total cost of treating PSFI per neutropenic cancer patient was lower for IVitra than for CAB, and this lower cost resulted from a reduced need for second-line antifungals. In a cost-effectiveness analysis, IVitra treatment was superior to CAB treatment. Compared with current treatment with CAB, IVitra therapy was shown to be a cost-effective and cost-saving empirical treatment for PSFI in neutropenic cancer patients and BMT patients.

The use of topical nonabsorbable gastrointestinal antifungal prophylaxis to prevent fungal infections in critically ill immunocompetent patients: A meta-analysis

OBJECTIVE

To investigate the preventive effect of topical nonabsorbable gastrointestinal antifungal prophylaxis on the incidence of fungal infection in critically ill immunocompetent patients.

DATA SOURCE

Randomized controlled studies involving critically ill pediatric and adult patients in different languages from the Cochrane Controlled Trial Register (2004, issue 1), EMBASE, and MEDLINE databases (1966 to 30 April 2004) were included. Studies evaluating absorbable antifungal prophylaxis were excluded. Two reviewers assessed the quality of the studies and performed data extraction independently.

DATA

Amphotericin B and nystatin were used as the nonabsorbable antifungal prophylaxis in the 15 studies included in this meta-analysis. Ten studies used a concomitant systemic antibiotic and four more studies used concomitant topical nonabsorbable antibiotics in the treatment group. Only one study compared topical nonabsorbable antifungal prophylaxis alone with placebo. The total incidence of fungal infections (relative risk [RR], 0.30; 95% confidence interval [CI], 0.18-0.48; p < .00001; extent of inconsistency [I(2)] = 0%) and proportion of patients with fungal infection (RR, 0.50; 95% CI, 0.28-0.87; p = .02; I(2) = 0%) were significantly reduced with topical nonabsorbable antifungal prophylaxis. The incidence of fungal urinary tract infection was significantly reduced (RR, 0.27; 95% CI, 0.10-0.74; p = .01; I(2)= 0%) but not fungal pneumonia (RR, 0.57; 95% CI, 0.28-1.16; p = .12; I(2)= 0%). Fungemia and catheter-related fungal sepsis were rare and not significantly reduced with nonabsorbable antifungal prophylaxis. The results remained unchanged in the sensitivity analyses after exclusion of studies with unclear study quality or exclusion of the contribution of fungal urinary tract infections to the total incidence of fungal infections.

CONCLUSIONS

In critically ill immunocompetent patients who are at high risk of fungal infection, topical nonabsorbable gastrointestinal antifungal prophylaxis was associated with a reduced incidence of urinary fungal infections and a trend toward reduction in respiratory fungal infections and fungemia. Limitations in study data are such that many of these infections may have represented superficial infections of uncertain clinical importance; a large, randomized, controlled trial is needed to assess the cost-effectiveness and safety of topical nonabsorbable antifungal prophylaxis in critically ill patients.

Novel modes of antifungal drug administration

Administration of antifungals by routes other than that for which the agent was designed or approved have been utilised in attempts to provide directed therapy, reduce adverse effects and improve drug penetration into selected infection sites, such as the central nervous system, lungs and peritoneum. The most widely investigated agent utilising a novel method of drug delivery is amphotericin B. Dose forms for this agent include topicals (aerosol, nasal spray, irrigations, pastes, absorbable sponges, impregnated bone cement and gelatin), oral dosage forms (solutions, suspensions, tablets and so on) and ophthalmic preparations (drops, ointments and injections). Amphotericin B has been administered by routes such as oral, endobronchial, intrathecal, intracisternal, intra-articular, intraperitoneal, ophthalmic and as an antibiotic 'line lock'. Nystatin has been administered as an aerosol, percutaneous paste and bladder washes. Azoles, such as miconazole, fluconazole, ketoconazole and posaconazole, have been administered by novel methods but to a lesser degree. Most of these reports involve miconazole. The dose forms and routes of administration for azoles have included irrigants (bladder, joint), ophthalmic preparations (eye drops, intraocular injections, ointments), impregnated bone cement, endobronchial and intrathecal administration. Finally, both methylene blue (bladder washes) and flucytosine (peritoneal lavage, ophthalmic eye drops) have also been employed. Adequate evaluations of both the safety and efficacy of these therapies are most often hindered by prior or concomitant antifungal therapies, comorbidities and the lack of controlled clinical trials. In addition, the availability of newer treatment options, which demonstrate significant improvement in drug distribution and treatment-related adverse effects make many such novel modes of administration less practical or necessary. In contrast, the inhalation of antifungal aerosols, such as amphotericin B, is rapidly becoming a viable prophylactic option.

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.

How to Improve the Design of Trials of Antifungal Prophylaxis among Neutropenic Adults with Acute Leukemia

The risk for invasive fungal infections in patients with acute leukemia is generally low (4%-8%), and the routine use of fungal prophylaxis is not warranted except in specific high-risk groups that should be identified among this population. In a prophylactic study with a new agent, fluconazole or itraconazole oral solution represent good choices for the comparator because they are proven better than placebo or oral nonabsorbable antifungal agents in reducing the risk of invasive fungal infections in patients with acute leukemia. Because prophylaxis is most valuable when the risk of infection is high, patients with well-understood risk factors (severe mucosal disruption caused by chemotherapy, impaired cell-mediated immunity caused by steroids or fludarabine, use of a central venous catheter, and colonization by Candida species) should be selected. The end points for antifungal prophylactic trials should focus on proven and probable invasive fungal infections. Superficial and mucosal fungal infections do not represent a primary end point for these studies. Poor compliance should be considered as an interruption of treatment due to side effects and should be included in the criteria for failure. Fungus-related mortality should be evaluated as a failure of prophylaxis, whereas overall mortality may be influenced by many other cofactors. Differences in gastrointestinal toxicity of antifungal agents may limit the use of double-blind designs in some situations.

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.

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.

Antifungal prophylaxis with azole derivatives

In recent years, several reports have underlined the increasing role of fungal infections as a cause of morbidity and mortality in hospitalised patients. For this reason, and also in light of the high mortality rate associated with these infections, chemoprophylaxis has been advocated by several authors. The available evidence suggests that both fluconazole and itraconazole are able to decrease candida colonisation and infection, when compared with placebo or with nonabsorbable antifungals. Data seem also to suggest that a decrease in fungus-related mortality can be achieved with prophylaxis, although with little effect on overall mortality, probably because of the importance of severe underlying diseases. Itraconazole proved to be effective in the prevention of fungal infections, including invasive aspergillosis, although with increased incidence of side-effects, often leading to treatment discontinuation. The other side of the coin is that antifungal prophylaxis might have untoward effects, such as the selection of triazole-resistant Candida strains or the induction of resistance. In addition, some authors have suggested that the use of triazoles might modulate the pattern of infecting organisms in cancer patients, increasing the risk of both aspergillosis and bacteremia. In conclusion, antifungal prophylaxis with triazole antifungals should be used with caution, only in patients at high risk for invasive fungal infections. These include allogeneic bone marrow transplant patients (especially those with mismatched or unrelated donors), acute myeloid leukaemia patients treated with high-dose cytarabine (C-ara), very-low-birth-weight infants, patients with chronic granulomatous disease, and high-risk surgical and intensive-care unit patients.

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.

Randomized trial of fluconazole versus low-dose amphotericin B in prophylaxis against fungal infections in patients undergoing hematopoietic stem cell transplantation

Over the past decade, invasive fungal infections have become an increasingly important problem in patients undergoing hematopoietic stem cell transplantation (HSCT). The optimal approach for prophylactic antifungal therapy has yet to be determined. To resolve this issue, we performed a prospective randomized study to compare the efficacy of fluconazole (FL) versus low-dose amphotericin B (AmB) in preventing fungal infections during the first 100 days after HSCT. Patients undergoing allogenic or autologous HSCT were randomized to receive fluconazole 200 mg/day PO or amphotericin B 0.2 mg/kg/day IV beginning 1 day prior to commencement of conditioning regimen and continuing until engraftment, drug-associated toxicity was suspected, or systemic fungal infection was suspected or proven. High-dose amphotericin B (0.5-1.0 mg/kg/day) was started for patients with suspected or proven fungal infections. From January 1993 to December 1998, a total of 186 patients were enrolled into the trial, with 100 receiving FL and 86 receiving AmB. Eighty (43%) patients were removed from prophylaxis for persistent fever despite broad-spectrum antibacterial therapy or suspected fungal infections (FL 46 vs. AmB 34, P > 0.05). The incidence of proven fungal infections (FL 12% vs. AmB 12.8%), suspected fungal infections (FL 4% vs. AmB 2.3%), superficial fungal infections (FL 1% vs. AmB 4.6%) did not show any significant difference. The survival at 100 days post transplant was similar between the 2 groups (FL 78% vs. AmB 70%, P = 0.254). Death attributable to fungal infections was similar in both groups (6% vs. 7%, P > 0.05). We conclude that fluconazole is as effective as low-dose amphotericin B in prophylaxis against fungal infections in patients undergoing hematopoietic cell transplantation.

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.

Amphotericin B versus fluconazole for controlling fungal infections in neutropenic cancer patients

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

To compare the effect of fluconazole and amphotericin B on morbidity and mortality in patients with cancer complicated by neutropenia.

SEARCH STRATEGY

MEDLINE and Cochrane Library (November 2001). Letters, abstracts, and unpublished trials. The industry and authors were contacted.

SELECTION CRITERIA

Randomised trials comparing fluconazole with amphotericin B.

DATA COLLECTION AND ANALYSIS

Data on mortality, invasive fungal infection, colonisation, use of additional (escape) antifungal therapy and adverse effects leading to discontinuation of therapy were extracted by both authors independently.

MAIN RESULTS

Sixteen trials (3760 patients, 341 deaths) were included. In 3 large 3-armed trials, results for amphotericin B were combined with results for nystatin in a "polyene" group. Because nystatin is an ineffective drug in these circumstances, this approach creates a bias in favour of fluconazole. Furthermore, most patients were randomised to oral amphotericin B, which is poorly absorbed and poorly documented. It was unclear whether there was overlap among the "polyene" trials. We were unable to obtain any information to clarify these issues from the trial authors or from Pfizer, the manufacturer of fluconazole. There were no significant differences in effect between fluconazole and amphotericin B, but the confidence intervals were wide. More patients dropped out of the study when they received amphotericin B, but as none of the trials were blinded, decisions on premature interruption of therapy could have been biased. Furthermore, amphotericin B was rarely given under optimal circumstances, with premedication to reduce infusion-related toxicity, slow infusion, and with potassium and magnesium supplements to prevent nephrotoxicity.

REVIEWER'S CONCLUSIONS

Amphotericin B had been disfavoured in several of the trials through their design or analysis. Since intravenous amphotericin B is the only antifungal agent for which there is good evidence suggesting an effect on mortality and is considerably cheaper than fluconazole, it should be preferred.

Revisiting the source of candidemia: skin or gut?

The source of candidemia has been the subject of considerable debate, with some suggesting a origin in the gastrointestinal tract and others suggesting a skin origin. To evaluate the potential sources of candidemia, we performed a computerized search of the MEDLINE database for studies published from January 1966 through September 2000 and we identified relevant abstracts presented at national meetings. We reviewed the literature with special emphasis on studies that used appropriate definitions, evaluated both gut and skin as sources, and conducted molecular-relatedness studies. Among 203 candidemia studies published, we identified 21 that evaluated a specific source for candidemia and only 5 that performed molecular typing. Those studies and additional experimental, epidemiologic, and molecular-relatedness studies strongly suggested that the gut is an important source of candidemia, and studies that supported the skin as a source for this infection were surprisingly incomplete.

Treatment of documented and suspected neutropenia-associated invasive fungal infections

Factors such as the intensification of anti-tumor regimens have enhanced both the depth and length of neutropenia and endorsed severe deficiencies in other immune systems. As a result, the risk of fungal infections has increased substantially. Clinicians should be aware of the possibility to enable a timely diagnosis because many of the problems in the management of invasive fungal infections during neutropenia are as much the consequence of diagnostic short-comings as of lack of therapeutic options. About 7% of all febrile episodes during neutropenia can ultimately be attributed to fungi, Candida and Aspergillus species being the paramount pathogens. Although the data in favor of prophylactic use of antifungals are not convincing, prophylaxis is still recommended in an attempt to protect particularly high-risk patients. Fluconazole still appears a suitable agent in recipients of a bone marrow transplant. Given the paucity of data, reappraisal of the value of empirical antifungal therapy is warranted. Amphotericin B with or without 5-flucytosine is considered the standard therapy for acute candidiasis with fluconazole as an alternative. Amphotericin B is also first-line therapy for invasive aspergillosis in neutropenic patients; lipid-based formulations are recommended for patients who develop nephrotoxity. Recovery of the granulocytes and other immune systems has shown to be of critical importance in the management of all invasive fungal infections.

Prophylactic antifungal therapy in the intensive care unit

Antifungal prophylaxis is regularly used during treatment of patients with some cancers, as subgroups with high rates of invasive fungal infections are readily identified; for these patients, prophylaxis has been shown to be of value. High-risk liver transplant recipients also benefit from antifungal prophylaxis. Although the idea of extending this concept to the prevention of candidal infections in the larger population of critically ill patients who are seen in the intensive care unit (ICU) and who do not have neutropenia is attractive, implementation of this strategy is difficult because of the widely varying characteristics of patients in the ICU. Two studies have shown the benefit of such prophylaxis, but the benefit was shown only in selected groups of patients who had an unusually high risk for invasive candidiasis. Although the concept is sound, broad-scale implementation of antifungal prophylaxis would be premature and costly, both financially and with regard to resistance and toxicity. Investigations are needed to define and prove the utility of predictive tools for the identification of patients in the ICU who would benefit from prophylaxis.

Oral antifungals as prophylaxis in haematological malignancy

In the standard treatment of patients with haematological malignancy, immunosuppressive therapy produces prolonged periods of neutropenia and mucositis, which increase the risk of systemic fungal infection. In allogeneic bone marrow transplantation, this risk extends well beyond the period of neutropenia when graft-versus-host disease, and its treatment, result in prolonged lymphocytopenia. Various agents are used for antifungal prophylaxis and treatment but all have limitations: amphotericin B is restricted by the need for intravenous infusion and the occurrence of adverse events, fluconazole by its narrow spectrum of activity and the emergence of fluconazole-resistant fungi and itraconazole capsules by erratic absorption. Oral administration of antifungals has clear advantages in prophylaxis and an important current strategy is to maximize the extent and reliability of the oral bioavailability of antifungal agents. Mucositis is the main obstacle for success of strategies based on oral delivery. In this review, the ability of these new oral formulations to deliver sufficient antifungal prophylaxis is evaluated.

Assessing risk factors for systemic fungal infections

The incidence of invasive fungal infection has increased in recent years. Most infections are caused by Candida albicans and Aspergillus spp. but the emergence of other fungal infections is changing the spectrum of disease. Immunosuppression and breakdown of anatomical barriers such as the skin are the major risk factors for fungal infections. Health care workers encounter at-risk patients in various settings, including AIDS clinics and intensive care, transplantation and oncology units. Patients with prolonged and deep neutropenia (haematological malignancy patients) are most at risk and are therefore most likely to receive prophylactic therapy. Practical measures can be taken to avoid exposing the patient to fungi (air filtration, regular hand washing, avoiding plants and flowers) and antifungal agents can be administered to prevent systemic fungal infection. Most fungal infections have non-specific symptoms; this makes recognition of the signs and symptoms of the disease important but also makes diagnosis difficult and empirical treatment necessary. Some antifungal agents have limitations but new formulations will improve therapy and play a key role in future antifungal strategies.

The combination of oral amphotericin B with azoles prevents the emergence of resistant Candida species in neutropenic patients

The role of antifungal prophylaxis remains controversial and concerns exist that the use of azoles may potentiate the emergence of resistant Candida species. We used a strategy of combining the latest azole/triazole with oral amphotericin B to reduce this risk. We analysed data on Candida colonization and candidaemia in neutropenic patients from four prophylaxis periods (1985/6: ketoconazole and amphotericin B suspension; 1991/2 & 1997: fluconazole and amphotericin B suspension; 1998/9: itraconazole) to look for evidence of the emergence of potentially resistant species. Overall, the percentage of patients colonized with Candida fell significantly (69.3%, 57.5%, 43.2% and 46%, respectively, P < 0.001) due to a decrease in colonization with C. albicans (49%, 23.1%, 22.2% and 25.2%, respectively, P < 0.001). However, in 1998/9, increased colonization, particularly with C. glabrata in the lower gastrointestinal tract, was noted to coincide with the omission of oral amphotericin B. Despite an increasing population of 'high risk' patients, the incidence of candidaemia has not changed significantly (2%, 1.4%, 1.2% and 2% respectively). However, species causing candidaemia have changed, with resistant organisms now predominating. Our findings support the use of azole prophylaxis although, in view of the trends noted when itraconazole was used alone, we would recommend the additional use of oral amphotericin B.

Fungal infections in patients with neutropenia: challenges in prophylaxis and treatment

Fungal infections are a leading cause of mortality in patients with neutropenia. Candidiasis and aspergillosis account for most invasive fungal infections. General prophylactic measures include strict hygiene and environmental measures. Haemopoietic growth factors shorten the duration of neutropenia and thus may reduce the incidence of fungal infections. Fluconazole is appropriate for antifungal prophylaxis and should be offered to patients with prolonged neutropenia, such as high-risk patients with leukaemia undergoing remission induction or consolidation therapy and high-risk stem cell transplant recipients. Empirical antifungal therapy is mandatory in patients with persistent febrile neutropenia who fail to respond to broad-spectrum antibacterials. Intravenous amphotericin B at a daily dose of 0.6 to 1 mg/kg is preferred whenever aspergillosis cannot be ruled out. Lipid formulations of amphotericin B have demonstrated similar efficacy and are much better tolerated. Fluconazole is the best choice for acute candidiasis in stable patients; amphotericin B should be used in patients with unstable disease. Use of fluconazole is restricted by the existence of resistant strains (Candida krusei and, to a lesser extent, C. glabrata). Amphotericin B still remains the gold standard for invasive aspergillosis. Lipid formulations of amphotericin B are effective in aspergillosis and because they are less nephrotoxic are indicated in patients with poor renal function. Itraconazole is an alternative in patients who have good intestinal function and are able to eat. Mucormycosis, trichosporonosis, fusariosis and cryptococcosis are less common but require specific management. New antifungal agents, especially new azoles, are under development. Their broad in vitro spectrum and preliminary clinical results are promising.