Voriconazole compared with liposomal amphotericin B for empirical antifungal therapy in patients with neutropenia and persistent fever

A double-blind trial on prophylactic voriconazole (VRC) or placebo during induction chemotherapy for acute myelogenous leukaemia (AML)

OBJECTIVES

Invasive fungal infections remain a frequent cause of morbidity and mortality in long-term neutropenic patients. The availability of tolerable broad-spectrum antifungals like voriconazole stimulated the discussion about optimal timing of antifungal therapy. We conducted a trial to analyze the efficacy and safety of voriconazole in the prevention of lung infiltrates during induction chemotherapy for acute myelogenous leukaemia (AML).

METHODS

This was a prospective, randomised, double-blind, placebo-controlled phase III trial in AML patients undergoing remission induction chemotherapy. Oral voriconazole 200 mg twice daily or placebo was administered until detection of a lung infiltrate or end of neutropenia. Primary efficacy parameter was the incidence of lung infiltrates until day 21 after initiation of chemotherapy. Secondary objectives were incidence of infections, length of stay in hospital, time to antifungal treatment, time to first fever, and drug safety.

RESULTS

A total of 25 patients were randomly assigned to receive voriconazole (N=10) or placebo (N=15). Incidence of lung infiltrates until day 21 was 0 (0%) in the voriconazole and 5 (33%) in the placebo group (P=0.06). Average length of stay in hospital was shorter in the voriconazole group (mean 31.9 days) than in the placebo group (mean 37.3 days, P=0.09). Four patients were diagnosed with hepatosplenic candidiasis until a 4 week follow-up, all in the placebo group (P=0.11). Adverse events and toxicity did not differ between the two treatment groups. The trial was stopped prematurely when another trial demonstrated reduced mortality by antifungal prophylaxis with posaconazole, thus rendering further randomisation against placebo unethical.

CONCLUSION

In AML patients undergoing induction chemotherapy, prophylactic oral voriconazole 200 mg twice daily resulted in trends towards reduced incidences of lung infiltrates and hepatosplenic candidiasis. Voriconazole was safe and well tolerated.

Recent advances and challenges in the treatment of invasive fungal infections

The frequency of invasive fungal infections (IFIs) has increased over the last decade with the rise in at-risk populations of patients. The morbidity and mortality of IFIs are high and management of these conditions is a great challenge. With the widespread adoption of antifungal prophylaxis, the epidemiology of invasive fungal pathogens has changed. Non-albicans Candida, non-fumigatus Aspergillus and moulds other than Aspergillus have become increasingly recognised causes of invasive diseases. These emerging fungi are characterised by resistance or lower susceptibility to standard antifungal agents. Invasive infections due to these previously rare fungi are therefore more difficult to treat. Recently developed antifungal agents provide the potential to improve management options and therapeutic outcomes of these infections. The availability of more potent and less toxic antifungal agents, such as second-generation triazoles and echinocandins, has led to considerable improvement in the treatment of IFIs. This article reviews the changing spectrum of invasive mycosis, the properties of recently developed antifungal agents and their role in the management of these infections.

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.

Indicaciones actuales de voriconazol en pacientes onco-hematológicos

Invasive fungal infections (IFI) are the main cause of infectious death in cancer patients, especially in hematological malignancies and hematopoietic transplant recipients. Current epidemiology is characterized by a predominance of IFI caused by molds, mainly aspergillosis, along with a emergence of hard-to-treat fungi such are Zygomicetes, Fusarium and Scedosporium. Voriconazole is a broad spectrum antifungal agent with oral and intravenous formulations, approved by the EMEA for the treatment of invasive aspergillosis, candidemia in non-neutropenic patients, IFI caused by fluconazole-resistant species of Candida as well as Scedosporium and Fusarium infections. However, its use in clinical practice is broader, as empirical antifungal treatment and as secondary prophylaxis. It should be kept in mind the possibility of breakthrough IFI, particularly zygomycosis, in patients treated with voriconazole for long periods.

Improved outcomes associated with advances in therapy for invasive fungal infections in immunocompromised hosts

Invasive fungal infections cause substantial morbidity and mortality in immunocompromised hosts. The response rate to therapy, in particular for invasive aspergillosis and invasive mould infections, has been poor. Recently a number of techniques to facilitate early diagnosis of these infections, in parallel with the development of a number of antifungals with increased potency and lower toxicity, have raised optimism that outcomes for invasive fungal infection can be improved upon. The availability of lipid formulations of amphotericin B, azoles with extended spectrum against filamentous fungi and the development of a new class of antifungal agents, the echinocandins, presents the clinician with a range of therapeutic choices. Recent clinical trials have provided important insights into how these agents should be used. In particular, voriconazole has demonstrated superior efficacy to amphotericin B in the management of invasive aspergillosis, posaconazole has been shown to have significant efficacy in the prophylaxis of invasive fungal infection in high-risk individuals and a role in salvage therapy of invasive aspergillosis, caspofungin has demonstrated efficacy in salvage therapy of invasive aspergillosis, and each of the echinocandins show activity without significant toxicity in invasive candidiasis. Nevertheless, many therapeutic areas of uncertainty remain, including the role of combination therapy, and will provide the focus for future studies.

Fulminant mulch pneumonitis: an emergency presentation of chronic granulomatous disease

BACKGROUND

Chronic granulomatous disease (CGD) is associated with multiple and recurrent infections. In patients with CGD, invasive pulmonary infection with Aspergillus species remains the greatest cause of mortality and is typically insidious in onset. Acute fulminant presentations of fungal pneumonia are catastrophic.

METHODS

Case records, radiograph findings, and microbiologic examination findings of patients with CGD who had acute presentations of dyspnea and diffuse pulmonary infiltrates caused by invasive fungal infection were reviewed and excerpted onto a standard format.

RESULTS

From 1991 through 2004, 9 patients who either were known to have CGD or who received a subsequent diagnosis of CGD presented with fever and new onset dyspnea. Eight patients were hypoxic at presentation; bilateral pulmonary infiltrates were noted at presentation in 6 patients and developed within 2 days after initial symptoms in 2 patients. All patients received diagnoses of invasive filamentous fungi; 4 patients had specimens that also grew Streptomyces species on culture. All patients had been exposed to aerosolized mulch or organic material 1-10 days prior to the onset of symptoms. Cases did not occur in the winter. Five patients died. Two patients, 14 years of age and 23 years of age, who had no antecedent history of recognized immunodeficiency, were found to have p47(phox)-deficient CGD.

CONCLUSIONS

Acute fulminant invasive fungal pneumonia in the absence of exogenous immunosuppression is a medical emergency that is highly associated with CGD. Correct diagnosis has important implications for immediate therapy, genetic counseling, and subsequent prophylaxis.

Fungal infections in bone marrow transplant recipients

Invasive fungal infections (IFIs) can cause significant morbidity and mortality in patients after haematopoietic stem cell transplantation. The two most notorious pathogenic fungal species in this group of patients are Candida and Aspergillus. Risk factors for IFIs include: prolonged neutropaenia; fungal overgrowth and conditioning regiment-related mucositis; graft versus host disease; and steroid therapy. Clinical manifestations can be protean, and radiological changes are frequently nonspecific. Diagnostic methods include culture- and nonculture-based techniques. Some experts recommend IFI prophylaxis in the high-risk groups, such as patients with severe graft versus host disease who require prolonged immunosuppressive therapy or patients with a previous history of aspergillosis. Treatment options include therapy with azoles, including the newer agent voriconazole, amphotericin and caspofungin.

Recent advances in antifungal chemotherapy

For over 50 years, amphotericin B deoxycholate (AmBD) has been the 'gold standard' in antifungal chemotherapy, despite its frequent toxicities. However, improved treatment options for invasive fungal infections (IFIs) have been developed during the last 15 years. Newer antifungal agents, including less toxic lipid preparations of AmBD, triazoles and the echinocandins, have been added to our armamentarium against IFIs. Some of these newer drugs can now replace AmBD as primary therapy (e.g. caspofungin for candidiasis, voriconazole for aspergillosis), whilst others offer new therapeutic options for difficult-to-treat IFIs (e.g. posaconazole for zygomycosis, fusariosis and chromoblastomycosis). It is interesting that extended use of newer antifungals such as fluconazole, despite decreasing the mortality attributed to candidiasis, resulted in selection of species resistant to several antifungals (Candida krusei, Candida glabrata); whilst several publications suggest that prolonged use of voriconazole may expose severely immunocompromised patients to the risk of zygomycosis (breakthrough). On the other hand, the differences in the mode of action of newer antifungals such as echinocandins raise the question whether combination antifungal therapy is more effective than monotherapy. Finally, the availability of an oral formulation with excellent biosafety of several newer antifungals (e.g. posaconazole) makes them candidates for prophylactic or prolonged maintenance therapy.

Antifungal prophylaxis in chemotherapy-associated neutropenia: a retrospective, observational study

Background

In August 2002, the antifungal prophylaxis algorithm for neutropenic hematology/oncology (NHO) patients at the Medical Center was changed from conventional amphotericin (AMB) to an azole (AZ) based regimen (fluconazole [FLU] in low-risk and voriconazole [VOR] in high-risk patients). The aim of our study was to compare outcomes associated with the two regimens, including breakthrough fungal infection, adverse drug events, and costs.

Methods

Adult, non-febrile, NHO patients who received prophylactic AMB from 8/01/01-7/30/02 or AZ from 8/01/02-7/30/03 were retrospectively evaluated.

Results

A total of 370 patients (AMB: n = 181; AZ: n = 216) associated with 580 hospitalizations (AMB: n = 259; AZ: n = 321) were included. The incidence of probable/definite breakthrough Aspergillus infections was similar among regimens (AMB: 1.9% vs AZ: 0.6%; p=0.19). A greater incidence of mild/moderate (24.7% vs. 5.3%; p < 0.0001) and severe renal dysfunction (13.5% vs. 4.4%; p < 0.0012) was observed with AMB. In contrast, patients treated with VOR were found to have an increased rate of severe hepatic toxicity (32.5%) compared with patients treated with either AMB (22.6%) or FLU (21.4%) (p = 0.05). While the AZ period was associated with a >$9,000 increase in mean total costs/hospitalization, the mean acquisition cost associated with AZ was only $947/hospitalization more than AMB.

Conclusion

While an AZ-based regimen is associated with increased cost, the reduced rate of nephrotoxicity and availability of oral dosage forms, suggests that azoles be used preferentially over AMB. However, an increased rate of severe hepatic toxicity may be associated with VOR.

Institutional Experience with Voriconazole Compared with Liposomal Amphotericin B as Empiric Therapy for Febrile Neutropenia

STUDY OBJECTIVE

To assess the effectiveness, safety, and cost of empiric treatment of febrile neutropenia before and after implementing an algorithm in which voriconazole was substituted for liposomal amphotericin B (L-AmB).

DESIGN

Retrospective cohort analysis.

SETTING

An 850-bed tertiary care hospital, which is also a referral site for patients with acute leukemia.

PATIENTS

Fifty-five adult patients who started empiric antifungal therapy for febrile neutropenia between January 1, 2002, and December 31, 2003, encompassing 58 treatment episodes (defined as a hospitalization during which empiric antifungal therapy was administered).

MEASUREMENTS AND MAIN RESULTS

Medical charts, including patients' pharmacy and laboratory data, were reviewed. Twenty-six and 32 episodes of L-AmB and voriconazole use, respectively, were identified. No significant differences between the L-AmB and voriconazole groups were noted at baseline. Rates of fever resolution (54% vs 59%, p=0.791) and breakthrough invasive fungal infections (11% vs 12%, p>0.999) were similar for the L-AmB and voriconazole episodes. Premature drug discontinuation due to the prescriber's perceived lack of efficacy occurred most frequently in the voriconazole group (25% vs 8%, p=0.160). Survival was significantly higher in the voriconazole than in the L-AmB group (100% vs 77%, p=0.006). Adverse effects that were significantly more common in the L-AmB group than in the voriconazole group were elevated serum creatinine levels (27% vs 3%, p=0.017) and electrolyte disturbances (19% vs 0%, p=0.014). Adverse effects reported more frequently in the voriconazole group than in the L-AmB group were visual disturbances (9% vs 0%, p=0.245) and elevated hepatic enzyme levels (9% vs 8%, p>0.999). Mean drug expenditures/episode for initial empiric antifungal therapy were lower for voriconazole than for L-AmB ($1593 vs $4144, or $153 vs $380/day).

CONCLUSION

Our institution's algorithm incorporating voriconazole into the empiric management of febrile neutropenia was associated with effectiveness outcomes comparable to those observed with L-AmB as well as a lower frequency of adverse effects and overall expenditures for antifungal drugs.

Breakthrough fungal infections after allogeneic hematopoietic stem cell transplantation in patients on prophylactic voriconazole

Seventy-one allograft recipients receiving voriconazole, in whom complete clinical, microbiologic and pharmacokinetic data were available, were studied to determine the efficacy of voriconazole in preventing fungal infections. The length of voriconazole therapy was 6-956 days (median 133). The total number of patient-days on voriconazole was 13 805 ( approximately 38 years). A total of 10 fungal infections were seen in patients on voriconazole (18% actuarial probability at 1 year): Candida glabrata (n=5), Candida krusei (n=1), Cunninghamella (n=1), Rhizopus (n=2) and Mucor (n=1). Two of the four zygomycosis cases were preceded by short durations of voriconazole therapy, but prolonged itraconazole prophylaxis. The plasma steady-state trough voriconazole levels around the time the infection occurred were <0.2, <0.2, 0.33, 0.55, 0.63 and 1.78 microg/ml in the six candidiasis cases. Excluding the four zygomycosis cases, all the six candidiasis cases were seen among the 43 patients with voriconazole levels of < or =2 microg/ml and none among the 24 with levels of >2 microg/ml (P=0.061). We conclude that voriconazole is effective at preventing aspergillosis. However, breakthrough zygomycosis is seen in a small proportion of patients. The role of therapeutic voriconazole monitoring with dose adjustment to avoid breakthrough infections with fungi that are otherwise susceptible to the drug needs to be explored prospectively.

Presumptive treatment strategy for aspergillosis in allogeneic haematopoietic stem cell transplant recipients

BACKGROUND

The onset of invasive aspergillosis (IA) after allogeneic haematopoietic stem cell transplantation (HSCT) is bimodal. However, IA early after HSCT has become less frequent due to the shortened neutropenic period, and the clinical significance of empirical treatment for aspergillosis based on persistent febrile neutropenia (FN) became less clear. Therefore, we started a presumptive treatment strategy, in which anti-Aspergillus agents were started when patients developed positive serum test and/or infiltrates or nodules on X-ray or CT-scan associated with persistent FN, in 2002.

METHODS

We retrospectively reviewed the records of 114 adult patients who underwent allogeneic HSCT between September 2002 and December 2005 in high-efficiency particulate air-filtered clean rooms. Fluconazole was given as anti-Candida prophylaxis. The primary endpoint was the development of early IA, which was defined as probable or proven IA according to the EORTC/MSG criteria that developed between the day of HSCT and 7 days after engraftment.

RESULTS

Among 73 patients who experienced persistent FN for 7 days or longer, anti-Aspergillus agents were empirically started in 13 patients at the discretion of attending physicians, whereas 60 patients actually followed presumptive treatment strategy. Only 4 of 60 patients received anti-Aspergillus agents. Two patients in the presumptive group developed early IA, but were successfully treated with anti-Aspergillus agents started after the diagnosis of IA.

CONCLUSIONS

These findings suggested the feasibility of a presumptive treatment strategy for aspergillosis in HSCT recipients. A randomized controlled trial is warranted to compare empirical and presumptive anti-Aspergillus strategy in allogeneic HSCT recipients.

Injectable paromomycin for Visceral leishmaniasis in India

BACKGROUND

Visceral leishmaniasis (kala-azar) affects large, rural, resource-poor populations in South Asia, Africa, and Brazil. Safe, effective, and affordable new therapies are needed. We conducted a randomized, controlled, phase 3 open-label study comparing paromomycin, an aminoglycoside, with amphotericin B, the present standard of care in Bihar, India.

METHODS

In four treatment centers for visceral leishmaniasis, 667 patients between 5 and 55 years of age who were negative for the human immunodeficiency virus and had parasitologically confirmed visceral leishmaniasis were randomly assigned in a 3:1 ratio to receive paromomycin (502 patients) at a dose of 11 mg per kilogram of body weight intramuscularly daily for 21 days or amphotericin B (165 patients) at a dose of 1 mg per kilogram intravenously every other day for 30 days. Final cure was assessed 6 months after the end of treatment; safety assessments included daily clinical evaluations and weekly laboratory and audiometric evaluations. Noninferiority testing was used to compare 6-month cure rates, with a chosen margin of noninferiority of 10 percentage points.

RESULTS

Paromomycin was shown to be noninferior to amphotericin B (final cure rate, 94.6% vs. 98.8%; difference, 4.2 percentage points; upper bound of the 97.5% confidence interval, 6.9; P<0.001). Mortality rates in the two groups were less than 1%. Adverse events, which were more common among patients receiving paromomycin than among those receiving amphotericin B (6% vs. 2%, P=0.02), included transient elevation of aspartate aminotransferase levels (>3 times the upper limit of the normal range); transient reversible ototoxicity (2% vs. 0, P=0.20); and injection-site pain (55% vs. 0, P<0.001); and in patients receiving amphotericin B, as compared with those receiving paromomycin, nephrotoxicity (4% vs. 0, P<0.001), fevers (57% vs. 3%), rigors (24% vs. 0, P<0.001), and vomiting (10% vs. <1%, P<0.001).

CONCLUSIONS

Paromomycin was shown to be noninferior to amphotericin B for the treatment of visceral leishmaniasis in India. (ClinicalTrials.gov number, NCT00216346.)

Empirical antimicrobial treatment for chemotherapy-induced febrile neutropenia

Febrile neutropenia in immunocompromised hosts is associated with a high mortality. Empirical treatment in such cases is instituted to cover the common pathogens. Generally, combination antibiotic treatment is used early in the febrile neutropenia phase. Recent studies demonstrate that monotherapy with certain beta-lactam antibiotics can be equally effective. Glycopeptide antibiotics are used in the absence of an adequate response to the initial antibiotics. Empirical antifungal therapy may be given if fever does not settle in 72-96 h despite antibiotics. Newer antifungal agents have increased the available options for initial antifungal agents though more data are needed before any conclusive recommendation can be made. Recent changes in the epidemiology of multiresistant organisms necessitate local microbiological input into empiric policies with increasing need to consider cover for methicillin-resistant Staphylococcus aureus, glycopeptide intermediate S. aureus, vancomycin-resistant S. aureus, vancomycin-resistant enterococci, Gram-negative bacilli that produce extended-spectrum beta-lactamases, Stenotrophomonas maltophilia, and multi-resistant Acinetobacter baumanii.

Liposomal amphotericin B as initial therapy for invasive mold infection: a randomized trial comparing a high-loading dose regimen with standard dosing (AmBiLoad trial)

BACKGROUND

Treatment of invasive mold infection in immunocompromised patients remains challenging. Voriconazole has been shown to have efficacy and survival benefits over amphotericin B deoxycholate, but its utility is limited by drug interactions. Liposomal amphotericin B achieves maximum plasma levels at a dosage of 10 mg/kg per day, but clinical efficacy data for higher doses are lacking.

METHODS

In a double-blind trial, patients with proven or probable invasive mold infection were randomized to receive liposomal amphotericin B at either 3 or 10 mg/kg per day for 14 days, followed by 3 mg/kg per day. The primary end point was favorable (i.e., complete or partial) response at the end of study drug treatment. Survival and safety outcomes were also evaluated.

RESULTS

Of 201 patients with confirmed invasive mold infection, 107 received the 3-mg/kg daily dose, and 94 received the 10-mg/kg daily dose. Invasive aspergillosis accounted for 97% of cases. Hematological malignancies were present in 93% of patients, and 73% of patients were neutropenic at baseline. A favorable response was achieved in 50% and 46% of patients in the 3- and 10-mg/kg groups, respectively (difference, 4%; 95% confidence interval, -10% to 18%; P>.05); the respective survival rates at 12 weeks were 72% and 59% (difference, 13%; 95% confidence interval, -0.2% to 26%; P>.05). Significantly higher rates of nephrotoxicity and hypokalemia were seen in the high-dose group.

CONCLUSIONS

In highly immunocompromised patients, the effectiveness of 3 mg/kg of liposomal amphotericin B per day as first-line therapy for invasive aspergillosis is demonstrated, with a response rate of 50% and a 12-week survival rate of 72%. The regimen of 10 mg/kg per day demonstrated no additional benefit and higher rates of nephrotoxicity.

A cost-effectiveness analysis of caspofungin vs. liposomal amphotericin B for treatment of suspected fungal infections in the UK

Objective:

To evaluate the cost-effectiveness of caspofungin vs. liposomal amphotericin B in the treatment of suspected fungal infections in the UK.

Methods:

The cost-effectiveness of caspofungin vs. liposomal amphotericin B was evaluated using a decision-tree model. The decision tree was populated using both data and clinical definitions from published clinical studies. Model outcomes included success in terms of resolution of fever, baseline infection, absence of breakthrough infection, survival and quality adjusted life years (QALYs) saved. Discontinuation due to nephrotoxicity or other adverse events were included in the model. Efficacy and safety data were based on additional analyses of a randomised, double blind, multinational trial of caspofungin compared with liposomal amphotericin B. Information on life expectancy, quality of life, medical resource consumption and costs were obtained from peer-reviewed published data.

Results:

The caspofungin mean total treatment cost was £9762 (95% uncertainty interval 6955–12 577), which was £2033 (−2489; 6779) less than liposomal amphotericin B. Treatment with caspofungin resulted in 0.40 (−0.12; 0.94) additional QALYs saved in comparison with liposomal amphotericin B. Probabilistic sensitivity analysis found a 95% probability of the incremental cost per QALY saved being within the generally accepted threshold for cost-effectiveness (£30 000). Additional analyses with varying dose of caspofungin and liposomal amphotericin B confirmed these findings.

Conclusion:

Given the underlying assumptions, caspofungin is cost-effective compared with liposomal amphotericin B in the treatment of suspected fungal infections in the UK.

Antifungal therapy in children with invasive fungal infections: a systematic review

Invasive fungal infections are associated with significant morbidity and mortality. Differences between children and adults are reported, yet few trials of antifungal agents have been performed in pediatric populations. We performed a systematic review of the literature to guide appropriate pediatric treatment recommendations. From available trials that compared antifungal agents in either prolonged febrile neutropenia or invasive candidal or Aspergillus infection, no clear difference in treatment efficacy was demonstrated, although few trials were adequately powered. Differing antifungal pharmacokinetics between children and adults were demonstrated, requiring dose modification. Significant differences in toxicity, particularly nephrotoxicity, were identified between classes of antifungal agents. Therapy needs to be guided by the pathogen or suspected pathogens, the degree of immunosuppression, comorbidities (particularly renal dysfunction), concurrent nephrotoxins, and the expected length of therapy.

Safety and efficacy of itraconazole compared to amphotericin B as empirical antifungal therapy for neutropenic fever in patients with haematological malignancy

BACKGROUND

Safety, tolerability and efficacy of itraconazole and amphotericin B (AMB) were compared for empirical antifungal treatment of febrile neutropenic cancer patients.

PATIENTS AND METHODS

In an open, randomised study, 162 patients with at least 72 h of antimicrobial treatment received either intravenous followed by oral itraconazole suspension or intravenous AMB for a maximum of 28 days. Permanent discontinuation of study medication due to any adverse event was the primary safety parameter. Efficacy parameters included response and success rate for both treatment groups.

RESULTS

Significantly fewer itraconazole patients discontinued treatment due to any adverse event (22.2 vs. 56.8% AMB; p < 0.0001). The main reason for discontinuation was a rise in serum creatinine (1.2% itraconazole vs. 23.5% AMB). Renal toxicity was significantly higher and more drug-related adverse events occurred in the AMB group. Intention-to-treat (ITT) analysis showed favourable efficacy for itraconazole: response and success rate were both significantly higher than for AMB (61.7 vs. 42% and 70.4 vs. 49.3%, both p < 0.0001). Treatment failure was markedly reduced in itraconazole patients (25.9 vs. 43.2%), largely due to the better tolerability.

CONCLUSIONS

Itraconazole was tolerated significantly better than conventional AMB and also showed advantages regarding efficacy. This study confirms the role of itraconazole as a useful and safe agent in empirical antifungal therapy of febrile neutropenic cancer patients.

A new in-vitro kinetic model to study the pharmacodynamics of antifungal agents: inhibition of the fungicidal activity of amphotericin B against Candida albicans by voriconazole

The aim of this study was to develop and validate a new in-vitro kinetic model for the combination of two drugs with different half-lives, and to use this model for the study of the pharmacodynamic effects of amphotericin B and voriconazole, alone or in combination, against a strain of Candida albicans. Bolus doses of voriconazole and amphotericin B were administered to a starting inoculum of C. albicans. Antifungal-containing medium was eliminated and replaced by fresh medium using a peristaltic pump, with the flow-rate adjusted to obtain the desired half-life of the drug with the shorter half-life. A computer-controlled dosing pump compensated for the agent with the longer half-life. Voriconazole and amphotericin B half-lives were set to 6 and 24 h, respectively. Pharmacokinetic parameters were close to target values when both single doses and sequential doses were simulated. Voriconazole and amphotericin B administered alone demonstrated fungistatic and fungicidal activity, respectively. Simultaneous administration resulted in fungicidal activity, whereas pre-exposure of C. albicans to voriconazole, followed by amphotericin at 8 and 32 h, resulted in fungistatic activity similar to that observed with voriconazole alone. Using this model, which allowed a combination of antifungal agents with different half-lives, it was possible to demonstrate an antagonistic effect of voriconazole on the fungicidal activity of amphotericin B. The characteristics and clinical relevance of this interaction require further investigation.

Pharmacoeconomic analysis of caspofungin versus liposomal amphotericin B as empirical antifungal therapy for neutropenic fever

PURPOSE

An analysis was conducted that evaluated and compared the cost differences between caspofungin and liposomal amphotericin B when the medications were used as empirical antifungal therapy for persistent fever during neutropenia.

METHODS

Rates of drug use and impaired renal function (IRF) were based on data from published studies. IRF was defined as a doubling of the serum creatinine level or, if the creatinine level was elevated at enrollment, an increase of at least 1 mg/dL. The estimates of the costs for drug acquisition and treating IRF were derived using published data and applied to compare caspofungin with liposomal amphotericin B. Sensitivity analyses were performed by varying the IRF and relative acquisition costs to assess the effect of these factors on the cost differences.

RESULTS

The acquisition costs per patient were 6942 dollars for liposomal amphotericin B and 3996 dollars for caspofungin. The estimated cost per patient from IRF was 3173 dollars for liposomal amphotericin B and 793 dollars for caspofungin. Combining drug acquisition and IRF costs, the overall treatment cost per patient for caspofungin was 5326 dollars less than for liposomal amphotericin B. In sensitivity analyses of drug costs, the price of liposomal amphotericin B would have to be 23.95 dollars per vial for the overall treatment costs to be equal.

CONCLUSION

Comparison of cost estimates derived from published data revealed that a combined estimate of acquisition costs and costs related to the treatment of IRF was lower for caspofungin than for liposomal amphotericin B for empirically treating patients with neutropenic fever.

Pulmonary complications of haematopoietic cell transplantation in children

Paediatric haematopoietic cell transplantation has experienced significant advances in the last few decades. However, pulmonary complications are an important limitation to the efficacy of this intervention, contributing to post-transplantation morbidity and mortality. Such complications persist even in experienced centres and occur in adult and paediatric recipients. This review identifies the paediatric pulmonary complications that are commonly seen following haematopoietic cell transplantation and addresses both infectious and non-infectious aetiologies and their clinical manifestations, evaluation, and potential therapy. Ultimately, improvement in outcomes will require attention to immunosuppression as well as traditional diagnostic procedures and treatment. This article aims to review the current state of pulmonary complications post-transplantation, to examine the impact of our recent advances and changes in treatment, and to identify potential future therapies and hypothesise what role these might have on long-term survival.

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.

X-linked severe combined immunodeficiency (X-SCID) with high blood levels of immunoglobulins and Aspergillus pneumonia successfully treated with micafangin followed by unrelated cord blood stem cell transplantation

In this report, we describe a patient with X-linked severe combined immunodeficiency (X-SCID) who had high serum IgG, IgA, and IgM levels. The boy did well until 6 months of age, when he developed interstitial pneumonia caused by Aspergillus species, with a white cell count of 12,840/microL and only 10% lymphocytes; IgG, 991 mg/dL; IgA, 65 mg/dL; IgM, 472 mg/dL. Cell markers showed only 6.3% CD3, 2.1% CD4, 0.7% CD8, but 92% CD19 and 0.1% CD16+CD56+ (NK cells). A mutation was detected within exon 2 (C196 A-->C), leading to the substitution of proline for glutamine, which has not been reported previously. The boy was successfully treated with the new antifungal drug, micafangin (MCFG), at 5 mg/kg/day for 89 days. After resolution of the pneumonia, the patient underwent successful hematopoietic stem cell transplantation with completely matched unrelated female cord blood. The CD34 stem cell dose was 3.4 x 10(4) cells/kg. In conclusion, MCFG can be a first line agent for Aspergillus pneumonia in immunocompromised hosts.

Prevention and Early Treatment of Invasive Fungal Infection in Patients with Cancer and Neutropenia and in Stem Cell Transplant Recipients in the Era of Newer Broad-Spectrum Antifungal Agents and Diagnostic Adjuncts

Invasive fungal infection (IFI) is a leading cause of infection-related mortality among patients with cancer and prolonged neutropenia and among allogeneic hematopoietic stem cell transplant recipients with graft-versus-host disease. Invasive candidiasis was the principal IFI in the period predating fluconazole prophylaxis, whereas today, invasive aspergillosis and other mold infections cause the majority of deaths from fungal infection in this patient population. The changing epidemiology of IFI, in addition to advances made in antifungal therapeutics and early diagnosis of IFI, warrant a reevaluation of earlier strategies aimed at prevention and early treatment of IFI that were developed several years ago. Here, we propose that persistent neutropenic fever is nonspecific for an IFI and should not be used as the sole criterion for empirical modification in the antifungal regimen in a patient receiving mold-active prophylaxis. We explore the potential benefits and gaps in knowledge associated with employing chest CT scans and laboratory markers as diagnostic adjuncts for IFI. Finally, we discuss the implications of newer antifungal agents and diagnostic adjuncts in the design of future clinical trials to evaluate prophylaxis and early prevention strategies.

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.

Breakthrough invasive pulmonary aspergillosis despite empirical voriconazole therapy for febrile neutropenia: case report and review of the literature

We report the development of invasive pulmonary aspergillosis in a patient treated for acute myeloid leukaemia during empirical voriconazole therapy for febrile neutropenia. The patient failed to respond to the institution of salvage combination therapy with amphotericin B and voriconazole, but survived after adjunctive surgical resection.

Efficacy and safety of micafungin in febrile neutropenic patients treated for hematological malignancies

OBJECTIVE

The purpose of this study was to prospectively evaluate the efficacy and safety of micafungin (MCFG) in empirical therapy for febrile neutropenic patients for whom antibiotic therapy was not effective for hematological malignancies.

PATIENTS AND METHODS

Twenty-three hematological patients aged 27-82 years with febrile neutropenia for whom antibiotic therapy was not effective were enrolled in this study and responses to treatment were evaluated.

RESULTS

Treatment success rate was 73.9%. Treatment success rates by primary diagnosis were 77.8% in patients with AML, 50.0% in patients with NHL and 87.5% in patients with other diseases. Moreover, MCFG at a dose of 100 mg or more have a tendency to be effective. One or more adverse events occurred in five (27.7%) of the patients during the study. All of these adverse events were below grade 2 toxicity.

CONCLUSIONS

Although the number of patients studied was limited, MCFG as a monotherapy seems to be effective and safe as an empirical therapy in patients with febrile neutropenia. However, further investigation using large-scale studies is needed. This study demonstrated the clinical efficacy and safety of MCFG in patients with febrile neutropenia and with hematological malignancies.

Fluconazole for empiric antifungal therapy in cancer patients with fever and neutropenia

Background

Several clinical trials have demonstrated the efficacy of fluconazole as empiric antifungal therapy in cancer patients with fever and neutropenia. Our objective was to assess the frequency and resource utilization associated with treatment failure in cancer patients given empiric fluconazole antifungal therapy in routine inpatient care.

Methods

We performed a retrospective cohort study of cancer patients treated with oral or intravenous fluconazole between 7/97 and 6/01 in a tertiary care hospital. The final study cohort included cancer patients with neutropenia (an absolute neutrophil count below 500 cells/mm³) and fever (a temperature above 38°C or 100.4°F), who were receiving at least 96 hours of parenteral antibacterial therapy prior to initiating fluconazole. Patients' responses to empiric therapy were assessed by reviewing patient charts.

Results

Among 103 cancer admissions with fever and neutropenia, treatment failure after initiating empiric fluconazole antifungal therapy occurred in 41% (95% confidence interval (CI) 31% – 50%) of admissions. Patients with a diagnosis of hematological malignancy had increased risk of treatment failure (OR = 4.6, 95% CI 1.5 – 14.8). When treatment failure occurred the mean adjusted increases in length of stay and total costs were 7.4 days (95% CI 3.3 – 11.5) and $18,925 (95% CI 3,289 – 34,563), respectively.

Conclusion

Treatment failure occurred in more than one-third of neutropenic cancer patients on fluconazole as empiric antifungal treatment for fever in routine clinical treatment. The increase in costs when treatment failure occurs is substantial.

Comparative pharmacokinetics of voriconazole administered orally as either crushed or whole tablets

Voriconazole is a triazole antifungal agent used to treat serious, invasive fungal infections including aspergillosis and candidemia. Limitations with existing formulations of voriconazole including restricted utility in patients with renal dysfunction (intravenous preparation) and the unavailability of an oral suspension in some countries make the administration of crushed tablets desirable in many clinical scenarios. However, concerns that this approach may alter the systemic absorption of voriconazole exist. Therefore, an open-label, randomized, two-way crossover comparative pharmacokinetic (PK) study using healthy volunteers was performed to compare these methods of tablet administration. In a random sequence, subjects received voriconazole tablets either crushed or whole. The voriconazole dose was 400 mg every 12 h for 1 day orally followed by 200 mg every 12 h orally for 5.5 days. Study periods were separated by 7 days. PK parameters were determined by the noncompartmental method. An equivalence approach with no-effect boundaries of 80 to 125% was used to assess bioequivalence. Twenty healthy subjects (10 males; aged 20 to 43 years) were enrolled in and completed the study. The adjusted mean areas under the plasma concentration-time curve from 0 to tau, where tau equals 12 h, for the crushed and whole tablet groups were 9,793 and 11,164 ng . h/ml, respectively (ratio, 87.72; 90% confidence interval [CI], 80.97, 95.04). The ratio of the maximum concentration of drug in serum for the crushed tablet versus whole tablet arms was 94.94 (90% CI, 86.51, 104.22). The only difference noted between groups was a slightly faster time to maximum concentration of drug in serum when subjects received crushed tablets, 0.5 h versus 1.5 h (90% CI, -0.75, -0.25). Treatment-related adverse events occurred in 12 subjects receiving whole tablets and 9 subjects receiving crushed tablets; all were mild. The administration of crushed voriconazole tablets is bioequivalent to whole-tablet administration.

Voriconazole: a broad spectrum triazole for the treatment of serious and invasive fungal infections

For many years, serious systemic fungal infections have been treated with amphotericin B or narrow-spectrum azole antifungals. These treatments have been effective in many patients, but are associated with tolerability or pharmacokinetic concerns, or suboptimal antifungal activity in some patient groups. Voriconazole is a second-generation triazole with an extended spectrum of activity offering the potential to treat life-threatening fungal infections. The drug is available for intravenous or oral administration and has been shown to be effective in invasive aspergillosis, fluconazole-susceptible and -resistant candidiasis, and infections caused by various other fungal pathogens, including some formerly refractory organisms. Voriconazole is generally well tolerated with transient visual disturbances, liver enzyme abnormalities and skin rashes being the most common adverse events reported, but these rarely lead to treatment discontinuation.

Voriconazole prophylaxis in lung transplant recipients

Lung transplant recipients have one of the highest rates of invasive aspergillosis (IA) in solid organ transplantation. We used a single center, nonrandomized, retrospective, sequential study design to evaluate fungal infection rates in lung transplant recipients who were managed with either universal prophylaxis with voriconazole (n = 65) or targeted prophylaxis (n = 30) with itraconazole +/- inhaled amphotericin in patients at high risk (pre- or posttransplant Aspergillus colonization [except Aspergillus niger]). The rate of IA at 1 year was better in lung transplant recipients receiving voriconazole prophylaxis as compared to the cohort managed with targeted prophylaxis (1.5% vs. 23%; p = 0.001). Twenty-nine percent of cases in the targeted prophylaxis group were in patients colonized with A. niger who did not receive itraconazole. A three-fold or higher increase in liver enzymes was noted in 37-60% of patients receiving voriconazole prophylaxis as compared to 15-41% of patients in the targeted prophylaxis cohort. Fourteen percent in the voriconazole group as compared to 8% in the targeted prophylaxis group had to discontinue antifungal medications due to side effects. Voriconazole prophylaxis can be used in preventing IA in lung transplant recipients. Regular monitoring of liver enzymes and serum concentrations of calcineurin inhibitors are required to avoid hepatotoxicity and nephrotoxicity.

Pharmacokinetic/pharmacodynamic profile of voriconazole

Voriconazole is the first available second-generation triazole with potent activity against a broad spectrum of clinically significant fungal pathogens, including Aspergillus,Candida, Cryptococcus neoformans, and some less common moulds. Voriconazole is rapidly absorbed within 2 hours after oral administration and the oral bioavailability is over 90%, thus allowing switching between oral and intravenous formulations when clinically appropriate. Voriconazole shows nonlinear pharmacokinetics due to its capacity-limited elimination, and its pharmacokinetics are therefore dependent upon the administered dose. With increasing dose, voriconazole shows a superproportional increase in area under the plasma concentration-time curve (AUC). In doses used in children (age < 12 years) voriconazole pharmacokinetics appear to be linear. Steady-state plasma concentrations are reached approximately 5 days after both intravenous and oral administration; however, steady state is reached within 24 hours with voriconazole administered as an intravenous loading dose. The volume of distribution of voriconazole is 2-4.6 L/kg, suggesting extensive distribution into extracellular and intracellular compartments. Voriconazole was measured in tissue samples of brain, liver, kidney, heart, lung as well as cerebrospinal fluid. The plasma protein binding is about 60% and independent of dose or plasma concentrations. Clearance is hepatic via N-oxidation by the hepatic cytochrome P450 (CYP) isoenzymes, CYP2C19, CYP2C9 and CYP3A4. The elimination half-life of voriconazole is approximately 6 hours, and approximately 80% of the total dose is recovered in the urine, almost completely as metabolites. As with other azole drugs, the potential for drug interactions is considerable. Voriconazole shows time-dependent fungistatic activity against Candida species and time-dependent slow fungicidal activity against Aspergillus species. A short post-antifungal effect of voriconazole is evident only for Aspergillus species. The predictive pharmacokinetic/pharmacodynamic parameter for voriconazole treatment efficacy in Candida infections is the free drug AUC from 0 to 24 hour : minimum inhibitory concentration ratio.