Fluconazole therapy for chronic disseminated candidiasis in patients with leukemia and prior amphotericin B therapy

New drugs and novel targets for treatment of invasive fungal infections in patients with cancer

Invasive fungal infections have emerged as important causes of morbidity and mortality in profoundly immunocompromised patients with cancer. Current treatment strategies for these infections are limited by antifungal resistance, toxicity, drug interactions, and expense. In order to overcome these limitations, new antifungal compounds are being developed, which may improve our therapeutic armamentarium for prevention and treatment of invasive mycoses in high-risk patients with neoplastic diseases.

Immunorestitution disease involving the innate and adaptive response

Immunorestitution disease (IRD) is defined as an acute symptomatic or paradoxical deterioration of a (presumably) preexisting infection that is temporally related to the recovery of the immune system. We report the temporal sequence of events that led to IRD caused by Pneumocystis carinii and Aspergillus terreus in 2 human immunodeficiency virus (HIV)-negative patients soon after the recovery of adaptive and innate immunity, respectively, and we review episodes noted in the English-language literature that fit the definition of IRD (109 episodes in 107 patients). The median time from the recovery of neutrophil counts or termination of steroid therapy to the development of IRD was 8 days in cases of pulmonary aspergillosis (23 episodes) and hepatosplenic candidiasis (8) and 21 days for viral diseases such as hepatitis B (24) and viral pneumonitis (6). For IRD due to mycobacteriosis (27 episodes) and cryptococcosis (4) in HIV-positive patients, the median interval between the initiation of highly active antiretroviral therapy (HAART) and the onset of IRD was 11 days; for viral infections, including those due to cytomegalovirus (14), hepatitis B virus (1), and hepatitis C virus (2), the median interval was 42 days. As an emerging clinical entity, IRD merits further study to optimize treatment of immunosuppressed patients.

Practice guidelines for the treatment of candidiasis. Infectious Diseases Society of America

Infections due to Candida species are the most common of the fungal infections. Candida species produce a broad range of infections, ranging from nonlife-threatening mucocutaneous illnesses to invasive process that may involve virtually any organ. Such a broad range of infections requires an equally broad range of diagnostic and therapeutic strategies. This document summarizes current knowledge about treatment of multiple forms of candidiasis and is the guideline of the Infectious Diseases Society of America (IDSA) for the treatment of candidiasis. Throughout this document, treatment recommendations are scored according to the standard scoring scheme used in other IDSA guidelines to illustrate the strength of the underlying data. The document covers 4 major topical areas. The role of the microbiology laboratory. To a greater extent than for other fungi, treatment of candidiasis can now be guided by in vitro susceptibility testing. The guidelines review the available information supporting current testing procedures and interpretive breakpoints and place these data into clinical context. Susceptibility testing is most helpful in dealing with infection due to non-albicans species of Candida. In this setting, especially if the patient has been treated previously with an azole antifungal agent, the possibility of microbiological resistance must be considered. Treatment of invasive candidiasis. In addition to acute hematogenous candidiasis, the guidelines review strategies for treatment of 15 other forms of invasive candidiasis. Extensive data from randomized trials are really available only for therapy of acute hematogenous candidiasis in the nonneutropenic adult. Choice of therapy for other forms of candidiasis is based on case series and anecdotal reports. In general, both amphotericin B and the azoles have a role to play in treatment. Choice of therapy is guided by weighing the greater activity of amphotericin B for some non-albicans species (e.g., Candida krusei) against the lesser toxicity and ease of administration of the azole antifungal agents. Flucytosine has activity against many isolates of Candida but is not often used. Treatment of mucocutaneous candidiasis. Therapy for mucosal infections is dominated by the azole antifungal agents. These drugs may be used topically or systemically and have been proven safe and efficacious. A significant problem with mucosal disease is the propensity for a small proportion of patients to suffer repeated relapses. In some situations, the explanation for such a relapse is obvious (e.g., relapsing oropharyngeal candidiasis in an individual with advanced and uncontrolled HIV infection), but in other patients the cause is cryptic (e.g., relapsing vaginitis in a healthy woman). Rational strategies for these situations are discussed in the guidelines and must consider the possibility of induction of resistance over time. Prevention of invasive candidiasis. Prophylactic strategies are useful if the risk of a target disease is sharply elevated in a readily identified group of patients. Selected patient groups undergoing therapy that produces prolonged neutropenia (e.g., some bone-marrow transplant recipients) or who receive a solid-organ transplant (e.g., some liver transplant recipients) have a sufficient risk of invasive candidiasis to warrant prophylaxis.

Amphotericin B and its new formulations: pharmacologic characteristics, clinical efficacy, and tolerability

Amphotericin B (amB) remains the gold standard for the treatment of invasive fungal infections. However, the efficacy is limited, with response rates from 10% to 80%. Moreover, amB is toxic, especially for the kidneys. New formulations have been developed in an attempt to improve both efficacy and tolerability. In an attempt to reduce toxicity, a number of investigators have reconstituted amB in a lipid emulsion, but few data are available on efficacy in documented infections. An improvement in immediate and renal tolerance was obtained with equivalent daily dose regimens, but the therapeutic index does not appear to be improved. This approach cannot be recommended at present. Three lipid formulations have been developed and are now available in most countries: amB colloidal dispersion (ABCD), amB lipid complex (ABLC), and liposomal amB (AmBisome). The efficacy of ABCD on various fungal infections has been assessed in open trials, with a response rate of 49% in aspergillosis, 70% in candidiasis, and 67% in mucormycosis. In two randomized trials comparing ABCD with amB in invasive aspergillosis and in persistent febrile neutropenia, the response rates were equivalent. ABCD was less nephrotoxic. In contrast, immediate reactions to ABCD were as frequent and severe as with amB. These immediate effects are more frequent during the first infusions and lessen as treatment continues. The recommended dose is 3-4 mg/kg/day. ABLC appeared to be effective as rescue therapy in various types of invasive mycoses, with a response rate of 42% in aspergillosis, 67% in candidiasis, and 82% in fusariosis. Efficacy identical to that of amB was demonstrated in a comparative randomized trial involving patients with invasive candidiasis. General and renal tolerability is improved compared with amB. The recommended dose regimen is 5 mg/kg/day. Liposomal amB (AmBisome) is the only truly liposomal formulation. The response rates in preliminary trials were 66% in aspergillosis and 81% in candidiasis. Several comparative studies have confirmed that this formulation has similar or superior efficacy relative to amB in various fungal infections and also in the empirical treatment of febrile neutropenia. Renal and general tolerability is excellent. The optimal dosing remains unclear but is generally between 3 and 5 mg/kg/day. A double-blind trial comparing the tolerance of liposomal amB and ABLC demonstrated that both infusion-related events and nephrotoxicity were significantly lower for liposomal amB. In sum, the new lipid formulations of amB are effective in various invasive fungal infections. The three formulations exhibit reduced nephrotoxicity compared with conventional amB. Large-scale comparative clinical trials may clarify issues of relative efficacy in various forms of mycotic infections.

The use of fluconazole and itraconazole in the treatment of Candida albicans infections: a review

Candida albicans is responsible for most fungal infections in humans. Fluconazole is well established as a first-line management option for the treatment and prophylaxis of localized and systemic C. albicans infections. Fluconazole exhibits predictable pharmacokinetics and is effective, well tolerated and suitable for use in most patients with C. albicans infections, including children, the elderly and those with impaired immunity. Prophylactic administration of fluconazole can help to prevent fungal infections in patients receiving cytotoxic cancer therapy. The increasing use of fluconazole for the long-term prophylaxis and treatment of recurrent oral candidosis in AIDS patients has led to the emergence of C. albicans infections that are not responsive to conventional doses. Second-line therapy with a wider spectrum antifungal, such as itraconazole, should be sought if treatment with fluconazole fails. A solution formulation of itraconazole has recently been introduced to overcome the poor and variable absorption of its original capsule formulation. Efficacy and tolerability studies in HIV-positive or immunocompromised patients with C. albicans infections have shown that, although itraconazole solution is as effective as fluconazole, it is less well tolerated as first-line therapy. Itraconazole solution can be effective in AIDS patients with C. albicans infections that are non-responsive to fluconazole. No efficacy or tolerability data are available on the use of itraconazole solution in children or the elderly.

Antifungal activity of LY303366, a novel echinocandin B, in experimental disseminated candidiasis in rabbits

The safety and antifungal activity of LY303366 (LY), a new broad-spectrum semisynthetic echinocandin, were studied against disseminated candidiasis in persistently neutropenic rabbits. In vitro time-kill assays demonstrated that LY has concentration-dependent fungicidal activity. The pharmacokinetics of LY in the plasma of nonneutropenic rabbits suggested a linear relationship between dose and area under the curve (AUC). The times spent above the MIC during the experimental dosing interval of 24 h were 4 h for LY at 0.1 mg/kg of body weight/day (LY0.1), 8 h for LY at 0.25 mg/kg/day (LY0.25), 12 h for LY at 0.5 mg/kg/day (LY0.5), and 20 h for LY at 1 mg/kg/day (LY1). Antifungal therapy was administered to infected rabbits for 10 days starting 24 h after the intravenous (i.v.) inoculation of 10(3) Candida albicans blastoconidia. Study groups consisted of untreated controls (UCs) and animals treated with amphotericin B (AmB; 1 mg/kg/day i.v.), fluconazole (FLU; 10 mg/kg/day i.v.), and LY0.1, LY0.25, LY0.5, or LY1 i.v. Rabbits treated with LY0.5, LY1, AmB, and FLU had similarly significant clearance of C. albicans from the liver, spleen, kidney, lung, vena cava, and brain in comparison to that for UCs. There was a dose-dependent clearance of C. albicans from tissues in response to LY. Among rabbits treated with LY0.1 there was a significant reduction of C. albicans only in the spleen. In animals treated with LY0.25 there was a significant reduction in all tissues but the brain. By comparison, LY0.5 and LY1 cleared all tissues, including the brain, of C. albicans. These in vivo findings were consistent with the results of in vitro time-kill assays. A dose-dependent effect of altered cell wall morphology was observed among UCs and animals treated with LY0.1, and LY0.25, with a progressive transition from hyphal structure to disrupted yeast forms. Serum creatinine levels were higher and serum potassium levels were lower in AmB-treated rabbits than in UCs and LY- and FLU-treated rabbits. LY0.5 and LY1 were well tolerated, displayed predictable pharmacokinetics in plasma, and had activities comparable to those of AmB and FLU in the treatment of disseminated candidiasis in persistently neutropenic rabbits.

Nosocomial fungal infections: candidemia

Candida species are frequently encountered as part of the human commensal flora. Colonization mostly precedes candidemia and is an independent risk factor for the development of candidemia. Genotyping methods showed the similarity between colonizing and infecting strains, thus making endogenous origin likely, though exogenous sources like total parenteral nutrition also have been described. Health care workers (HCWs) play an important role in the transmission of yeasts. Candida species are frequently isolated from the hands of HCWs and can be transmitted from hands to patients. Granulocytopenia and damage of the mucosal lining resulting from intensive chemotherapy due to cancer, the increasing use of broad spectrum antibiotics, and the use of intravenous catheters are other important risk factors for the development of candidemia. Candidemia is associated with a high mortality and prolonged hospitalization. Therefore, and because of the high frequency of dissemination, all candidemias should be treated. Amphotericin B was considered the standard drug for the systemic treatment of candidemia. Fluconazole has been shown to be an effective and safe alternative in non-neutropenic patients. 5-Fluorocytosine has been used in combination with amphotericin B in the treatment of deep-seated infections. Liposomal formulations of amphotericin B and other new antifungal drugs currently are under investigation. C. albicans is the most frequently isolated Candida species, although the proportion of infections caused by non-C. albicans species is increasing. Also, there are reports of development of resistance to amphotericin B. C. lusitaniae is known for primary resistance and the development of resistance to amphotericin B. Development of resistance to fluconazole is mainly seen in AIDS patients with recurrent oropharyngeal candidiasis who receive longer courses of therapy.

Successful treatment of candidal osteomyelitis with fluconazole following failure with liposomal amphotericin B

A case of multiple relapses of Candida albicans infection of deep tissues is described. Treatment was complicated by renal impairment, but therapy with a liposomal amphotericin product failed to eradicate the third recurrence which subsequently resolved after protracted exposure to oral fluconazole.

Antifungal agents. Part II. The azoles

Before 1978, amphotericin B and flucytosine were the only drugs available for the treatment of systemic fungal infections. The imidazoles, miconazole and ketoconazole, were introduced during the next 3 years. Intravenously administered miconazole served a limited therapeutic role and is no longer available. Orally administered ketoconazole, an inexpensive, effective, and convenient option for treating mucosal candidiasis, was widely used for a decade because it was the only available oral therapy for systemic fungal infections. During the 1990s, use of ketoconazole diminished because of the release of the triazoles--fluconazole and itraconazole. Fluconazole is less toxic and has several pharmacologic advantages over ketoconazole, including penetration into the cerebrospinal fluid. In addition, it has superior efficacy against systemic candidiasis, cryptococcosis, and coccidioidomycosis. Despite a myriad of drug interactions and less favorable pharmacologic and toxicity profiles in comparison with fluconazole, itraconazole has become a valuable addition to the antifungal armamentarium. It has excellent activity against sporotrichosis and seems promising in the treatment of aspergillosis. Itraconazole has replaced ketoconazole as the therapy of choice for nonmeningeal, non-life-threatening cases of histoplasmosis, blastomycosis, and paracoccidioidomycosis and is effective in patients with cryptococcosis and coccidioidomycosis, including those with meningitis. Further investigation into the development of new antifungal agents is ongoing.

A randomized comparison of fluconazole with amphotericin B as empiric anti-fungal agents in cancer patients with prolonged fever and neutropenia

PURPOSE

Several studies have documented the efficacy of amphotericin B as empiric antifungal therapy in cancer patients with prolonged fever and neutropenia. Amphotericin, however, is a toxic drug. Fluconazole has broad-spectrum antifungal activity with an excellent safety profile. Although prophylactic use of fluconazole is widespread, its efficacy as an empiric antifungal agent has not been extensively investigated.

PATIENTS AND METHODS

We randomly assigned 106 patients with absolute neutropenia (< or = 500 cells microL) and persistent fever of undetermined origin (> 38 degrees C) despite 1 week of broad-spectrum antibiotic therapy to receive either fluconazole 400 mg orally daily or amphotericin B 0.5 mg/kg/day. Patients with obvious invasive fungal infections were excluded, as were those with abnormal renal or hepatic function. Success was defined as defervescence with the initially assigned antifungal regimen without development of clinically evident invasive fungal infection.

RESULTS

Six patients were excluded from the analysis, mostly because they did not have severe neutropenia. Forty-eight patients received amphotericin B, and 52 received fluconazole. Baseline clinical characteristics and laboratory parameters as well as duration of neutropenia (7.7 versus 6.9 days), duration of fever (7.8 versus 8.1 days), and duration of hospitalization (10.4 versus 8.3 days) were similar between those receiving amphotericin and fluconazole. Treatment success rates and mortality rates were similar in the two groups: 22 (46%) patients in the amphotericin group and 29 (56%) patients in the fluconazole group responded successfully to therapy (P = 0.3), whereas 16 (33%) patients in the amphotericin group and 14 (27%) patients in the fluconazole group died during hospitalization (P = 0.5). Adverse events such as chills and fever (4 versus 1), bronchospasm (2 versus none), severe hypokalemia (25 versus 12) and nephrotoxicity (9 versus 3) were more frequently observed in patients receiving amphotericin. Adverse prognostic factors included prolonged duration of neutropenia and pneumonia.

CONCLUSIONS

These results suggest that fluconazole is an equally effective but less toxic alternative to amphotericin B as empiric antifungal therapy in cancer patients with prolonged fever and neutropenia.

The effect of prophylactic fluconazole on the clinical spectrum of fungal diseases in bone marrow transplant recipients with special attention to hepatic candidiasis. An autopsy study of 355 patients

We reviewed 355 autopsies performed between 1990 and 1994 at a major marrow transplant center to determine whether fluconazole prophylaxis prevented visceral fungal infection. Fluconazole prophylaxis was defined by a minimum of 5 prophylactic doses. Fungal infection (any site) was found in 40% of patients transplanted and autopsied at the center. Overall, the proportion of autopsies with any fungal infection was not different for those patients receiving no fluconazole prophylaxis versus those with prophylactic fluconazole. With fluconazole prophylaxis, candidal infections were less frequent, decreasing from 27% to 8%, while Aspergillus infections were more frequent, increasing from 18% to 29%. No increase in deaths related to non-albicans Candida infections was seen. Of the 329 patients with livers examined, hepatic infection caused by Candida species was significantly less common in patients who had received fluconazole. Fungal liver infection was found in 31 patients (9%), 16% of those who were not treated with fluconazole and 3% of those who were treated with fluconazole. Since patients with candidal infections died earlier after marrow transplant than patients with mold infections, we speculate that a longer length of survival may dispose toward acquisition of mold infections. Fluconazole prophylaxis in this cohort of marrow transplant patients undergoing autopsy resulted in a significant reduction in infection caused by Candida species and an increase in mold infections.

Epidemiology, diagnosis and treatment of systemic Candida infection in surgical patients under intensive care

The incidence of systemic Candida infections in patients requiring intensive care has increased substantially in recent years as a result of a combination of factors. More patients with severe underlying disease or immunosuppression from anti-neoplastic or anti-rejection chemotherapy and at risk from fungal infection are now admitted to the ICU. Improvements in supportive medical and surgical care have led to many patients who would previously have died as a result of trauma or disease surviving to receive intensive care. Moreover, some therapeutic interventions used in the ICU, most notably broad-spectrum antibiotics and intravascular catheters, are also associated with increased risks of candidiasis. Systemic Candida infections are associated with a high morbidity and mortality, but remain difficult to diagnose and ICU staff need to be acutely aware of this often insidious pathogen. A number of studies have identified risk factors for systemic Candida infection which may be used to identify those at highest risk. Such patients may be potential candidates for early, presumptive therapy. Here we review the epidemiology, pathogenesis, morbidity and mortality of systemic Candida infections in the ICU setting, and examine predisposing risk factors. Antifungal treatment, including the use of amphotericin B, flucytosine and fluconazole, and the roles of early presumptive therapy and prophylaxis, is also reviewed.

Hepatic Lesions of Chronic Disseminated Candidiasis May Become Invisible During Neutropenia

We describe the phenomenon of waning of focal hepatic and/or splenic lesions on abdominal computed tomographic (CT) scan during neutropenia in patients with chronic disseminated candidiasis. After observation of the phenomenon in one patient, a total of five cases were prospectively monitored with serial CT scans. After the diagnosis of disseminated candidiasis, hepatic lesions decreased in size and conspicuousness in three patients, while in two others they disappeared completely during a subsequent chemotherapy-induced neutropenia. After recovery of the neutrophils, the lesions reappeared or increased in conspicuousness in all five patients. Of three patients treated with a second cycle of myeloablative chemotherapy, lesions again decreased in two patients during neutropenia and increased again in one patient after neutrophil recovery. In all five patients, candidiasis eventually resolved after prolonged antifungal treatment. In chronic disseminated candidiasis, hepatic or splenic lesions may transiently disappear during neutropenia. Thus, antifungal therapy should not be discontinued on the basis of radiologic findings alone.

High dose cytosine arabinoside is a major risk factor for the development of hepatosplenic candidiasis in patients with leukemia

A retrospective study of hepatosplenic candidiasis in patients with acute leukemia from a single centre was performed. The significance of age, sex, type of leukemia, dose of cytosine arabinoside (Ara-C), duration of neutropenia, steroid use and period of therapeutic antibiotics in the development of hepatosplenic candidiasis was analyzed, using logistic regression analysis. Nine of 51 patients had hepatosplenic candidiasis. Ara-C use was highly associated with the development of hepatosplenic candidiasis (p = 0.001); with a high association with a higher dose (p < 0.0001). On the basis of these results consideration should be given to further trial of antifungal prophylaxis for patients receiving high dose Ara-C.

Safety, tolerance, and pharmacokinetics of amphotericin B lipid complex in children with hepatosplenic candidiasis

The safety, tolerance, and pharmacokinetics of amphotericin B lipid complex (ABLC) were studied in a cohort of pediatric cancer patients. Six children with hepatosplenic candidiasis (HSC) received 2.5 mg of ABLC/kg of body weight/day for 6 weeks for a total dosage of 105 mg/kg. Mean serum creatinine (0.85 +/- 0.12 mg/dl at baseline) was stable at the end of therapy at 0.85 +/- 0.18 mg/dl and at 1-month follow-up at 0.72 +/- 0.12 mg/dl. There was no increase in hepatic transaminases. Mean plasma concentrations over the dosing interval (C(ave)) and area under the curve from 0 to 24 h (AUC(0-24h)) increased between the first and seventh doses but were similar between doses 7 and 42, suggesting that steady state was achieved by day 7 of therapy. Following the final (42nd) dose of ABLC, mean AUC(0-24h) was 11.9 +/- 2.6 microg h/ml, C(ave) was 0.50 +/- 0.11 microg/ml, maximum concentration of the drug in whole blood was 1.69 +/- 0.75 microg/ml, and clearance was 3.64 +/- 0.78 ml/min/kg. Response of hepatic and splenic lesions was monitored by serial computerized tomographic and magnetic resonance imaging scans. The five evaluable patients responded to ABLC with complete or partial resolution of physical findings and of lesions of HSC. During the course of ABLC infusions and follow-up, there was no progression of HSC, breakthrough fungemia, or posttherapy recurrence. Hepatic lesions continued to resolve after the completion of administration of ABLC. Thus, ABLC administered in multiple doses to children was safe, was characterized by a steady state attainable within 1 week of therapy, and was effective in treatment of HSC.

Diagnostic laparoscopy in patients with acute leukemia and suspected hepatic candidiasis

To assess the value of laparoscopy in the diagnosis of suspected hepatosplenic candidiasis in patients with acute leukemia, a retrospective analysis of 28 laparoscopies was conducted. In all but two cases, imaging of the liver showed focal lesions before laparoscopy. Diagnosis of hepatic candidiasis was established significantly more often when the biopsy was targeted at white nodules (in 12 of 22 laparoscopies) than when targeted randomly or at scars (0 of 6 laparoscopies) (p = 0.017, chi-square test). Yeast was detected more often if the laparoscopy was performed during the three-week period after recovery from neutropenia (in 8 of 12 laparoscopies) than when performed later (in 4 of 16 laparoscopies) (p = 0.028, chi-square test). In addition to the 12 laparoscopically diagnosed patients, eight (29%) patients were diagnosed with disseminated Candida infection by other methods. In another eight (29%) patients the causative agent was not identified. No bleeding or other problems occurred after the laparoscopy. Laparoscopy-guided liver biopsy is most useful if biopsies are targeted to macroscopic lesions and if laparoscopy is performed soon after recovery from neutropenia.

Sequential treatment of deep fungal infections with amphotericin B deoxycholate and amphotericin B colloidal dispersion

Amphotericin B colloidal dispersion (ABCD) is a novel lipid formulation of amphotericin B designed to diminish toxic effects of the drug. In the following report, nine cases of suspected (n = 4) and proven (n = 5) deep Candida infection, treated sequentially with amphotericin B deoxycholate and ABCD, are presented. The treatment was successful in seven cases. During treatment with amphotericin B deoxycholate, a rise in serum creatinine was observed in seven patients, hypokalemia in five, and metabolic acidosis in four. After replacing amphotericin B deoxycholate with ABCD, laboratory parameters improved in four of the seven patients with increased creatinine, in four of the five patients with hypokalemia, and in two of the four patients with metabolic acidosis. Infusion-related rigors were observed in four patients receiving amphotericin B deoxycholate and in one patient treated with ABCD. Reversible elevation of liver enzymes was found in one patient receiving ABCD. In this study ABCD proved less toxic than amphotericin B deoxycholate. The efficacy of ABCD alone cannot be assessed because of previous treatment with amphotericin B deoxycholate, but sequential treatment of deep Candida infections with amphotericin B deoxycholate and ABCD seems to be an effective therapeutic modality, especially in patients requiring prolonged administration of amphotericin B.

Antifungal prophylaxis during neutropenia and immunodeficiency

Fungal infections represent a major source of morbidity and mortality in patients with almost all types of immunodeficiencies. These infections may be nosocomial (aspergillosis) or community acquired (cryptococcosis), or both (candidiasis). Endemic mycoses such as histoplasmosis, coccidioidomycosis, and penicilliosis may infect many immunocompromised hosts in some geographic areas and thereby create major public health problems. With the wide availability of oral azoles, antifungal prophylactic strategies have been extensively developed. However, only a few well-designed studies involving strict criteria have been performed, mostly in patients with hematological malignancies or AIDS. In these situations, the best dose and duration of administration of the antifungal drug often remain to be determined. In high-risk neutropenic or bone marrow transplant patients, fluconazole is effective for the prevention of superficial and/or systemic candidal infections but is not always able to prolong overall survival and potentially selects less susceptible or resistant Candida spp. Primary prophylaxis against aspergillosis remains investigative. At present, no standard general recommendation for primary antifungal prophylaxis can be proposed for AIDS patients or transplant recipients. However, for persistently immunocompromised patients who previously experienced a noncandidal systemic fungal infection, prolonged suppressive antifungal therapy is often indicated to prevent a relapse. Better strategies for controlling immune deficiencies should also help to avoid some potentially life-threatening deep mycoses. When prescribing antifungal prophylaxis, physicians should be aware of the potential emergence of resistant strains, drug-drug interactions, and the cost. Well-designed, randomized, multicenter clinical trials in high-risk immunocompromised hosts are urgently needed to better define how to prevent severe invasive mycoses.

Multicenter randomized trial of fluconazole versus amphotericin B for treatment of candidemia in non-neutropenic patients. Canadian Candidemia Study Group

A randomized trial was conducted to compare the efficacy and safety of fluconazole versus that of amphotericin B in the treatment of candidemia in non-neutropenic adults. Enrollment was stratified by disease severity (APACHE II score). Patients were randomized (1:1) to receive amphotericin B 0.6 mg/kg/day (cumulative dose 8 mg/kg) or fluconazole 800 mg intravenous loading dose, then 400 mg daily for four weeks (intravenous for at least 10 days). Patients were monitored for six months. A total of 106 patients were enrolled. A protocol amendment implemented midway through the trial required patients to be removed from the study and treated with amphotericin B if species identification indicated candidemia due to Candida glabrata or Candida krusei. Baseline characteristics were similar for the two groups; 103 patients (fluconazole, 50; amphotericin B, 53) met the major enrollment criteria. The intention-to-treat analysis indicated successful therapy in 50% of fluconazole recipients compared to 58% of the amphotericin B group (p = 0.39; one-sided 95% CI, -8 to 24%). The efficacy analysis included 84 patients (fluconazole, 42; amphotericin B, 42); successful outcomes were observed in 57% and 62% of cases in the fluconazole and amphotericin B groups, respectively (p = 0.66: one-sided 95% CI, -12 to 22%). The mortality at day 14 for the fluconazole group was 26% and for the amphotericin B group 21% (p = 0.52; chi-square test) and remained similar throughout the course of follow-up, Drug-related adverse events were more frequent with amphotericin B than with fluconazole and prompted switching of therapy for two (4%) and zero cases, respectively. Fluconazole and amphotericin B were associated with similar clinical response rates and survival in the treatment of candidemia among non-neutropenic patients; however, drug-related adverse events were more frequent with amphotericin B.

Large-scale multicentre study of fluconazole in the treatment of hospitalised patients with fungal infections. Multicentre European Study Group

The purpose of this prospective, open-label, noncomparative, multicentre study was to evaluate the efficacy and safety of fluconazole in the treatment of hospitalised patients with mycoses. A total of 587 patients with diagnosed fungal infections were enrolled. Fluconazole was given orally or intravenously in a 200 or 400 mg loading dose, followed by 100 or 200 mg once daily. The most common candidal infections were fungemia, esophageal candidiasis, bronchopulmonary candidiasis, peritonitis, oropharyngeal candidiasis, urinary tract infection and deep wound infection. Meningitis was the most common cryptococcal infection. Of the 291 evaluable patients with candidiasis, 96% (70/73) of AIDS patients and 79% (171/218) of non-AIDS patients were clinically cured or improved. Of the 36 evaluable patients with cryptococcosis, 69% (20/29) of AIDS patients and 100% (7/7) of non-AIDS patients responded clinically. The overall mycological eradication rate was 85%; eradication was similar in patients with and without AIDS. Most adverse events during fluconazole therapy were mild to moderate in severity. This investigation confirms the results of previous studies demonstrating high response rates to fluconazole therapy in AIDS and non-AIDS patients with fungal infections. Even during long-term therapy treatment-limiting adverse events were uncommon with fluconazole.

Clinical and laboratory diagnosis of invasive candida infection in neutropenic patients

Cancer patients, especially those with acute leukaemia, represent a group that has the greatest risk for deep fungal infection. Almost no cases were seen before the advent of modern chemotherapy, and prior to the availability of antibacterial agents, less than 5% of patients with acute leukaemia died of fungal infection. These infections are now responsible for 40% or more of the deaths at some institutions. Candida species continues to be the most common fungal pathogen. Rapid and specific diagnosis of invasive candiosis enabling early effective therapy is therefore an important measure for reducing mortality in patients. Here the current status of clinical and laboratory diagnosis of invasive candida infection in neutropenic patients is discussed and recommendations made as to future development programmes.

Effect of fluconazole on viability of Candida albicans over extended periods of time

The treatment of chronic mycoses may expose the infecting organisms to antimicrobial agents for extended periods of time. It is possible that an azole antifungal drug such as fluconazole, with primarily fungistatic activity in standard in vitro susceptibility tests, might be able to damage the fungal cells and reduce their viability over prolonged incubations under nonproliferating conditions. To test this possibility, Candida albicans yeast cells were exposed to various concentrations of fluconazole in RPMI 1640 tissue culture medium for 4 h at 37 degrees C, washed free of the drug, and then incubated at 37 degrees C for a 28-day period; enumeration of the remaining CFU at various times during this period revealed no increased loss of viability for the fluconazole-exposed organisms. However, when fluconazole was added to the organisms maintained in distilled water (with or without pretreatment with the drug), a marked reduction of viability was found. At 14 days of incubation with two strains of C. albicans, negative cultures were found for 7 of 10 and 10 of 11 samples, respectively, containing 1.0 microgram of fluconazole per ml versus 0 of 10 and 1 of 11 control samples (P of < 0.01 and 0.001, respectively). The effect of fluconazole on fungal viability under these conditions became noticeable at approximately 7 days and was greater when the samples were incubated at 37 degrees C rather than 25 degrees C. These findings suggest that fluconazole may have fungicidal effects on fungal cells during prolonged exposures under conditions in which the organisms are prevented from proliferating by lack of nutrients.

Fluconazole in the prophylaxis of fungal infection after bone marrow transplantation

An open, non-comparative study was conducted to investigate the efficacy and safety of fluconazole in the prophylaxis of superficial or systemic fungal infections in patients having received bone marrow transplantation (BMT). The study population consisted of a total of 53 patients, including 10 children between the ages of 3 and 14 years who were scheduled for BMT. Fluconazole prophylaxis was initiated at 200 mg day-1 in adults and 100 mg day-1 in children. It was started at a mean of 7 days before treatment and continued for up to 112 days in the paediatric patients and 393 days in the adult patients. Apart from the baseline examination and the final evaluation, the patients were evaluated mycologically and serologically for the presence of fungal infections on a weekly basis, if feasible. Proven fungal infection, oesophageal candidosis or oropharyngeal candidosis was not found in any of the patients under study during the fluconazole prophylaxis. Thirteen of the adult patients developed unexplained fevers and had their treatment supplemented by antibiotic therapy and treatment with amphotericin B. In all 10 children, the prophylactic treatment proved successful. Adverse events were seen in 15 patients. In one case only, the event was judged to be causally related or possibly causally related to the study drug. Hence, fluconazole proves to be an effective and well-tolerated agent in the prophylaxis of fungal infections in recipients of bone marrow transplants.

Recent progress and current problems in treatment of invasive fungal infections in neutropenic patients

Invasive fungal infections, including disseminated candidiasis and invasive pulmonary aspergillosis, are important causes of morbidity and mortality in neutropenic patients. The recent development of fluconazole, itraconazole, lipid formulations of amphotericin B, and recombinant cytokines have expanded our therapeutic armamentarium. Clinical trials have elucidated new strategies for utilizing these compounds in the prevention and treatment of opportunistic mycoses. The population of more severely immunocompromised patients, however, continues to expand and the spectrum of drug-resistant fungi, including but not limited to Candida spp, Fusarium spp, Zygomycetes, and dematiaceous moulds, continues to evolve, thus presenting new challenges to recent therapeutic advances. Development of new antifungal chemotherapeutic agents and novel approaches for augmentation of host response will be required to meet these new mycologic challenges.

Emerging fungal infections in cancer patients

The increasing number of reports in cancer patients that describe unusual or new fungal pathogens in severe systemic infections may be due, in part, to new treatment regimens but also to increased recognition of clinical disease by physicians and unusual organisms by microbiologists. Identification of these pathogens requires specialized expertise but the diagnosis may often be too late to permit effective therapeutic intervention. An unfortunate limitation of current antifungal agents is their limited efficacy in the heavily immunosuppressed, even when the drugs show good activity in vitro. Infections with Candida spp., and non-Candida yeasts and moulds are often disseminated and are frequently fatal in patients with severe immunosuppression. Therapeutic outcomes could be improved with more precise and rapid diagnostic procedures, standardized treatments for each pathogen and improved therapeutic agents. Liposomal amphotericin B formulations, new azole antifungals, more aggressive surgery and haemopoietic growth factors may improve the poor outcome that currently occurs with many of those infections.

[Antifungal prophylaxis in neutropenic cancer patients and in allogeneic bone marrow transplantation]

Severe and prolonged neutropenia and fungal colonization during the long term administration of broad-spectrum antibiotics are well known factors increasing the risk of invasive fungal infections. This is in particular true in patients undergoing allgeneic bone marrow transplantation due to the intensity of the conditioning regimen, the immuno-suppressive effect of allografting and the administration of immunosuppressive agents to prevent graft-versus-host-disease. Therefore, strategies in the prevention of fungal infections decreasing the morbidity and mortality in patients with hematological malignancies need to be developed. In this review, we discussed fungal infections an important cause of morbidity and mortality in patients with hematological disorders and attempted to provide some insights in the current status of antifungal prophylaxis.

Fluconazole treatment of candidal infections caused by non-albicans Candida species

Fluconazole is an effective alternative to amphotericin B for the treatment of serious infections caused by Candida albicans. Through a literature survey of candidal infections caused by non-albicans Candida spp., 43 cases treated with fluconazole were found. The most common causative organisms were Candida parapsilosis (14 patients), Candida glabrata (12 patients), and Candida tropicalis (11 patients). The dose of fluconazole varied from 50 to 400 mg daily. The median duration of treatment was 21 days. Overall efficacy was 77%. The efficacy against the various species was 93% for Candida parapsilosis, 50% for Candida glabrata, and 82% for Candida tropicalis. In conclusion, fluconazole is effective against the most common non-albicans Candida spp., although higher doses may be required for infections caused by Candida glabrata. Infections caused by Candida krusei should not be treated with fluconazole.

Prophylaxis of candidiasis in patients with leukemia and bone marrow transplants

OBJECTIVES

The increased risk for systemic fungal infection and the potential fatal consequences of disseminated candidiasis in bone marrow transplant patients has prompted study of prophylaxis and early treatment of candida colonization and infection.

STUDY DESIGN

Patients with leukemia who received fluconazole prophylaxis were compared with a concurrent group of patients not given prophylaxis for fungal organisms.

RESULTS

A trend to reduction of oropharyngeal colonization by Candida albicans was seen (p = 0.07) although no significant differences in systemic candidiasis were seen. In patients with documented systemic candidiasis, oral colonization was present and systemic infection was identified after the development of ulcerative oral mucositis.

CONCLUSIONS

Our results support the potential of fluconazole to reduce oropharyngeal colonization by Candida albicans, however, we did not show prophylaxis of oral candidiasis or systemic candidiasis. These findings and reports of fluconazole-resistant candidal species and a rising number of cases of infection as a result of Candida krusei indicate the need for further studies of prophylaxis of candidal infection in patients who are anticipated to develop profound neutropenia.

Comparison of fluconazole and amphotericin B for treatment of experimental Candida albicans endocarditis in rabbits

Amphotericin B (AmB) and fluconazole, administered intraperitoneally for 7 days, were compared in a rabbit model for Candida albicans endocarditis. When given early, AmB was more effective than fluconazole for reducing CFU counts in vegetations (P < 0.01) and kidneys. Forty-eight hours after the last dose, AmB was still detected in all vegetations whereas fluconazole was detected in only one case.

Successful treatment of hepatosplenic candidiasis through repeated cycles of chemotherapy and neutropenia

BACKGROUND

Hepatosplenic candidiasis (HSC) or chronic disseminated candidiasis is an increasingly recognized problem in patients with cancer. Whether patients with HSC should continue to receive antineoplastic therapy, which may cause neutropenia with the risk for progressive HSC or breakthrough fungemia, can be a major dilemma. Patients with HSC at the National Cancer Institute continue antineoplastic therapy, when possible during antifungal therapy for HSC, despite repeated bouts of neutropenia. Therefore, whether this strategy resulted in breakthrough fungemia or progression of HSC was investigated.

METHODS

All patients consecutively treated at the National Cancer Institute at the Warren-Grant Magnuson Clinical Center from 1982-1992 for HSC were prospectively studied for therapeutic and outcome variables of antifungal and antineoplastic management. Each case was summarized on a time-event line to quantify the duration of simultaneous periods of antineoplastic therapy and antifungal therapy (AFT).

RESULTS

Sixteen patients (median age, 22 years) with HSC were studied. Eleven patients had relapsed tumor and 5 had newly diagnosed tumor. During antifungal therapy for HSC, 12 of 16 patients were neutropenic for a median of 10 days (range, 6-91 days) and 11 were profoundly neutropenic for a median of 13 days (range, 1-55 days). Hepatosplenic candidiasis was successfully treated with complete antifungal response in 12 patients and a partial response in 2; 2 patients continued to receive AFT. No patient had breakthrough fungemia and two patients had progression of HSC, only one episode of which occurred during neutropenia.

CONCLUSIONS

Hepatosplenic candidiasis in patients with cancer may be treated successfully under careful observation through repeated courses of chemotherapy-induced neutropenia without progression of hepatosplenic candidiasis or breakthrough fungemia.

Antifungal Prophylaxis in Severely Neutropenic Patients: How Much Fluconazole is Necessary?

OBJECTIVES: To evaluate the efficacy of low dose fluconazole treatment for the prevention of yeast colonization and infection in severely neutropenic patients. METHODS: An open randomized trial, comparing fluconazole (100 mg per day) with nystatin (800,000 IU per day), in a University Hospital setting. RESULTS: Antifungal prophylaxis was given during the period of neutropenia, defined as less than 500 polymorphonuclear cells (PMN)/mm3). Thirty-six patients were randomly assigned to fluconazole and 33 to nystatin treatment groups. New oropharyngeal colonizations were significantly reduced by fluconazole (P=0.005), and oropharyngeal infections occurred less frequently in the fluconazole group (3% versus 16%, P=0.07). Stool colonization was identical between both groups. Systemic fungal infections were rare; one fluconazole patient had pulmonary aspergillosis and one nystatin patient developped Candida pseudotropicalis fungemia. Empiric amphotericin B was given with the same frequency in both groups. No side effects were associated with fluconazole. However, the administration of nystatin became impossible for three patients because of vomiting and lack of compliance. CONCLUSIONS: Fluconazole (100 mg per day) is more effective than nystatin for the prevention of oropharyngeal yeast colonization. Comparison with results in the literature suggests that a 100-mg dose of fluconazole has similar effects to 200 or 400 mg per day.

Fluconazole penetration in cerebral parenchyma in humans at steady state

We studied fluconazole penetration in the brain in five patients who had a deep cerebral tumor whose removal required the excision of healthy brain tissue. Plasma and brain samples were simultaneously obtained after oral ingestion of 400 mg of fluconazole daily for 4 days (90% of steady state). Fluconazole penetration in healthy cerebral parenchyma was determined. Plasma and brain samples were assayed by high-pressure liquid chromatography. Concentrations in plasma and brain tissue were 13.5 +/- 5.5 micrograms/ml and 17.6 +/- 6.6 micrograms/g, respectively. The average ratio of concentrations in the brain and plasma (four patients) was 1.33 (range, 0.70 to 2.39). Despite the lack of data concerning the penetration of fluconazole in brain abscesses, these results should permit the use of a daily dose of 400 mg of fluconazole in prospective clinical studies that evaluate the effectiveness of this drug in the treatment of brain abscesses due to susceptible species of fungi.

Fluconazole is removed by continuous venovenous hemofiltration in a liver transplant patient

Fluconazole is effective for the treatment of fungal infections. A continuous venovenous hemofiltration (CVVH) was necessary in a liver transplant patient with anuria. Fluconazole treatment was started after the diagnosis of systemic candidiasis. There was no adverse effect on liver function, and the immunosuppression with cyclosporine was not affected. It is shown for the first time that CVVH effectively removes fluconazole from the blood circulation by a clearance into the hemofiltrate of approximately 21 ml/min. These data suggest that the treatment of fungal infections with fluconazole does not necessitate a reduction of the dosage during CVVH.

An open study on the safety and efficacy of fluconazole in the treatment of disseminated Candida infections in patients treated for hematological malignancy

Disseminated candidiasis is a serious infectious complication with a mortality as high as 50%. Standard therapy consists of parenteral amphotericin B which is associated with major side effects and prolonged hospitalization. The aim of the study was to assess the efficacy and safety of fluconazole in an open, noncomparative study. Fluconazole, as a single agent, was given intravenously for the first 3 days at a dose of 200 mg twice daily, followed by 200 mg twice daily orally until resolution of signs and symptoms or evident treatment failure. The study group comprised 24 consecutive patients of whom nine had acute and 15 chronic disseminated candidiasis. A clinical response was achieved in 67% of cases of acute disseminated candidiasis and in 86% of cases of chronic disseminated candidiasis. The median duration of therapy was 15 days and 6 months, respectively. Superinfections with Aspergillus fumigatus developed in five patients who were persistently neutropenic. No drug-related toxicity was registered.