Comparison of amphotericin B with fluconazole in the treatment of acute AIDS-associated cryptococcal meningitis. The NIAID Mycoses Study Group and the AIDS Clinical Trials Group

Use of antifungal therapy in hospitalized patients. II. Results after the marketing of fluconazole

OBJECTIVE

To evaluate the prescribing patterns of antifungal agents in the hospital setting after the introduction of fluconazole, a new broad-spectrum bis-triazole antifungal agent. Also compared are the prescribing patterns of antifungal agents prior to (phase I) and following (phase II) fluconazole marketing.

DESIGN

A prospective cohort of hospitalized patients prescribed topical or systemic antifungal agents. Data were collected from December 1990 to April 1991.

SETTING

Fifty-seven hospitals ranging in size from 100 to more than 500 beds. Sixty-three percent are affiliated with medical schools.

PATIENTS

Participating pharmacists consecutively identified 15 patients receiving systemic antifungal therapy and 5 patients receiving topical antifungal therapy.

INTERVENTIONS

Observational data on patient antifungal therapy, risk factors for fungal infections, comorbidities, concurrent medications, and culture data were collected.

MEASURES

Differences in prescribing patterns before and after the marketing of fluconazole were assessed using t-tests and chi-square tests.

RESULTS

Of 818 patients studied, 615 (75.2 percent) received systemic antifungal therapy. Five hundred forty-six patients received a single antifungal agent; 348 (63.7 percent) received fluconazole, 105 (19.2 percent) received ketoconazole, 92 (16.8 percent) received amphotericin B, and 1 (0.2 percent) received flucytosine. Sixty-nine patients received two or more systemic agents either concurrently or consecutively. The use of parenteral amphotericin B, alone or in combination with flucytosine and/or an azole, declined from 56.8 percent in the phase I study to 24.2 percent in the current study. The use of parenteral therapy also declined from 56.8 to 40.2 percent. Ketoconazole was used in more than 90 percent of the oral and esophageal infections in the phase I study, but its use declined to only 33 percent in this study. Fluconazole was used most frequently across all sites of presumed or documented infections, with the exception of fungemia. Of the presumed or proven systemic or blood infections, amphotericin B was used alone or in combination in 48.4 percent of the patients and fluconazole was used exclusively in 39.0 percent of the patients. Fluconazole was used more often than amphotericin B (22 vs. 3 patients, respectively) for prophylaxis of systemic infections. The overall use of antifungal prophylaxis also increased from the phase I (9.5 percent) to phase II (13.7 percent).

CONCLUSIONS

The introduction of fluconazole had a major impact on the prescribing patterns of antifungal therapy. Although amphotericin B remained the preferred agent for treatment of suspected or proven systemic, central nervous system, or blood infections, use of fluconazole for these indications approached nearly 40 percent. Further studies are needed to address the role of fluconazole in the prophylaxis and treatment of systemic mycoses.

Oral azole drugs as systemic antifungal therapy

The oral azole drugs--ketoconazole, fluconazole, and itraconazole--represent a major advance in systemic antifungal therapy. Among the three, fluconazole has the most attractive pharmacologic profile, including the capacity to produce high concentrations of active drug in cerebrospinal fluid and urine. Ketoconazole, the first oral azole to be introduced, is less well tolerated than either fluconazole or itraconazole and is associated with more clinically important toxic effects, including hepatitis and inhibition of steroid hormone synthesis. However, ketoconazole is less expensive than fluconazole and itraconazole--an especially important consideration for patients receiving long-term therapy. All three drugs are effective alternatives to amphotericin B and flucytosine as therapy for selected systemic mycoses. Ketoconazole and itraconazole are effective in patients with the chronic, indolent forms of the endemic mycoses, including blastomycosis, coccidioidomycosis, and histoplasmosis; itraconazole is also effective in patients with sporotrichosis. Fluconazole is useful in the common forms of fungal meningitis--namely, coccidioidal and cryptococcal meningitis. In addition, fluconazole is effective for selected patients with serious candida syndromes such as candidemia, and itraconazole is the most effective of the azoles for the treatment of aspergillosis.

Treatment of human immunodeficiency virus infection and its associated complications in children

Providing care to human immunodeficiency virus (HIV)-infected children requires a comprehensive, multidisciplinary approach. This review will address the current status of supportive care, treatment of HIV-associated complications and specific antiretroviral therapy. HIV affects multiple locations in the body resulting in a myriad of possible complications. These include opportunistic infections and malignancies secondary to immunodeficiency and central nervous system or other specific organ-related disease secondary to direct HIV involvement. Recent scientific advances have markedly enhanced the quantity and quality of life of HIV-infected children. Prophylaxis of Pneumocystis carinii pneumonia is the single most important therapeutic advance for the HIV-infected patient. Other advances for the treatment and prevention of HIV-related infections should similarly improve survival and reduce hospital stays. Antiretroviral therapy is relatively new. The currently available nucleoside reverse transcriptase inhibitors have proven efficacy. The role of single agents or combinations is being established. However, this group of antivirals has limitations that make alternate approaches essential. Augmentation of the patient's immune response will likely be a key to any future successful treatment regimen.

Cellulitis as first clinical presentation of disseminated cryptococcosis in renal transplant recipients

Two renal transplant recipients with cellulitis due to Cryptococcus neoformans are described. The patients were treated empirically for a presumed bacterial erysipelas, but without response. Examination of skin biopsies revealed C. neoformans as the causative organism. In both patients the cellulitis was the presenting clinical manifestation of disseminated cryptococcosis. Therapy with antifungal agents was successful. Disseminated cryptococcal disease occurs mainly in immunocompromised patients. When left untreated, it nearly always has a fatal course. Early diagnosis and appropriate therapy are therefore essential.

Ophthalmic manifestations of infections with Cryptococcus neoformans in patients with the acquired immunodeficiency syndrome

The present study was undertaken to determine the nature and the prevalence of ophthalmic manifestations of infections with Cryptococcus neoformans in human immunodeficiency virus seropositive patients and to analyze whether the presence or absence of ocular signs is associated with improved survival. Eighty human immunodeficiency virus seropositive patients with cryptococcal infection were enrolled. We observed papilledema in 26 of the 80 patients (32.5%). Visual loss and abducens nerve palsy occurred in seven patients (9%). Only two patients (2.5%) had optic atrophy. Visual loss caused by optic nerve involvement was less frequent among the 62 patients treated with oral conazoles exclusively than among the 18 patients who had received amphotericin B or a combination of amphotericin B and conazoles. Actual invasion of the intraocular structures with Cryptococcus neoformans was an uncommon complication in our series. In addition to the ocular manifestations attributable to cryptococcal disease, human immunodeficiency virus-related retinopathy was present in nearly half of the patients. Cytomegalovirus retinitis was diagnosed in four patients (5%). The 26 patients (32.5%) with papilledema had a median survival of 182 days vs 160 days for the patients without papilledema. The median survival for 18 patients (22.5%) with cotton-wool spots was 102 days vs 186 days for those without cotton-wool spots. The differences between these subgroups were not statistically significant.

Comparative study of the efficacy of fluconazole versus amphotericin B/flucytosine in surgical patients with systemic mycoses

In an open, prospective, randomized study, the efficacy of fluconazole was compared with that of the combination amphotericin B/flucytosine. Forty surgical patients with deep-seated mycoses were included in the study. Absolute inclusion criteria were histological finding of fungi in a tissue sample taken during surgery from e.g. peritoneum, pancreas, lungs or trachea, a positive blood culture or candida lesion of the eye. According to the random list 20 patients received up to 0.5 mg amphotericin B per kg body weight in combination with 3 x 2.5 g flucytosine (5-FC) daily and 20 patients received fluconazole, 400 mg on the first day and then 300 mg daily. The two therapy groups were comparable in terms of age, sex and underlying diseases. Gastrointestinal perforations (27 times) were the most frequent underlying diseases. Candida albicans was the fungus most frequently detected microbiologically (34 times). The pathogens were eliminated from 12 patients in the fluconazole group and 14 patients in the combination group. The median elimination time was 8.5 days in the fluconazole group and 5.5 days in the amphotericin B/5-FC group. Six patients died in the fluconazole group, whereas five patients died in the comparison group. Side effects which necessitated switching of therapy occurred twice in the combination group. In deep-seated candida mycoses, surgical patients receiving the combination therapy with amphotericin B/5-FC showed an earlier elimination than patients on monotherapy with fluconazole. With respect to cure rates there was no difference between these two regimens.

Cryptococcal meningitis with severe visual and hearing loss and radiculopathy in a patient without immunodeficiency

Cryptococcosis is an important cause of lymphocytic meningitis, especially but not necessarily in immunocompromised patients. We present the case of a 23-year-old man with a severe and rapid course of a cryptococcal meningoencephalitis, which led to visual and hearing loss, psychotic illness and radiculopathy. There was no evidence of immunodeficiency. Treatment with amphotericin B and flucytosine led to improvement of the symptoms but did not eradicate the micro-organisms from the cerebrospinal fluid (CSF). Maintenance therapy with fluconazole was necessary and led to improvement of the CSF pathology.

The gene encoding phosphoribosylaminoimidazole carboxylase (ADE2) is essential for growth of Cryptococcus neoformans in cerebrospinal fluid

A cryptococcal meningitis model in corticosteroid-treated rabbits was used to assess the requirement for the phosphoribosylaminoimidazole gene (ADE2) for virulence of Cryptococcus neoformans. A wild-type strain (H99), an ade2 auxotroph of H99 (M001), and a randomly selected prototrophic transformant of M001 (M001.1c) which had received the cloned ADE2 cDNA copy were inoculated intrathecally into immunosuppressed rabbits. While M001 was avirulent in the central nervous system model, virulence was completely restored to wild-type pathogenicity in the prototrophic transformant. This study identifies the pathogenic importance of an endogenous adenine pathway in this yeast and confirms that purine biosynthesis is a potential target for antifungal therapy. It also demonstrates that the virulence of C. neoformans can be molecularly changed and detected within a clinically relevant animal model.

Pharmacokinetics of 18F-labeled fluconazole in healthy human subjects by positron emission tomography

The distribution of fluconazole in tissue of human volunteers was determined by positron emission tomographic scanning over a 2-h period following the infusion of a tracer dose of 18F-fluconazole (5 to 7 mCi) plus 400 mg of unlabeled drug (the standard daily dose of fluconazole). Previous studies have validated this approach for animals. From serial positron emission tomographic imaging and blood sampling, pharmacokinetics of fluconazole in tissue were determined. There was significant distribution of the radiolabeled drug in all organs studied, with nearly constant levels achieved by 1 h. Plateau concentrations of fluconazole in key organs (micrograms per gram) included the following: whole brain, 4.92 +/- 0.17; heart, 6.98 +/- 0.20; lung, 7.81 +/- 0.46; liver, 12.94 +/- 0.24; spleen, 22.96 +/- 2.5; kidney, 11.23 +/- 0.61; prostate, 8.24 +/- 0.58; and blood, 3.76 +/- 0.30. Since levels of fluconazole of > 6 micrograms/g are needed to treat infection with most strains of Candida and levels of > 10 micrograms/g are needed for Cryptococcus neoformans, Coccidioides immitis, and Histoplasma capsulatum, the following predictions can be made. The current standard dose of 400 mg/day should be more than adequate in the treatment of urinary tract and hepatosplenic candidiasis but problematic in the treatment of candidal osteomyelitis, even with the higher levels that develop after multiple doses. Similarly, higher doses should be considered, particularly in immunocompromised patients, with infection with C. neoformans, H. capsulatum, and C. immitis that involves the central nervous and musculoskeletal systems.

Experimental hematogenous candidiasis caused by Candida krusei and Candida albicans: species differences in pathogenicity

Hematogenous infections caused by Candida krusei have been noted with increasing frequency, particularly in cancer patients receiving prophylaxis with antifungal triazoles. Progress in understanding the pathogenesis of this emerging infection has been limited by the lack of an animal model. We developed a CF1 mouse intravenous inoculation model of candidiasis to evaluate the pathogenicity of C. krusei in normal and immunosuppressed mice and to compare it with that of Candida albicans. Several inocula (10(6) to 10(8) CFU per animal) of two clinical strains of C. krusei and three American Type Culture Collection strains of C. albicans were tested. Groups of 20 mice each were injected with a single intravenous dose of one inoculum. Animals randomized to receive C. krusei were immunosuppressed by intraperitoneal injection of cyclophosphamide or the combination of cyclophosphamide plus cortisone acetate or they did not receive immunosuppressive agents (normal mice). One hundred percent mortality was observed in normal mice injected with 10(6) CFU of C. albicans per mouse compared with no mortality in normal mice that received 10(8) CFU of C. krusei per mouse (P < 0.01). Resistance to C. krusei infection was markedly lowered by immunosuppression, particularly by the combination of cyclophosphamide plus cortisone acetate, with a significantly shorter survival and a higher organ fungal burden in immunosuppressed than in normal animals (P < 0.01). Tissue infection was documented by culture and histopathologic findings in all examined organs.

The neurologic complications of human immunodeficiency virus infection

The physician caring for HIV-1-infected patients must have a good working knowledge of the broad spectrum of neurologic diseases that occur in association with this infection. As with any other neurologic disorder, the site of the neuraxis that is affected must be properly identified. In HIV-1-infected persons, more than one site may be involved simultaneously, such as the coexistence of myelopathy and peripheral neuropathy, often resulting in a confusing array of neurologic signs and symptoms. The frequent occurrence of two or more diseases affecting the neuraxis, such as progressive multifocal leukoencephalopathy and toxoplasmosis, further complicates the picture. With the AIDS patient, the physician cannot rely on the clinical adage that all attempts should be made to ascribe the patient's problems to one disease. Often, it is not the case. As with other illnesses, the approach to the HIV-1-infected person with neurologic disease needs to be thorough and fluid. After rendering a diagnosis and embarking on therapy, the physician needs to be open minded about the possibility of an incorrect or additional diagnosis not previously considered. Lastly, despite all the knowledge that has been accumulated in the first decade of the AIDS epidemic, new illnesses occurring with HIV-1 infection are recognized with regularity. The physician must always bear in mind that the illness with which he or she is confronted may be one that has not been previously described.

Clinical pharmacokinetics of fluconazole

Fluconazole was recently developed for the treatment of superficial and systemic fungal infections. Triazole groups and insertion of 2 fluoride atoms increase the polarity and hydrosolubility of the drug, allowing it to be used in a parenteral form. Bioassay methods using Candida pseudotropicalis as a test organism were the first techniques used for the determination of fluconazole in body fluids. Gas chromatographic and high performance liquid chromatographic methods were later developed with better accuracy and sensitivity. Prediction of efficacious concentrations in patients from the minimum inhibitory concentrations in vitro seems to be uncertain because of low efficacy of the drug on some yeasts in vitro compared with efficacy in vivo in animal models. Oral forms (capsule and solution) are quickly absorbed and bioavailability is nearly complete (about 90%). Plasma protein binding is low (11 to 12%) and fluconazole circulates as active drug. Distribution is extensive throughout the tissues and allows the treatment of a variety of systemic fungal infections. The average elimination half-life (t1/2) of 31.6 +/- 4.9h is long, with a minimum of 6 days needed to reach steady-state; thus, a loading dose (equal to double the maintenance dose) is recommended. The metabolism of fluconazole is not qualitatively or quantitatively significant. The main route of elimination is renal. The mean +/- SD (calculated from published data) total and renal clearance values are 19.5 +/- 4.7 and 14.7 +/- 3.7 ml/min (1.17 +/- 0.28 and 0.88 +/- 0.22 L/h), respectively. Concentrations of fluconazole in blood after administration of single doses correlated well with the administered dose. There was very little interassay variation between the data reported in literature. Concentrations in blood after multiple doses also exhibit little variation and the accumulation factor was between 2.1 and 2.8. Fluconazole was found in many body fluids, especially in cerebrospinal fluid and dialysis fluid, allowing the treatment of systemic fungal infections such as coccidioidal meningitis and fungal peritonitis. Concentrations of 1 to 3 mg/L and 20 mg/L are the extreme values expected in clinical practice. In renal insufficiency the fluconazole t1/2 is longer, requiring dosage adjustment in relation to creatinine clearance. In continuous ambulatory peritoneal dialysis a 150mg dose in a 2L dialysis solution every 2 days has been proposed. In haemodialysis, a dose of 100 or 200mg should be given at the end of each dialysis session. Neither old age nor irradiation affect fluconazole pharmacokinetics, but the t1/2 was shorter in children.(ABSTRACT TRUNCATED AT 400 WORDS)

What's new in fungal infection in leukemic patients

Fungal infections have become an important cause of mortality in patients with hematological malignancies. In recent years, fungi such as Candida tropicalis, Aspergillus spp, Fusarium spp and Trichosporon spp have emerged as important pathogens. Amphotericin B remains the antifungal agent with the broadest spectrum of activity, although some of the newer pathogens may be resistant. The administration of this drug in lipid vehicles reduces the toxicities, permitting the administration of higher doses that may be more effective. The new agents, fluconazole and itraconazole, have activity against some fungal pathogens, although their role in therapy has not been fully determined. Fluconazole has been shown to be effective for prophylaxis of Candida infections.

Current status of HIV therapy: II. Opportunistic diseases

Infections and malignancies account for most deaths in patients with AIDS and will continue to do so as long as HIV-induced immunosuppression is progressive and irreversible. Co-trimoxazole has emerged as the preferred agent for prevention of Pneumocystis carinii pneumonia. As appropriate broad-spectrum agents are developed, multiple opportunistic pathogen prophylaxis could become effective.

Parenteral and oral fluconazole for acute cryptococcal meningitis in AIDS: experience with thirteen patients

OBJECTIVE

Cryptococcus neoformans infections of the central nervous system affect up to ten percent of AIDS patients. Standard therapy with amphotericin B with or without 5-flucytosine has a high rate of failure, relapse, and toxicity. Fluconazole is a new triazole antifungal agent available in both oral and intravenous forms that has shown efficacy in the primary and maintenance treatment of cryptococcal meningitis in AIDS patients. In this open, noncomparative trial, we evaluated the safety and efficacy of intravenous fluconazole followed by oral fluconazole in the treatment of acute cryptococcal meningitis in AIDS patients.

METHODS

Thirteen AIDS patients with acute cryptococcal meningitis, or relapse after successful primary therapy, received 400 mg of intravenous fluconazole daily for 12-16 days followed by oral fluconazole 400 mg/d for the duration of primary therapy. If cerebrospinal fluid (CSF) cultures converted to negative within 32 weeks of treatment, the fluconazole dose was decreased to 200 mg/d as maintenance therapy.

RESULTS

Fluconazole therapy was successful in six patients (46 percent) and unsuccessful in seven (54 percent). Of the seven patients considered unsuccessful, one demonstrated clinical improvement but remained CSF-culture positive, five were clinical failure and were switched to amphotericin B therapy, and one died after two weeks secondary to cryptococcal meningitis. No patient experienced any adverse reactions necessitating discontinuation of therapy.

CONCLUSIONS

In this small group of patients, moderate doses of parenteral and oral fluconazole for acute cryptococcal meningitis in AIDS patients demonstrated failure rates similar to those reported in other studies with fluconazole and with amphotericin B. As there was no difference in initial Karnofsky scores or the severity of disease in treatment successes versus failures, it is difficult to determine who might respond to fluconazole as initial therapy or who should be treated initially with another agent. Further studies and clinical experience are needed.

Efficacy of fluconazole in the treatment of systemic fungal infections

The efficacy of fluconazole in the treatment of systemic fungal infections was evaluated in an open non-comparative trial. A total of 48 patients with proven or suspected fungal infections were enrolled in 40 of whom efficacy was evaluable. Candida albicans accounted for 90% of the infections. Candida parapsilosis, Candida glabrata, Histoplasma capsulatum and Aspergillus fumigatus caused the infection in one case each. Fluconazole was administered at a dosage of 200-400 mg daily for a mean duration of 15 days. Fluconazole treatment was successful in 53% of the patients. In patients with proven or probable Candida albicans infections a clinical and mycological response was achieved in 62% and 65%, respectively. In 11 patients elevation of liver enzymes was considered to be possibly related to fluconazole treatment; modification of treatment was not necessary in any case. Fluconazole was found to be a well tolerated and effective agent for the treatment of systemic Candida albicans infections.