A controlled trial of fluconazole or amphotericin B to prevent relapse of cryptococcal meningitis in patients with the acquired immunodeficiency syndrome. The NIAID AIDS Clinical Trials Group and Mycoses Study Group

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.

A randomized trial comparing fluconazole with clotrimazole troches for the prevention of fungal infections in patients with advanced human immunodeficiency virus infection. NIAID AIDS Clinical Trials Group

BACKGROUND

Cryptococcal meningitis and other serious fungal infections are common complications in patients infected with the human immunodeficiency virus (HIV). Fluconazole is effective for long-term suppression of many fungal infections, but its effectiveness as primary prophylaxis had not been adequately evaluated.

METHODS

We conducted a prospective, randomized trial that compared fluconazole (200 mg per day) with clotrimazole troches (10 mg taken five times daily) in patients who were also participating in a randomized trial of primary prophylaxis for Pneumocystis carinii pneumonia.

RESULTS

After a median follow-up of 35 months, invasive fungal infections had developed in 4.1 percent of the patients in the fluconazole group (9 of 217) and in 10.9 percent of those in the clotrimazole group (23 of 211; relative hazard, as adjusted for the CD4+ count, 3.3; 95 percent confidence interval, 1.5 to 7.6). Of the 32 invasive fungal infections, 17 were cryptococcosis (2 in the fluconazole group and 15 in the clotrimazole group; adjusted relative hazard, 8.5; 95 percent confidence interval, 1.9 to 37.6). The benefit of fluconazole was greater for the patients with 50 or fewer CD4+ cells per cubic millimeter than for the patients with higher counts. Fluconazole was also effective in preventing esophageal candidiasis (adjusted relative hazard, 5.8; 95 percent confidence interval, 1.7 to 20.0; P = 0.004) and confirmed and presumed oropharyngeal candidiasis (5.7 and 38.1 cases per 100 years of follow-up in the fluconazole and clotrimazole groups, respectively; P < 0.001). Survival was similar in the two groups.

CONCLUSIONS

Fluconazole taken prophylactically reduces the frequency of cryptococcosis, esophageal candidiasis, and superficial fungal infections in HIV-infected patients, especially those with 50 or fewer CD4+ lymphocytes per cubic millimeter, but the drug does not reduce overall mortality.

Primary prevention of cryptococcal meningitis by fluconazole in HIV-infected patients

To evaluate whether oral fluconazole reduces the risk of a first episode of cryptococcal meningitis in HIV-infected patients, we conducted a case-control study of patients cared for in a university teaching hospital and two urban HIV-outpatient clinics. Cases consisted of HIV-infected patients with CD4 cell counts less than 250/microL who developed a first episode of cryptococcal meningitis between July 1, 1990, and June 30, 1993. For each case (n = 18), 4 control subjects were chosen from HIV-infected patients (CD4 count < 250/microL) whose cerebrospinal fluid was negative for cryptococcal antigen and culture, and who were matched by age, sex, and time of lumbar puncture. There were no significant differences between cases and controls in age, sex, insurance status, mean CD4 count, history of oral candidosis, presence of a previous AIDS-defining illness, the number of visits to the HIV-outpatient clinic, or use of antiretroviral therapy. In the 6 months before lumbar puncture, 2 of 18 cases (11%) and 26 of 72 controls (36%) were exposed to fluconazole, a finding that gives a matched odds ratio (adjusted for race, route of HIV infection, and CD4 count) of 0.08 (95% CI 0.01-0.84; p = 0.035) and indicates a 92% protective efficacy. We conclude that fluconazole reduces the risk of a first episode of cryptococcal meningitis in HIV-infected patients with a CD4 count less than 250/microL. Although the optimum dose and duration of fluconazole could not be determined, our results suggest that less than daily use was effective in the prevention of cryptococcal meningitis.

Fluconazole for primary prophylaxis of AIDS-associated cryptococcosis: a case-control study

In order to verify whether fluconazole has a prophylactive effect against the occurrence of cryptococcosis in HIV-infected patients and to identify other factors capable of increasing or reducing the risk of this infection, we arranged a case-control study of 17 patients with cryptococcal infection. 34 controls were selected, matched by presence of an AIDS-defining event, CD4 cell count, and date of T-cell phenotyping. No significant difference in exposure to fluconazole, in total days of treatment, or in total dose administered was observed between cases and controls. However, control patients took a significantly higher average daily dosage of fluconazole and a linear tendency in risk reduction (p = 0.04) in relation to increasing dosage was observed. Antiretroviral therapy and an average daily fluconazole dose exceeding 150 mg both each reduced the risk of a cryptococcal infection.

Targeted gene replacement demonstrates that myristoyl-CoA: protein N-myristoyltransferase is essential for viability of Cryptococcus neoformans

Cryptococcus neoformans is a major cause of systemic fungal infection in immunocompromised patients. Myristoyl-CoA:protein N-myristoyltransferase (Nmt) catalyzes the transfer of myristate (C14:0) from myristoyl-CoA to the N-terminal glycine of a subset of cellular proteins produced during vegetative growth of C. neoformans. A Gly487-->Asp mutation was introduced into C. neoformans NMT by targeted gene replacement. The resulting strains are temperature-sensitive myristic acid auxotrophs. They are killed at 37 degrees C when placed in medium lacking myristate and, in an immunosuppressed animal model of cryptococcal meningitis, are completely eliminated from the subarachnoid space within 12 days of initial infection. C. neoformans and human Nmts exhibit differences in their peptide substrate specificities. These differences can be exploited to develop a new class of fungicidal drugs.

Therapy for fungal infections

In the past, few pharmacologic agents were available for management of fungal disease. After the early introduction of amphotericin B and miconazole, the more recent advent of several new antifungal agents, including ketoconazole, fluconazole, and itraconazole has expanded the options for treatment of fungal infections. The dramatic increase in number of immunocompromised patients--both those with acquired immunodeficiency syndrome (AIDS) and those with immunosuppression for other reasons, such as organ transplantation--emphasizes the importance of therapeutic strategies for combating systemic mycoses. In this article, we review our personal recommendations for treating histoplasmosis, blastomycosis, coccidioidomycosis, and cryptococcosis, along with other less common fungal infections, and discuss the efficacy and toxic effects of the various antifungal drugs.

Management of systemic manifestations of fungal disease in patients with AIDS

In patients with AIDS with cryptococcosis, prompt diagnosis is essential. Poor results with conventional therapy (amphotericin-5FC) have led to exploration of the azoles. Both fluconazole and itraconazole have given good short-term results with less toxicity. However, cure is achieved far less often than in other compromised hosts. Fluconazole is also useful to prevent relapse after successful initial amphotericin therapy, particularly from genitourinary foci. In both histoplasmosis and aspergillosis, itraconazole has produced impressive therapeutic results, and in histoplasmosis, secondary prophylaxis as well. In coccidioidomycosis results thus far have not been better than conventional amphotericin therapy, especially in initial treatment.

The pharmacokinetics of fluconazole after a single intravenous dose in AIDS patients

The pharmacokinetics of fluconazole after a single 100 mg i.v. dose were studied in 10 healthy subjects (5 M; 5 F) and 10 HIV-positive patients (8 M; 2 F). The mean value of plasma clearance was 25% lower in the patient groups (17 +/- 6 (s.d.) vs 23 +/- 4 ml min-1; 95% CI of difference -11 to -0.7; P < 0.05). This difference may have been related to slightly reduced kidney function in the patient group (mean creatinine clearance -18%) but is unlikely to be clinically significant. Therefore, no adjustment of the dose of intravenously administered fluconazole appears to be necessary in AIDS patients without clinical signs of enteropathy.

Disseminated cryptococcosis in a patient with AIDS

We report the case of a 31-year-old AIDS patient who had generalized cryptococcal disease with involvement of the lungs, bone marrow, gastrointestinal tract and skin as well as chorioretinitis which may have been due also to Cryptococcus neoformans infection. Initially there was no involvement of the central nervous system. The patient recovered after 43 days' treatment with fluconazole and amphotericin B and flucytosine initially. Four months later he presented with a cryptococcal splenic abscess despite secondary prevention with fluconazole and twice-weekly liposomal amphotericin B. After splenectomy the patient was discharged in good health. One year later he died of cryptococcal meningitis.

Antifungal agents: an overview. Part II

The recent introduction of a new generation of antifungal drugs promises to alter significantly therapy for both systemic and superficial mycoses, in particular, onychomycosis. This article presents an in-depth review of the azoles (the triazoles itraconazole and fluconazole), the allylamines (naftifine and terbinafine), and the morpholine derivative amorolfine.

Cutaneous involvement with Cryptococcus neoformans in AIDS

Patients infected with HIV are susceptible to many opportunistic fungal infections. Cryptococcus neoformans infection is particularly common in patients with AIDS. We describe a patient with disseminated cryptococcosis resembling molluscum contagiosum and review the typical cutaneous manifestations of disseminated cryptococcosis. A synopsis of case reports in the English literature is also presented.

Racial differences in the use of drug therapy for HIV disease in an urban community

BACKGROUND

Guidelines for drug therapy in human immunodeficiency virus (HIV) disease are based primarily on the stage of the disease. To determine whether sociodemographic characteristics of patients influence drug therapy in practice, we analyzed the use of antiretroviral therapy and prophylactic therapy for Pneumocystis carinii pneumonia (PCP) in an urban population infected with HIV.

METHODS

All patients presenting for the first time to our HIV clinic from March 1990 through December 1992 were enrolled. Data on sociodemographic and clinical variables and on drug use were collected at the time of presentation and after six months. We asked whether patients with CD4+ cell counts of 500 or less per cubic millimeter were receiving antiretroviral therapy at the time of presentation, and whether patients with CD4+ cell counts of 200 or less per cubic millimeter were receiving PCP prophylaxis.

RESULTS

Among the 838 patients enrolled, 656 (79 percent) were blacks, 167 (20 percent) were non-Hispanic whites, and 15 (2 percent) were Asian or Hispanic descent or were not racially classified. There were no racial differences in the stage of HIV disease at the time of presentation. However, there were racial disparities in the receipt of antiretroviral therapy: 63 percent of eligible whites but only 48 percent of eligible blacks received such therapy (P = 0.003). PCP prophylaxis was received by 82 percent of eligible whites but only 58 percent of eligible blacks (P < 0.001). There were no significant differences in the receipt of drug therapy with respect to age, sex, mode of HIV transmission, type of insurance, income, education, or place of residence. In a logistic-regression analysis, race was the feature most strongly associated with the receipt of drug therapy. When blacks were compared with whites, the adjusted relative odds were 0.59 (95 percent confidence interval, 0.38 to 0.93) for the receipt of an antiretroviral agent and 0.27 (95 percent confidence interval, 0.13 to 0.56) for the receipt of PCP prophylaxis.

CONCLUSIONS

Among patients infected with HIV, blacks were significantly less likely than whites to have received antiretroviral therapy or PCP prophylaxis when they were first referred to an HIV clinic. This disparity suggests a need for culturally specific interventions to ensure uniform access to care, including drug therapy, and uniform standards of care.

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.

Fungicidal properties of defensin NP-1 and activity against Cryptococcus neoformans in vitro

Defensin NP-1, derived from the neutrophils of rabbits, was tested for its fungistatic and fungicidal activity against strains of Cryptococcus neoformans. The MICs for the encapsulated strains tested ranged from 3.75 to 15.0 micrograms of NP-1 per ml. The minimum fungicidal concentrations for these strains were similar to the MICs. An acapsular strain, however, had a lower MIC of 0.93 and minimum fungicidal concentration of 1.88 micrograms/ml. NP-1 demonstrated time-dependent and concentration-dependent killing of C. neoformans. Killing occurred rapidly in the first 20 min of exposure to NP-1 and was maximum at 90 to 120 min. Killing of C. neoformans by NP-1 was concentration dependent with 31% +/- 9% survival at 25 micrograms/ml, 13% +/- 4% survival at 50 micrograms/ml, 9% +/- 5% survival at 75 micrograms/ml, and 5% +/- 3% survival at 100 micrograms/ml. NP-1's fungicidal effect on C. neoformans was also inoculum dependent, with increased activity observed at 10(4) versus 10(5) or 10(6) cells per ml. In addition, stationary-phase C. neoformans was less susceptible to NP-1 killing than yeast cells in the logarithmic phase. Subinhibitory concentrations of both NP-1 (0.25 x MIC) and fluconazole (0.25 x MIC) acted synergistically in inhibiting growth of C. neoformans. Similar combinations of NP-1 and amphotericin B, however, did not yield synergy.

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.

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.

Dapsone-pyrimethamine compared with aerosolized pentamidine as primary prophylaxis against Pneumocystis carinii pneumonia and toxoplasmosis in HIV infection. The PRIO Study Group

BACKGROUND

Pneumocystis carinii pneumonia and toxoplasmic encephalitis are frequent life-threatening opportunistic infections in patients with human immunodeficiency virus (HIV) infection. Primary prophylaxis against P. carinii pneumonia is now common, but there are few data on regimens for primary prophylaxis against toxoplasmosis.

METHODS

We conducted a randomized trial that compared two prophylactic regimens: dapsone (50 mg per day) plus pyrimethamine (50 mg per week) was compared with aerosolized pentamidine (300 mg per month). The patients had symptomatic HIV infection, no history of P. carinii pneumonia or symptomatic toxoplasmosis, and CD4+ counts below 200 per cubic millimeter (0.2 x 10(9) per liter).

RESULTS

In an intention-to-treat analysis, after a median follow-up of 539 days P. carinii pneumonia developed in 10 patients in each group, whereas toxoplasmosis developed in 32 of 176 patients in the pentamidine group and 19 of 173 patients in the dapsone-pyrimethamine group. Those assigned to pentamidine had a risk of P. carinii pneumonia that was similar to the risk in those assigned to dapsone-pyrimethamine (adjusted relative risk, 1.13; 95 percent confidence interval, 0.44 to 2.92; P = 0.79), but a higher risk of toxoplasmosis (adjusted relative risk, 1.81; 95 percent confidence interval, 1.12 to 2.94; P = 0.02). Among the 262 patients with serologic evidence of past exposure to Toxoplasma gondii, the relative risk of symptomatic toxoplasmosis was 2.37 times higher in those assigned to pentamidine (95 percent confidence interval, 1.3 to 4.4; P = 0.006). More patients discontinued dapsone-pyrimethamine than pentamidine because of toxicity (42 vs. 3; P < 0.001). Survival was similar in the two groups.

CONCLUSIONS

For primary prevention of P. carinii pneumonia, dapsone-pyrimethamine is as effective, though not as well tolerated, as aerosolized pentamidine. Dapsone-pyrimethamine also prevents first episodes of toxoplasmosis.

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)

Antifungal prophylaxis in immunocompromised hosts

OBJECTIVE

To review the literature on the efficacy and safety of antifungal agents for prophylaxis of fungal infections in populations of immunocompromised hosts (key words: hematology-oncology, surgical, solid organ transplant, HIV infection), and to develop guidelines and recommendations regarding safe and effective drug regimens for antifungal prophylaxis in this patient population.

DATA EXTRACTION

Comprehensive review of clinical trials of antifungal prophylaxis published in the English literature, with an emphasis on controlled trials, and discussion of key clinical trials illustrating efficacy and safety of agents for antifungal prophylaxis in immunocompromised patients.

RESULTS

Much of the clinical data evaluating the efficacy and safety of antifungal prophylaxis has been generated in cancer patients. The choice of antifungal agent for prophylaxis in this population remains controversial. However, azole compounds such as clotrimazole, ketoconazole and fluconazole appear to be more effective and better tolerated than nystatin suspension. Although ketoconazole has been shown to reduce fungal colonization in surgical patients, current data do not support the routine use of antifungal prophylaxis in this population. In renal transplant recipients, clotrimazole troches have been shown to be more effective than placebo or nystatin suspension. Selective bowel decontamination with nonabsorbable antibiotics and nystatin may be useful in reducing Candida colonization in liver transplant patients but no definitive recommendations may be made at this time regarding optimal antifungal prophylaxis in these patients. In patients with advanced HIV disease or history of prior fungal disease prophylaxis for oropharyngeal candidiasis is indicated, although the agent of choice remains controversial. Fluconazole is the drug of choice for prevention of relapse of cryptococcal meningitis in patients with AIDS. Finally, only limited data exist assessing the relationship between local colonization and systemic fungal infection. Adverse effects associated with antifungal prophylaxis, generally limited to nausea and vomiting and transient elevations in hepatic transaminases, occur with similar frequency among available oral or topical agents. However, the incidence of nausea and vomiting with resultant poor patient tolerance and compliance is usually higher with nystatin.

CONCLUSIONS

Based on available data from controlled clinical trials, azole agents are currently the most effective and best-tolerated drugs for antifungal prophylaxis in immunocompromised hosts. Choice of one agent in this group over another may be dictated by cost. As new antifungal treatments are released onto the market, these drugs should be compared with existing agents in controlled clinical trials. Future studies should be designed to evaluate the relationship between local colonization and disseminated infection.

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.