New antifungal agents

Design, synthesis, docking and in vitro antifungal study of 1,2,4-triazole hybrids of 2-(aryloxy)quinolines

Substituted quinolines containing a 1,2,4-triazole moiety were synthesized using reported methods. The molecular docking studies support the experimental results that these compounds are active against

An MDR1 promoter allele with higher promoter activity is common in clinically isolated strains of Candida albicans

In the opportunistic fungal pathogen Candida albicans, up-regulation of MDR1, encoding an efflux transporter, leads to increased resistance to the antifungal drug fluconazole. Antifungal resistance has been linked to several types of genetic change in C. albicans, including changes in genome structure, genetic alteration of the drug target, and overexpression of transporters. High-level over-expression of MDR1 is commonly mediated by mutation in a trans-acting factor, Mrr1p. This report describes a second mechanism that contributes to up-regulation of MDR1 expression. By analyzing the sequence of the MDR1 promoter region in fluconazole-resistant and fluconazole-susceptible strains, we identified sequence polymorphisms that defined two linkage groups, corresponding to the two alleles in the diploid genome. One of the alleles conferred higher MDR1 expression compared with the other allele. Strains in which both alleles were of the higher activity type were common in collections of clinically isolated strains while strains carrying only the less active allele were rare. As increased expression of MDR1 confers higher resistance to drugs, strains with the more active MDR1 promoter allele may grow or survive longer when exposed to drugs or other selective pressures, providing greater opportunity for mutations that confer high-level drug resistance to arise. Through this mechanism, higher activity alleles of the MDR1 promoter could promote the development of drug resistance.

Fungal urinary tract infections in the dog and cat: a retrospective study (2001-2004)

Thirty-five animals (23 dogs, 12 cats) with fungal urinary tract infections (UTIs) were retrospectively studied. Dysuria, hematuria, increased frequency of micturition, anorexia, depression, and pyrexia were the most common clinical signs noted. Seven species of fungi were identified in the affected animals. Candida albicans was the most common isolate. Most animals diagnosed with fungal UTI also had other concurrent urinary tract or medical problems. Lower urinary tract diseases, diabetes mellitus, neoplasia, and renal failure were the most common concurrent or preceding diseases identified. Resolution of fungal UTI occurred in 12 animals that received specific antifungal treatment.

Paranasal sinus aspergillosis: its categorization to develop a treatment protocol. Nasennebenhohlen-Aspergillose: Kategorisiertes Behandlungsprotokoll

A prospective study was conducted in 25 consecutive patients of paranasal sinus aspergillosis to categorize and treat them based on a fixed treatment protocol. The three types of aspergillosis categorized as per definitive criteria were chronic invasive (six), non-invasive (fungus ball) (seven) and non-invasive destructive (12). Adjuvant chemotherapy was employed in non-invasive destructive and chronic invasive disease. Ketoconazole was used in the first variety and itroconazole in the latter. Only two patients had recurrence after a mean follow-up of 11 months (range: 6-20 months). They belonged to the non-invasive destructive category and the recurrence had progressed to invasive variety. It is suggested that non-invasive destructive disease should be followed up regularly with endoscopic examination, CT and fungal serology to detect recurrence. Categorization of the paranasal sinus aspergillosis helps to institute proper treatment. Adjuvant chemotherapy in the form of ketoconazole along with surgery is effective in non-invasive destructive disease to prevent recurrence and progression to invasive disease. Chronic invasive disease with its propensity to involve orbit and intracranial cavity should be managed at the earliest with surgery and itraconazole.

In vitro and in vivo antifungal activities of TAK-456, a novel oral triazole with a broad antifungal spectrum

TAK-456 is a novel oral triazole compound with potent and broad-spectrum in vitro antifungal activity and strong in vivo efficacy against Candida albicans and Aspergillus fumigatus. TAK-456 inhibited sterol synthesis of C. albicans and A. fumigatus by 50% at 3 to 11 ng/ml. TAK-456 showed strong in vitro activity against clinical isolates of Candida spp., Aspergillus spp., and Cryptococcus neoformans, except for Candida glabrata. The MICs at which 90% of the isolates tested were inhibited byTAK-456, fluconazole, itraconazole, voriconazole, and amphotericin B were 0.25, 4, 0.5, 0.13, and 0.5 microg/ml, respectively, for clinical isolates of C. albicans and 1, >64, 0.5, 0.5, and 0.5 microg/ml, respectively, for clinical isolates of A. fumigatus. Therapeutic activities of TAK-456 and reference triazoles against systemic lethal infections caused by C. albicans and A. fumigatus in mice were investigated by orally administering drugs once daily for 5 days, and efficacies of the compounds were evaluated by the prolongation of survival. In normal mice, TAK-456 and fluconazole were effective against infection caused by fluconazole-susceptible C. albicans at a dose of 1 mg/kg. In transiently neutropenic mice, therapeutic activity of TAK-456 at 1 mg/kg of body weight against infection with the same strain was stronger than those at 1 mg/kg of fluconazole. TAK-456 was effective against infections with two strains of fluconazole-resistant C. albicans at a dose of 10 mg/kg. TAK-456 also expressed activities similar to or higher than those of itraconazole against the infections caused by two strains of A. fumigatus in neutropenic mice at a dose of 10 mg/kg. These results suggest that TAK-456 is a promising candidate for development for the treatment of candidiasis and aspergillosis in humans.

Efficacy of TAK-457, a novel intravenous triazole, against invasive pulmonary Aspergillosis in neutropenic mice

TAK-457 is an injectable prodrug of TAK-456, which is a novel oral triazole compound with potent antifungal activity. The in vivo efficacy of TAK-457 was evaluated in two models of invasive pulmonary aspergillosis with CDF(1) mice and CBA/J mice with transient neutropenia induced by cyclophosphamide. Against the infection in CDF(1) mice, treatment with 10 mg of TAK-457 and 1 mg of amphotericin B/kg reduced the fungal burden in lungs and rescued all mice. In the infection model with CBA/J mice, TAK-457 at a dose of 10 mg/kg significantly prolonged the survival time of mice, showing significant reduction of lung chitin levels and the plasma beta-D-glucan levels. On the other hand, amphotericin B at 1 mg/kg which was a maximum tolerable dose showed slight but not significant prolongation of survival time of mice, although it also reduced the lung chitin levels and the plasma beta-D-glucan levels to a lower extent but still significantly. These results suggest that TAK-457 is a promising candidate for development for the treatment of invasive aspergillosis in humans.

Optically active antifungal azoles. XII. Synthesis and antifungal activity of the water-soluble prodrugs of 1-[(1R,2R)-2-(2,4-difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-triazol-1-yl)propyl]-3-[4-(1H-1-tetrazolyl)phenyl]-2-imidazolidinone

1-[(1R,2R)-2-(2,4-Difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-triazol-1-yl)propyl]-3-[4-(1H-1-tetrazolyl)phenyl]-2-imidazolidinone (1: TAK-456) was selected as a candidate for clinical trials, but since its water-solubility was insufficient for an injectable formulation, the quaternary triazolium salts 2 were designed as water-soluble prodrugs. Among the prodrugs prepared, 4-acetoxymethyl-1-[(2R,3R)-2-(2,4-difluorophenyl)-2-hydroxy-3-[2-oxo-3-[4-(1H-1-terazolyl)phenyl]-1-imidazolidinyl]butyl]-1H-1,2,4-triazolium chloride (2a: TAK-457) was selected as an injectable candidate for clinical trials based on the results of evaluations on solubility, stability, hemolytic effect and in vivo antifungal activities.

In vitro and in vivo activities of syn2836, syn2869, syn2903, and syn2921: new series of triazole antifungal agents

The in vitro and in vivo activities of four azole compounds belonging to a new series of 2(2,4-difluorophenyl)-3-(4-substituted piperazin-1-yl)-1-(1,2,4-triazol-1-yl) butanol antifungal agents is described. The compounds were selected from a library of azole compounds synthesized by our group. The in vitro activities of Syn2869, Syn2836, Syn2903, and Syn2921 against a panel of over 240 recently collected clinical isolates of yeast and molds were determined, and the results were compared with those obtained with fluconazole (FLC), itraconazole (ITC), and amphotericin B (AMB). The MICs at which 90% of the isolates were inhibited (MIC(90)s) for the four test compounds for strains of Candida spp. ranged from <0.048 to 0.78 microg/ml. All compounds were also active against FLC-resistant Candida albicans and other Candida sp. strains. Moreover, MIC(90)s for strains of Cryptococcus neoformans, Aspergillus spp., Trichophyton spp., and Microsporum spp. were also low and ranged from <0.048 to 0.39 microg/ml. The test compounds produced a fungistatic pattern during the time-kill kinetic studies. In vivo studies indicated that all four test compounds have good efficacies against C. albicans in a murine systemic infection model and significantly improved the survival rates of the infected mice. The results for Syn2903 were similar to those for FLC, while the other compounds were slightly less effective but had ranges of activities similar to the range of activity of ITC. The compounds were also evaluated against an Aspergillus fumigatus systemic infection. Syn2903 was also superior to ITC, whereas the efficacy data for the other compounds were similar to those for ITC. It was concluded from the data generated for this new series of azole compounds in the studies described above that further pharmacokinetic and toxicologic evaluations are warranted prior to selection of a candidate compound for preclinical testing.

Systemic antifungal therapy

Systemic antifungal therapy for superficial mycoses has advanced greatly since the introduction of griseofulvin in 1958. The discovery of the azole antifungal compounds, ketoconazole, itraconazole, and fluconazole, allowed for a broader spectrum of treatment and a shorter treatment duration. Terbinafine, through a unique mechanism of action, has a fungicidal power not seen previously in the other antifungals. It is important to use our knowledge of the pharmacology in combination with clinical experience and cost of therapy in order to select the proper drug. The search to identify new oral antifungal agents should continue, since none of the five currently used drugs fulfill the criteria of the "ideal" antifungal.

Efficacies of two new antifungal agents, the triazole ravuconazole and the echinocandin LY-303366, in an experimental model of invasive aspergillosis

The efficacy of ravuconazole, a new triazole antifungal agent, and the echinocandin LY-303366 were evaluated in an immunosuppressed, temporarily leukopenic rabbit model of invasive aspergillosis. Oral therapy with ravuconazole at a dosage of 30 mg/kg of body weight per day or the echinocandin LY-303366, given intravenously in a dosage of 5 or 10 mg/kg, was begun 24 h after a lethal or sublethal challenge, and results were compared with those for amphotericin B therapy and untreated controls. Prophylaxis was also studied with LY-303366 given at a dosage of 5 or 10 mg/kg/day 48 h before lethal or sublethal challenge. Ravuconazole eliminated mortality, cleared aspergillus antigen from the serum, and eliminated Aspergillus fumigatus organisms from tissues of both lethally and sublethally challenged immunosuppressed animals with invasive aspergillosis. Although LY-303366, at both doses, prolonged survival and reduced aspergillus antigenemia, it did not eliminate aspergillus organisms from organ tissues. The half-lives of ravuconazole and LY-303366 in rabbits were 13 and 12.5 h, respectively, and no accumulation of either drug was seen after 6 days of treatment. Although LY-303366 showed activity in this rabbit model of invasive aspergillosis, ravuconazole was the more active agent, comparable to amphotericin B. Additional studies are needed to determine the potential of ravuconazole for use in the treatment of this infection.

Efficacy of voriconazole in a guinea pig model of disseminated invasive aspergillosis

Voriconazole (VRC) was evaluated in an immunosuppressed-guinea pig model of invasive aspergillosis. VRC was more effective than amphotericin B or similar doses of itraconazole in the clearance of Aspergillus from tissues. VRC treatment regimens improved survival and significantly reduced tissue colony counts compared with those of controls.

Effects of fluconazole on viable cell count in experimental intraperitoneal Candida abscesses

We investigated the effects of fluconazole in experimental intraperitoneal Candida abscesses in neutropenic mice treated with cyclophosphamide to assess a clinically appropriate method for the application of fluconazole in fungal infections in patients with neutropenia. The efficacy of fluconazole in fungal infection was investigated in treatments started immediately after Candida albicans inoculation and before C. albicans inoculation (preventive use of fluconazole). In this intraabdominal fungal abscess model, it was confirmed that fungi in already formed abscess were not reduced in number by fluconazole, even when those fungi were susceptible to fluconazole. Fluconazole was effective with both administration methods. We conclude from this study that the effect of the preventive use of fluconazole was equivalent to the effect when treatment was started immediately after fungal inoculation.

Interspecies comparison of pharmacokinetics of the novel triazole antifungal agent SYN-2869 and its derivatives

The pharmacokinetics and distribution in tissue of several novel triazole antifungal agents were studied in different animal species in order to select an appropriate lead compound. The purpose of the study was also to determine species differences in pharmacokinetics for SYN azoles to select the most appropriate species for secondary efficacy and toxicological evaluation of the selected compound. SYN-2836, SYN-2869, SYN-2903, and SYN-2921 were rapidly absorbed into the systemic circulation and reached maximum concentrations (C(max)s) of 7.31 +/- 2.53, 6.29 +/- 0.85, 6.16 +/- 0.39, and 3.41 +/- 0.34 microg/ml, respectively, in BALB/c mice after administration of an oral dose of 50 mg/kg of body weight, with bioavailability being greater than 45% in all mice. The areas under the concentration-time curve from time zero to infinity (AUC(0-infinity)s) after administration of a single intravenous dose of 20 mg/kg to mice varied between 25.0 and 63.6 microg. h/ml. The half-life was in the range of 4.5 to 6 h. In Sprague-Dawley rats there was no significant difference in AUC(0-infinity) after administration of a single intravenous dose of 20 mg/kg, but on oral administration, the bioavailability of SYN-2836 was extremely low, while that of SYN-2869 was only 14.7%. In New Zealand White rabbits the C(max) and the time to reach C(max) for SYN-2836 and SYN-2869 after administration of a single oral dose of 50 mg/kg were similar. There were significant differences in AUC(0-infinity) and half-life between SYN-2836 and SYN-2869. On the other hand, in beagle dogs the C(max) and AUC(0-infinity) of SYN-2836 after administration of a single oral dose of 30 mg/kg were 4.82 +/- 1.54 microg/ml and 41.8 +/- 15.7 microg. h/ml, respectively, which were threefold higher than those of SYN-2869. The concentrations of the SYN compounds in tissue indicated that the AUC(0-infinity)s of SYN-2836, SYN-2869, SYN-2903, and SYN-2921 in mouse lungs were significantly different from each other. The ratios of the concentrations of the SYN azoles in lungs to those in plasma were also significantly different from those for itraconazole. Among the SYN azoles the highest concentration in the lungs was found for SYN-2869. The higher level of distribution of SYN-2869 into lung tissue was considered to contribute to the potent efficacy in respiratory tract infection models compared with the potency of itraconazole. Significant differences in the pharmacokinetics of these compounds were observed in different animal species, and selection of an animal model for further evaluation was based on results obtained from these studies.

Efficacy of SCH56592 in a rabbit model of invasive aspergillosis

SCH56592 (SCH) was evaluated in an immunosuppressed rabbit model of invasive aspergillosis. SCH was more effective than similar doses of itraconazole and as effective as amphotericin B in the clearance of Aspergillus spp. from tissues. Compared with controls, SCH regimens reduced mortality, improved survival, and significantly reduced tissue colony counts.

Remarkable case of early Aspergillus endophthalmitis

BACKGROUND

This case demonstrates the early stage of Aspergillus endophthalmitis and is the second ultrastructural study of endogenous Aspergillus endophthalmitis. It is the first description of phagocytosis of Aspergillus fungi by retinal pigment epithelium (RPE).

METHODS

A case report and detailed light- and electron microscopic findings are presented.

RESULTS

Histopathological examination of serial sections of the affected right eye displayed a spread of Aspergillus fumigatus fungi along two separate paths: via the retinal and choroidal vessels. The retinal and choroidal lesions were not contiguous. The organisms penetrated blood vessel walls, Bruch's membrane and the internal limiting membrane, but not the RPE layer. A curious accumulation of the Aspergillus fungi was present on the internal aspect of Bruch's membrane, where the RPE acted as a barrier and the subretinal space was not invaded. Phagocytosis of fungi by the RPE was observed. No inflammatory cells were present between Bruch's membrane and the RPE.

CONCLUSIONS

This report describes a remarkable barrier function, possible local immunosuppression and phagocytosis by the RPE cells in a case of early Aspergillus endophthalmitis.

Clinical management of selected oral fungal and viral infections during HIV-disease

The purpose of this review is to describe current possibilities of management of selected fungal and viral oral opportunistic infections including oral candidiasis, herpes simplex type 1 and 2-related lesions (HSV1,2), oral hairy leukoplakia (OHL) and oral lesions associated with human papilloma viruses (HPV). Less common diseases such as cytomegalovirus infection or human herpes virus type 8 associated with Kaposi's sarcoma and others are not considered. In a number of instances lifelong therapy or prophylaxis has to be instituted. Antiretroviral combination therapy, also called highly active antiretroviral therapy (HAART), has considerably changed the frequency of oral lesions caused by opportunistic agents. A short description of the antiretroviral agents available including respective side-effects is presented.

The prognostic factors of cryptococcal meningitis in HIV-negative patients

Seventy-one patients with cryptococcal meningitis, 46 males and 25 females, aged 15-83 years, were included in this study. Their initial clinical manifestations, cerebrospinal fluid (CSF) features, and therapeutic results were analysed. Patients were treated with three different regimens: amphotericin B, fluconazole, and combination therapy. Based on the therapeutic results, the 71 patients were also divided into cured, improved, and failed groups. For statistical comparison, the clinical manifestations and CSF features, were compared according to therapeutic outcome. There was no statistical difference in outcome among the three different antifungal regimens. However, patients treated with fluconazole required 36% fewer days of hospitalization compared with those receiving amphotericin B. Significant prognostic factors, included low CSF glucose, high CSF lactate, high CSF cryptococcal antigen titre (> or = 1:1024), initial level of consciousness, the presence of seizure, hydrocephalus, and central nervous system vasculitis. Multiple logistic regression analysis showed that only initial level of consciousness, and CSF antigen titre were strongly associated with therapeutic failure after other potentially confounding factors were adjusted for. Because some of the prognostic factors in cryptococcal meningitis can be corrected, early diagnosis, early use of appropriate antifungal treatment, and the correction of the underlying metabolic derangements are important in management.

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.

Paranasal sinus mycoses in north India

Recognizing the high incidence of paranasal sinus mycoses in north India, we analysed retrospectively the clinical, mycological and management aspects of 178 patients with proven disease attending our institute. On the basis of clinical, radiological, histopathological and mycological findings, the patients could be categorized into those with allergic (8), non-invasive (92) and invasive (78) disease types. Bony erosion without mucosal invasion by fungi was seen in 16 patients with non-invasive disease. Young men from rural areas were the most commonly affected. Rhinorrhoea with nasal polyposis (45.8%) and proptosis (46.4%) was the most common presentation. Concurrent involvement of the maxillary and ethmoid sinuses was common in these patients, whereas isolated sphenoid and frontal sinuses were involved in the invasive variety only. Orbital and intracranial extensions were detected in 100% and 13.2%, respectively, of patients with the invasive type of disease. Aspergillus flavus (79.7%) was the most common isolate. Surgical debridement and sinus ventilation were adequate for the effective management of the non-invasive disease. However, adjuvant medical therapy was included in treatment of the semi-invasive and invasive varieties of the disease. Itraconazole was found to be most useful in prevention of recurrence in the invasive type. Mortality was highest (33.3%) among patients with zygomycotic infection. Invasive fungal granuloma with orbital and intra-cranial invasion is a distinct entity in terms of its clinical course and treatment compared with non-invasive fungal sinusitis, and it needs to be treated aggressively with surgical excision and postoperative itraconazole.

The treatment of systemic candidiasis in neonates with oral fluconazole

Fungal septicaemia has become a frequent problem in neonatal intensive care units. The usual treatment for this condition, amphotericin B alone or in combination with 5-fluorocytosine, is sometimes unsatisfactory, especially in neonates. We report our experience of fluconazole in neonates. Neonates who developed Candida septicaemia in the neonatal unit of Ga-Rankuwa Hospital (MEDUNSA) over a 1-year period were treated with oral fluconazole. The diagnosis was based on fungal cultures obtained from sites which are normally sterile. Blood cultures and renal, haematological and liver functions were monitored regularly. Therapy was continued for at least 1 week after the first negative culture was obtained. Twenty-one neonates were treated; the clinical and microbiological cure rate was 90.5%. No serious renal, haematological or hepatic complications were detected; mild hepatotoxicity was evidenced by elevated enzymes in a third of the children. Relapse occurred in one baby who received inadequate doses of fluconazole. Two babies died of causes unrelated to a systemic fungal infection. We conclude that fluconazole may be a safe and effective alternative for the management of systemic candidiasis in neonates. A comparative trial is necessary.

Pradimicins: a novel class of broad-spectrum antifungal compounds

Pradimicins are a new class of antifungal compounds currently undergoing preclinical and early phase I clinical trials. The pradimicin structure is characterized by an aglycone of dihydrobenzo (alpha) naphthacenequinone with substitutions by a D-amino acid and hexose sugar. Pradimicins possess a novel mechanism of action consisting of a specific binding recognition to terminal D-mannosides of the cell wall of Candida albicans, resulting in the formation of a ternary complex consisting of D-mannoside, pradimicin, and calcium that leads to disruption of the integrity of the fungal cell membrane. Pradimicin in the form of BMS-181184 has broad-spectrum in vitro antifungal activity against Candida spp., Cryptococcus neoformans, Aspergillus spp., dematiaceous molds, and the Zygomycetes. Fusarium spp. are comparatively resistant to high concentrations of pradimicin. Initial vivo studies indicate that pradimicins have antifungal activity against experimental murine disseminated candidiasis and disseminated aspergillosis. Early studies indicate an excellent therapeutic index with no major end-organ toxicity. Pradimicins warrant further investigation for treatment of opportunistic mycoses in immuno-compromised hosts.

T-8581, a new orally and parenterally active triazole antifungal agent: in vitro and in vivo evaluations

T-8581 is a new water-soluble triazole antifungal agent. The geometric mean IC80s (GM-IC80S; where the IC80 is the lowest drug concentration which reduced the optical density at 630 nm by 80% compared with the optical density at 630 nm of the drug-free control) for Candida albicans were as follows: T-8581, 0.218 microgram/ml; fluconazole; 0.148 microgram/ml; and itraconazole, 0.0170 microgram/ml. For Cryptococcus neoformans the GM-IC80s were as follows: T-8581, 9.28 micrograms/ml; fluconazole, 4.00 micrograms/ml; and itraconazole, 0.119 microgram/ml. For Aspergillus fumigatus the GM-IC80s were as follows: T-8581, 71.0 micrograms/ml; fluconazole, 239 micrograms/ml; and itraconazole, 0.379 microgram/ml. Against systemic candidiasis in mice, the 50% effective doses (ED50s) of T-8581, fluconazole, and itraconazole (given orally) were 0.412, 0.392, and > 320 mg/kg of body weight, respectively. Against systemic aspergillosis in mice, the ED50s of T-8581, fluconazole, and itraconazole (given orally) were 50.5, 138, > 320 mg/kg, respectively. T-8581 was also efficacious when it was given parenterally (ED50, 59.2 mg/kg), while the ED50 of fluconazole given parenterally was > 20 mg/kg. Against systemic aspergillosis in rabbits, T-8581 was more effective than fluconazole and itraconazole in prolonging the life span. The high concentrations of T-8581 were observed in the sera of mice, rats, rabbits and dogs. Species differences in half-lives and areas under the concentration-time curves were observed, with the values for mice, rats, rabbits, and dogs increasing in that order. These results suggest that T-8581 would be a potentially effective antifungal drug for oral and parenteral use.

In vitro and in vivo antifungal activities of ER-30346, a novel oral triazole with a broad antifungal spectrum

ER-30346 is a novel oral triazole with a broad spectrum of potent activity against a wide range of fungi. ER-30346, with MICs at which 90% of the strains tested are inhibited (MIC90s) ranging from 0.025 to 0.78 microgram/ml, was 4 to 32 times more active than itraconazole, fluconazole, and amphotericin B against Candida albicans, Candida parapsilosis, and Candida glabrata. Against Candida tropicalis, ER-30346, with an MIC90 of 12.5 micrograms/ml, was 2 to > 8 times more active than itraconazole and fluconazole, but was 16 times less active than amphotericin B. ER-30346 (MIC90, 0.78 microgram/ml) was four to eight times more active than fluconazole and amphotericin B and had activity comparable to that of itraconazole against Trichosporon beigelli. The MIC90s of ER-30346 were 0.10 microgram/ml for Cryptococcus neoformans and 0.39 microgram/ml for Aspergillus fumigatus. ER-30346 was 2 to 8 times more active than itraconazole and amphotericin B and 32 to > 256 times more active than fluconazole. ER-30346 also showed good activity against dermatophytes, with MICs ranging from 0.05 to 0.39 microgram/ml, and its activity was comparable to or 2 to 16 times higher than those of itraconazole and amphotericin B and > 32 times higher than that of fluconazole. In vivo activity was evaluated with systemic infections in mice. Against systemic candidiasis and cryptococcosis, ER-30346 was comparable in efficacy to fluconazole and was more effective than itraconazole. Of the drugs tested, ER-30346 was the most effective drug against systemic aspergillosis. We studied the levels of ER-30346 in mouse plasma. The maximum concentration of drug in plasma and the area under the concentration-time curve for ER-30346 showed good linearity over a range of doses from 2 to 40 mg/kg of body weight.

Efficacy of ER-30346, a novel oral triazole antifungal agent, in experimental models of aspergillosis, candidiasis, and cryptococcosis

ER-30346 is a novel oral triazole with a broad spectrum of potent activity against a wide range of fungi. In the present study, we investigated the therapeutic effects of oral ER-30346 on experimental local infections caused by Aspergillus fumigatus, Candida albicans, and Cryptococcus neoformans and compared them with those of itraconazole and fluconazole. In experimental murine models of pulmonary aspergillosis, candidiasis, and cryptococcosis, ER-30346 reduced the numbers of CFU in the lungs significantly compared with the numbers of CFU in the lungs of the controls (P < 0.05). ER-30346 was as effective as or more effective than itraconazole against pulmonary aspergillosis. Against pulmonary candidiasis and cryptococcosis, ER-30346 was more effective than itraconazole and was as effective as fluconazole. ER-30346 was also effective against pulmonary candidiasis caused by fluconazole-resistant C. albicans. In mice with intracranial cryptococcosis, ER-30346 reduced the numbers of CFU in the brains significantly compared with the numbers of CFU in the brains of the controls (P < 0.05) and was more effective than itraconazole and as effective as fluconazole. In an experimental model of oral candidiasis in rats, ER-30346 reduced the numbers of CFU in oral swabs significantly compared with the numbers of CFU in oral swabs from the controls (P < 0.05) and was more effective than itraconazole and as effective as fluconazole. Thus, ER-30346 shows efficacy in murine aspergillosis, candidiasis, and cryptococcosis models. Further studies are needed to determine the potential of ER-30346 for use in the treatment of these infections.

Systemic availability of itraconazole in lung transplantation

Systemic availability of itraconazole in lung transplantation was evaluated by serially measuring the bioactivity of itraconazole in lung transplant patients who received itraconazole for prophylaxis (n = 12) or therapy (n = 5). These patients also received concomitant antacid and H2 blocker therapy. In patients receiving itraconazole at 200 and 400 mg/day, the median concentrations in serum were 0.5 microgram/ml (range, < 0.05 to 2.7) and 3.5 micrograms/ml (< 0.5 to 14), respectively. The concentration following administration of 400 mg/day was > 2.5 micrograms/ml in 56% of samples, while only 4% of samples from patients who were administered 200 mg/day had levels over 2.5 micrograms/ml. This study documents that itraconazole can be absorbed in patients receiving concomitant antacid and H2 blocker therapy. However, the reduced and variable absorption suggests the importance of confirming drug delivery by measurement of concentrations in serum.

Correlation between in vitro resistance to fluconazole and clinical outcome of oropharyngeal candidiasis in HIV-infected patients

Fifty episodes of oropharyngeal candidiasis in HIV-infected patients were analyzed prospectively in order to evaluate the clinical response to fluconazole. The minimum inhibitory concentrations (MICs) of fluconazole for the Candida strains isolated from the pharynx were correlated with the clinical response. Treatment with fluconazole (100 mg/day) was successful in 86% of the cases. A good clinical outcome followed in 97% of the cases when a strain sensitive to fluconazole was isolated. This figure fell to 22% when the strain was resistant to fluconazole (p < 0.001). The rate of post-treatment colonization was high (87%), and selection of non-albicans Candida species occurred in 23% of the cases. In conclusion, fluconazole treatment for oropharyngeal candidiasis of HIV-infected patients was useful in most cases, but less sensitive non-albicans species can be selected. Most treatment failures were associated with increased MICs of fluconazole for the strains isolated before treatment; therefore, susceptibility testing is recommended as an aid in clinical decision-making for the use of the azole group of drugs.

Efficacy of UK-109496, a new azole antifungal agent, in an experimental model of invasive aspergillosis

The efficacy of UK-109496, a new azole antifungal agent, was evaluated in an immunosuppressed, temporarily leukopenic rabbit model of invasive aspergillosis. Oral therapy with UK-109496 at a dosage of 10 or 15 mg/kg of body weight every 8 h was begun 24 h after a lethal or sublethal challenge, and results were compared with those for amphotericin B therapy and untreated controls. UK-109496 eliminated mortality and also reduced the tissue burden of Aspergillus fumigatus 10- to 100-fold in liver and kidney tissues and to a lesser degree in lung tissue, and at the higher dose, no viable organisms were recovered from brain tissue from these animals. Both dosages of UK-109496 decreased or eliminated circulating antigen. The half-life of UK-109496 in rabbits was 2.5 to 3 h, and no accumulation of drug was seen even after 15 doses in either uninfected or infected animals. Thus, UK-109496 shows activity in this rabbit model of invasive aspergillosis. Additional studies are needed to determine the potential of the drug for use in the treatment of this infection.

Prophylactic use of fluconazole in neutropenic cancer patients

This study was carried out on 70 patients with haematological or solid malignancies who were receiving chemotherapy and/or radiotherapy. Forty-one patients were randomly assigned to receive fluconazole, 400 mg/day, while they were neutropenic. Systemic fungal infection developed in four of the 41 patients (9%) receiving prophylaxis in comparison to nine of 29 patients (31%) not receiving prophylaxis. The incidence of systemic fungal infection was significantly different between the groups receiving prophylaxis and those not receiving it (p < 0.05). Fluconazole was found to be effective for preventing systemic fungal infections in neutropenic patients with cancer.

Pharmacokinetics of fluconazole in cerebrospinal fluid and serum of rabbits: validation of an animal model used to measure drug concentrations in cerebrospinal fluid

Complete concentration-time data describing the pharmacokinetics of fluconazole in the cerebrospinal fluid (CSF) following a single dose are not available for humans or animals. We studied the pharmacokinetics of fluconazole with an indwelling intracisternal needle as described by R.G. Dacey and M.A. Sande (Antimicrob. Agents Chemother. 6:437-441, 1974). To determine whether the presence of an intracisternal needle alters pharmacokinetics in the CSF, we validated this model with uninfected rabbits by measuring pharmacokinetic constants following direct intracisternal and intravenous administration of fluconazole. Following direct injection, there was no alteration of elimination rates in the CSF with increasing sample number or time. Following intravenous administration, the penetration and kinetic constants were the same in individual animals from which multiple CSF samples were obtained as in a composite subject constructed by pooling virgin samples from different animals. The presence of the intracisternal needle did not alter CSF chemistry or leukocyte counts, and erythrocyte contamination was < 0.001%. While drug concentrations were measured by a microbiological assay, we also compared the sensitivity and reproducibility of a high-performance liquid chromatography (HPLC) assay with those of the microbiological assay. Following a single intravenous dose, the maximum concentration of the drug in serum, the time to maximum concentration of the drug in serum, the terminal elimination half-life in the CSF, and the percent penetration by fluconazole were 6.12 micrograms/ml, 1 h, 9.0 h, and 84.3%, respectively. We conclude that the sampling of CSF via an indwelling needle does not alter fluconazole pharmacokinetics, cause inflammation, or alter chemical parameters; that the microbiological assay is at least equivalent in sensitivity and reproducibility to the HPLC assay; and that robust parameters describing the pharmacokinetics of fluconazole are possible with this model.

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.

Candida and oral candidosis: a review

Candida species are the most common fungal pathogens isolated from the oral cavity. Their oral existence both as a commensal and an opportunist pathogen has intrigued clinicians and scientists for many decades, and recent investigations have revealed many attributes of this fungus contributing to its pathogenicity. In addition, the advent of the human immunodeficiency virus infection and AIDS has resulted in a resurgence of oral Candida infections. Clinicians are witnessing not only classic forms of the diseases but also newer clinical variants such as erythematous candidosis, rarely described hithertofore. Therefore, this review is an attempt at detailing the current knowledge on Candida and oral candidoses together with the newer therapeutic regimes employed in treating these mycoses.

Efficacy of itraconazole solution in a rabbit model of invasive aspergillosis

The efficacy of an itraconazole-cyclodextrin solution against Aspergillus fumigatus was assessed in an immunosuppressed, temporarily leukopenic rabbit model of invasive aspergillosis and compared with that of amphotericin B. Oral itraconazole solution at dosages of 20 and 40 mg/kg/day improved survival as compared with that of controls. Itraconazole (40 mg/kg/day) not only improved survival and reduced antigen levels but also significantly eradicated A. fumigatus from tissues and was as effective as amphotericin B in these studies. The higher dose of itraconazole produced higher levels in serum, which correlated with improved efficacy of the drug. This itraconazole-cyclodextrin solution was well absorbed and was effective in the treatment of experimental invasive aspergillosis; it demonstrates the potential of this class of agents in improving therapy for invasive aspergillosis.

Comparative efficacy of amphotericin B, clotrimazole and itraconazole against Aspergillus spp. An in vitro study

The susceptibilities of two isolates of Aspergillus flavus, one from a human case of recalcitrant mycotic keratitis, and an environmental isolate of A. fumigatus, to itraconazole, clotrimazole and amphotericin B were measured. Observations of macroscopic growth and microscopic evaluations of conidia germination both indicated that the two isolates of A. flavus were markedly more resistant to amphotericin B than to itraconazole and clotrimazole. Itraconazole was more effective than clotrimazole for all isolates. Our in vitro susceptibility results suggest the use of itraconazole should be a primary consideration in the treatment of Aspergillus keratitis.

Short report: the absorption of fluconazole and itraconazole under conditions of low intragastric acidity

The study investigated the oral absorption of two antifungal agents, fluconazole and itraconazole, under conditions of low intragastric acidity. Twelve healthy male volunteers received each of 4 dosing regimens: 200 mg itraconazole alone, 200 mg itraconazole and famotidine, 100 mg fluconazole alone, and 100 mg fluconazole and famotidine. Two oral doses of 40 mg famotidine were used to induce hypochlorhydria. Serum drug concentrations were measured (by high pressure liquid chromatography) for 48 h after a single dose of each anti-fungal agent. When dosed with famotidine, there was a significant 52.9% decrease of the peak intraconazole concentration (P < 0.011), and a significant 51.1% decrease of the 48-h integrated serum intraconazole concentration (P = 0.005). Famotidine-induced hypochlorhydria did not affect the absorption of fluconazole.

Complete eradication of Aspergillus fumigatus from the lung in an immunocompromised patient by oral itraconazole

Itraconazole is a new orally active antifungal agent shown to have in vitro and experimental activity against Aspergillus spp. This case report documents the successful eradication of biopsy-proven invasive pulmonary aspergillosis in a 17 year old boy with acute lymphocytic leukaemia. Cerebral involvement by the fungal infection was suspected clinically but was not biopsy proven. Although the patient subsequently died following bone marrow transplant and Escherichia coli septicaemia there was no evidence of residual Aspergillus at autopsy.

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)

Pharmacokinetics of SCH-39304 in human immunodeficiency virus-infected patients following chronic oral dosing

The pharmacokinetics of SCH-39304, an investigational, orally active, broad-spectrum antifungal agent, were evaluated in 17 adult, human immunodeficiency virus-positive males. Patients were studied on days 1 and 16 and were divided into the following three treatment groups: (i) patients with culture-proven oropharyngeal candidiasis who were not receiving concurrent zidovudine therapy and who were treated with 50 mg of SCH-39304 daily (n = 6); (ii) patients with culture-proven oropharyngeal candidiasis who were receiving concurrent zidovudine therapy and who were treated with 50 mg of SCH-39304 daily (n = 5); and (iii) patients with or without oropharyngeal candidiasis who were receiving concurrent zidovudine therapy and who were treated with 200 mg of SCH-39304 daily (n = 6). All patients received a single daily dose of the study medication for 16 days. Plasma samples for SCH-39304 concentration measurement were collected for 6 h following the initial dose and for 504 h following the day 16 dose. Urine was collected for 24 h following SCH-39304 administration on days 1 and 16. All samples were assayed for SCH-39304 by gas chromatography. Wide intersubject variations in SCH-39304 plasma concentration-versus-time profiles were observed on each study day. Absorption appeared to be slow, with mean day 1 peak plasma SCH-39304 concentrations of 1.2 micrograms/ml at 2.1 h (50 mg) and 3.9 micrograms/ml at 4.0 h (200 mg) after drug administration. Mean peak plasma SCH-39304 concentrations on day 16 were 7.6 micrograms/ml at 4.3 h (50 mg) and 17.2 micrograms/ml at 3.2 h (200 mg) after drug administration. Mean elimination half-lives on day 16 for the 50- and 200-mg daily dosages were 100 and 89 h, respectively. SCH-39304 was cleared primarily unchanged in the urine. Mean areas under the plasma concentration-versus-time curve (from 0 to 24 h) on day 16 reflect a lower than expected increase with the 200-mg/day regimen (314.5 microgram.h/ml) compared with that for the 50-mg/day regimen (139.9 microgram.h/ml), suggesting the potential for reduced bioavailability at higher dosages. No significant effect of concurrent zidovudine therapy on the kinetics of SCH-39304 was observed.

Saperconazole therapy in a rabbit model of invasive aspergillosis

The efficacy of orally and intravenously administered saperconazole against Aspergillus fumigatus was assessed in an immunosuppressed temporarily leukopenic rabbit model of invasive aspergillosis and compared with that of amphotericin B. Oral saperconazole at dosages of 5, 10, and 15 mg/kg of body weight per day improved survival compared with that of controls. In addition, saperconazole at 10 and 15 mg/kg/day reduced the tissue burden and reduced levels of circulating antigen, which correlated with increasing dosages of saperconazole. Intravenous saperconazole produced levels in serum more than 10-fold that of oral therapy. Intravenous saperconazole not only improved survival and reduced antigen levels but also significantly eradicated A. fumigatus from tissues compared with those of controls and was as effective as amphotericin B in these studies. Saperconazole was effective in the treatment of experimental invasive aspergillosis and demonstrates the potential of the newer azoles in therapy for invasive aspergillosis.