Microgranulomatous aspergillosis in a patient with chronic granulomatous disease: cure with voriconazole

Voriconazole

Each month, subscribers to The Formulary Monograph Service receive five to six well-documented monographs on drugs that are newly released or are in late Phase III trials. The monographs are targeted to your Pharmacy and Therapeutics Committee. Subscribers also receive monthly one-page summary monographs on the agents that are useful for agendas and pharmacy/nursing in-ser-vices. A comprehensive target drug utilization evaluation (DUE) is also provided each month. The monographs are published in printed form and on diskettes that allow customization. Subscribers to the The Formulary Monograph Service also receive access to a pharmacy bulletin board, The Formulary Information Exchange (The F.I.X.). All topics pertinent to clinical and hospital pharmacy are discussed on The F.I.X.

Through the cooperation of The Formulary, Hospital Pharmacy publishes selected reviews in this column. If you would like information about The Formulary Monograph Service or The F.I.X., call The Formulary at 800-322-4349. The September 2002 monograph topics are ziprasidone mesylate for injection; lanthanum carbonate, artesunate rectal capsules, ZD1839, and memantine. The DUE is on ziprasidone.

Voriconazole: therapeutic review of a new azole antifungal

The new triazole antifungal, voriconazole (Vfend, Pfizer Ltd), was developed for the treatment of life-threatening fungal infections in immunocompromised patients. The drug, which is available for both oral and intravenous administration, has broad-spectrum activity against pathogenic yeasts, dimorphic fungi and opportunistic moulds. Unlike fluconazole (Diflucan, Pfizer Ltd), voriconazole has potent in vitro activity against Aspergillus spp., Fusarium spp. and Scedosporium apiospermum. In Phase II/III trials, voriconazole was well-tolerated and had excellent clinical efficacy in patients with fluconazole-sensitive and -resistant candida infection, aspergillosis, and various refractory fungal infections. The US Food and Drug Administration approved voriconazole in May 2002 for the treatment of invasive aspergillosis, and serious infections caused by Fusarium and S. apiospermum in patients who are intolerant of, or refractory to, other antifungal agents. In Europe, voriconazole is approved by the European Medicines Agency for the treatment of invasive aspergillosis, serious infections caused by Fusarium and S. apiospermum, and fluconazole-resistant serious invasive candida infections (including C. krusei).

Invasive fungal infection in chronic granulomatous disease: insights into pathogenesis and management

PURPOSE OF REVIEW

Invasive fungal infections (IFIs) remain a major cause of death in patients with chronic granulomatous disease (CGD). We discuss the new insights into the pathogenesis, diagnosis, prevention, and management of invasive fungal infections in patients with CGD.

RECENT FINDINGS

CGD has the highest prevalence of IFIs among the immunodeficiencies. Infections typically involve the lung, and the most commonly isolated pathogen is Aspergillus spp. However, IFIs due to rare opportunistic filamentous fungi are increasingly reported. Most IFIs are diagnosed on routine chest imaging, and serum markers such as galactomannan and 1,3-β-D-glucan are of limited value in CGD. Routine use of itraconazole for prophylaxis continues to be recommended, although posaconazole may be an alternative. Management of IFIs is typically centered on prolonged courses of antifungal therapy. Surgery may be required for complete resolution, especially in the setting of osteomyelitis or infections due to Aspergillus nidulans or other poorly responsive molds. Hematopoietic stem cell transplantation (HSCT) cures CGD and may be appropriate in select patients with refractory IFIs.

SUMMARY

Management of IFIs in CGD has significantly improved over the last decade. Earlier diagnosis of IFIs, accurate identification of pathogens, and development of reliable susceptibility testing are areas for future emphasis. HSCT is a promising therapy, even during refractory infections in CGD.

Invasive fungal infections in patients with chronic granulomatous disease

Invasive fungal infections are a major threat for chronic granulomatous disease (CGD) patients. The present study provides a comprehensive overview of published invasive fungal infections in the CGD host through an extensive review of epidemiological, clinical, diagnostic and therapeutic data. In addition to the often mild clinical presentation, the currently used diagnostics for invasive aspergillosis have low sensitivity in CGD patients and cannot be easily translated to this non-neutropenic host. Aspergillus fumigatus and A. nidulans are the most commonly isolated species. A. nidulans infections are seldom reported in other immunocompromised patients, indicating a unique interaction between this fungus and the CGD host. The occurrence of mucormycosis is mainly noted in the setting of treatment of inflammatory complications with immunosuppressive drugs. Candida infections are infrequently seen and do not cause mucocutaneous disease but do show an age-dependent clinical presentation. The CGD patient is susceptible to a wide range of fungal pathogens, indicating the need to determine the causative fungus, often by invasive diagnostics, to guide optimal and rational treatment. This review summarizes current understanding of invasive fungal infections in patients with CGD and will serve as a starting point to guide optimal treatment strategies and to direct further research aimed at improving outcomes.

The invasive and saprophytic syndromes due to Aspergillus spp

Aspergillus spp. produce a wide range of invasive and sapropytic syndromes which may involve any tissue. Within a given tissue or organ the pathology and pathogenesis varies enormously, ranging from angioinvasive disease to noninvasive saprophytic disease. The individual invasive and saprophytic syndromes in which a causative role can be attributed to Aspergillus spp. are detailed specifically with reference to the underlying pathology and pathogenesis, the clinical setting and features, and the manner in which a diagnosis can be established.

Voriconazole treatment for less-common, emerging, or refractory fungal infections

Treatments for invasive fungal infections remain unsatisfactory. We evaluated the efficacy, tolerability, and safety of voriconazole as salvage treatment for 273 patients with refractory and intolerant-to-treatment fungal infections and as primary treatment for 28 patients with infections for which there is no approved therapy. Voriconazole was associated with satisfactory global responses in 50% of the overall cohort; specifically, successful outcomes were observed in 47% of patients whose infections failed to respond to previous antifungal therapy and in 68% of patients whose infections have no approved antifungal therapy. In this population at high risk for treatment failure, the efficacy rates for voriconazole were 43.7% for aspergillosis, 57.5% for candidiasis, 38.9% for cryptococcosis, 45.5% for fusariosis, and 30% for scedosporiosis. Voriconazole was well tolerated, and treatment-related discontinuations of therapy or dose reductions occurred for <10% of patients. Voriconazole is an effective and well-tolerated treatment for refractory or less-common invasive fungal infections.

Voriconazole: in the treatment of invasive aspergillosis

Voriconazole, a broad-spectrum triazole antifungal agent, inhibits the cytochrome P450-dependent enzyme 14-alpha-sterol demethylase, thereby disrupting the fungal membrane and stopping fungal growth. The drug shows excellent in vitro activity against Aspergillus spp., including itraconazole- and amphotericin B-resistant A. fumigatus isolates. At 12 weeks, 52.8% of voriconazole recipients achieved a successful outcome (complete or partial response) versus 31.6% of amphotericin B recipients in a randomised, nonblind trial in 392 patients (aged > or =12 years) with invasive aspergillosis. Patients received intravenous voriconazole (6 mg/kg once every 12 hours on day 1, then 4 mg/kg once every 12 hours for > or =7 days; patients could then be switched to oral voriconazole 200mg once every 12 hours) or intravenous amphotericin B (1 to 1.5 mg/kg/day for > or=14 days). At the investigators' discretion, those who failed to respond to or experienced toxicity with the initial randomised drug could be switched to other licensed antifungal therapy. Voriconazole was generally well tolerated. The most common treatment-related adverse events were transient visual disturbances (approximately 30% of patients) and skin rashes (6%). Voriconazole was generally better tolerated than amphotericin B; voriconazole recipients experienced significantly (p < 0.02 both comparisons) fewer treatment-related adverse events or serious adverse events. The incidence of visual disturbances was significantly (p < 0.001) higher with voriconazole than amphotericin B treatment.

Arthritis and osteomyelitis due to Aspergillus fumigatus: a 17 years old boy with chronic granulomatous disease

BACKGROUND

Invasive Aspergillus infections are frequently seen in immunocompromised patients but arthritis is a rare complication of Aspergillus infections in the absence of immune suppressive therapy, trauma or surgical intervention.

CASE PRESENTATION

A 17 years old male patient with arthritis and patellar osteomyelitis of the left knee whose further investigations revealed chronic granulomatous disease as the underlying disease is followed. Aspergillus fumigatus was isolated from the synovial fluid and the tissue samples cultures. He was treated with Amphotericin B deoxicolate 0.7 mg/kg/day. Also surgical debridement was performed our patient. Amphotericin B nephrotoxicity developed and the therapy switched to itraconazole 400 mg/day. Itraconazole therapy were discontinued at the 6th month. He can perform all the activities of daily living including.

CONCLUSION

We think that, chronic granulomatous disease should be investigated in patients who have aspergillar arthritis and osteomyelitis.

Six novel antimycotics

We have reviewed six new antimycotic agents which have potential applications for human cutaneous and mucosal diseases. Information on these six drugs was obtained via an English language search of PubMed through the US National Library of Medicine. The antimycotic agents reviewed include rilopirox, lanoconazole, NND-502, butenafine, eberconazole and voriconazole. Rilopirox is a synthetic pyridone derivative, related to ciclopirox, with a fungicidal action. Rilopirox is a hydrophobic, topical agent with potential application in mucosal candida infections, tinea versicolor and seborrheic dermatitis. Lanoconazole, an imidazole, is a topical agent with potential application in tinea infections and cutaneous candidiasis. The drug has been available for clinical use in Japan since 1994 and once-daily application to affected areas is recommended. In addition to its antifungal effect, animal data suggest that application of lanoconazole 0.5 or 1% cream is associated with accelerated wound healing. NND-502, a stereoselective analog of lanoconazole, is a topical agent with potential application in tinea pedis infection. NND-502 appears to be more effective in inhibiting ergosterol biosynthesis than lanoconazole or bifonazole and clinical trials comparing these agents are awaited. Butenafine is the first member of a new class of antifungals, the benzylamine derivatives, and has been approved for topical use in Japan (since 1992) and the US. Butenafine has a potent fungicidal action and the drug has been shown to be effective in multiple clinical trials in patients with tinea pedis, tinea corporis and tinea cruris. Butenafine has also been reported to exert an anti-inflammatory action after topical application and this may offer potential benefit over other topical antifungal agents. Eberconazole, an imidazole derivative, is a topical antifungal agent that has been shown to be effective in clinical trials in patients with tinea infections. Preliminary data indicate that the eberconazole is effective against some triazole-resistant yeasts such as Candida krusei and Candida glabrata. Voriconazole is an azole antifungal derivative of fluconazole. The drug is available in both oral and parenteral formulations. Oral voriconazole 200mg twice daily has been effective in treating oropharyngeal candidiasis and apergillosis in immunocompromised patients. After 12 weeks' treatment, a similar dosage of the drug elicited a positive response in 69% of nonimmunocompromised patients with invasive aspergillosis.

Review of the safety and efficacy of voriconazole

Voriconazole is a new triazole antifungal agent structurally related to fluconazole, but with improved potency and spectrum of activity. Voriconazole has good in vitro activity against Candida species, Cryptococcus neoformans, Aspergillus spp. and other mould spp. Initial clinical studies and case reports demonstrate efficacy with voriconazole against invasive aspergillosis and infections caused by C. neoformans, Scedosporium apiospermum, Blastomyces dermatitidis, Coccidioides immitis and Histoplasma capsulatum. Voriconazole is available both as oral and iv. preparations and exhibits complex pharmacokinetics. This drug is metabolised by the cytochrome (CYP) P450 enzyme system and therefore, has potential drug interactions. This review evaluates the current literature regarding the safety and efficacy of voriconazole.

Isolation and in vitro susceptibility to amphotericin B, itraconazole and posaconazole of voriconazole-resistant laboratory isolates of Aspergillus fumigatus

OBJECTIVES

To select voriconazole-resistant mutants of Aspergillus fumigatus in the laboratory from drug-susceptible clinical isolates and examine their in vitro susceptibility to amphotericin B and investigational azoles, and to compare the intramycelial accumulation of voriconazole in the resistant isolates with that in the susceptible parent.

METHODS

Voriconazole-resistant Aspergillus fumigatus isolates were selected in the laboratory from three highly susceptible (MIC < or = 0.5 mg/L) clinical isolates by stepwise selection on peptone yeast extract glucose (PYG) agar containing 0.5 mg and 4 mg voriconazole/L. Twenty-three colonies that grew in the presence of 4 mg voriconazole/L on PYG agar (frequency 1.9 x 10(-8)) were tested for their in vitro susceptibility to amphotericin B, itraconazole, voriconazole and posaconazole by a broth macrodilution technique. The accumulation of voriconazole in the mycelia of two representative resistant isolates (VCZ-W42 and VCZ-W45) was determined by a previously described bioassay.

RESULTS

The geometric mean MICs (mg/L) of amphotericin B, itraconazole, voriconazole and posaconazole for these isolates were 0.45 +/- 0.19, 0.69 +/- 0.45, 5.24 +/- 3.74 and 0.27 +/- 0.18, respectively. A comparison of the geometric mean MICs of the antifungals obtained for the resistant isolates to those of the susceptible parents showed 1.15-, 2.76-, 16.90- and 1.42-fold increases, respectively, for amphotericin B, itraconazole, voriconazole and posaconazole, suggesting that low-level cross-resistance exists between the azole antifungals. The susceptible parent and the resistant isolates accumulated similar amounts of voriconazole.

CONCLUSIONS

These results suggest that spontaneous mutants of Aspergillus fumigatus resistant to voriconazole could emerge among clinical isolates under selection pressure and that the observed reduced in vitro susceptibility to voriconazole may not be due to reduced accumulation of the drug in the mycelia.

Susceptibility testing of voriconazole, fluconazole, itraconazole and amphotericin B against yeast isolates in a Turkish University Hospital and effect of time of reading

Voriconazole is a promising azole effective against a variety of fungi, including yeasts. In this study, we tested in vitro activities of voriconazole, fluconazole, itraconazole and amphotericin B against some ATCC and reference strains and 250 clinical yeast isolates. We also evaluated the effect of time of reading on MIC results. Voriconazole was the most active agent against Candida and Trichosporon isolates, including the putatively fluconazole-resistant C. krusei (MIC(90) 0.25 microg/ml) and C. glabrata (MIC(90) 0.5 microg/ml). Amphotericin B MICs were scattered in a considerably narrow range in both RPMI 1640 and Antibiotic Medium 3. MICs at 24 hours and 48 hours were similar in general for all antifungals tested. The highest percentage of strains that showed 24-hour and 48-hour MICs within +/-1-log(2) dilution was observed for amphotericin B tested in RPMI (99%), and the lowest for amphotericin B tested in Antibiotic Medium 3 (80%). In conclusion, voriconazole is very effective against a wide spectrum of Candida species and 24-hour readings could substitute 48-hour MIC evaluation.

Voriconazole: a new triazole antifungal

OBJECTIVE

To review the currently available information on the pharmacology, pharmacokinetics, efficacy, adverse effects, drug interactions, and dosage guidelines of voriconazole. Comparative data for voriconazole and other azole antifungal agents are described where available.

DATA SOURCES

A MEDLINE search restricted to English-language articles (1966 to September 1999) was conducted, and an extensive review of journals and meeting abstracts was performed. MeSH headings included itraconazole, fluconazole, voriconazole, UK-109,496, and amphotericin B.

DATA EXTRACTION

The data on pharmacokinetics, adverse effects, and drug interactions were obtained from open-label and controlled studies and case reports. Controlled studies and case reports were evaluated to demonstrate the efficacy of voriconazole in treatment of various fungal infections.

DATA SYNTHESIS

Voriconazole is a derivative of fluconazole that demonstrates enhanced in vitro activity against existent and emerging fungal pathogens. Limited data have revealed a favorable pharmacokinetic and safety profile for the agent. Moreover, select clinical trials and case studies of voriconazole suggest good in vivo efficacy against several fungal pathogens including Candida, Aspergillus, and Scedosporium.

CONCLUSIONS

Voriconazole has shown promise in the treatment of superficial and systemic mycoses. While several unresolved issues remain, voriconazole may be a viable therapeutic alternative for fluconazole-resistant mucocutaneous candidiasis and in cases of mild to moderate systemic mycoses requiring chronic treatment or that are refractory to currently available agents.

Invasive aspergillosis caused by Aspergillus ustus: case report and review

A case of invasive pulmonary aspergillosis in an allogeneic bone marrow transplant recipient caused by Aspergillus ustus is presented. A. ustus was also recovered from the hospital environment, which may indicate that the infection was nosocomially acquired. A literature review revealed seven cases of invasive infections caused by A. ustus, and three of these were primarily cutaneous infections. In vitro susceptibility testing of 12 A. ustus isolates showed that amphotericin B and terbinafine had fungicidal activity and that itraconazole and voriconazole had fungistatic activity.