Caspofungin

Caspofungin is the first in a new class of antifungal agents, the glucan synthesis inhibitors, that interfere with fungal cell wall synthesis. Caspofungin exhibited in vitro and in vivo efficacy against a wide range of fungi and yeasts including Aspergillus and Candida species. A complete or partial response to caspofungin therapy was seen in 40.7% of immunocompromised adults with invasive aspergillosis who did not respond to, or did not tolerate, other antifungal agents in a noncomparative multicentre study. Caspofungin was effective in patients with oropharyngeal or oesophageal candidiasis, according to the preliminary results of 2 randomised double-blind trials. Caspofungin was generally well tolerated in a multicentre noncomparative trial involving patients with invasive aspergillosis. One or more drug-related clinical adverse effects were experienced by 13.8% of caspofungin recipients (the most common were fever, nausea, vomiting and complications associated with the vein into which caspofungin was infused). The tolerability of caspofungin appeared to be better than that of amphotericin B and similar to that of fluconazole in double-blind, randomised trials involving patients with mucosal candidiasis.     

Caspofungin: a review of its use in the treatment of fungal infections

Caspofungin (Cancidas) is the first of a new class of antifungal agents, the echinocandins, that inhibit the synthesis of the fungal cell wall component beta-(1,3)-D-glucan. Caspofungin is administered once daily by slow intravenous infusion and is used to treat infections caused by Candida spp. and Aspergillus spp.Caspofungin is a valuable new antifungal agent with a novel mechanism of action. In comparative clinical trials, caspofungin was no less effective than liposomal amphotericin B in the empirical treatment of neutropenic patients with persistent fever, amphotericin B deoxycholate in the treatment of invasive candidiasis or fluconazole in the treatment of oesophageal candidiasis. Caspofungin also displayed broadly similar efficacy to amphotericin B deoxycholate in oesophageal or oropharyngeal candidiasis and was effective as salvage therapy in patients with invasive aspergillosis who were refractory to or intolerant of standard therapy. The tolerability profile of caspofungin was similar to that of fluconazole and superior to that of amphotericin B deoxycholate and liposomal amphotericin B. Therefore, in the appropriate indications, caspofungin is a viable alternative to amphotericin B deoxycholate, liposomal amphotericin B or fluconazole.     

Micafungin: a review of its use in adults for the treatment of invasive and oesophageal candidiasis, and as prophylaxis against Candida infections

Intravenous micafungin (Mycamine; Fungard), an echinocandin, inhibits the synthesis of 1,3-beta-D-glucan, an essential cell wall component in many fungi. It is approved in adults (focus of this review) and in neonates and paediatric patients (Pediatric Drugs [in press]) in the EU and elsewhere for the treatment of invasive candidiasis and oesophageal candidiasis, and as prophylactic treatment to prevent Candida infections in haematopoietic stem cell transplant (HSCT) recipients.Intravenous micafungin shows very good activity against clinically relevant isolates of Candida spp. Furthermore, the pharmacokinetic profile of micafungin permits once-daily treatment and means that it is associated with relatively few drug-drug interactions. However, like all of the echinocandins and all formulations of amphotericin B, micafungin must be given intravenously. In large, well designed clinical trials in adult patients (>or=16 years of age) with invasive candidiasis, intravenous micafungin was shown to be noninferior to intravenous caspofungin or liposomal amphotericin B. In similarly designed trials in adult patients with oesophageal candidiasis, intravenous micafungin was shown to be noninferior to fluconazole or caspofungin treatment. As prophylactic treatment in adult and paediatric patients who had undergone HSCT, micafungin was superior to fluconazole therapy in a large, well designed trial. Micafungin was generally well tolerated by participants in these clinical trials. Furthermore, it was as well tolerated as caspofungin and fluconazole, and better tolerated than liposomal amphotericin B. The position of micafungin relative to newer antifungal therapies, such as anidulafungin, voriconazole and posaconazole, remains to be fully determined. Thus, micafungin is an emerging option for the treatment of adult patients with invasive or oesophageal candidiasis, and as prophylaxis against Candida infections in HSCT recipients.     

Caspofungin: new indication. No progress in invasive candidiasis

(1) The reference treatment for invasive candidiasis in patients without neutropenia is standard amphotericin B. If this treatment fails or is too nephrotoxic, second-line alternatives are liposomal amphotericin B and fluconazole. Voriconazole is a third-line option. (2) Caspofungin, an antifungal drug belonging to the echinocandin class, is now approved for use in this indication in France. (3) The clinical evaluation dossier contains no data from comparative trials with fluconazole or voriconazole. It only gives the results of a double-blind trial in 239 patients, designed to show simply that caspofungin was not inferior to standard amphotericin B. Most of the patients did not have neutropenia. About one-third of the patients died. There was no difference in mortality between the two groups. No data are available from trials versus other forms of amphotericin B. (4) In this trial, caspofungin had fewer adverse effects (especially nephrotoxicity) than standard amphotericin B. However, in other trials in other indications, caspofungin had more adverse effects than fluconazole. (5) In France, caspofungin costs nearly 100 times more than standard amphotericin B. (6) In practice, caspofungin has no proven advantages over existing options for the treatment of invasive candidiasis in patients without neutropenia.     

Caspofungin: pharmacology,safety and therapeutic potential in superficial and invasive fungal infections

Invasive fungal infections are important causes of morbidity and mortality in hospitalised patients. Current therapy with amphotericin B and antifungal triazoles has overlapping targets and is limited by toxicity and resistance. The echinocandin lipopeptide caspofungin is the first of a new class of antifungal compounds that inhibit the synthesis of 1,3-β-D-glucan. This homopolysaccharide is a major component of the cell wall of many pathogenic fungi and yet is absent in mammalian cells. It provides osmotic stability and is important for cell growth and cell division. In vitro, caspofungin has broad-spectrum antifungal activity against Candida and Aspergillus spp. without cross-resistance to existing agents. The compound exerts prolonged post-antifungal effects and fungicidal activity against Candida spp. and causes severe damage of Aspergillus fumigatus at the sites of hyphal growth. Animal models have demonstrated efficacy against disseminated candidiasis and disseminated and pulmonary aspergillosis, both in normal and in immunocompromised animals. Caspofungin possesses favourable pharmacokinetic properties and is not metabolised through the cytochrome P450 (CYP) enzyme system. It showed highly promising antifungal efficacy in Phase II and III clinical trials in immunocompromised patients with oesophageal candidiasis. Caspofungin was effective in patients with invasive aspergillosis intolerant or refractory to standard therapies. Based on its documented antifungal efficacy and an excellent safety profile, caspofungin has been approved recently by the US Food and Drug Administration for the treatment of invasive aspergillosis in patients who are refractory to or intolerant of other therapies (i.e., amphotericin B, lipid formulations of amphotericin B, and/or itraconazole). Phase III clinical trials in patients with candidaemia and in persistently febrile neutropenic patients requiring empirical antifungal therapy are ongoing. This paper reviews the preclinical and clinical pharmacology of caspofungin and its potential role for treatment of invasive and superficial fungal infections in patients.     

symbol: see text]Caspofungin and [symbol: see text]voriconazole for fungal infections

Systemic fungal infections are difficult to treat and often fatal. Established treatment options include conventional amphotericin B or one of its lipid-based or liposomal formulations, or a triazole antifungal such as fluconazole or itraconazole. [symbol: see text]Caspofungin (Cancidas--Merck Sharp & Dohme) and [symbol: see text]voriconazole (Vfend--Pfizer) are two new antifungals for severe infections caused by Candida spp. (invasive candidiasis) and Aspergillus spp. (invasive aspergillosis). Caspofungin is the first licensed echinocandin antifungal, while voriconazole is a triazole. Promotional claims for caspofungin include that it "provides an effective, yet less toxic, alternative to amphotericin B" while voriconazole is claimed to offer "significantly improved survival in invasive aspergillosis compared with amphotericin B". Here we consider the place of caspofungin and voriconazole in managing patients with severe fungal infections.     

Caspofungin: first approved agent in a new class of antifungals

Caspofungin (Cancidas, Merck & Co. Inc.) is the first echinocandin antifungal agent to gain FDA-approval for use in the US. It has excellent clinical activity against Candida spp. and Aspergillus spp. but lacks significant activity against Cryptococcus neoformans. Caspofungin may have some activity against dimorphic fungi such as Histoplasma capsulatum and Coccidioides immitis, but no clinical data is available for treatment of these infections. Caspofungin has demonstrated poor activity against most filamentous fungi in vitro. Several clinical trials have demonstrated its efficacy in the treatment of oropharyngeal, oesophageal and invasive candidiasis, as well as invasive aspergillosis. As a result of caspofungin's unique mechanism of action, and the high morbidity and mortality of invasive fungal infections, there is considerable interest in using this new antifungal agent as part of a combination antifungal therapy. In vitro studies and small case series indicate that caspofungin does not appear to be antagonistic when combined with other antifungals, such as itraconazole, voriconazole or amphotericin B against Aspergillus spp. Caspofungin exerts concentration-dependent killing effects in many different in vitro and animal models of disseminated fungal infection. The usual daily dose is 50 mg/day i.v. following a 70 mg i.v. loading dose. However, higher caspofungin doses have been safely administered and up to 70 mg/day can be administered for patients who fail to respond to lower doses. Caspofungin has an excellent safety profile with reduced toxicities, compared to other licensed antifungal agents. Fever, thrombophlebitis, headache and liver enzyme elevations were the most common drug-related side effects reported in clinical trials so far. Additional data are needed to document its safety in long-term use, and with higher doses in patients with invasive fungal infections. Caspofungin is a promising agent as first-line therapy for invasive candidiasis, and as salvage therapy for invasive aspergillosis. However, more clinical data are needed to define its role as primary therapy for invasive aspergillosis, and its role in combination antifungal therapy.     

Micafungin

Micafungin, an echinocandin antifungal agent with a novel mechanism of action, inhibits beta-(1,3)-D-glucan synthase interfering with fungal cell wall synthesis. It shows excellent antifungal activity against a broad range of Candida spp., including azole-resistant strains, and Aspergillus spp. in in vitro and animal studies. In HIV-positive patients, intravenous micafungin 50-150 mg/day dose-dependently eradicated endoscopically confirmed oesophageal candidiasis, with micafungin 100 and 150 mg/day being more effective than micafungin 50 mg/day and as effective as fluconazole 200 mg/day in a double-blind trial. In nonblind trials, micafungin (monotherapy or combination therapy) was effective against invasive aspergillosis, candidiasis and candidaemia in paediatric and adult patients with newly diagnosed or refractory infections. Micafungin 50 mg/day provided significantly better antifungal prophylaxis than fluconazole 400 mg/day in 882 haematopoietic stem cell transplant recipients in a randomised, double-blind trial. Respective overall success rates were 80% and 73.5%. Micafungin is generally well tolerated. Adverse events were not dose- or infusion-related with micafungin 12.5-900 mg/day; no histamine-like reactions occurred. Micafungin was as well tolerated as fluconazole, with numerically fewer micafungin recipients discontinuing treatment (4.2% vs 7.2%).     

Caspofungin: new preparation. A last resort in invasive aspergillosis

(1) Invasive aspergillosis is rare. It usually occurs in immunocompromised patients and is fatal despite treatment in 40-90% of cases. The reference treatments are standard amphotericin B, liposomal amphotericin B, and itraconazole. (2) Caspofungin, an antifungal drug, is now approved in the Europe Union for the treatment of invasive aspergillosis, when reference drugs fail or are poorly tolerated. (3) In a non comparative trial in 69 patients, intravenous caspofungin infusion was at least partly effective: 40% of patients survived with few relapses for at least one year following treatment. A historical comparison also favours caspofungin therapy. (4) The safety profile of caspofungin is poorly documented. It includes local reactions at the injection site, systemic reactions linked to the infusion (especially due to histamine release) and hepatic disorders. (5) Caspofungin is known to interact with tacrolimus (lower tacrolimus concentrations), ciclosporin (increased caspofungin bioavailability) and rifampicin (reduced caspofungin bioavailability). (6) In practice, caspofungin is an acceptable option for the treatment of invasive aspergillosis when standard amphotericin B, liposomal amphotericin B, and itraconazole are ineffective or poorly tolerated. Its clinical assessment is limited and must be continued.     

Caspofungin acetate: an antifungal agent.

The pharmacology, bioavailability and pharmacokinetics, clinical efficacy, and adverse effects of caspofungin acetate are reviewed. Caspofungin acetate is an echinocandin with fungicidal activity against a wide range of pathogens, including Candida spp., Aspergillus spp., and Histoplasma spp. It is active against fluconazole-resistant and fluconazole-susceptible strains of Candida albicans. Caspofungin acetate irreversibly inhibits the enzyme 1,3-beta-D-glucan synthase, preventing the formation of glucan polymers and disrupting the integrity of the fungal cell wall. Caspofungin acetate has an elimination half-life of 9-10 hours and is suitable for once-daily regimens. Data from animal and human studies demonstrate that the drug is 80-96% protein bound. Less than 3% of the dose is eliminated unchanged in the urine, and the proposed route of elimination is hepatic. In a trial of 128 patients with Candida esophagitis, clinical response rates were higher with caspofungin acetate 50 or 70 mg/day (85%) than with amphotericin B 0.5 mg/kg/day (67%). Most enrolled patients had HIV infection, and almost half had CD4+ lymphocyte counts of less than 50 cells/microL in another study, 56 immunocompromised patients with aspergillosis were treated with one 70-mg dose of caspofungin acetate, then 50 mg once a day. All patients had refractory invasive aspergillosis or were intolerant of amphotericin B, liposomal amphotericin B, or azole therapy. In patients who received at least one dose of caspofungin acetate, a favorable response was reported in 41%. In 128 patients who received either caspofungin acetate or amphotericin B, fewer caspofungin acetate recipients (1.4%) had elevated serum creatinine levels and discontinued therapy because of adverse effects (4%) than amphotericin B recipients (15% and 22%, respectively). The manufacturer's recommended dose for infections caused by Candida or Aspergillus spp. has not been determined. Caspofungin acetate appears to be fungicidal, with a wide spectrum of antifungal activity and a good safety profile. The lack of adequate efficacy and safety data in humans makes a recommendation to add this drug to the formulary premature. Pending advanced clinical trials and cost information, caspofungin acetate may be a reasonable addition to the formulary, particularly in hospitals with large immunocompromised patient populations.     

Anidulafungin

Anidulafungin is a novel antifungal agent which, like other echinocandins, inhibits beta-(1,3)-D-glucan synthase and disrupts fungal cell-wall synthesis. It has marked antifungal activity against a broad spectrum of Candida spp. and Aspergillus spp., including amphotericin B- and triazole-resistant strains. In clinical trials, anidulafungin has primarily been evaluated in patients with oesophageal and invasive candidiasis. Preliminary data are emerging for other indications such as invasive aspergillosis. In a large, multicentre, double-blind, double-dummy, randomised trial in patients with oesophageal candidiasis, intravenous anidulafungin 50 mg/day was as effective as oral fluconazole 100 mg/day regarding end-of-treatment rates of endoscopic cure and clinical and microbiological success. Duration of treatment was approximately 2-3 weeks, and patients in both groups received a loading dose of study drug (twice the daily maintenance dose) on day 1. Anidulafungin is generally well tolerated. Across the dosage range 50-100 mg/day, adverse events appear not to be dose- or infusion-related. In the largest clinical trial to date, the most common treatment-related adverse events were phlebitis/thrombophlebitis, headache, nausea, vomiting and pyrexia.     

新型抗真菌药物caspofungin

caspofungin是新型葡聚糖合成酶抑制剂类抗真菌药物中第 1个上市的药物 ,它能有效抑制 β ( 1,3) D 葡聚糖的合成 ,从而干扰真菌细胞壁的合成。caspofungin在体内、外具有广泛的抗真菌活性 ,包括曲菌和念珠菌。多中心试验表明 ,caspofungin治疗难治性或不能耐受其他治疗的侵袭性曲菌感染病人的临床有效率为 4 0 .7%。 2个随机双盲试验表明 ,caspofungin能有效治疗咽或食道念珠菌感染。侵袭性曲菌病人对caspofungin的耐受性较好。本文综述了caspofungin的药效学、药动学特性、临床疗效和不良反应等。     

The echinocandins: comparison of their pharmacokinetics, pharmacodynamics and clinical applications

Caspofungin, micafungin and anidulafungin are three drugs of the echinocandin class of antifungals available for intravenous treatment of invasive candidiasis and aspergillosis. They exhibit high in vitro and in vivo activities against Candida spp. and Aspergillus spp. In various clinical studies investigating candidemia and invasive candidiasis, Candida esophagitis, and fever in neutropenia, the clinical efficacy of the echinocandin tested was similar to that of established antifungals. Antifungal activity against strains no longer susceptible to conventional antifungal agents, such as fluconazole and amphotericin B suggests that echinocandins can be used as salvage therapy in life-threatening fungal infections. There is no cross-resistance to other antifungals. Excellent safety and tolerability of treatment with caspofungin has been documented over a total of 4.3 million patient days. Echinocandins are poor substrates of the cytochrome P450 enzyme family and can be safely co-administered with most drugs without the need for dosage adaptation. No dose reduction is required in renal impairment. A reduction in the daily maintenance dose has been recommended for caspofungin, but not for micafungin and anidulafungin in patients presenting with mild to moderate hepatic failure.     

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.     

Emerging echinocandins for treatment of invasive fungal infections

The echinocandins are a new class of antifungals, developed in response to the need for safe and effective antifungals for the treatment of invasive fungal infections. These agents work by inhibiting 1,3-beta-d-glucan synthase, an enzyme essential for production of cell walls in select fungi. Echinocandins appear to demonstrate favourable activity in vitro against a variety of yeasts (including both Candida albicans and non-albicans Candida) as well as select moulds (including Aspergillus spp.) In general, all echninocandins demonstrate a favourable safety profile and require once-daily parenteral administration. Caspofungin is the first of these agents to be available in the US, and is approved for empirical antifungal therapy in febrile neutropenic patients, candidaemia and select forms of invasive candidiasis, and for management of invasive aspergillosis in patients refractory to or intolerant of other therapies. Micafungin was recently approved by the FDA for treatment of oesophageal candidiasis, and for the prophylaxis of fungal infections in haematopoietic stem cell transplant recipients. Emerging data indicate micafungin may have an important role in the treatment of invasive forms of candidiasis. Anidulafungin is an echinocandin approved in the US for treatment of candidaemia and oesophageal candidiasis. Aminocandin (HMR-3702, IP-960) is an investigational agent, with published experience limited to in vitro studies and animal models of infection.     

Echinocandins: A ray of hope in antifungal drug therapy

Invasive fungal infections are on the rise. Amphotericin B and azole antifungals have been the mainstay of antifungal therapy so far. The high incidence of infusion related toxicity and nephrotoxicity with amphotericin B and the emergence of fluconazole resistant strains of Candida glabrata egged on the search for alternatives. Echinocandins are a new class of antifungal drugs that act by inhibition of β (1, 3)-D- glucan synthase, a key enzyme necessary for integrity of the fungal cell wall.Caspofungin was the first drug in this class to be approved. It is indicated for esophageal candidiasis, candidemia, invasive candidiasis, empirical therapy in febrile neutropenia and invasive aspergillosis. Response rates are comparable to those of amphotericin B and fluconazole. Micafungin is presently approved for esophageal candidiasis, for prophylaxis of candida infections in patients undergoing hematopoietic stem cell transplant (HSCT) and in disseminated candidiasis and candidemia. The currently approved indications for anidulafungin are esophageal candidiasis, candidemia and invasive candidiasis.The incidence of infusion related adverse effects and nephrotoxicity is much lower than with amphotericin B. The main adverse effect is hepatotoxicity and derangement of serum transaminases. Liver function may need to be monitored. They are, however, safer in renal impairment. Even though a better pharmacoeconomical choice than amphotericin B, the higher cost of these drugs in comparison to azole antifungals is likely to limit their use to azole resistant cases of candidial infections and as salvage therapy in invasive aspergillosis rather than as first line drugs.     

Voriconazole : a review of its use in the management of invasive fungal infections

Voriconazole (VFEND), a synthetic second-generation, broad-spectrum triazole derivative of fluconazole, inhibits the cytochrome P450 (CYP)-dependent enzyme 14-alpha-sterol demethylase, thereby disrupting the cell membrane and halting fungal growth. In the US, intravenous and/or oral voriconazole is recommended in adults for the treatment of invasive aspergillosis, candidaemia in non-neutropenic patients, disseminated infections caused by Candida spp., oesophageal candidiasis, and in patients with scedosporiosis and fusariosis who are refractory to or intolerant of other antifungal therapy. In Europe, intravenous and/or oral voriconazole is recommended in adults and paediatric patients of at least 2 years of age for the treatment of invasive aspergillosis, candidaemia in non-neutropenic patients, fluconazole-resistant serious invasive Candida spp. infections, scedosporiosis and fusariosis.In large randomised trials, voriconazole was an effective and generally well tolerated primary treatment for candidiasis and invasive aspergillosis in adults and adolescents. More limited data also support the use of voriconazole for the treatment of invasive fungal infections in children, in those with rare fungal infections, such as Fusarium spp. or Scedosporium spp., and in those refractory to or intolerant of other standard antifungal therapies. The availability of both parenteral and oral formulations and the almost complete absorption of the drug after oral administration provide for ease of use and potential cost savings, and ensure that therapeutic plasma concentrations are maintained when switching from intravenous to oral therapy. On the other hand, the numerous drug interactions associated with voriconazole may limit its usefulness in some patients. Further clinical experience will help to more fully determine the position of voriconazole in relation to other licensed antifungal agents. In the meantime, voriconazole is a valuable emerging option for the treatment of invasive aspergillosis and rare fungal infections, including Fusarium spp. and Scedosporium spp. infections, and provides an alternative option for the treatment of candidiasis, particularly where the causative organism is inherently resistant to other licensed antifungal agents.     

Newer systemic antifungal agents : pharmacokinetics, safety and efficacy

The past few years have seen the advent of several new antifungal agents, including those of a new class and a new generation of an existing class. Caspofungin, the first available echinocandin, has greatly expanded the antifungal armamentarium by providing a cell wall-active agent with candidacidal activity as well as demonstrated clinical efficacy in the therapy of aspergillosis refractory to available therapy. In addition, in clinical trials, caspofungin had comparable efficacy to amphotericin B for candidaemia and invasive Candida infections. Caspofungin and two more recently introduced echinocandins, micafungin and anidulafungin, are available as intravenous formulations only and characterised by potent anti-candidal activity, as well as few adverse events and drug interactions. Voriconazole, the first available second-generation triazole, available in both intravenous and oral formulations, has added a new and improved therapeutic option for primary therapy of invasive aspergillosis and salvage therapy for yeasts and other moulds. In a randomised trial, voriconazole demonstrated superior efficacy and a survival benefit compared with amphotericin B followed by other licensed antifungal therapy. This and data from a noncomparative study led to voriconazole becoming a new standard of therapy for invasive aspergillosis. Voriconazole has several important safety issues, including visual adverse events, hepatic enzyme elevation and skin reactions, as well as a number of drug interactions. Posaconazole, only available orally and requiring dose administration four times daily, shows encouraging efficacy in difficult to treat infections due to zygomycetes. Ravuconazole, available in both intravenous and oral formulations, has broad-spectrum in vitro potency and in vivo efficacy against a wide range of fungal pathogens. Clinical studies are underway. Despite the advances offered with each of these drugs, the morbidity and mortality associated with invasive fungal infections remains unacceptable, especially for the most at-risk patients. For individuals with severe immunosuppression as a result of chemotherapy, graft-versus-host disease and its therapy, or transplantation, new drugs and strategies are greatly needed.     

Fungal infections in patients with neutropenia: challenges in prophylaxis and treatment

Fungal infections are a leading cause of mortality in patients with neutropenia. Candidiasis and aspergillosis account for most invasive fungal infections. General prophylactic measures include strict hygiene and environmental measures. Haemopoietic growth factors shorten the duration of neutropenia and thus may reduce the incidence of fungal infections. Fluconazole is appropriate for antifungal prophylaxis and should be offered to patients with prolonged neutropenia, such as high-risk patients with leukaemia undergoing remission induction or consolidation therapy and high-risk stem cell transplant recipients. Empirical antifungal therapy is mandatory in patients with persistent febrile neutropenia who fail to respond to broad-spectrum antibacterials. Intravenous amphotericin B at a daily dose of 0.6 to 1 mg/kg is preferred whenever aspergillosis cannot be ruled out. Lipid formulations of amphotericin B have demonstrated similar efficacy and are much better tolerated. Fluconazole is the best choice for acute candidiasis in stable patients; amphotericin B should be used in patients with unstable disease. Use of fluconazole is restricted by the existence of resistant strains (Candida krusei and, to a lesser extent, C. glabrata). Amphotericin B still remains the gold standard for invasive aspergillosis. Lipid formulations of amphotericin B are effective in aspergillosis and because they are less nephrotoxic are indicated in patients with poor renal function. Itraconazole is an alternative in patients who have good intestinal function and are able to eat. Mucormycosis, trichosporonosis, fusariosis and cryptococcosis are less common but require specific management. New antifungal agents, especially new azoles, are under development. Their broad in vitro spectrum and preliminary clinical results are promising.     

Emerging echinocandins for treatment of invasive fungal infections

The echinocandins are a new class of antifungals, developed in response to the need for safe and effective antifungals for the treatment of invasive fungal infections. These agents work by inhibiting 1,3-β-d-glucan synthase, an enzyme essential for production of cell walls in select fungi. Echinocandins appear to demonstrate favourable activity in vitro against a variety of yeasts (including both Candida albicans and non-albicans Candida) as well as select moulds (including Aspergillus spp.) In general, all echninocandins demonstrate a favourable safety profile and require once-daily parenteral administration. Caspofungin is the first of these agents to be available in the US, and is approved for empirical antifungal therapy in febrile neutropenic patients, candidaemia and select forms of invasive candidiasis, and for management of invasive aspergillosis in patients refractory to or intolerant of other therapies. Micafungin was recently approved by the FDA for treatment of oesophageal candidiasis, and for the prophylaxis of fungal infections in haematopoietic stem cell transplant recipients. Emerging data indicate micafungin may have an important role in the treatment of invasive forms of candidiasis. Anidulafungin is an echinocandin approved in the US for treatment of candidaemia and oesophageal candidiasis. Aminocandin (HMR-3702, IP-960) is an investigational agent, with published experience limited to in vitro studies and animal models of infection.