A randomized and blinded multicenter trial of high-dose fluconazole plus placebo versus fluconazole plus amphotericin B as therapy for candidemia and its consequences in nonneutropenic subjects

Clinical characteristics and risk factors for nosocomial candidemia in medical intensive care units: experience in a single hospital in Korea for 6.6 years

The aim of this study was to determine candidemia incidence among patients in a medical intensive-care unit (MICU) and the associated mortality rate and to identify risk factors associated with candidemia. We retrospectively performed a 1:3 matched case-control study of MICU patients with candidemia. Controls were matched for sex, age, and Acute Physiology and Chronic Health Evaluation (APACHE) II score. Candidemia incidence was 9.1 per 1,000 admissions. The most common pathogen was Candida albicans. Crude mortality was 96% among candidemia patients and 52% among controls (P<0.001). Mortality differed significantly between the groups according to Kaplan-Meier survival analysis (P=0.024). Multivariate analysis identified the following independent risk factors for candidemia: central venous catheterization (odds ratio [OR] = 3.2, 95% confidence interval [CI]=1.2-9.0), previous steroid therapy (OR=4.7, 95% CI=1.8-12.1), blood transfusion during the same admission period (OR=6.3, 95% CI=2.4-16.7), and hepatic failure upon MICU admission (OR=6.9, 95% CI=1.7-28.4). In conclusion, we identify an additional independent risk factor for candidemia, the presence of hepatic failure on MICU admission. Therefore, increased awareness of risk factors, including hepatic failure, is necessary for the management of candidemia.

Candidemia and invasive candidiasis: a review of the literature for the burns surgeon

Advances in critical care, operative techniques, early fluid resuscitation, antimicrobials to control bacterial infections, nutritional support to manage the hypermetabolic response and early wound excision and coverage has improved survival rates in major burns patients. These advances in management have been associated with increased recognition of invasive infections caused by Candida species in critically ill burns patients. Candida albicans is the most common species to cause invasive Candida infections, however, non-albicans Candida species appear to becoming more frequent. These later species may be less fluconazole susceptible than Candida albicans. High crude and attributable mortality rates from invasive Candida sepsis are multi-factorial. Diagnosis of invasive candidiasis and candidemia remains difficult. Prophylactic and pre-emptive therapies appear promising strategies, but there is no specific approach which is well-studied and clearly efficacious in high-risk burns patients. Treatment options for invasive candidiasis include several amphotericin B formulations and newer less toxic antifungal agents, such as azoles and echinocandins. We review the currently available data on diagnostic and management strategies for invasive candidiasis and candidemia; whenever possible providing reference to the high-risk burn patients. We also present an algorithm for the management of candidemia and invasive candidiasis in burn patients.

Clinical aspects of invasive candidiasis in critically ill patients

Invasive candidiasis has emerged as an important cause of morbidity and mortality in intensive care unit patients. This short review focuses on many aspects of Candida infection in critically ill patients including epidemiology, impact on mortality, problems related to diagnosis, strategies to identify patients at risk of developing fungal infections, role of prophylaxis and pre-emptive strategies, empiric treatment and the role of different classes of antifungal drugs. New antifungal agents, specifically new azoles and echinocandins are discussed.

Invasive fungal infections in the ICU

Invasive fungal infections are major causes of morbidity and mortality in critically ill patients. Foremost among these is invasive candidiasis. In recent years, invasive aspergillosis (IA) and zygomycosis have emerged as major problems in susceptible, critically ill patients. Risk factors for invasive fungal infections, including disrupted anatomic barriers, suppressed antifungal host responses, and exposure to potentially opportunistic fungi are common in critically ill patients. The expanded antifungal armamentarium and advent of rapid diagnostic techniques are altering the approach to invasive fungal infections in the intensive care unit (ICU). Herein, we review recent developments in the field of antifungal host defenses, the changing epidemiology of fungal infections in the ICU, the pharmacology of antifungal agents of importance to critically ill patients, and the evolving approaches to therapy in this setting.

Treatment of candidemia and invasive candidiasis in the intensive care unit: post hoc analysis of a randomized, controlled trial comparing micafungin and liposomal amphotericin B

Introduction

Invasive candidiasis and candidemia are life-threatening nosocomial infections in intensive care patients.

Methods

A post hoc analysis of a phase 3 trial assessing micafungin (100 mg/day for subjects > 40 kg; 2 mg/kg/day for subjects ≤ 40 kg) versus liposomal amphotericin B (3 mg/kg/day). Subgroups were defined according to the type of ward on the first day of treatment: intensive care unit (ICU) or non-ICU. Multivariate regression was performed to identify factors associated with treatment success at end of therapy and all-cause mortality at days 8 and 30.

Results

In non-ICU subjects, treatment success was significantly higher for micafungin versus liposomal amphotericin B (85% (n = 108/127) versus 72.1% (n = 98/136); P = 0.0113). However, for ICU subjects, treatment success rates for micafungin versus liposomal amphotericin B were similar (62.5% (n = 75/120) versus 66.4% (n = 73/110); P = 0.5828). Overall, treatment success was significantly lower in ICU subjects compared with non-ICU subjects (64.3% (n = 148/230) versus 78.3% (n = 206/263); P = 0.0006). Multivariate regression analysis revealed a lower likelihood of treatment success for: ICU versus non-ICU subjects; persistent neutropenia; and high versus low Acute Physiology and Chronic Health Evaluation (APACHE) II scores. However, when interactions between potential explanatory factors were included in the analysis model, ICU status no longer emerged as a significant associated variable but the association between APACHE II score and treatment outcome remained. Further analyses indicated that the likelihood of mortality at day 8 and day 30 was lower for subjects with lower APACHE II scores. Renal function was significantly better in micafungin versus liposomal amphotericin B subjects: a difference (liposomal amphotericin B - micafungin in mean peak change in estimated glomerular filtration rate (ml/minute/1.73 m²) of -18.2 (P < 0.0001) and -17.7 (P = 0.0124) in non-ICU and ICU subjects, respectively.

Conclusions

Overall, ICU subjects had lower treatment success rates than non-ICU subjects for both liposomal amphotericin B and micafungin. Multivariate regression after controlling for potential confounding factors suggested the APACHE II score remained a potential explanatory factor associated with treatment success, mortality at day 8, and mortality at day 30.

Trial registration

Post hoc analysis - clinicaltrials.gov trial NCT00106288.

Excess mortality, length of stay and cost attributable to candidaemia

BACKGROUND

There were 1967 reports of Candida species isolated from blood specimens in 2007 in the UK (excluding Scotland). Such infections are particularly common in the intensive care unit (ICU). The impact of candidaemia on mortality, length of stay (LOS) and cost in a UK hospital was examined.

METHODS

A retrospective analysis of candidaemia episodes and appropriate matched controls was undertaken based on data from the ICU, high dependency units and hospital wards at Wythenshawe Hospital in Manchester. The study covered the period November 2003-February 2007.

RESULTS

In total, 48 case-patients of candidaemia and 81 control-patients were identified. The attributable mortality due to candidaemia varied from 21.5% to 34.7%. Candidaemia patients spend on average 5.6 days more in the ICU than matched patients and generate mean additional costs of at least 8252 UK pounds per patient, 16,595 pounds in adults only.

CONCLUSION

Candidaemia remains a severe disease associated with high attributable mortality in the UK. In addition, candidaemia leads to additional ICU length of stay and costs. The implication is an attributable cost of at least 16.2 million UK pounds with 683 deaths attributable to candidaemia per year in the UK.

Recent advances in antifungal prevention and treatment

Invasive fungal infections are important causes of morbidity and mortality in patients with bone marrow failure syndromes and hematological malignancies, or who are undergoing allogeneic hematopoietic stem cell transplantation (HSCT). Current epidemiological trends indicate a shift toward infections by Aspergillus spp., non-albicans Candida spp., and previously uncommon fungal pathogens that have decreased susceptibility to the available antifungal agents. The last two decades have seen substantial improvements in the clinical, laboratory, and radiological diagnosis of these infections and the development of new antifungal compounds. Progress has been made in establishing disease definitions and paradigms for antifungal intervention and in the design and conduct of interventional clinical trials. Collectively, these advances have led to major but ongoing changes in the management of patients at risk of or being affected by invasive fungal infections. This article reviews current approaches to prevention and treatment of opportunistic fungal infections in immunocompromised patients with hematological disorders and discusses novel approaches to antifungal chemotherapy and adjunctive treatments.

Empiric anti-Candida therapy for patients with sepsis in the ICU: how little is too little?

Prior analyses suggest that empiric fluconazole for ICU patients with sepsis is cost-effective. Using updated estimates of efficacy and cost, Zilberberg and colleagues compare the use of micafungin with that of fluconazole. The authors conclude that micafungin is an attractive alternative to fluconazole. This conclusion is driven by recent reduction in micafungin's cost and by better activity of micafungin against azole-resistant Candida species. Their results are limited by inflated estimates of efficacy, life expectancy and risk of Candida sepsis. This commentary explores the rationale for early anti-Candida strategies in the ICU and highlights the contribution and limitations of the article by Zilberberg and colleagues.

Fluconazole dosing for the prevention or treatment of invasive candidiasis in young infants

BACKGROUND

Young infants are susceptible to developmental factors influencing the pharmacokinetics of drugs. Fluconazole is increasingly used to prevent and treat invasive candidiasis in infants. Dosing guidance remains empiric and variable because limited pharmacokinetic data exist.

METHODS

Our population pharmacokinetic model derived from 357 fluconazole plasma concentrations from 55 infants (23-40 week gestation) illustrates expected changes in fluconazole clearance based upon gestational age, postnatal age, weight, and creatinine. We used a Monte Carlo simulation approach based on parametric description of a patient population's pharmacokinetic response to fluconazole to predict fluconazole exposure (median: 10th and 90th percentile population variability range) after 3, 6, and 12 mg/kg dosing.

RESULTS

For the treatment of invasive candidiasis, a dose of at least 12 mg/kg/d in the first 90 days after birth is needed to achieve an area under the concentration curve (AUC) of >400 mg*h/L and an AUC/minimum inhibitory concentration (MIC) >50 for Candida species with MIC <8 microg/mL in > or =90% of <30 week gestation infants and 80% of 30 to 40 week gestation infants. The more preterm infants achieve a higher median AUC (682 mg*hr/L) compared with more mature infants (520 mg*hr/L). For early prevention of candidiasis in 23 to 29 week infants, a dose of 3 or 6 mg/kg twice weekly during the first 42 days of life is equivalent to an AUC of 50 and 100 mg*hr/L, respectively, and maintains fluconazole concentrations > or =2 or 4 microg/mL, respectively, for half of the dosing interval. For late prevention, the 6 mg/kg dose every 72 hours provides similar exposure to 3 mg/kg daily dose. Infants with serum creatinine > or =1.3 mg/dL have delayed drug clearance and dose adjustment is indicated if creatinine does not improve within 96 hours.

CONCLUSIONS

A therapeutic concentration of fluconazole in premature infants with invasive candidiasis requires dosing substantially greater than commonly recommended in most reference texts. To prevent invasive candidiasis, twice weekly prophylaxis regimens can provide adequate exposure when unit specific MICs are taken into account.

Candida in the ICU

Invasive Candida infections are becoming increasingly recognized in critically ill patients. These infections result in serious morbidity, can be life threatening, and are expensive to manage. Early suspicion of Candida infection and the use of timely and proper antifungal treatment can improve outcome. Although treatment of documented, deep-seated Candida infections in nonneutropenic patients has been studied extensively, guidelines for the management of suspected but undocumented cases of invasive Candida infections in critically ill patients have not been clearly established. Future work should focus on better delineation of the sector of critically ill patients who have suspected invasive Candida infection and who could benefit from the use of empiric antifungal therapy, and on the investigation of novel approaches for the potential salvage of devices infected with Candida species.

Clinical outcomes of dialysis catheter-related candidemia in hemodialysis patients

BACKGROUND AND OBJECTIVES

Candidemia is a rare complication in catheter-dependent hemodialysis patients. As a result, there is uncertainty about its optimal medical management. The goal of this retrospective study was to compare the clinical outcomes of catheter-related candidemia managed with two different strategies: Guidewire exchange of the infected catheter versus removal with delayed replacement.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We retrospectively queried a prospective, computerized vascular access database to identify 40 hemodialysis patients with catheter-related candidemia. All patients underwent treatment with antifungal medications for 2 wk, in conjunction with guidewire catheter exchange or catheter removal with delayed replacement. The primary outcomes were major complications, recurrent candidemia, and patient survival.

RESULTS

Candidemia represented approximately 2% of all cases of catheter-related bloodstream infections. Of the 40 patients with candidemia, 27 underwent guidewire catheter exchange and 13 had prompt catheter removal with delayed replacement. The two treatment groups were similar in demographic, clinical, and catheter characteristics. Only 1 (2.5%) patient developed a serious complication (endophthalmitis). Recurrence of candidemia within 3 mo was observed in 15% of each treatment group. Patient survival at 6 mo was similar in both groups.

CONCLUSIONS

Catheter-related candidemia is rare in hemodialysis patients and has a low complication rate. Catheter exchange over a guidewire in conjunction with antifungal therapy is an effective and safe treatment regimen.

Clinical practice guidelines for the management of candidiasis: 2009 update by the Infectious Diseases Society of America

Guidelines for the management of patients with invasive candidiasis and mucosal candidiasis were prepared by an Expert Panel of the Infectious Diseases Society of America. These updated guidelines replace the previous guidelines published in the 15 January 2004 issue of Clinical Infectious Diseases and are intended for use by health care providers who care for patients who either have or are at risk of these infections. Since 2004, several new antifungal agents have become available, and several new studies have been published relating to the treatment of candidemia, other forms of invasive candidiasis, and mucosal disease, including oropharyngeal and esophageal candidiasis. There are also recent prospective data on the prevention of invasive candidiasis in high-risk neonates and adults and on the empiric treatment of suspected invasive candidiasis in adults. This new information is incorporated into this revised document.

Treatment of critically ill patients with candidemia

Early initiation of effective antimicrobial therapy is crucial for the prognosis of any infection, especially in the critically ill patient. This is particularly true in the case of candidemia. However, the earlier an empirical antimicrobial regimen is started, the greater the probability of diagnostic error and the possibility of side-effects. Recent experience of the clinical efficacy and good tolerance of echinocandins in the treatment of candidemia obliges us to review the indications for empirical antifungal treatment and the choice of antifungal agent in the critically ill patient.

Treatment of invasive fungal infections in immunocompromised and transplant patients: AmBiLoad trial and other new data

Opportunistic invasive fungal infections (IFIs) have changed. Moreover, a significantly greater therapeutic armamentarium is now available, with liposomal amphotericin B (L-AmB) administered in new ways, for example in higher doses, in combination with other compounds or inhaled. The objective of this study was to review these three aspects. The AmBiLoad study was designed to clarify whether higher doses of L-AmB could be more efficacious than the licensed dose of 3-5 mg/kg. It was a multicentric study where patients were randomised to receive a 14-day course of 3 mg/kg/day or 10 mg/kg/day L-AmB. A total of 339 patients were enrolled during the study period (April 2003 to October 2004). Discontinuation of treatment, mainly due to adverse events, was frequent (13% in the standard dose group vs. 24% in the high dose group), and only 66% and 50%, respectively, completed 14 days of randomised treatment. There was no statistically significant difference with regard to favourable overall responses between the treatment groups (50% in the standard dose group vs. 46% in the high dose group; P = 0.65). In addition, there was no significant difference according to type of IFI (invasive aspergillosis, 50% vs. 46% in the standard and high dose groups, respectively). The obvious conclusion of this study was that administration of 10 mg/kg/day L-AmB to patients with IFI does not improve efficacy but increases toxicity and price. In vitro and experimental data suggest that the combination of AmB with other antifungal agents may be more effective than monotherapy; however, data regarding the clinical efficacy of L-AmB in combination with other agents are scarce. The use of inhaled L-AmB has shown promising results for use as antifungal prophylaxis in high-risk patients.

Isavuconazole: a new and promising antifungal triazole for the treatment of invasive fungal infections

Invasive fungal infections (IFIs) are an important cause of morbidity and mortality. Isavuconazole (BAL4815) is a promising novel broad-spectrum triazole in late-stage clinical development that has proven to be active in vitro against Aspergillus, Candida and Cryptococcus neoformans, the most common agents of IFIs. Furthermore, isavuconazole has a pharmacokinetic profile that allows oral and intravenous administration with no severe toxicity. In vivo data from animal models are also encouraging. However, very little information on clinical efficacy is available. Four clinical trials are currently in progress to demonstrate the safety and efficacy of isavuconazole for the treatment and prevention of IFIs. In the absence of clinical and cost data, the real possibilities of this agent as a competitor for the treatment and prevention of IFIs in the clinical setting are still unknown.

Therapeutic strategies for invasive fungal infections in neonatal and pediatric patients

Invasive Candida and Aspergillus infections are the most commonly encountered fungal infections. They appear to be life threatening in the setting of profound immunosuppression, whereas cases that are resistant to antifungal therapy are occasionally encountered. Novel antifungal triazole and echinocandin agents appear to exhibit good activity as first-line or salvage therapy, whereas the use of amphotericin B formulations is particularly valuable in neonates. Significant differences in toxicity have been demonstrated among various antifungal agents with in vitro activity from available comparative data on fungal infections in children: however, no clear difference in treatment efficacy has been demonstrated. However, very little data are available about neonates. Host factors and responsible fungal species most frequently guide the choice of therapy.

Pharmacotherapy of yeast infections

The rise of immunocompromised individuals in our society has provoked a significant emergence in the number of patients affected by opportunistic pathogenic yeast. The microorganisms with a major clinical incidence are species from the genera Candida (especially Candida albicans) and Cryptococcus (particularly Cryptococcus neoformans), although there has been a significant increase in other pathogenic yeasts, such as Trichosporon spp. and Rhodotorula spp. In addition, there are an increasing number of patients infected by yeasts that were not previously considered as pathogenic, such as Saccharomyces cerevisiae. The management of these infections is complicated and is highly dependent on the susceptibility profile not only of the species but also of the strain. The available antifungal compounds belong mainly to the polyene, azole and candin families, which show a distinct spectrum of activity. This review summarizes the current knowledge about the use of the main antifungals for treating infections caused by the yeast species with the most significant clinical relevance, including the susceptibility profiles exhibited by these species in vitro.

Is it possible to blind a trial for community-acquired pneumonia?

Blinding a randomized, controlled clinical trial provides benefits on several levels but often is not perfectly executed or well described. Most recent registration trials of therapy for community-acquired pneumonia were designed and conducted as blinded trials, although the descriptions of blinding were frequently incomplete. Issues related to definitions, conduct, testing success, and reporting of blinding are addressed in this article. The benefits of blinding clinical trial participants, study drug assignment, microbiological data, and outcome assessments of both efficacy and safety are presented. Particular attention is paid to challenges inherent in the blinding of trials of therapy for pneumonia, especially in trials involving seriously ill patients who require intravenous therapy.

Antifungals in the ICU

PURPOSE OF REVIEW

Invasive fungal infections remain a serious complication for critically ill ICU patients. The aim of this article is to review recent efficacy data of newer antifungal agents for the treatment of invasive candidiasis. The influence that recent epidemiological trends, advances in diagnostic testing, and risk prediction methods exert on the optimization of antifungal therapy for critically ill ICU patients will also be reviewed.

RECENT FINDINGS

Recent clinical trials have documented the clinical efficacy of the echinocandins and the newer triazoles for the management of invasive candidiasis. Thus far, resistance to echinocandins remains rare. Changes in the epidemiology of Candida spp. causing invasive candidiasis, such as an increasing relative proportion of non-albicans Candida spp., have not been universally reported, although they have important implications for the use of fluconazole as first-line therapy for invasive candidiasis. Efforts to improve the timeliness and accuracy of laboratory diagnostic techniques and clinical prediction models to allow early and accurately targeted antifungal intervention strategies continue.

SUMMARY

Echinocandins, given their clinical efficacy, spectrum of activity, and favourable pharmacological properties, are likely to replace fluconazole as initial antifungal agents of choice among critically ill ICU patients. The optimization of patient outcomes will require more accurately targeted early antifungal intervention strategies based upon sensitive and specific biological and clinical markers of risk.

Management of invasive candidiasis and candidemia in adult non-neutropenic intensive care unit patients: Part II. Treatment

BACKGROUND

Invasive candidiasis and candidemia are frequently encountered in the nosocomial setting particularly in the intensive care unit (ICU).

OBJECTIVE AND METHODS

To review the current management of invasive candidiasis and candidemia in non-neutropenic adult ICU patients based on a review of the literature and an European expert panel discussion.

RESULTS AND CONCLUSIONS

Empiric and directed treatment for invasive candidiasis are predicated on the hemodynamic status of the patient. Unstable patients may benefit from broad-spectrum antifungal agents, which can be narrowed once the patient has stabilized and the identity of the infecting species is established. In stable patients, a more classical approach using fluconazole may be satisfactory provided that the patient is not colonized with fluconazole resistant strains or there has been recent past exposure to an azole (<30 days). In contrast, pre-emptive therapy is based on the presence of surrogate markers.

Recommendations for the treatment of established fungal infections

Evidence-based guidelines for the treatment of established fungal infections in the adult haematology/oncology setting were developed by a national consensus working group representing clinicians, pharmacists and microbiologists. These updated guidelines replace the previous guidelines published in the Internal Medicine Journal by Slavin et al. in 2004. The guidelines are pathogen-specific and cover the treatment of the most common fungal infections including candidiasis, aspergillosis, cryptococcosis, zygomycosis, fusariosis, scedosporiosis, and dermatophytosis. Recommendations are provided for management of refractory disease or salvage therapies, and special sites of infections such as the cerebral nervous system and the eye. Because of the widespread use newer broad-spectrum triazoles in prophylaxis and empiric therapy, these guidelines should be implemented in concert with the updated prophylaxis and empiric therapy guidelines published by this group.

Treatment of invasive candidal infections: systematic review and meta-analysis

OBJECTIVE

To compare available antifungal treatments for invasive candidiasis, a leading cause of nosocomial bloodstream infections.

METHODS

We performed a systematic review and meta-analysis of randomized controlled trials that compared different antifungal agents for the treatment of candidemia and other forms of invasive candidiasis. Two reviewers independently appraised the quality of trials and extracted data. The primary outcome was all-cause mortality, and secondary outcomes were microbiological failure, treatment failure, and adverse events. Relative risks (RRs) with 95% confidence intervals (CIs) were pooled.

RESULTS

Of the 15 included trials, 9 compared fluconazole with other drugs (amphotericin B, itraconazole, or a combination of fluconazole and amphotericin B), 4 compared echinocandins with other drugs (fluconazole, amphotericin B, liposomal amphotericin B), 1 compared micafungin and caspofungin, and 1 compared amphotericin B plus fluconazole and voriconazole. No difference in mortality was observed with fluconazole vs amphotericin B (RR, 0.92; 95% CI, 0.72-1.17); however, the rate of microbiological failure increased in the fluconazole arm (RR, 1.52; 95% CI, 1.12-2.07). Anidulafungin decreased the rate of microbiological failure compared with fluconazole (RR, 0.50; 95% CI, 0.29-0.86) with fewer adverse events. Caspofungin was comparable to amphotericin B in mortality and efficacy, with fewer adverse events requiring discontinuation (RR, 0.11; 95% CI, 0.04-0.36). Micafungin was comparable to liposomal amphotericin B in mortality.

CONCLUSION

All assessed antifungal agents showed similar efficacy, but the rate of microbiological failure increased with fluconazole vs amphotericin B or anidulafungin. Amphotericin B is associated with a higher rate of adverse events than fluconazole and echinocandins.

New options for treatment of candidaemia in critically ill patients

Bloodstream infections caused by Candida spp. are increasingly recognised in critically ill adult and paediatric individuals, with significant associated morbidity and mortality. Candida albicans is the single most common fungal species to cause nosocomial infections. However, non-C. albicans spp., including Candida glabrata and Candida krusei, which are less susceptible to fluconazole, have become more common. Until the 1980s, the therapeutic possibilities for invasive candidosis were limited to amphotericin B, but with the advent of new antifungal agents, such as azoles and echinocandins, less toxic therapeutic options have become available and there are now possibilities for prevention and optimised therapy for documented Candida infections. In this review, the currently available options for the treatment of candidaemia and invasive candidosis are discussed with regard to the role of liposomal amphotericin B in comparison with the echinocandins and azoles.

Combination antifungal therapy: a critical review of the evidence

Invasive fungal infections have extremely high rates of morbidity and mortality, particularly in immunocompromised hosts. Combination antifungal therapy is conceptually attractive as a life-saving measure. However, in-vitro and in-vivo evidence is often conflicting and clinical trials in this area are limited. Most clinical studies show similar outcomes for combination antifungal therapy when compared to monotherapy, although secondary endpoints and sub-analyses often show advantages for the combinations in endpoints such as culture sterilisation. The logistics of large clinical trials of combination therapy are highly complex. Combination of antifungals with immune modulators is an exciting new research area. Until more data are available, clinicians should approach combination antifungal therapy with caution.

Evaluation of aminocandin and caspofungin against Candida glabrata including isolates with reduced caspofungin susceptibility

BACKGROUND

Aminocandin is an investigational echinocandin with excellent activity against Candida species, including Candida albicans and Candida tropicalis. However, few data are available for this agent versus Candida glabrata. We compared the in vitro potency and in vivo efficacy of aminocandin and caspofungin against clinical isolates of C. glabrata including those with reduced caspofungin susceptibility (MIC > 2 mg/L).

METHODS

In vitro activity was assessed using microdilution broth susceptibility testing. Three isolates, one with a low and two with elevated caspofungin MICs, were chosen and mice were infected with C. glabrata followed by a single dose of aminocandin or caspofungin (0.5-100 mg/kg), or daily doses of caspofungin (0.07-14.3 mg/kg) begun 1 day after inoculation. Reduction in fungal burden, assessed in kidney tissue on day 8 post-inoculation, was the marker of antifungal response.

RESULTS

Aminocandin was more potent than caspofungin against each isolate with reduced caspofungin susceptibility. Mice infected with the caspofungin-susceptible isolate had significant decreases in tissue burden with low doses of either drug. Higher single doses of aminocandin (> or = 10 mg/kg) were required to reduce fungal burden against the two isolates with elevated caspofungin MICs. Single dose administration of caspofungin was ineffective against one of these isolates, and higher daily doses were required to reduce fungal burden.

CONCLUSIONS

These studies suggest that aminocandin has the potential for extended interval dosing in the treatment of C. glabrata infections caused by susceptible isolates. However, higher doses may be required against isolates with reduced caspofungin susceptibility.

Fungicidal versus Fungistatic: what's in a word?

BACKGROUND

Historically clinicians have preferred to use 'cidal' antifungal agents, particularly in critically ill patients. However, data to support the belief that the preferential use of a 'cidal' agent results in better patient outcomes has been lacking.

OBJECTIVE

This review examined the in vitro definitions of fungicidal and fungistatic as well as their strengths and limitations.

METHODS

A Medline search was performed in order to identify literature that examined the in vitro or in vivo impact of fungicidal and fungistatic activity. The study examined three common invasive fungal infections, namely cryptococcal meningitis, candidemia and invasive aspergillosis, where sufficient comparisons of fungicidal and fungistatic agents have been performed to allow for the evaluation of the clinical importance of these in vitro findings.

RESULTS AND CONCLUSION

A clear clinical benefit of fungicidal agents over those with fungistatic activity remains elusive. Patients with cryptococcal meningitis clearly benefit from early fungicidal therapy but require long-term suppression. The data in invasive Candida sp. infections are tantalizing and suggest that fungicidal therapy may be important. However, the data for invasive aspergillosis do not support the hypothesis that fungicidal activity improves outcomes.

Advances in antifungal therapy

The prevalence of invasive fungal infections (IFIs) has increased over the past three decades owing to the increasing numbers of immunocompromised hosts. These infections are associated with significant morbidity and mortality. Recent significant advances in antifungal therapy include the broad-spectrum triazoles (voriconazole and posaconazole) and a new class of antifungals, the echinocandins (caspofungin, micafungin, and anidulafungin). New treatment strategies, such as combination therapy and pre-emptive therapy, are being investigated. There have also been significant improvements in diagnostics; the galactomannan enzyme immunoassay and the beta-glucan test are now part of the EORTC/MSG criteria for diagnosis of IFI. Despite these advances, there remain a number of unanswered questions regarding optimal management of serious fungal infections, and research continues to discover and develop new therapies and evaluate new management strategies.

Current options in antifungal pharmacotherapy

Infections caused by yeasts and molds continue to be associated with high rates of morbidity and mortality in both immunocompromised and immunocompetent patients. Many antifungal drugs have been developed over the past 15 years to aid in the management of these infections. However, treatment is still not optimal, as the epidemiology of the fungal infections continues to change and the available antifungal agents have varying toxicities and drug-interaction potential. Several investigational antifungal drugs, as well as nonantifungal drugs, show promise for the management of these infections.