Posaconazole as Salvage Therapy in Patients With Invasive Fungal Infections After Solid Organ Transplant

Model-Informed Dose Justifications of Posaconazole in Japanese Patients for Prophylaxis and Treatment Against Fungal Infection

Posaconazole is a globally approved broad-spectrum triazole antifungal compound. In Japanese patients, posaconazole has identical dosing regimens as those approved globally for both tablet and intravenous formulations. This article aims to describe a model-informed approach for dose justification of posaconazole in the Japanese population as either high-risk patients with fungal infections (prophylaxis patients) or patients with fungal infections (treatment patients). A simultaneous population pharmacokinetic (PK) model for tablet and intravenous formulation was developed on the basis of a data set including Japanese data from healthy participants and treatment patients. The PK profiles and exposure distributions in Japanese patients were predicted and compared against foreign patients, that is, patients outside of Japan. Relationships between the post hoc posaconazole exposures and frequently observed clinical adverse events were evaluated. Although clinical trials for Japanese prophylaxis patients were not conducted, PK profiles in Japanese prophylaxis patients were predicted using the population PK model and demographic covariate information obtained from the published literature. Based upon the globally approved dosing regimen, posaconazole exposure distribution was predicted to be the highest in Japanese treatment patients, and generally similar between Japanese and foreign prophylaxis patients. Exposures in Japanese patients exceeded the efficacy target level (500 ng/mL). Safety profiles in Japanese treatment patients with the highest exposures were clinically acceptable without specific concerns to Japanese patients and appeared to have no relationship with posaconazole exposures. From PK, safety, and efficacy perspectives, the use of the same dosing regimen as in foreign patients was justified in Japanese prophylaxis and treatment patients.

Therapeutic Approaches for Combating Aspergillus Associated Infection

Now-a-days fungal infection emerges as a significant problem to healthcare management systems due to high frequency of associated morbidity, mortality toxicity, drug-drug interactions, and resistance of the antifungal agents. Aspergillus is the most common mold that cause infection in immunocompromised hosts. It's a hyaline mold that is cosmopolitan and ubiquitous in nature. Aspergillus infects around 10 million population each year with a mortality rate of 30-90%. Clinically available antifungal formulations are restricted to four classes (i.e., polyene, triazole, echinocandin, and allylamine), and each of them have their own limitations associated with the activity spectrum, the emergence of resistance, and toxicity. Consequently, novel antifungal agents with modified and altered chemical structures are required to combat these invasive fungal infections. To overcome these limitations, there is an urgent need for new antifungal agents that can act as potent drugs in near future. Currently, some compounds have shown effective antifungal activity. In this review article, we have discussed all potential antifungal therapies that contain old antifungal drugs, combination therapies, and recent novel antifungal formulations, with a focus on the Aspergillus associated infections.

Evaluating posaconazole, its pharmacology, efficacy and safety for the prophylaxis and treatment of fungal infections

INTRODUCTION

Invasive fungal diseases (IFDs) are a significant cause of morbidity and mortality among immunocompromised patients. Safe and effective antifungal medications used for prophylaxis and treatment are pivotal in their management. Posaconazole is a promising triazole antifungal agent.

AREAS COVERED

The authors discuss the pharmacological properties of posaconazole, including pharmacokinetics/pharmacodynamics, safety and tolerability profile, together with efficacy data for prophylaxis and treatment as well as its use in special populations based on current literature.

EXPERT OPINION

Posaconazole has a favorable safety and tolerability profile; however, caution is advised when co-administered with agents that are CYP3A4 inhibitors, because their concentration may significantly increase, and their levels should be closely monitored. It has an extended spectrum of activity against yeasts and filamentous fungi. It is successfully used as prophylaxis for patients with acute myeloid leukemia (AML)/myelodysplastic syndrome (MDS) and post-hematopoietic cell transplantation (HCT) with graft-versus-host disease (GVHD). It is the first line treatment for oropharyngeal candidiasis and is also used as a salvage treatment for refractory IFDs. Currently available formulations include the oral suspension, delayed-release tablets and solution for intravenous infusion, all with different PK/PD properties and indications. Its use in children and adolescents is currently being examined in Phase-II clinical trials.

Isavuconazole treatment of invasive fungal sinusitis: a post hoc analysis of the SECURE and VITAL trials

This post-hoc analysis of international phase III isavuconazole trials identified 50 patients (90% immunocompromised or diabetic) with invasive fungal sinusitis (88% mucormycetes, Aspergillus) who received isavuconazole as primary (33) or salvage (17) therapy for median 82 days (range 2-882). Overall survival was 82% at day 42, 70% at day 84.

Clinical considerations on posaconazole administration and therapeutic drug monitoring in allogeneic hematopoietic cell transplant recipients

There is a paucity of data on posaconazole (PCZ) dosing and therapeutic-drug-monitoring (TDM) in allogeneic hematopoietic cell transplant recipients (allogeneic-HCTr). This was a 3-year retrospective multicenter study (January 1, 2016 to December 31, 2018) in adult allogeneic-HCTr who received PCZ (intravenously, IV and/or as delayed-release tablet, DRT) as prophylaxis or treatment for ≥7 consecutive days (D) with at least 1-PCZ-level available using data of the Swiss Transplant Cohort Study. The primary objective was to describe the distribution of PCZ-level and identify predictors of therapeutic PCZ-level and associations between PCZ-dosing and PCZ-level. A total of 288 patients were included: 194 (67.4%) and 94 (32.6%) received PCZ as prophylaxis and treatment, respectively, for a median of 90 days (interquartile range, IQR: 42-188.5). There were 1944 PCZ-level measurements performed, with a median PCZ level of 1.3 mg/L (IQR: 0.8-1.96). PCZ-level was <0.7 mg/L in 383/1944 (19.7%) and <1.0 mg/L in 656/1944 (33.7%) samples. PCZ-level was <0.7 mg/L in 260/1317 (19.7%) and <1.0 mg/L in 197/627 (31.4%) in patients who received PCZ-prophylaxis versus treatment, respectively. There were no significant differences in liver function tests between baseline and end-of-treatment. There were nine (3.1%) breakthrough invasive fungal infections (bIFI), with no difference in PCZ levels between patients with or without bIFI. Despite a very intensive PCZ-TDM, PCZ-levels remain below target levels in up to one-third of allogeneic-HCTr. Considering the low incidence of bIFI observed among patients with PCZ levels in the targeted range, our data challenge the clinical utility of routine universal PCZ-TDM.

Cryptococcosis in solid organ transplantation-Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of cryptococcosis in the pre- and post-transplant period. The current update now includes a discussion of cryptococcosis, which is the third most common invasive fungal infection in SOT recipients. Infection often occurs a year after transplantation; however, early infections occur and donor-derived infections have been described within 3 months after transplant. There are two main species that cause infection, Cryptococcus neoformans and C gattii. Clinical onset may be insidious, but headaches, fevers, and mental status changes should warrant diagnostic testing. The lateral flow cryptococcal antigen assay is now the preferred test from serum and cerebrospinal fluid due to its rapidity, accuracy, and cost. A lumbar puncture with measurement of opening pressure is recommended for patients with suspected or proven cryptococcosis. Lipid amphotericin B plus 5-flucytosine is used as initial treatment of meningitis, disseminated infection, and moderate-to-severe pulmonary infection, followed by fluconazole as consolidation therapy. Fluconazole is effective for mild-to-moderate pulmonary infection. Immunosuppression reduction as part of management may lead to immune reconstitution syndrome that may resemble active disease.

Emerging fungal infections in solid organ transplant recipients: Guidelines of the American Society of Transplantation Infectious Diseases Community of Practice

These updated AST-IDCOP guidelines review the epidemiology, diagnosis, and management of emerging fungi after organ transplantation. Infections due to numerous generally innocuous fungi are increasingly recognized in solid organ transplant (SOT) recipients, comprising about 7%-10% of fungal infections in this setting. Such infections are collectively referred to as emerging fungal infections and include Mucormycetes, Fusarium, Scedosporium, and dematiaceous fungi among others. The causative organisms are diverse in their pathophysiology, uncommon in the clinical setting, have evolving nomenclature, and are often resistant to multiple commonly used antifungal agents. In recent years significant advances have been made in understanding of the epidemiology of these emerging fungal infections, with improved diagnosis and expanded treatment options. Still, treatment guidelines are generally informed by and limited to experience from cohorts of patients with hematological malignancies and/or solid and stem cell transplants. While multicenter randomized controlled trials are not feasible for these uncommon infections in SOT recipients, collaborative prospective studies can be valuable in providing information on the epidemiology, clinical manifestations, treatment strategies, and outcomes associated with the more commonly encountered infections.

Posaconazole salvage therapy: The Posifi study

BACKGROUND

Posaconazole (PCZ) is used mainly for the prevention of invasive fungal infection (IFI).

METHODS

A multicentre retrospective, investigational study using a non-randomized, single-arm design carried out in six tertiary hospitals in Spain to evaluate the use of PCZ in different forms of administration in the (non-prophylactic) treatment of IFI.

RESULTS

Over an eight-year-period, 67 patients were included in this study. PCZ was administered as salvage therapy (intolerant or refractory to a previous antifungal agent) in 65/67 (97%); of these, it was used against Aspergillosis (68.6%), Zygomycosis (13.4%), other moulds (8.9%) and yeast (10.5%). The median duration of PCZ therapy was 75 days. The oral solution was associated with low serum levels (<0.7 mg/L) in 63% of available patients. Clinical response at 3 and 12 months of PCZ therapy were for aspergillosis: 47.8% and 41.3%; for zygomycosis: 55.5% and 55.5%; and for other mycoses: 69.2% and 69.2%, respectively. Suspension by toxicity was only observed in 6% and 7.5% of patients at 3 and 12 months, respectively, mainly with grade III/IV elevations of liver function test (LFTs).

CONCLUSIONS

Posaconazole salvage therapy, especially oral tablets, can be an effective alternative option for patients with IFI who cannot tolerate or do not respond to other antifungal therapies.

Mold Infections in Solid Organ Transplant Recipients

Mold infections carry a substantial clinical and economic burden in solid organ transplant (SOT) recipients with a high overall mortality of near 30%. The most important pathogens include Aspergillus, the Zygomycetes, Fusarium, Scedosporium/Pseudallescheria, and the dematiaceous (dark) molds. Risk factors for the infections vary by transplant type but include degree of immune suppression and loss of skin or mucosal integrity. Correct diagnosis usually requires histopathology and/or culture. Management often requires a multidisciplinary team approach with combined antifungal and surgical therapies. This article reviews the epidemiology, risk factors, microbiology, diagnostic, and treatment approach to mold infections in SOT recipients.

Emerging Candida species isolated from renal transplant recipients: Species distribution and susceptibility profiles

Candidiasis is a major challenge among renal transplant recipients (RTRs) worldwide and is associated with high morbidity and mortality rates. Fluconazole is the most commonly used agent for Candida infections. However, frequent relapse and treatment failure are still reported among patients affected with this infection. In the present study, Candida species obtained from RTRs were characterized based on conventional and molecular assays. Furthermore, the antifungal susceptibility profiles of these species were determined. This study was conducted on a total of 126 RTRs within 2012-2016. The patients were categorized according to the referenced diagnostic criteria. The identification of Candida species was accomplished based on conventional examination, assimilation profile test, and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The minimum inhibitory concentrations (MICs) of amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, and caspofungin were determined based on the guidelines of Clinical and Laboratory Standards Institute. The patients with Candida infection were diagnosed with urinary tract candidiasis (n = 17), peritonitis (n = 8), intra-abdominal candidiasis (n = 6), candidemia (n = 4), hepatosplenic candidiasis (n = 3), and Candida pneumonia (n = 3). A total of 41 Candida isolates, including C. albicans (n = 18), C. famata (n = 8), C. kefyr (n = 4), C. tropicalis (n = 4), C. parapsilosis (n = 3), C. glabrata (n = 2), and C. lusitaniae (n = 2), were isolated from 32.5% (41/126) renal transplant recipients. Fluconazole-resistance was observed in seven isolates, entailing C. albicans (n = 6) and C. tropicalis (n = 1). Fluconazole MIC for C. lusitaniae isolates was above the epidemiologic cut-off value (4-16 μg/ml). Furthermore, MIC range values of fluconazole against C. famata and C. kefyr were obtained as 4-32 μg/ml and 4-8 μg/ml, respectively. Posaconazole exhibited potent activity against Candida isolates, followed by caspofungin. The identification of Candida species, together with susceptibility testing, provides important data about the geographic trends of the fluconazole-resistance profiles of Candida species. It is necessary to maintain a consistent method for the implementation of early diagnosis and adoption of treatment regimen.

Treatment of Aspergillosis

Infections caused by Aspergillus spp. remain associated with high morbidity and mortality. While mold-active antifungal prophylaxis has led to a decrease of occurrence of invasive aspergillosis (IA) in those patients most at risk for infection, breakthrough IA does occur and remains difficult to diagnose due to low sensitivities of mycological tests for IA. IA is also increasingly observed in other non-neutropenic patient groups, where clinical presentation is atypical and diagnosis remains challenging. Early and targeted systemic antifungal treatment remains the most important predictive factor for a successful outcome in immunocompromised individuals. Recent guidelines recommend voriconazole and/or isavuconazole for the primary treatment of IA, with liposomal amphotericin B being the first alternative, and posaconazole, as well as echinocandins, primarily recommended for salvage treatment. Few studies have evaluated treatment options for chronic pulmonary aspergillosis (CPA), where long-term oral itraconazole or voriconazole remain the treatment of choice.

A Drug-drug Interaction Between Cyclosporine and Nystatin

We present a case of increased cyclosporine concentration and liver function right after the combinational use of cyclosporine and nystatin, which indicated a drug-drug interaction between them. Both the concentration and liver function were decreased after discontinuation of nystatin and remained normal after taking on cyclosporine again. To our knowledge, this is the first case report of the interactions between nystatin and cyclosporine. Enteric P-glycoprotein could play an important role in the pharmacokinetic profile of cyclosporine, which needs further identification by physicians and pharmacists.

Fungal Infections of the Central Nervous System in Children

Although uncommon in children, fungal infections of the central nervous system can be devastating and difficult to treat. A better understanding of basic mycologic, immunologic, and pharmacologic processes has led to important advances in the diagnosis and management of these diseases, but their mortality rates remain unacceptably high. In this focused review, we examine the epidemiology and clinical features of the most common fungal pathogens of the central nervous system in children and explore recent advances in diagnosis and antifungal therapy.

Utilization of posaconazole oral suspension or delayed-released tablet salvage treatment for invasive fungal infection

Posaconazole may be useful for salvage treatment (ST) for invasive fungal infections (IFIs). The aim of this study was to evaluate the efficacy of posaconazole ST with either posaconazole oral suspension (SUS) or delayed-released tablet (TAB) in patients with IFI. A retrospective review of patients who received posaconazole ST for IFI at the University of Utah Health Sciences Center between December 2007 and March 2014 was conducted. A total of 14 episodes of posaconazole ST for proven (9 episodes) and probable (5 episodes) IFI were identified in 14 patients. The median age was 54 years and the majority of patients (64.3%) had underlying haematological diseases. Posaconazole SUS and TAB were used in 11 episodes and 3 episodes respectively. The duration of posaconazole ST ranged from 28 to 370 days with a median of 65 days. Posaconazole ST with TAB achieved favourable serum posaconazole trough concentrations (median 1.4 μg mL^-1 ) compared to posaconazole SUS (median 1.0 μg mL^-1 ). The overall clinical success rate with posaconazole ST was 71.4% (10 of 14 episodes). One patient died of progression of IFI. Adverse events were noted in two patients. Posaconazole SUS or TAB may be used effectively for IFI ST.

Salvage Treatment of Mucormycosis Post-Liver Transplant With Posaconazole During Sirolimus Maintenance Immunosuppression

We describe the first successful case of posaconazole salvage therapy for mucormycosis with concomitant sirolimus (SRL) maintenance immunosuppression following liver transplantation, despite black box drug interaction following intolerance to first-line tacrolimus and amphotericin due to nephrotoxicity and neurotoxicity. This case describes a 55-year-old female who developed rhinocerebral mucormycosis 108 days after liver transplantation. After 3 months of posaconazole therapy, the patient remains free of disease at 3 years posttransplant. This case report illustrates successful resolution of mucormycosis without SRL toxicity to resolve nephrotoxicity of long-term amphotericin on top of already nephrotoxic immunosuppression. With higher bioavailability of recently FDA-approved posaconazole delayed release tablets, this azole may be a therapeutic option for transplant patients who need to remain on CYP3A4-metabolized immunosuppressive agents.

Switching to anidulafungin from caspofungin in cancer patients in the setting of liver dysfunction is associated with improvement of liver function tests

BACKGROUND

Anidulafungin does not undergo hepatic metabolism like the other echinocandins. Therefore, there is a perception that anidulafungin may be less hepatotoxic or less likely to exacerbate existing liver damage. This has not been substantiated in the literature.

METHODS

We retrospectively reviewed all cancer patients in whom anidulafungin treatment was immediately preceded by treatment with caspofungin and there existed clinical or laboratory evidence of hepatic damage or dysfunction at M. D. Anderson Cancer Center from January 2010 to December 2013.

RESULTS

Sixty-one patients were included in the study. Most patients had haematological malignancies (58, 95%), and the patients were administered hepatotoxic agents such as chemotherapeutic agents (47, 77%) and other medications (38, 62%) simultaneously. There were significant decreases in AST and ALT (P < 0.029 and P < 0.0017, respectively) between two timepoints (switch from caspofungin to anidulafungin and end of anidulafungin therapy). The median changes in AST, ALT and total bilirubin during anidulafungin therapy were -43 IU/L, -25 IU/L and -0.15 mg/dL, respectively. Over 70% of patients had favourable changes in hepatic enzymes or function, and values were stable and decreased at the end of anidulafungin therapy. On average, the percentage of patients with laboratory results meeting common terminology criteria for adverse events (CTCAE) grade ≥2 at the time of switching to anidulafungin was decreased at the end of treatment.

CONCLUSIONS

Median serum values and trajectory of hepatic enzymes and hepatotoxicity usually decreased after switching to anidulafungin treatment in patients with abnormal liver function tests. Anidulafungin could be useful in the management of cancer patients with hepatotoxicity occurring during caspofungin therapy.

Posaconazole liquid suspension in solid organ transplant recipients previously treated with voriconazole

BACKGROUND

Posaconazole (PCZ) has become an attractive alternative to voriconazole (VCZ) in transplant recipients with suspected or proven invasive filamentous fungal infections, causing fewer drug interactions. Here, we describe our experience with PCZ after VCZ in solid organ transplant (SOT) recipients.

METHODS

VCZ was replaced by PCZ liquid solution in 19 SOT recipients (15 lung, 2 kidney, 1 liver, and 1 heart/lung) with invasive pulmonary aspergillosis (12/19; 63.2%), possible invasive pulmonary fungal infection (2/19; 10.5%), prophylaxis (2/19; 10.5%), or pulmonary scedosporiosis, mucormycosis, and mixed fungal species (1 each). Rationales for switch were suspected adverse reactions to VCZ (17/19; 89.4%) and desire to broaden spectrum of coverage to include agents of mucormycosis (3/19; 15.8%).

RESULTS

PCZ was well tolerated in all patients. In those patients with baseline liver enzyme abnormalities, a median change occurred in concentrations of alanine transaminase (-20 IU/L), aspartate aminotransferase (-17.5 IU/L), and alkaline phosphatase (-61.5 IU/L). Clinical success (resolution, stabilization, or prevention of infection) was achieved in 16/19 (84%) people.

CONCLUSION

PCZ appears to have a reasonable safety and tolerability profile and may be an effective alternative in SOT patients who require an agent with anti-mold activity, but are unable to tolerate VCZ.

Therapeutic drug monitoring for triazoles: A needs assessment review and recommendations from a Canadian perspective

Invasive fungal infections cause significant morbidity and mortality in patients with concomitant underlying immunosuppressive diseases. The recent addition of new triazoles to the antifungal armamentarium has allowed for extended-spectrum activity and flexibility of administration. Over the years, clinical use has raised concerns about the degree of drug exposure following standard approved drug dosing, questioning the need for therapeutic drug monitoring (TDM). Accordingly, the present guidelines focus on TDM of triazole antifungal agents. A review of the rationale for triazole TDM, the targeted patient populations and available laboratory methods, as well as practical recommendations based on current evidence from an extended literature review are provided in the present document.

Posaconazole salvage treatment for invasive fungal infection

Invasive fungal infection (IFI) is an important cause of morbidity and mortality. Posaconazole is a second generation triazole with a broad spectrum, and it may be suitable for salvage antifungal treatment although posaconazole is not usually considered to be as first-line antifungal therapy for IFI. The purpose of this study was to assess the utility of posaconazole salvage treatment for IFI. We conducted a retrospective review of patients with salvage antifungal treatment with posaconazole for IFI at our institution between December 2007 and July 2012. A total of ten patients received posaconazole salvage IFI. Etiology of IFI was consisting of mucormycosis (four patients), Paecilomyces variotii (one patient), and unspecified IFI etiology (five patients). Causes of posaconazole treatment were following; intolerance of previous antifungal therapy in five patients, refractory IFI on previous antifungal therapy in four patients, and both intolerance of previous antifungal therapy and refractory IFI on previous antifungal therapy in one patient. Duration of posaconazole salvage treatment ranged from 15 to 355 days with median 47 days. The overall successful posaconazole salvage treatment response rate was 80.0 % (8 of 10 patients). There were three patients who died during the study period. However, only one death was attributed to the progression of IFI. Two patients discontinued posaconazole due to adverse events. Posaconazole salvage treatment was effective antifungal therapy for IFI. Further studies are needed to define the optimal therapeutic strategy.

Scedosporium prolificans fungaemia in a patient with acute lymphoblastic leukaemia

Aggressive chemotherapy and immunosuppressive treatment may prolong patients' life, but influence the risk of severe, life-threatening infections. Here, we report the case of a 21-year-old caucasian female who developed a disseminated infection of Scedosporium prolificans after allogenic stem cell transplantation performed for treatment of relapsed acute lymphoblastic leukaemia. The pathogen was isolated from the blood and identified on the basis of its macroscopic and microscopic morphological features. The empirical treatment with amphotericin B provided no improvement. However, introduction of intravenous voriconazole resulted in amelioration of fever. Unfortunately, the patient died due to progression of underlying disease and multiorgan failure. However, this case report indicates a possible relevance of voriconazole-based treatment regimens in invasive S. prolificans infections.

Emerging fungal infections in solid organ transplant recipients

The most important emerging and rare fungal pathogens in solid organ transplant recipients are the Zygomycetes, Scedosporium, Fusarium, and the dark molds. Factors affecting the emergence of these fungi include the combination of intensive immunosuppressive regimens with increasingly widespread use of long-term azole antifungal therapy; employment of aggressive diagnostic approaches (eg, sampling of bronchoalveolar lavage fluid); and changes in patients' interactions with the environment. This article reviews the epidemiology, microbiology, and clinical impact of emerging fungal infections in solid organ transplant recipients, and provides up-to-date recommendations on their treatment.

Safety of posaconazole

INTRODUCTION

The increasing number of invasive fungal infections (IFI) among immunocompromised hosts is a significant clinical issue. Diagnosis of IFI, choosing among the available antifungal drugs, and the high morbidity/mortality associated with IFI pose clinical challenges for healthcare providers. Besides efficacy, a thorough knowledge of the pharmacokinetics, drug-drug interactions and safety profile of the antifungal drugs is critical for appropriate drug selection. Among the commonly used triazoles, the recently released posaconazole is relatively less well investigated in terms of its safety. With expanding clinical use of posaconazole, the present review examines the safety of the drug and its propensity for drug-drug interaction.

AREAS COVERED

This paper mainly discusses the safety profile of posaconazole, its adverse effects and drug-drug interaction.

EXPERT OPINION

Posaconazole is generally safe and well tolerated. Lack of an intravenous formulation and unpredictable bioavailability of the suspension form are significant factors limiting the widespread use of posaconazole.

Fungal infection in solid organ recipients

In solid organ recipients, as with other immunosuppressed patients, infections by Candida spp. and Aspergillus spp. are the most frequent invasive mycoses. Infections by Cryptococcus spp. and fungi of the Mucorales order are less common. Infections by Fusarium spp. and Scedosporium spp. are very uncommon, except in patients undergoing hematopoietic stem cell transplant and patients with prolonged neutropenia. The risk factors for fungal infection are immunosuppression, surgery, viral co-infection, and environmental exposure. Diagnosis is challenging: blood culture is of little use, except in candidiasis and cryptococcosis, and the poor accuracy of antigen-based techniques, except in cryptococcosis, favors widespread use of empirical therapy. A delay in the initiation of therapy increases the already high mortality of these infections. The agents used to treat fungal infection are azoles, echinocandins, and lipid amphotericin. Administration depends on antifungal activity, drug-drug interactions with calcineurin inhibitors, and safety profiles (effects on grafts and other side effects).

Invasive fungal infections in solid organ transplant recipients

Invasive fungal infections are a major problem in solid organ transplant (SOT) recipients. Overall, the most common fungal infection in SOT is candidiasis, followed by aspergillosis and cryptococcosis, except in lung transplant recipients, where aspergillosis is most common. Development of invasive disease hinges on the interplay between host factors (e.g., integrity of anatomical barriers, innate and acquired immunity) and fungal factors (e.g., exposure, virulence and resistance to prophylaxis). In this article, we describe the epidemiology and clinical features of the most common fungal infections in organ transplantation. Within this context, we review recent advances in diagnostic modalities and antifungal chemotherapy, and their impact on evolving prophylaxis and treatment paradigms.

Mucormycosis treated with posaconazole: review of 96 case reports

Mucormycosis is an emerging invasive fungal infection, primarily affecting immunocompromised patients. The disease is difficult to diagnose and mortality reaches 40% even if treated adequately. Depending on site of infection and risk factors, surgical debridement in combination with systemically active antifungal drugs are the mainstay treatment strategies. Lipid-based amphotericin B is the treatment of choice for first-line therapy while posaconazole may be a promising alternative. We performed a PubMed search on reports of patients with mucormycosis treated with posaconazole. From 2003 to 2011, 96 cases have been published. Diagnosis was based on histology alone in 2 (2.1%) and microbiological evidence in 67 (69.8%), while no data on the diagnostic approach was reported in 27 (28.1%) patients. The most frequent pathogens were Rhizopus spp. (31.2%), followed by Mucor spp. (14.6%). The site of infection was predominantly rhino-orbital (38.5%, of which 43% also had central nervous system [CNS] involvement), followed by disseminated disease (22.1%). A complete response was achieved in 62 (64.6%), partial response in 7 (7.3%) patients, and stable disease in 1 (1%). Overall mortality was 24% (lacking data for three patients). In published case reports on posaconazole treatment for mucormycosis, the drug was frequently and successfully used in combination or as second line therapy.

[Antifungal therapy update: new drugs and medical uses]

Increases in the rates of fungal infections, as well as their associated morbidity and mortality has led to a need for additional antifungal agents. The most common serious fungal agents in immunosuppressed and critically ill patients are Candida spp. and Aspergillus spp., although other emerging fungi must be considered. Rational, early systemic antifungal treatment should be based on diagnostic imaging techniques and conventional mycological and non-culture-based procedures. While the availability of new therapeutic options is an important advance, antifungal therapy has become increasingly complex. In addition to the available antifungal armamentarium, recent research has resulted in the introduction of three new antifungal agents: micafungin, anidulafungin, and posaconazole. This article provides an update, based on the latest scientific evidence, of the clinical efficacy, pharmacokinetics, safety and dosing of antifungal drugs administered in the management of Candida spp., Aspergillus spp., Cryptococcus spp., Zygomycetes, Scedosporium spp. and Fusarium spp.

The impact of the host on fungal infections

Outcomes of fungal infections in immunocompromised individuals depend on a complex interplay between host and pathogen factors, as well as treatment modalities. Problems occur when host responses to an infection are either too weak to effectively help eradicate the pathogen, or when they become too strong and are associated with host damage rather than protection. Immune reconstitution syndrome (IRS) can be generally defined as a restoration of host immunity in a previously immunosuppressed patient that becomes dysregulated and overly robust, resulting in host damage and sometimes death. IRS associated with opportunistic mycoses presents as new or worsening clinical symptoms or radiographic signs consistent with an inflammatory process that occur during receipt of an appropriate antifungal, and that cannot be explained by a newly acquired infection. Because there are currently no established tests or biomarkers for IRS, it can be difficult to distinguish from progression of the original infection, although culture and biomarkers for the fungal pathogen or infection are typically negative during diagnostic workup. IRS was originally characterized in human immunodeficiency virus-infected patients receiving antiretroviral therapy, but has subsequently been described in solid-organ transplant recipients, neutropenic patients, women in the postpartum period, and recipients of tumor necrosis factor-α inhibitor therapy. In each of these cases, recovery of the host's immunity during treatment of an initial infection results in a powerful proinflammatory environment that overshoots and leads to host damage. Optimal management of IRS has not been established at present, but often involves treatment with a corticosteroid or other anti-inflammatory compounds. This article uses a number of patient cases to explore the intricacies of diagnosing and managing a patient with IRS, as well as the other extreme, namely patients who are so immunocompromised without immune recovery that they essentially become breeding grounds for a wide range of opportunistic pathogens, often simultaneously.

Invasive mycoses: strategies for effective management

Effective management of invasive fungal infections (IFIs) depends on early individualized therapy that optimizes efficacy and safety. Considering the negative consequences of IFI, for some high-risk patients the potential benefits of prophylactic therapy may outweigh the risks. When using a prophylactic, empiric, or preemptive therapeutic approach, clinicians must take into account the local epidemiology, spectrum of activity, pharmacokinetic and pharmacodynamic parameters, and safety profile of different antifungal agents, together with unique host-related factors that may affect antifungal efficacy or safety. Therapeutic drug monitoring is increasingly recognized as important or necessary when employing lipophilic triazoles (itraconazole, voriconazole, posaconazole) or flucytosine. Because early diagnostics remain limited for uncommon, yet emerging opportunistic molds (e.g., Mucorales), and treatment delay is associated with increased mortality, early effective management often depends on a high index of suspicion, taking into account predisposing factors, host cues favoring mucormycosis, and local epidemiology. Antifungal options for mucormycosis are limited, and optimal management depends on a multimodal approach that includes early diagnosis/clinical suspicion, correction of underlying predisposing factors, radical debridement of affected tissues, and extended antifungal therapy. This article discusses strategies for the effective management of invasive mycoses, with a particular focus on antifungal hepatotoxicity.

Posaconazole: when and how? The clinician's view

Posaconazole is the newest triazole antifungal agent available as an oral suspension with an extended spectrum of activity against Candida species, Aspergillus species, Cryptococcus neoformans, Zygomycetes and endemic fungi. Among posaconazole advantages are the relatively low potential of cross-resistance with other azoles, few drug interactions compared with other azoles and its activity against Zygomycetes. Randomised, double-blind trials have shown that posaconazole is effective for prophylaxis against invasive fungal infections (IFI), especially aspergillosis, in high-risk patients. Results of Phase III clinical trials and case/series reports indicate that posaconazole is effective in treating oesophageal candidiasis, including azole-refractory disease, and other IFI refractory to standard antifungal therapies. To date, posaconazole has appeared to be well tolerated even in long-term courses; it has an excellent safety profile with gastrointestinal disturbances being the most common adverse events reported. The dose of posaconazole is 200 mg three times daily for prophylaxis, 800 mg daily in two or four divided doses for the treatment of IFI and 100 mg daily (200 mg loading dose) for the treatment of oropharyngeal candidiasis. On the basis of early clinical experience, it appears that posaconazole will be a valuable aid in the management of life-threatening fungal infections.

[Guidelines for the treatment of invasive fungal disease by Aspergillus spp. and other fungi issued by the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC). 2011 Update]

The guidelines on the treatment of invasive fungal disease by Aspergillus spp. and other fungi issued by the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) are presented. These recommendations are focused on four clinical categories: oncology-haematology patients, solid organ transplant recipients, patients admitted to intensive care units, and children. An extensive review is made of therapeutical advances and scientific evidence in these settings. These guidelines have been prepared according the SEIMC consensus rules by a working group composed of specialists in infectious diseases, clinical microbiology, critical care medicine, paediatrics and oncology-haematology. Specific recommendations on the prevention of fungal infections in these patients are included.

Development, clinical utility, and place in therapy of posaconazole for prevention and treatment of invasive fungal infections

Posaconazole is an extended-spectrum azole antifungal that exhibits activity against a broad range of fungal pathogens, including yeasts and moulds. Clinical data have demonstrated the clinical utility of posaconazole against many therapy-refractory pathogens, including Aspergillus spp, Fusarium spp, and Zygomycetes. These data have provided clinicians with hope in these difficult situations. Some of the limitations that have emerged with the use of posaconazole are the lack of an intravenous formulation and erratic drug absorption. This fact is further complicated by the existence of saturable posaconazole absorption. Despite these drawbacks, posaconazole appears poised to become a prominent therapeutic modality for the prophylaxis and management of various fungal infections among high-risk patients.

Prophylaxis of invasive mycoses in solid organ transplantation

Solid organ transplantation is emerging as a lifesaving procedure for increasing numbers of patients, and invasive fungal infections are a significant cause of mortality and morbidity for patients undergoing such procedures. Risks for developing these infections are continuing to evolve, leading to shifts in the epidemiology of invasive mycoses occurring after transplantation. Targeting preventive efforts to select solid organ transplantation groups at highest risk for invasive fungal infections is critical to optimizing prophylaxis strategies. The epidemiology of posttransplantation fungal infections, antifungal drug interactions and side effects, and new diagnostic capabilities should be considered when choosing an approach to antifungal prophylaxis for this population.

Fungal infections in transplant and oncology patients

Recent shifts in the epidemiology of invasive fungal infections (IFIs) among transplant and oncology populations have led to new recommendations on treatment; however, they have also brought new controversies. New pharmacologic therapies are being studied and guidelines for management of several IFIs have been changed accordingly. More information is being discovered about unique genetic factors that put some transplant recipients at greater risk than others for fungal infection. The role of immunomodulation continues to be investigated, and the delicate balance of maintaining some immune integrity while assuring protection of the graft remains critical. For transplant and oncology patients, the diagnosis and management of IFIs remain challenging, and improving outcomes depends on continued progress in all of these arenas. This article highlights recent advances and important factors to consider when treating transplant and oncology patients with IFIs.

Clinical safety and tolerability issues in use of triazole derivatives in management of fungal infections

There has been an increase in the number of patients susceptible to invasive fungal infections (IFIs) leading to a greater need for effective, well tolerated, and easily administered antifungal agents. The advent of triazoles has revolutionized the care of patients requiring treatment or prophylaxis for IFIs. However, triazoles have been associated with a number of adverse events and significant drug–drug interactions. While commonly used, physicians and patients should be aware of the distinct properties of these agents in order to ensure that patients are optimally treated with the least amount of toxicity possible. Clinicians should have a full understanding of the basic pharmacokinetics, absorption, and bioavailability of triazoles. Moreover, knowledge of the drug–drug interactions and potential toxicities of each agent is critical prior to administering a triazole. Careful history taking, thorough review of the patient’s medication list, and detailed discussion with the patients and their families about the efficacy, safety, and tolerability of these agents should be performed. Clinicians treating patients with triazoles should closely follow them, monitor pertinent laboratory tests, and consider measuring drug levels as needed. This article will review the basic pharmacokinetic properties and most frequently encountered adverse events and pitfalls associated with triazoles in clinical practice.