Echinocandin exposures in obese patients: A scoping review and clinical perspectives.

PURPOSE: Echinocandins are favored drugs for the treatment of fungal infections. There is growing evidence that obese patients treated with echinocandins have lower exposures due to pharmacokinetic (PK) alterations. We conducted a scoping review to characterize, evaluate, and summarize the available evidence on echinocandins exposures in obese patients. SUMMARY: A comprehensive search of PubMed, Embase, and Cochrane Library for studies on echinocandins published from database inception to October 28, 2022, was conducted using PRISMA-ScR methodology. A total of 25 studies comprising more than 3,174 subjects (8 micafungin studies, 7 caspofungin studies, 9 anidulafungin studies, and 1 rezafungin study) were included in this review. Seventeen studies reported lower echinocandins exposures in overweight and obese individuals compared with normal-weight individuals; the authors of these studies recommended dose adjustments. Conversely, 8 studies did not find significant differences in echinocandin exposure among subjects in varying body weight categories. Clinicians may consider dose adjustments of echinocandins in obese patients; however, there is limited evidence on the ideal dose adjustment strategy to overcome the low echinocandins exposures in obese patients. CONCLUSION: This scoping review shed light on a growing body of evidence indicating that obese patients have lower echinocandin exposures relative to targeted PK indices, which may lead to negative therapeutic implications. Currently, a lack of high-quality evidence impedes reaching consensus on recommendations for echinocandin dosing adjustment in obese patients. Future research evaluating the optimal echinocandin dosing strategy for obese patients is needed.

An overview of micafungin as a treatment option for invasive candidiasis in pediatric patients younger than 4 months old.

INTRODUCTION: Invasive candidiasis remains a leading cause of morbidity and mortality in various categories of patients at risk. AREAS COVERED: Structure and mechanism of action, pharmacokinetics and pharmacodynamics, clinical studies, safety, and regulatory status of micafungin are explored in the present review, focusing on pediatric patients younger than 4 months old. EXPERT OPINION: Although limited, the available data on the efficacy and safety of micafungin in pediatric patients younger than 4 months old support its use for the treatment of invasive candidiasis in this particular population, in line with the most updated recommendations from the European Medicines Agency and the US Food and Drug Administration. Additional study, especially of high-dose micafungin, could further optimize the use of this drug in pediatric patients younger than 4 months old with Candida meningoencephalitis. The recent worrisome worldwide diffusion of Candida auris, more frequently resistant to polyenes than to echinocandins and showing high rates of resistance to azoles, could render micafungin even more crucial for guaranteeing an efficacious antifungal treatment for invasive candidiasis in pediatric patients younger than 4 months old.

Ibrexafungerp: A new triterpenoid antifungal.

PURPOSE: The pharmacology, microbiology, pharmacokinetics, pharmacodynamics, efficacy, safety, and role of ibrexafungerp in the treatment of fungal infections are reviewed. SUMMARY: Ibrexafungerp is the first triterpenoid antifungal. Similarly to echinocandins, it inhibits the synthesis of 1,3-ß-d-glucan. However, it binds to a different site on the enzyme than echinocandins, resulting in limited cross-resistance. Ibrexafungerp exerts concentration-dependent fungicidal activity against Candida species and retains in vitro activity against most fluconazole-resistant strains. It is also active against Aspergillus species. Ibrexafungerp has been shown to be safe and effective in the treatment of vulvovaginal candidiasis caused by Candida albicans in phase 2 and phase 3 clinical trials. It is approved for vulvovaginal candidiasis in adult and postmenarchal pediatric females and is given as two 150-mg tablets orally, administered 12 hours apart. Ibrexafungerp is contraindicated in pregnancy. The most commonly reported adverse reactions were diarrhea, nausea, abdominal pain, dizziness, and vomiting. Ibrexafungerp should be avoided with strong or moderate CYP3A inducers, and the dose should be reduced with strong CYP3A inhibitors. Ibrexafungerp may be useful for patients who are not able to receive fluconazole or prefer oral therapy for the treatment of vulvovaginal candidiasis. However, it is more expensive than the 150-mg tablet of generic fluconazole, which is the current standard of care for vulvovaginal candidiasis. Clinical trials are ongoing for recurrent and complicated vulvovaginal candidiasis as well as invasive candidiasis and pulmonary aspergillosis. CONCLUSION: Ibrexafungerp is an alternative to fluconazole for the treatment of vulvovaginal candidiasis in nonpregnant females. It has the potential to be useful for recurrent and complicated vulvovaginal candidiasis as well as certain invasive fungal infections.

Pharmacokinetics/Pharmacodynamics of Caspofungin in Plasma and Peritoneal Fluid of Liver Transplant Recipients.

The weaker diffusion of echinocandins in the peritoneal fluid (PF) could promote Candida-resistant isolates. The aim of this study was to analyze the pharmacokinetics (PK)/pharmacodynamics (PD) of caspofungin in plasma and PF samples from liver transplant recipients. Liver transplant patients received caspofungin as postoperative prophylaxis. Caspofungin concentrations were quantified in plasma and PF samples on days 1, 3, and 8. Data were analyzed using nonlinear mixed-effect modeling and Monte Carlo simulations. Area under the curve (AUC) values for plasma and PF were simulated under three dosing regimens. Probabilities of target attainment (PTAs) were calculated using area under the unbound plasma concentration-time curve from 0 to 24 h at steady state (fAUC0-24)/MIC ratios, with MICs ranging from 0.008 to 8 mg/L. All of the patients included were monitored weekly for Candida colonization and for Candida infections. Twenty patients were included. The median daily dose of caspofungin was 0.81 mg/kg. Plasma (n = 395) and PF (n = 50) concentrations at steady state were available. A two-compartment model with first-order absorption and elimination was described. Our two-compartment model with first-order absorption and elimination produced an effective PK/PD relationship in plasma, achieving a PTA of ≥90% with MICs ranging from 0.008 to 0.12 mg/L for Candida albicans and Candida glabrata. In PF, PTAs at D8 were optimal only for a MIC of 0.008 mg/L in patients weighing 60 kg under the three dosing regimens. Among the 16 patients colonized, all MIC values were below the maximal concentration (Cmax) in plasma but not in PF. PF concentrations of caspofungin were low. Simulations showed that the PTAs for Candida spp. in PF were not optimal, which might suggest a potential risk of resistance.

Population Pharmacokinetics of Rezafungin in Patients with Fungal Infections.

Rezafungin is a novel antifungal agent of the echinocandin class with potent activity against species of Candida and Aspergillus, including subsets of resistant strains, and Pneumocystis jirovecii. The objective of this analysis was to develop a population pharmacokinetic (PK) model to characterize the disposition of rezafungin in plasma following intravenous (IV) administration in healthy volunteers and in patients with candidemia and/or invasive candidiasis. The population PK model was based on a previous model from phase 1 data; formal covariate analyses were conducted to identify any relationships between subject characteristics and rezafungin PK variability. A four-compartment model with linear elimination and zero-order drug input provided a robust fit to the pooled data. Several statistically significant relationships between subject descriptors (sex, infection status, serum albumin, and body surface area [BSA]) and rezafungin PK parameters were identified, but none were deemed clinically relevant. Previous dose justification analyses conducted using data from phase 1 subjects alone are expected to remain appropriate. The final model provided a precise and unbiased fit to the observed concentrations and can be used to reliably predict rezafungin PK in infected patients.

Natural products targeting the synthesis of ß(1,3)-D-glucan and chitin of the fungal cell wall. Existing drugs and recent findings.

BACKGROUND: During the last three decades systemic fungal infections associated to immunosuppressive therapies have become a serious healthcare problem. Clinical development of new antifungals is an urgent requirement. Since fungal but not mammalian cells are encased in a carbohydrate-containing cell wall, which is required for the growth and viability of fungi, the inhibition of cell wall synthesizing machinery, such as ß(1,3)-D-glucan synthases (GS) and chitin synthases (CS) that catalyze the synthesis of ß(1-3)-D-glucan and chitin, respectively, represent an ideal mode of action of antifungal agents. Although the echinocandins anidulafungin, caspofungin and micafungin are clinically well-established GS inhibitors for the treatment of invasive fungal infections, much effort must still be made to identify inhibitors of other enzymes and processes involved in the synthesis of the fungal cell wall. PURPOSE: Since natural products (NPs) have been the source of several antifungals in clinical use and also have provided important scaffolds for the development of semisynthetic analogues, this review was devoted to investigate the advances made to date in the discovery of NPs from plants that showed capacity of inhibiting cell wall synthesis targets. The chemical characterization, specific target, discovery process, along with the stage of development are provided here. METHODS: An extensive systematic search for NPs against the cell wall was performed considering all the articles published until the end of 2020 through the following scientific databases: NCBI PubMed, Scopus and Google Scholar and using the combination of the terms "natural antifungals" and "plant extracts" with "fungal cell wall". RESULTS: The first part of this review introduces the state of the art of the structure and biosynthesis of the fungal cell wall and considers exclusively those naturally produced GS antifungals that have given rise to both existing semisynthetic approved drugs and those derivatives currently in clinical trials. According to their chemical structure, natural GS inhibitors can be classified as 1) cyclic lipopeptides, 2) glycolipids and 3) acidic terpenoids. We also included nikkomycins and polyoxins, NPs that inhibit the CS, which have traditionally been considered good candidates for antifungal drug development but have finally been discarded after enduring unsuccessful clinical trials. Finally, the review focuses in the most recent findings about the growing field of plant-derived molecules and extracts that exhibit activity against the fungal cell wall. Thus, this search yielded sixteen articles, nine of which deal with pure compounds and seven with plant extracts or fractions with proven activity against the fungal cell wall. Regarding the mechanism of action, seven (44%) produced GS inhibition while five (31%) inhibited CS. Some of them (56%) interfered with other components of the cell wall. Most of the analyzed articles refer to tests carried out in vitro and therefore are in early stages of development. CONCLUSION: This report delivers an overview about both existing natural antifungals targeting GS and CS activities and their mechanisms of action. It also presents recent discoveries on natural products that may be used as starting points for the development of potential selective and non-toxic antifungal drugs.

Pharmacokinetics of echinocandins in suspected candida peritonitis: A potential risk for resistance.

INTRODUCTION: A possible increase in Candida resistance, especially in Candida glabrata, has been speculated according to poor diffusion of echinocandins to peritoneal fluid. MATERIALS/METHODS: Peritoneal and serum concentrations of caspofungin, micafungin and anidulafungin were analysed in surgical patients with suspected candida peritonitis. After 4 days of starting therapy, serum and peritoneal samples (through peritoneal drainage) were obtained at baseline, 1, 6, 12 and 24 h of drug administration. Micafungin and anidulafungin concentrations were determined using high-performance liquid chromatography (HPLC/F), whereas caspofungin concentrations were established by bioassay. RESULTS: Twenty-three critically ill patients with suspected abdominal fungal infection who were receiving an echinocandin were prospectively recruited. No specific criteria were applied to prescribe one specific echinocandin. No special clinical differences were observed among the three groups of patients. All were receiving antibiotic therapy, 80% required inotropic drugs, and fungal peritonitis was confirmed in 74% of them. The AUC0_24h (mg × h/L) obtained in serum and peritoneal fluid were: 126.84 and 34.38, 98.52 and 18.83, and 66.9 and 8.78 for anidulafungin, micafungin and caspofungin, respectively. The median concentration in peritoneal fluid ranged from 0.66 to 1.82 µg/mL for anidulafungin, 0.68-0.88 µg/mL for micafungin and 0.21-0.46 µg/mL for caspofungin. CONCLUSION: The results showed moderate penetration of echinocandins into the peritoneal fluid of these patients. These levels are below the threshold of resistance mutant selection published by other authors. This could justify a potential risk of resistance in patients with prolonged treatment with echinocandins and suboptimal control of abdominal infection.

Antifungal drugs: An updated review of central nervous system pharmacokinetics.

Invasive fungal infections (IFIs) in the central nervous system (CNS) are particularly hard to treat and are associated with high morbidity and mortality rates. Four chemical classes of systemic antifungal agents are used for the treatment of IFIs (eg meningitis), including polyenes, triazoles, pyrimidine analogues and echinocandins. This review will address all of these classes and discuss their penetration and accumulation in the CNS. Treatment of fungal meningitis is based on the antifungal that shows good penetration and accumulation in the CNS. Pharmacokinetic data concerning the entry of antifungal agents into the intracranial compartments are faulty. This review will provide an overview of the ability of systemic antifungals to penetrate the CNS, based on previously published drug physicochemical properties and pharmacokinetic data, for evaluation of the most promising antifungal drugs for the treatment of fungal CNS infections. The studies selected and discussed in this review are from 1990 to 2019.

Pharmacokinetic/pharmacodynamics variability of echinocandins in critically ill patients: A systematic review and meta-analysis.

WHAT IS KNOWN AND OBJECTIVE: Anidulafungin, caspofungin and micafungin are three widely used echinocandin drugs licensed for the treatment of invasive fungal infections, and their clinical use is widespread. To evaluate pharmacokinetic/pharmacodynamics variability of echinocandins in critically ill patients by comparing the differences in pharmacokinetic parameters between critically ill patients and healthy volunteers or general patients. METHODS: MEDLINE, EMBASE, The Cochrane Library and Pubmed were searched from inception until 6 September 2018. Studies investigating the pharmacokinetic parameters of echinocandins in critically ill patients, healthy volunteers or general patients were included. Our primary outcomes included AUC0-24 h , Cmax and Cmin (24 hours). Two reviewers independently reviewed all titles, abstracts and text, and extracted data. We applied R software (R 2017) to conduct meta-analysis. RESULTS AND DISCUSSION: Of 3235 articles screened, 17 studies were included in the data synthesis. Descriptive data from single-arm studies show that critically ill patients who received caspofungin had more stable AUC0-24 h than those who received anidulafungin and micafungin. The Cmax of critically ill patients who received caspofungin and micafungin was similar to healthy volunteers. However, the Cmax in critically ill patients who received anidulafungin was lower than in healthy volunteers. The Cmin and T1/2 of critically ill patients who received caspofungin were larger than in healthy volunteers. The Vd and CL of critically ill patients receiving anidulafungin and micafungin were larger than in healthy volunteers. WHAT IS NEW AND CONCLUSION: This systematic review provides an analysis of the pharmacokinetic/pharmacodynamics variability of echinocandins in critically ill patients. Based on the limited data available, caspofungin has less pharmacokinetic/pharmacodynamics variability than anidulafungin and micafungin.

Antifungal therapeutic drug monitoring: focus on drugs without a clear recommendation.

BACKGROUND: The goal of therapeutic drug monitoring (TDM) is to determine the appropriate exposure of difficult-to-manage medications to optimize the clinical outcomes in patients in various clinical situations. Concerning antifungal treatment, and knowing that this procedure is expensive and time-consuming, TDM is particularly recommended for certain systemic antifungals: i.e., agents with a well-defined exposure-response relationship and unpredictable pharmacokinetic profile or narrow therapeutic index. Little evidence supports the routine use of TDM for polyenes (amphotericin B), echinocandins, fluconazole or new azoles such as isavuconazole, despite the fact that a better understanding of antifungal exposure may lead to a better response. AIMS: The aim of this work is to review published pharmacokinetic/pharmacodynamic data on systemically administered antifungals, focusing on those for which monitoring is not routinely recommended by experts. SOURCES: A MEDLINE search of the literature in English was performed introducing the following search terms: amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, triazoles, caspofungin, micafungin, anidulafungin, echinocandins, pharmacokinetics, pharmacodynamics, and therapeutic drug monitoring. Review articles and guidelines were also screened. CONTENT: This review collects different pharmacokinetic/pharmacodynamic aspects of systemic antifungals and summarizes recent threshold values for clinical outcomes and adverse events. Although for polyenes, echinocandins, fluconazole and isavuconazole extensive clinical validation is still required for a clear threshold and a routine monitoring recommendation, particular points such as liposome structure or complex pathophysiological conditions affecting final exposure are discussed. For the rest, their better-defined exposure-response/toxicity relationships allow access to useful threshold values and to justify routine monitoring. Additionally, clinical data are needed to better define thresholds that can minimize the development of antifungal resistance. IMPLICATIONS: General TDM for all systemic antifungals is not recommended; however, this approach may help to establish an adequate antifungal exposure for a favourable response, prevention of toxicity or development of resistance in special clinical circumstances.

From bench to bedside: Perspectives on the utility of pharmacokinetics/pharmacodynamics in predicting the efficacy of antifungals in invasive candidiasis.

The aim of this perspective is to give an overlook on the utility of pharmacokinetics/pharmacodynamics (PK/PD) in predicting the efficacy of antifungals in invasive candidiasis. Overall, from the available literature it appears that bridging data of PK/PD of antifungals from the laboratory to the clinic for the treatment of invasive candidiasis are feasible only partially. Fluconazole is the only antifungal agent having the pharmacodynamic threshold of efficacy identified in experimental animal models convincingly validated in the clinical setting of invasive candidiasis as well. Conversely, for voriconazole and posaconazole data on this topic are very limited. For the echinocandins, robust PK/PD identified in the laboratory represented the rationale for defining differential clinical breakpoints of echinocandins against different species of Candida by the regulatory agencies. However, translation of the findings in the clinical setting provided conflicting results. Data on PK/PD of amphotericin B and flucytosine in models of invasive candidiasis are quite limited, and clinical studies assessing the role of drug exposure on efficacy are currently lacking. The expectation is that prospective studies could test more and more frequently the validity of experimental PK/PD data of antifungals in the clinical setting of invasive candidiasis. The findings could represent a step forward in addressing adequate antifungal stewardship programmes.

Rezafungin treatment in mouse models of invasive candidiasis and aspergillosis: Insights on the PK/PD pharmacometrics of rezafungin efficacy.

Rezafungin acetate is a novel echinocandin in clinical development for prevention and treatment of invasive fungal infections. Rezafungin is differentiated by a pharmacokinetic/pharmacodynamic (PK/PD) profile that includes a long half-life allowing once-weekly administration, front-loaded plasma drug exposures associated with antifungal efficacy, and penetration into deep-seated infections, such as intra-abdominal abscesses. In this series of in vivo studies, rezafungin demonstrated efficacy in the treatment of neutropenic mouse models of disseminated candidiasis, including infection caused by azole-resistant Candida albicans, and aspergillosis. These results contribute to a growing body of evidence demonstrating the antifungal efficacy and potential utility of rezafungin in the treatment of invasive fungal infections.

Determination of Pharmacodynamic Target Exposures for Rezafungin against Candida tropicalis and Candida dubliniensis in the Neutropenic Mouse Disseminated Candidiasis Model.

Rezafungin (CD101) is a novel echinocandin under development for once-weekly intravenous (i.v.) dosing. We evaluated the pharmacodynamics (PD) of rezafungin against 4 Candida tropicalis and 4 Candida dubliniensis strains, using the neutropenic mouse invasive candidiasis model. The area under the concentration-time curve (AUC)/MIC was a robust predictor of efficacy (R2 = 0.93 and 0.72, respectively). The stasis free-drug 24-h AUC/MIC target exposure for the group ranged from 3 to 25, whereas the 1-log-kill free-drug 24-h AUC/MIC target exposure ranged from 4.3 to 62. These values are similar to those found in previous rezafungin PD studies with other Candida spp. Based on recent surveillance susceptibility data, AUC/MIC targets are likely to be exceeded for >99% of C. tropicalis and C. dubliniensis isolates with the previously studied human dose of 400 mg i.v. once weekly.

MSG-10: a Phase 2 study of oral ibrexafungerp (SCY-078) following initial echinocandin therapy in non-neutropenic patients with invasive candidiasis.

OBJECTIVES: To evaluate the safety and efficacy of two dosing regimens of oral ibrexafungerp (formerly SCY-078), a novel orally bioavailable ß-glucan synthase inhibitor, in subjects with invasive candidiasis versus the standard of care (SOC) and to identify the dose to achieve target exposure (15.4 µM·h) in >80% of the intended population. METHODS: In a multinational, open-label study, patients with documented invasive candidiasis were randomized to receive step-down therapy to one of three treatment arms: two dosing regimens of novel oral ibrexafungerp or the SOC treatment following initial echinocandin therapy. Plasma samples were collected to evaluate exposure by population pharmacokinetic (PK) modelling. Safety was assessed throughout the study and global response at the end of treatment. RESULTS: Out of 27 subjects enrolled, 7 received ibrexafungerp 500 mg, 7 received ibrexafungerp 750 mg and 8 received the SOC. Five did not meet criteria for randomization. Population PK analysis indicated that an ibrexafungerp 750 mg regimen is predicted to achieve the target exposure in ∼85% of the population. The rate of adverse events was similar among patients receiving ibrexafungerp or fluconazole. Similar favourable response rates were reported among all groups: 86% (n = 6) in the ibrexafungerp 750 mg versus 71% (n = 5) in both the fluconazole and ibrexafungerp 500 mg treatment arms. The one subject treated with continued micafungin had a favourable global response. CONCLUSIONS: The oral ibrexafungerp dose estimated to achieve the target exposure in subjects with invasive candidiasis is 750 mg daily. This dose was well tolerated and achieved a favourable global response rate, similar to the SOC.

Chromatographic methods for echinocandin antifungal drugs determination in bioanalysis.

The increase of fungal resistance to drugs, such as azole family, gave rise to the development of new antifungals. In this context, echinocandins emerged as a promising alternative for antifungal therapies. Following the commercialization of caspofungin in 2001, echinocandins became the first-line therapy for invasive candidiasis in different patient populations. The quantification of these drugs has gained importance since pharmacokinetic/pharmacodynamic and resistance studies are a paramount concern. This fact has led us to exhaustively examine the methodologies used for the analysis of echinocandins in biological fluids, which are mainly based on LC coupled to different detection techniques. In this review, we summarize the analytical methods for the quantification of echinocandins focusing on sample treatment, chromatographic separation and detection methods.

Impact of empirical treatment with antifungal agents on survival of patients with candidemia / Impacto del tratamiento antifúngico empírico en la supervivencia de pacientes con candidemia

Introduction: The objective of this study was to evaluate the impact of echinocandins and fluconazole) on mortality 7 and 30 days after candidemia onset and overall in-hospital mortality), in patients with candidemia at a Spanish tertiary hospital. Methods: A retrospective study was conducted that enrolled all non-neutropenic adult patients diagnosed with candidemia at Hospital Clínico Universitario de Valladolid between 2007 and 2016. A total of 179 patients were evaluated, they were divided into two sub-groups: surviving patients (n = 92) and non-surviving patients (n = 87). Results: The 7-day mortality was 25,1% (45), 30-day mortality was 46,9% (84), and overall in-hospital mortality was 48,6% (87). 40.8% of patients received no antifungal treatment (43.8% of surviving patients and 37.8% of non-surviving patients; p=0.15). A total of 106 (59.2%) patients were treated, of which 90 patients (50.3%) received empiric treatment. 19.6% and 47.8% of surviving patients were treated with echinocandins and fluconazole, respectively. By contrast, of non-surviving patients, 31.0% were treated with echinocandins and 47.1% received fluconazole. Survival for the first 7 days was significantly higher in treated with antifungal agents (log-rank = 0.029), however, there were not significant differences in 30-day survival. Factors linked to a significant increase in overall in-hospital mortality were age (OR 1.040), septic shock (OR 2.694) and need for mechanical ventilation > 48 h (OR 2.812). Conclusion: Patients who received antifungal treatment, regardless of whether they received fluconazole or echinocandins, had a significantly lower mortality rate after 7 days than untreated patients, although no significant differences in 30-day mortality were seen

Introducción: El objetivo del estudio es evaluar el impacto del tratamiento antifúngico en la mortalidad hospitalaria a los 7 y 30 días en pacientes con candidemia en un hospital terciario español. Métodos: Se realizó un estudio retrospectivo que incluyó los pacientes adultos no neutropénicos diagnosticados de candidemia en el Hospital Clínico Universitario entre 2007 y 2016. Se evaluaron 179 pacientes, se dividieron en grupo de supervivientes (n=92) y no supervivientes (n=87). Resultados: La mortalidad a 7 días fue 25,1% (45), a los 30 días 46,9% (84) y la hospitalaria 48,6% (87). El 40,8% no recibieron antifúngico (43,8% de supervivientes y 37,8% de no supervivientes; p=0,15). El 50,3% (90) recibieron tratamiento empírico. De los supervivientes el 19,6% y 47,8% se trataron con equinocandinas y fluconazol, respectivamente. De los no supervivientes el 31% recibió equinocandinas y el 47,1% fluconazol. La supervivencia a los 7 días fue significativamente mayor en los tratados (log-rank = 0.029), no hubo diferencias a los 30 días. Los factores asociados a mortalidad hospitalaria fueron edad (OR: 1.040), shock séptico (OR: 2.694) y ventilación mecánica> 48 h (OR: 2.812). Conclusión: Los pacientes tratados con antifúngicos (ya sean equinocandinas o fluconazol) tienen una tasa de mortalidad inferior a los 7 días que los no tratados, sin embargo no hallamos diferencias a los 30 días

Aspergilosis invasiva en el paciente crítico / Invasive aspergillosis in critically ill patients

Los pacientes críticos sin una grave inmunosupresión es una población en la que la aspergilosis invasiva (AI) es una enfermedad en alza. El tratamiento crónico con corticoides, la enfermedad pulmonar obstructiva crónica y la cirrosis hepática son factores de riesgo repetidamente identificados en las series publicadas. No obstante, debido a la inespecificidad de los síntomas y signos en el paciente crítico y a la relativa baja capacidad diagnóstica de las pruebas complementarias, el diagnóstico de la AI supone un reto para el especialista en medicina intensiva. La aplicación de algoritmos diagnósticos adaptados al paciente crítico, cuya activación dependerá del aislamiento de Aspergillus en una muestra respiratoria, es la metodología diagnóstica más eficaz en esta población. Entre los elementos diagnósticos, la determinación de galactomanano en el líquido broncoalveolar es la prueba diagnóstica que ha demostrado más utilidad. Una vez establecida la sospecha el tratamiento debe iniciarse precozmente. El voriconazol, la anfotericina B y el isavuconazol son los tratamientos más eficaces. Aunque el voriconazol y la anfotericina B son los fármacos con mayores evidencias científicas, adolecen de problemas con relación a efectos adversos y dificultades farmacocinéticas. Por ello, el isavuconazol, que ha demostrado una elevada eficacia y seguridad en otras poblaciones, supone una potencial alternativa de extremado interés para el paciente crítico

Critically ill patients without severe immunosuppression make up a population in which invasive aspergillosis (IA) has been identified as an emergent pathology. Chronic treatment with corticosteroids, chronic obstructive pulmonary disease, and liver cirrhosis are repeatedly identified risk factors. However, due to the non-specificity of the symptoms and signs in the critical patient, and the relative low diagnostic capacity of the complementary tests, the diagnosis of the IA is a challenge for the specialist in critical care medicine. The application of diagnostic algorithms adapted to critical patients, in whom activation will depend on the isolation of Aspergillus in a respiratory specimen, is the most efficient diagnostic methodology in this population. Among the diagnostic approaches, the determination of galactomannan in bronchoalveolar fluid is the most useful diagnostic test. Once the suspicion is established, treatment should be started as soon as possible. Voriconazole, amphotericin B, and isavuconazole are the most effective treatments. Although voriconazole and amphotericin B are the drugs with the most scientific evidence, they are related with adverse effects and pharmacokinetic difficulties. Therefore, isavuconazole, which has shown high efficacy and safety in other populations, is a potential alternative of great interest for critically ill patients

Significantly Improved Pharmacokinetics Enhances In Vivo Efficacy of APX001 against Echinocandin- and Multidrug-Resistant Candida Isolates in a Mouse Model of Invasive Candidiasis.

APX001 is a first-in-class, intravenous and orally available, broad-spectrum antifungal agent in clinical development for the treatment of life-threatening invasive fungal infections. The half-life of APX001A, the active moiety of APX001, is significantly shorter in mice than in humans (1.4 to 2.75 h in mice versus 2 to 2.5 days in humans), making the exploration of efficacy in mouse models difficult. After pretreatment with 1-aminobenzotriazole (ABT), a nonspecific cytochrome P450 inhibitor, greatly increased plasma APX001A exposure was observed in mice of different strains and of both genders. As a consequence, 26 mg/kg APX001 plus ABT sterilized kidneys in mice infected with Candida albicans, while APX001 alone at the same dose resulted in a modest burden reduction of only 0.2 log10 CFU/g, relative to the vehicle control. In the presence of ABT, 2 days of once-daily dosing with APX001 at 26 mg/kg also demonstrated significant in vivo efficacy in the treatment of Candida glabrata infections in mice. Potent kidney burden reduction was achieved in mice infected with susceptible, echinocandin-resistant, or multidrug-resistant strains. In contrast, the standard of care (micafungin) was ineffective in treating infections caused by the resistant C. glabrata isolates.

Simple and robust LC-MS/MS analysis method for therapeutic drug monitoring of micafungin.

AIM: To develop a simple and robust LC-MS/MS method to quantify concentrations of micafungin in human plasma for pharmacokinetic studies and therapeutic drug monitoring. METHODS: Sample preparation involved protein precipitation with acetonitrile:methanol (83:17% v/v) and [13C6]-micafungin as internal standard. A rapid and selective method for micafungin was validated across a range of 0.200-10.0 mg/l. RESULTS: The calculated accuracy for the eight-point calibration ranged from 0.7 to 5.3%. Within-run precision ranged from 0.8 to 5.9%, between-run precision ranged from 0.7 to 3.1%, and overall precision ranged from 1.3 to 6.6%. CONCLUSION: A simple and robust LC-MS/MS method for analyzing micafungin in human plasma has been validated and was utilized for quantification of micafungin.

Drug susceptibility profile of Candida glabrata clinical isolates from Iran and genetic resistant mechanisms to caspofungin / Perfil de sensibilidad antifúngica de aislamientos clínicos de Candida glabrata de Irán y mecanismos genéticos de resistencia a la caspofungina

Background: Candida glabrata is a yeast that can cause hazardous fungal infections with high mortality and drug resistance. Aims: The aim of this study was to determine the profile of drug susceptibility in clinical isolates of C. glabrata and review the resistance mechanisms to caspofungin. Methods: A total of 50 C. glabrata clinical isolates from Iran were tested for in vitro susceptibilities to amphotericin B, caspofungin, fluconazole and voriconazole. To investigate the mechanism of resistance to caspofungin, hotspot areas of FKS1 and FKS2 genes were sequenced and gene expression profile was evaluated. Results: All the isolates were susceptible to amphotericin B and caspofungin. Fluconazole resistance was exhibited in four isolates. In addition, only one isolate was resistant to voriconazole. FKS2 with 12 point mutations showed more mutations compared to FKS1 that had only two mutations. All substitutions were synonymous. FKS genes were expressed at comparable levels (no statistical significance) in caspofungin-treated and non-treated cultures. Conclusions: The silent mutations in the hotspot areas of FKS genes and inconsiderable changes in gene expression were not associated with increased MIC (0.25μg/ml). Other mechanisms of resistance which include mutations outside the hotspot area of FKS genes could be involved in a slight increase of MIC, and they should be identified through complete FKS gene sequencing

Antecedentes: Candida glabrata es una levadura que puede causar infecciones de una alta mortalidad, además de presentar resistencia a los tratamientos antifúngicos. Objetivos: El objetivo del presente estudio fue determinar la sensibilidad a diversos antifúngicos de aislamientos clínicos de C. glabrata, además de revisar sus mecanismos de resistencia a la caspofungina. Métodos: Se estudió la sensibilidad in vitro de 50 aislamientos clínicos de C. glabrata de Irán a los antifúngicos anfotericina B, caspofungina, fluconazol y voriconazol. Con el fin de investigar el mecanismo de resistencia a la caspofungina se secuenciaron secciones hotspot de los genes FKS1 y FKS2, y se evaluó su grado de expresión. Resultados: Todos los aislamientos fueron sensibles a la anfotericina B y a la caspofungina. Cuatro aislamientos fueron resistentes al fluconazol. Un solo aislamiento presentó resistencia al voriconazol. FKS2 mostró un mayor número de mutaciones (12) que FKS1, donde se encontraron solo dos; todas las sustituciones fueron silentes. No se encontró diferencia estadística en la expresión de los genes FKS entre los aislamientos crecidos en cultivo con caspofungina y los que crecieron en cultivo sin la presencia del antifúngico. Conclusiones: Las mutaciones silentes en las areas hotspot de los genes FKS y los cambios insignificantes en la expresión de los genes no se asociaron con un incremento de la MIC (0,25μg/ml). Otros mecanismos de resistencia, como mutaciones fuera de las áreas hotspot de los genes FKS, podrían conllevar un ligero aumento de la MIC, pero para determinar claramente su papel debería realizarse una secuenciación completa de los genes FKS