Pharmacokinetics and Pharmacodynamics of Posaconazole

How can we optimize antifungal use and stewardship in the treatment of acute leukemia?

INTRODUCTION

The global need for antifungal stewardship is driven by spreading antimicrobial and antifungal resistance. Triazoles are the only oral and relatively well-tolerated class of antifungal medications, and usage is associated with acquired resistance and species replacement with intrinsically resistant organisms. On a per-patient basis, hematology patients are the largest inpatient consumers of antifungal drugs, but are also the most vulnerable to invasive fungal disease.

AREAS COVERED

In this review we discuss available and forthcoming antifungal drugs, antifungal prophylaxis and empiric antifungal therapy, and how a screening based and diagnostic-driven approach may be used to reduce antifungal consumption. Finally, we discuss components of an antifungal stewardship program, interventions that can be employed, and how impact can be measured. The search methodology consisted of searching PubMed for journal articles using the term antifungal stewardship plus program, intervention, performance measure or outcome before 1 January 2024.

EXPERT OPINION

Initial focus should be on implementing effective antifungal stewardship programs by developing and implementing local guidelines and using interventions, such as post-prescription review and feedback, which are known to be effective. Technologies such as microbiome analysis and machine learning may allow the development of truly individualized risk-factor-based approaches to antifungal stewardship in the future.

Posaconazole-hemp seed oil loaded nanomicelles for invasive fungal disease

Invasive fungal infections (IFI) pose a significant health burden, leading to high morbidity, mortality, and treatment costs. This study aims to develop and characterize nanomicelles for the codelivery of posaconazole and hemp seed oil for IFI via the oral route. The nanomicelles were prepared using a nanoprecipitation method and optimized through the Box Behnken design. The optimized nanomicelles resulted in satisfactory results for zeta potential, size, PDI, entrapment efficiency, TEM, and stability studies. FTIR and DSC results confirm the compatibility and amorphous state of the prepared nanomicelles. Confocal laser scanning microscopy showed that the optimized nanomicelles penetrated the tissue more deeply (44.9µm) than the suspension (25µm). The drug-loaded nanomicelles exhibited sustained cumulative drug release of 95.48 ± 3.27% for 24 h. The nanomicelles showed significant inhibition against Aspergillus niger and Candida albicans (22.4 ± 0.21 and 32.2 ± 0.46 mm, respectively). The pharmacokinetic study on Wistar rats exhibited a 1.8-fold increase in relative bioavailability for the nanomicelles compared to the suspension. These results confirm their therapeutic efficacy and lay the groundwork for future research and clinical applications, providing a promising synergistic antifungal nanomicelles approach for treating IFIs.

Dosing of IV posaconazole to treat critically ill patients with invasive pulmonary aspergillosis: a population pharmacokinetics modelling and simulation study

BACKGROUND

Posaconazole is used for the prophylaxis and treatment of invasive fungal infections in critically ill patients. Standard dosing was shown to result in adequate attainment of the prophylaxis Cmin target (0.7 mg/L) but not of the treatment Cmin target (1.0 mg/L).

OBJECTIVES

To provide an optimized posaconazole dosing regimen for IV treatment of patients with invasive pulmonary aspergillosis in the ICU.

METHODS

A population pharmacokinetics (popPK) model was developed using data from the POSA-FLU PK substudy (NCT03378479). Monte Carlo simulations were performed to assess treatment Cmin and AUC0-24 PTA. PTA ≥90% was deemed clinically acceptable. PopPK modelling and simulation were performed using NONMEM 7.5.

RESULTS

Thirty-one patients with intensive PK sampling were included in the PK substudy, contributing 532 posaconazole plasma concentrations. The popPK of IV posaconazole was best described by a two-compartment model with linear elimination. Interindividual variability was estimated on clearance and volume of distribution in central and peripheral compartments. Posaconazole peripheral volume of distribution increased with bodyweight. An optimized loading regimen of 300 mg q12h and 300 mg q8h in the first two treatment days achieved acceptable PTA by Day 3 in patients <100 kg and ≥100 kg, respectively. A maintenance regimen of 400 mg q24h ensured ≥90% Cmin PTA, whereas the standard 300 mg q24h was sufficient to achieve the AUC0-24 target throughout 14 days, irrespective of bodyweight.

CONCLUSIONS

We have defined a convenient, optimized IV posaconazole dosing regimen that was predicted to attain the treatment target in critically ill patients with invasive aspergillosis.

Hard Gelatin Capsules with Alginate-Hypromellose Microparticles as a Multicompartment Drug Delivery System for Sustained Posaconazole Release

Microparticles as a multicompartment drug delivery system are beneficial for poorly soluble drugs. Mucoadhesive polymers applied in microparticle technology prolong the contact of the drug with the mucosa surface enhancing drug bioavailability and extending drug activity. Sodium alginate (ALG) and hydroxypropyl methylcellulose (hypromellose, HPMC) are polymers of a natural or semi-synthetic origin, respectively. They are characterized by mucoadhesive properties and are applied in microparticle technology. Spray drying is a technology employed in microparticle preparation, consisting of the atomization of liquid in a stream of gas. In this study, the pharmaceutical properties of spray-dried ALG/HPMC microparticles with posaconazole were compared with the properties of physical mixtures of powders with equal qualitative and quantitative compositions. Posaconazole (POS) as a relatively novel antifungal was utilized as a model poorly water-soluble drug, and hard gelatin capsules were applied as a reservoir for designed formulations. A release study in 0.1 M HCl showed significantly prolonged POS release from microparticles compared to a mixture of powders. Such a relationship was not followed in simulated vaginal fluid (SVF). Microparticles were also characterized by stronger mucoadhesive properties, an increased swelling ratio, and prolonged residence time compared to physical mixtures of powders. The obtained results indicated that the pharmaceutical properties of hard gelatin capsules filled with microparticles were significantly different from hard gelatin capsules with mixtures of powders.

Investigating the potential of mono-chalcone compounds in targeting breast cancer receptors through network pharmacology, molecular docking, molecular dynamics simulation, antiproliferative effects, and gene expressions

The study aims to investigate various aspects of synthesized mono-chalcone compounds 5 and 8 concerning breast cancer, including network pharmacology, molecular docking, molecular dynamics (MD) simulations, antiproliferative effects, and gene expressions. Initially, the compounds underwent a network pharmacology analysis targeting breast cancer-related targets, with MalaCards, SwissTargetPrediction, and PharmMapper identifying 70 breast cancer target receptors. Subsequently, protein-protein interaction (PPI) network analysis revealed two distinct target gene clusters. Survival analysis identified seven significant target genes following Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment and Gene Ontology (GO) evaluation. Molecular docking and MD simulations were conducted on these seven target genes (AKT2, BRAF, ESR1, FGFR1, IGF1, IGF1R, and KIT), revealing that compound 8 exhibited the highest binding affinities, as well as better stability and compactness when interacting with the targeted proteins. Next, the compounds underwent cell viability assay and gene expression analysis to validate the in silico findings. Both compounds demonstrated the ability to suppress breast cancer proliferation, with compound 8 showing increased selectivity in targeting breast cancer cells while causing minimal harm to normal breast cells. The suppression of breast cancer cell proliferation was attributed to decreased expression levels of AKT2, BRAF, FGFR1, IGF1, IGF1R, KIT, and ESR1. Hence, the results provide insights into the molecular interaction responsible for the anti-breast cancer capabilities of mono-chalcone compounds.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-024-03991-y.

Development of posaconazole nanocrystalline solid dispersion: preparation, characterization and in vivo evaluation

OBJECTIVE

Posaconazole (PCZ) is an antifungal drug, which acts by inhibiting the lanosterol-14α-demethylase enzyme. It is a biopharmaceutical classification system class II drug with its bioavailability being limited by poor aqueous solubility. The aim of this study was to improve the oral bioavailability of PCZ by preparing nanocrystalline solid dispersion (NCS).

METHODS

PCZ-NCS was prepared by a combination of precipitation and high-pressure homogenization followed by freeze-drying. Several different surfactants and polymers were screened to produce NCS with smaller particle size and higher stability.

RESULTS

The optimized NCS formulation containing 0.2% Eudragit S100 and 0.2% SLS was found to provide the average particle size of 73.31 ± 4.7 nm with a polydispersity index of 0.23 ± 0.03. Scanning electron microscopy revealed the preparation of homogeneous and rounded particles. Differential scanning calorimetry and X-ray diffraction confirmed crystalline nature of NCS. Nanonization increased the saturation solubility of PCZ by about 18-fold in comparison with the neat drug. Intrinsic dissolution study showed 93% dissolution of PCZ within the first 10 min. In vivo pharmacokinetic study in Wistar rats showed that Cmax and AUCtotal of PCZ-NCS increased by 2.58- and 2.64-fold compared to the marketed formulation.

CONCLUSION

PCZ-NCS formulation presents a viable approach for enhancing the oral bioavailability of PCZ.

Safety and efficacy of new generation azole antifungals in the management of recalcitrant superficial fungal infections and onychomycosis

INTRODUCTION

Terbinafine is considered the gold standard for treating skin fungal infections and onychomycosis. However, recent reports suggest that dermatophytes are developing resistance to terbinafine and the other traditional antifungal agents, itraconazole and fluconazole. When there is resistance to terbinafine, itraconazole or fluconazole, or when these agents cannot used, for example, due to potential drug interactions with the patient's current medications, clinicians may need to consider off-label use of new generation azoles, such as voriconazole, posaconazole, fosravuconazole, or oteseconazole. It is essential to emphasize that we do not advocate the use of newer generation azoles unless traditional agents such as terbinafine, itraconazole, or fluconazole have been thoroughly evaluated as first-line therapies.

AREAS COVERED

This article reviews the clinical evidence, safety, dosage regimens, pharmacokinetics, and management algorithm of new-generation azole antifungals.

EXPERT OPINION

Antifungal stewardship should be the top priority when prescribing new-generation azoles. First-line antifungal therapy is terbinafine and itraconazole. Fluconazole is a consideration but is generally less effective and its use may be off-label in many countries. For difficult-to-treat skin fungal infections and onychomycosis, that have failed terbinafine, itraconazole and fluconazole, we propose consideration of off-label voriconazole or posaconazole.

Cytochrome P450 Enzymes as Drug Targets in Human Disease

Although the mention of cytochrome P450 (P450) inhibition usually brings to mind unwanted variability in pharmacokinetics, in several cases P450s are good targets for inhibition. These P450s are essential, but in certain disease states, it is desirable to reduce the concentrations of their products. Most of the attention to date has been with human P450s 5A1, 11A1, 11B1, 11B2, 17A1, 19A1, and 51A1. In some of those cases, there are multiple drugs in use, e.g., exemestane, letrozole, and anastrozole with P450 19A1, the steroid aromatase target in breast cancer. There are also several targets that are less developed, e.g., P450s 2A6, 8B1, 4A11, 24A1, 26A1, and 26B1. SIGNIFICANCE STATEMENT: The selective inhibition of certain cytochrome P450s that have major physiological functions has been shown to be very efficacious in certain human diseases. In several cases, the search for better drugs continues.

Real-world Experience of Posaconazole Therapeutic Drug Monitoring in Oncology Patients: Clinical Implications of Hypoalbuminemia as a Predictor of Subtherapeutic Posaconazole Levels

Background

Posaconazole maintains broad antifungal activity and is employed for prevention and treatment of invasive fungal infections in oncology patients. Older formulations required therapeutic drug monitoring, and specific plasma drug levels have been recommended. This study evaluated factors associated with subtherapeutic concentrations with the newer delayed-release tablet formulation.

Methods

In this retrospective, single-center cohort study at a national comprehensive cancer center, all oncology patients receiving delayed-release posaconazole at standard dosing of 300 mg orally per day from 06/2021 to 07/2023 with plasma drug concentration evaluation were identified. Demographic, clinical, and laboratory data were evaluated to identify risk factors associated with subtherapeutic drug levels at targets of ≥1.25 µg/mL and ≥1.8 µg/mL.

Results

Of 110 patients identified, 98 met criteria for inclusion in the study. The median time from initiation of posaconazole to drug level assessment was 13 days, and the median concentration was 1.29 µg/mL. Of the 22 patients receiving posaconazole for prophylaxis, 5 (22.7%) failed to achieve concentrations ≥0.7 µg/mL, and of 76 patients receiving posaconazole for treatment, 38 (50%) failed to achieve concentrations of ≥1.25 µg/mL. In multivariable analysis, albumin of ≤3 g/dL and ideal body weight ≥60 kg were found to be associated with subtherapeutic levels. For a higher target of ≥1.8 µg/mL, only albumin ≤3 g/dL was associated with subtherapeutic levels for the variables evaluated.

Conclusions

A higher initial dosing strategy and therapeutic drug monitoring for oncology patients with albumin ≤3 g/dL receiving posaconazole, particularly for the treatment of invasive fungal infection, could be considered.

Therapeutic drug monitoring of antifungal therapies: do we really need it and what are the best practices?

INTRODUCTION

Despite advancements, invasive fungal infections (IFI) still carry high mortality rates, often exceeding 30%. The challenges in diagnosis, coupled with limited effective antifungal options, make managing IFIs complex. Antifungal drugs are essential for IFI management, but their efficacy can be diminished by drug-drug interactions and pharmacokinetic variability. Therapeutic Drug Monitoring (TDM), especially in the context of triazole use, has emerged as a valuable strategy to optimize antifungal therapy.

AREAS COVERED

This review provides current evidence regarding the potential benefits of TDM in IFI management. It discusses how TDM can enhance treatment response, safety, and address altered pharmacokinetics in specific patient populations.

EXPERT OPINION

TDM plays a crucial role in achieving optimal therapeutic outcomes in IFI management, particularly for certain antifungal agents. Preclinical studies consistently show a link between therapeutic drug levels and antifungal efficacy. However, clinical research in mycology faces challenges due to patient heterogeneity and the diversity of fungal infections. TDM's potential advantages in guiding Echinocandin therapy for critically ill patients warrant further investigation. Additionally, for drugs like Posaconazole, assessing whether serum levels or alternative markers like saliva offer the best measure of efficacy is an intriguing question.

Oral delivery of posaconazole-loaded phospholipid-based nanoformulation: Preparation and optimization using design of experiments, machine learning, and TOPSIS

Phospholipid-based nanosystems show promising potentials for oral administration of hydrophobic drugs. The study introduced a novel approach to optimize posaconazole-loaded phospholipid-based nanoformulation using the design of experiments, machine learning, and Technique for Order of Preference by Similarity to the Ideal Solution. These approaches were used to investigate the impact of various variables on the encapsulation efficiency (EE), particle size, and polydispersity index (PDI). The optimized formulation, with %EE of ∼ 74 %, demonstrated a particle size and PDI of 107.7 nm and 0.174, respectively. The oral pharmacokinetic profiles of the posaconazole suspension, empty nanoformulation + drug suspension, and drug-loaded nanoformulation were evaluated. The nanoformulation significantly increased maximum plasma concentration and the area under the drug plasma concentration-time curve (∼3.9- and 6.2-fold, respectively) and could be administered without regard to meals. MTT and histopathological examinations were carried out to evaluate the safety of the nanoformulation and results exhibited no significant toxicity. Lymphatic transport was found to be the main mechanism of oral delivery. Caco-2 cell studies demonstrated that the mechanism of delivery was not based on an increase in cellular uptake. Our study represents a promising strategy for the development of phospholipid-based nanoformulations as efficient and safe oral delivery systems.

Population pharmacokinetics of posaconazole in allogeneic haematopoietic stem cell transplant patients

BACKGROUND

Invasive fungal disease (IFD) in the early post-allogeneic HSCT (alloHCT) period is associated with increased likelihood of catastrophic outcomes. The utility of oral modified release (MR) posaconazole tablets is limited by reduced drug absorption from gastrointestinal toxicity induced by cytotoxic chemotherapy, necessitating a switch to the IV posaconazole formulation.

OBJECTIVES

To describe the population pharmacokinetics of posaconazole for oral MR and IV formulations in alloHCT patients and determine dosing regimens likely to achieve therapeutic exposures.

METHODS

We performed a prospective observational pharmacokinetic study in adult patients in the early post-alloHCT period requiring a change in posaconazole formulation (oral to IV). Samples were analysed using a validated LC-MS/MS method. Population pharmacokinetic analysis and Monte Carlo simulations (n = 1000) were performed using Pmetrics for R.

RESULTS

Twenty patients aged between 21 and 70 years were included in the study. A two-compartment model, incorporating mucositis/diarrhoea to modify the bioavailability for oral administration best described the data. To achieve ≥90% PTA, simulations showed that higher than currently recommended doses of oral MR posaconazole were required for prophylaxis Cmin targets (≥0.5 and ≥0.7 mg/L), while increased doses of both formulations were required for IFD treatment PK/PD targets, with patients experiencing oral mucositis/diarrhoea unlikely to achieve these.

CONCLUSIONS

Increased doses of posaconazole should be considered for both prophylaxis and treatment of IFD to increase the proportion of alloHCT patients achieving therapeutic exposures, particularly the oral formulation in patients with mucositis and/or diarrhoea. Posaconazole therapeutic drug monitoring should be considered for all formulations in this setting.

Supratherapeutic posaconazole concentrations associated with hyperlipidemia in a patient with HSCT

Posaconazole is a potent, extended-spectrum triazole antifungal used for the treatment and prophylaxis of serious fungal infections. Previous reports have demonstrated hyperlipidemia resulted in significant changes in posaconazole pharmacokinetics and tissue distribution in rats. However, the effect of hyperlipidemia on the pharmacokinetics of posaconazole in patients has not yet been reported. We report a case of a 34-year-old woman who experienced a supratherapeutic posaconazole trough concentration (PTC) associated with hyperlipidemia after haploidentical hematopoietic stem cell transplantation (HSCT). The patient was admitted 13 months after HSCT for recurrent cough and sputum. She was treated with caspofungin due to developing invasive fungal infection of Candida tropicalis. After 10 days, caspofungin was discontinued due to the poor therapeutic efficacy and replaced with amphotericin B. Afterwards, the condition of the patient improved significantly and she was switched to daily oral posaconazole tablet. Therapeutic drug monitoring (TDM) of posaconazole showed a PTC was 3.2 mg/L. After discharge, she continued to receive posaconazole tablet as antifungal treatment. Two months later, laboratory tests at outpatient showed her blood lipid levels were significantly elevated and PTC was increased to 9.38 mg/L. Therefore, the posaconazole tablet was discontinued and she received lipid-lowering therapy. A few days later, the PTC was down to 5.22 mg/L. No medication errors and significant drug interactions were found. Hence, supratherapeutic PTC for this patient may be caused by hyperlipidemia which altered pharmacokinetics of posaconazole. Our findings highlight the need for close TDM in order to avoid supratherapeutic PTC if hyperlipidimia occurs during posaconazole use.

Utilization of nanotechnology and experimental design in the development and optimization of a posaconazole‒calendula oil nanoemulgel for the treatment of mouth disorders

Introduction: Essential oil‒based nanoemulsions (NEs) are the subjects of extensive investigation due to their potential to address a variety of oral health issues. NEs are delivery systems that improve lipid medicine solubility and distribution to intended sites. The goal of the current study was to create and enhance a self-nanoemulsifying drug delivery paradigm based on calendula oil (CO) and decorated with chitosan (CS) that could deliver posaconazole (PSZ) for the treatment of gingivitis. Method: Employing a response-surface Box‒Behnken design, PSZ-CO-CS NEs were created with varying amounts of PSZ (10, 15, and 20 mg), percentages of CO (6%, 12%, and 18%), and percentages of CS (0.5%, 1.5%, and 2.5%). Results and conclusion: The optimized formulation resulted in a 22-mm bacterial growth suppression zone, 25-mm fungal growth inhibition zone, droplet sizes of 110 nm, and a viscosity of 750 centipoise (cP). Using the appropriate design, the ideal formulation was produced; it contained 20 mg of PSZ, 18% of CO, and 1.35% of CS. Furthermore, the optimal formulation had a more controlled drug release, larger inhibition zones of bacterial and fungal growth, and desirable rheologic properties. Additionally, the optimized formulation substantially lowered the ulcer index in rats when tested against other formulations. Thus, this investigation showed that PSZ-CO-CS NEs could provide efficient protection against microbially induced gingivitis.

Three cases of recalcitrant Paecilomyces keratitis in Southern California within a short period

BACKGROUND

The aim of this report is to describe the risk factors, clinical course, and characteristics of three cases of Paecilomyces keratitis presenting concurrently within three months in the same location. We used in vivo confocal microscopy and histopathology to corroborate our clinical findings.

OBSERVATIONS

Three eyes of three elderly patients with culture-proven Paecilomyces keratitis were included in this series. These patients resided within a 15-mile radius and presented to a tertiary care eye institute in Southern California between February and April 2022. All three eyes experienced a prolonged, recalcitrant course with recurrence of keratitis in donor corneal tissue despite antifungal therapy and multiple therapeutic penetrating keratoplasties. In vivo confocal microscopy, histopathology, and microbiologic findings corroborated the diagnosis of fungal keratitis with Paecilomyces. With surgical intervention and extensive medical therapy, all three cases resolved after the addition of oral Posaconazole.

CONCLUSIONS

Paecilomyces is a rare cause of infectious keratitis. Herein we report three similar cases in elderly patients. All had prolonged, recalcitrant infections that required multiple treatment modalities. Our cases, which were supported by in vivo confocal microscopy and histopathology, highlight the importance of timely and aggressive therapy to prevent recurrence.

Single-Dose Crossover Comparative Bioavailability Study of Two Different Posaconazole 100 mg Gastro-Resistant Tablets Under Fasted and Fed Conditions in Healthy Volunteers

Objective

This study aimed to compare the bioavailability of two different gastro-resistant oral tablet formulations of posaconazole under fasted and fed conditions and to evaluate a potential food effect on the bioavailability of each formulation.

Materials and Methods

Healthy volunteers randomly assigned to receive a test product (Posagil® 100 mg gastro-resistant tablet) or reference product (Noxafil® 100 mg gastro-resistant tablet) were included in this single-center, randomized, four-period (days 1, 15, 29 and 43), four-sequence crossover comparative bioavailability study. Data on posaconazole plasma concentrations and related pharmacokinetic profile (the maximum observed plasma concentration [Cmax] from time 0 to the time of last observed quantifiable plasma concentration [AUC0-T] and from time zero to infinity [AUC0-∞]) were recorded to evaluate efficacy of the test product in relation to the reference product under both fasted and fed conditions, based on bioequivalence (T-fasted vs. R-fasted and T-fed vs. R-fed) and food effect (T-fasted vs. T-fed and R-fasted vs. R-fed) assessments. Safety was evaluated through assessment of adverse events (AEs), standard laboratory evaluations, and vital signs.

Results

The bioequivalence criteria were met under fed conditions (T-fed vs. R-fed: geometric LSMean ratios of Cmax, AUC0-T, and AUC0-∞ of posaconazole were 97.41%, 97.45%, and 97.08%, respectively; all within the range of 80% to 125%) but not under fasted conditions. There was a food effect on the reference product (R-fed vs. R-fasted: geometric LSMean ratios of Cmax, AUC0-T, and AUC0-∞ of posaconazole were 145.32%, 138.84%, and 138.46%, respectively) but not on the test product. No safety concerns were identified.

Conclusions

Our findings suggest that the pharmacokinetic profile of Posagil® is similar to the pharmacokinetic profile of Noxafil®. The generic Posagil® seems to have similarly high bioavailability under fed and fasted conditions, offering a higher posaconazole exposure than the original Noxafil® in the fasted state. Hence, Posagil® may be considered a value-added generic product that offers adequate posaconazole exposure under fasted state and fed state, regardless of the concomitant high-fat meal intake.

Clinical Consequences of Altered Drug Disposition in Obesity: Call for Change

Obesity is a serious condition with many known comorbid conditions and other health risks. Despite the rising global rates of obesity, drug disposition in this population is typically understudied, which results in limited information guiding the use of drugs in patients with obesity. Presently, dosing adjustments for patients with obesity typically focus on addressing altered drug clearance with body size and are therefore limited to chronic dosing recommendations. These instructions are variable and rarely based on dedicated studies in people with obesity. This review briefly discusses the current clinical use of body measurements to guide chronic dosing instructions and highlights the need for obesity-specific dosing instructions when the half-life of a drug is prolonged (typically through increased volume of distribution) in people with obesity. Examples of drugs with apparent opportunities for either ramp-up, loading, or washout instructions for patients based on body mass index are identified, specifically for vortioxetine, posaconazole, and brexpiprazole. We call for inclusion of people with obesity in clinical studies as a special subpopulation during drug development and propose the use of body mass index to guide dosing decisions among these patients.

Evaluation of the inhibitory effect of azoles on pharmacokinetics of lenvatinib in rats both in vivo and in vitro by UPLC-MS/MS

BACKGROUND

Lenvatinib is a multitargeted tyrosine kinase inhibitor used in the treatment of a variety of solid tumors. This study aims to investigate the potential pharmacokinetic interactions between lenvatinib and various azoles (ketoconazole, voriconazole, isavuconazole and posaconazole) when orally administered to rats.

METHODS

A total of 30 Sprague-Dawley rats were randomly allocated into five groups and administered 20 mg/kg of ketoconazole, voriconazole, isavuconazole and 30 mg/kg of posaconazole and 0.5% CMC-Na, through gavage for a duration of 7 days prior to the commencement of the experiment. On the final day, the rats were given 10 mg/kg of lenvatinib. The blood concentration of lenvatinib was determined using UPLC-MS-MS. In vitro lenvatinib were incubated with azoles and rat liver microsomes (RLMs) or human liver microsomes (HLMs). Molecular docking was lastly used to examine the binding strength of the enzymes and ligands with Autodock Vina.

RESULTS

AUC and Cmax of lenvatinib significantly increased with each of the azoles (p < 0.05), whereas CLz/F decreased 0.83-flod, 0.41-fold (p < 0.05) and 0.72-fold (p < 0.01) in voriconazole, isavuconazole and ketoconazole in rats. The IC50 of lenvatinib with the azoles were 0.237, 1.300, 0.355 and 2.403 μM in RLMs and 0.160, 1.933, 3.622 and 1.831 μM in HLMs. Molecular docking analysis suggested that azoles exhibited a strong binding ability towards the target enzymes.

CONCLUSION

It is imperative to acknowledge the potential drug-drug interactions mediated by CYP3A4 between azoles and lenvatinib, as these interactions hold significant implications for their clinical utilization.

Observed isavuconazole exposure: 5-year experience of azole TDM from a Spanish reference laboratory

We aimed to assess patient exposure to isavuconazole (ISZ) from samples received in our laboratory for therapeutic antifungal monitoring. We used liquid chromatography coupled with ultraviolet (UV) absorbance detection adapted from a multiplex-validated method with photodiode array (PDA) detection to monitor the analytes. The latter device allows the characterization of the azoles UV spectra. The method was validated according to international guidelines for efficient ISZ monitoring. The assay exhibited linearity between 0.25 and 16 mg/l for ISZ. Accuracy and intra- and inter-day precision were within acceptable ranges, and the method was successfully applied to quantify azoles and major metabolites from clinical samples collected from treated patients. We focus on ISZ blood concentrations and compared them to those of voriconazole, posaconazole, and itraconazole for a period of 5 years (2017-2021). Median ISZ concentration was 2.92 mg/l (interquartile range 1.82-5.33 mg/l) with 89% of measurements classified as adequate exposure (> 1 mg/l). Additionally, 71% of samples reach concentration values > 2 mg/l. Different ISZ exposure between adults to children were found. In conclusion, ISZ achieves excellent blood concentrations compared to other azole drugs, they are almost identical to those previously described, they exceed the MICs of most fungi for which its use was recommended and they differ depending on the patient's age. The method we describe for antifungal monitoring is simple, robust, and efficient. It simultaneously analyzes azoles and metabolites, and can be used for tailored interventions, achieve exposures associated with therapeutic success, decrease treatment-related toxicity, and help prevent resistance emergence due to continuous azole sub-optimal concentrations.

Ileus induced by the combination of vinca alkaloids and posaconazole in a patient with acute lymphoblastic leukemia: a case report and literature review

Vinca alkaloid (VA)-induced ileus, a rare but severe autonomic neuropathy, can be enhanced by concomitant use of antifungal triazole agents. We herein present a case of VA-induced ileus in a 17-year-old girl who was diagnosed with B-cell acute lymphoblastic leukemia. On day 1, the patient received cyclophosphamide, vincristine, and methylprednisolone. On day 2, she began treatment with posaconazole oral suspension at 200 mg three times daily for prophylaxis against invasive fungal infection. On day 5, she began induction therapy consisting of vindesine, methylprednisolone, daunorubicin, and cyclophosphamide. The patient developed severe abdominal pain with marked constipation on day 11 and was diagnosed with incomplete ileus. After switching the antifungal agent to micafungin, performing gastrointestinal decompression, administering parenteral nutrition, and omitting the fourth dose of vindesine, the ileus symptoms were relieved. This case emphasizes the potential interaction between VAs and posaconazole. We also herein present a review of the literature on ileus caused by the combination of VAs and antifungal triazole agents. In clinical practice, physicians and pharmacists should be aware of the possibility of ileus caused by the use of VAs in combination with posaconazole. It is important to reduce complications during chemotherapy to improve patients' prognosis.

Model Based Estimation of Posaconazole Tablet and Suspension Bioavailability in Hospitalized Children Using Real-World Therapeutic Drug Monitoring Data in Patients Receiving Intravenous and Oral Dosing

Invasive fungal infections are a major cause of morbidity and mortality for immunocompromised patients. Posaconazole is approved for treatment and prophylaxis of invasive fungal infection in adult patients, with intravenous, oral suspension, and gastroresistant/delayed-released tablet formulations available. In Europe, until very recently, posaconazole was used off-label in children, although a new delayed-release suspension approved for pediatric use is expected to become available soon. A population pharmacokinetic model was developed which uses posaconazole therapeutic drug monitoring data following intravenous and oral dosing in hospitalized children, thus enabling estimation of pediatric suspension and tablet oral bioavailability. In total, 297 therapeutic drug monitoring plasma levels from 104 children were included in this analysis. The final model was a one-compartment model with first-order absorption and nonlinear elimination. Allometric scaling on clearance and volume of distribution was included a priori. Tablet bioavailability was estimated to be 66%. Suspension bioavailability was estimated to decrease with increasing doses, ranging from 3.8% to 32.2% in this study population. Additionally, concomitant use of proton pump-inhibitors was detected as a significant covariate, reducing suspension bioavailability by 41.0%. This is the first population pharmacokinetic study to model posaconazole data from hospitalized children following intravenous, tablet, and suspension dosing simultaneously. The incorporation of saturable posaconazole clearance into the model has been key to the credible joint estimation of tablet and suspension bioavailability. To aid rational posaconazole dosing in children, this model was used alongside published pharmacodynamic targets to predict the probability of target attainment using typical pediatric dosing regimen.

The Impact of Hypromellose on Pharmaceutical Properties of Alginate Microparticles as Novel Drug Carriers for Posaconazole

Fungal infections are a group of diseases which are challenging to treat because of drug-resistant fungi species, drug toxicity, and often severe patient conditions. Hence, research into new treatments, including new therapeutic substances and novel drug delivery systems, is being performed. Mucoadhesive dosage forms are beneficial to improving drug bioavailability by prolonging the residence time at the site of application. Sodium alginate is a natural polymer with favorable mucoadhesive and gelling properties, although its precipitation in acidic pH significantly disrupts the process of drug release in gastric conditions. Hypromellose is a hydrophilic, semi-synthetic cellulose derivative with mucoadhesive properties, which is widely used as a control release agent in pharmaceutical technology. The aim of this study was to evaluate the impact of hypromellose on alginate microparticles with posaconazole, designed to modify drug release and to improve their mucoadhesive properties for both oral or vaginal application.

High-throughput identification and determination of antifungal triazoles in human plasma using UPLC-QDa

Triazoles are common agents for invasive fungal infections, while therapeutic drug monitoring is needed to improve antifungal efficacy and reduce toxicity. This study aimed to exploit a simple and reliable liquid chromatography-mass spectrometry method for high-throughput monitoring of antifungal triazoles in human plasma using UPLC-QDa. Triazoles in plasma were separated by chromatography on a Waters BEH C18 column and detected using positive ions electrospray ionization fitted with single ion recording. M⁺ for fluconazole (m/z 307.11) and voriconazole (m/z 350.12), M²⁺ for posaconazole (m/z 351.17), itraconazole (m/z 353.13) and ketoconazole (m/z 266.08, IS) were selected as representative ions in single ion recording mode. The standard curves in plasma showed acceptable linearities over 1.25-40 μg/mL for fluconazole, 0.47-15 μg/mL for posaconazole and 0.39-12.5 μg/mL for voriconazole and itraconazole. The selectivity, specificity, accuracy, precision, recovery, matrix effect, and stability met acceptable practice standards under Food and Drug Administration method validation guidelines. This method was successfully applied to the therapeutic monitoring of triazoles in patients with invasive fungal infections, thereby guiding clinical medication.

The Specific Binding and Promotion Effect of Azoles on Human Aldo-Keto Reductase 7A2

Human AKR 7A2 broadly participates in the metabolism of a number of exogenous and endogenous compounds. Azoles are a class of clinically widely used antifungal drugs, which are usually metabolized by CYP 3A4, CYP2C19, and CYP1A1, etc. in vivo. The azole-protein interactions that human AKR7A2 participates in remain unreported. In this study, we investigated the effect of the representative azoles (miconazole, econazole, ketoconazole, fluconazole, itraconazole, voriconazole, and posaconazole) on the catalysis of human AKR7A2. The steady-state kinetics study showed that the catalytic efficiency of AKR7A2 enhanced in a dose-dependent manner in the presence of posaconazole, miconazole, fluconazole, and itraconazole, while it had no change in the presence of econazole, ketoconazole, and voriconazole. Biacore assays demonstrated that all seven azoles were able to specifically bind to AKR7A2, among which itraconazole, posaconazole, and voriconazole showed the strongest binding. Blind docking predicted that all azoles were apt to preferentially bind at the entrance of the substrate cavity of AKR7A2. Flexible docking showed that posaconazole, located at the region, can efficiently lower the binding energy of the substrate 2-CBA in the cavity compared to the case of no posaconazole. This study demonstrates that human AKR7A2 can interact with some azole drugs, and it also reveals that the enzyme activity can be regulated by some small molecules. These findings will enable a better understanding of azole-protein interactions.

Systemic Antifungal Therapy for Invasive Pulmonary Infections

Antifungal therapy for pulmonary fungal diseases is in a state of flux. Amphotericin B, the time-honored standard of care for many years, has been replaced by agents demonstrating superior efficacy and safety, including extended-spectrum triazoles and liposomal amphotericin B. Voriconazole, which became the treatment of choice for most pulmonary mold diseases, has been compared with posaconazole and itraconazole, both of which have shown clinical efficacy similar to that of voriconazole, with fewer adverse events. With the worldwide expansion of azole-resistant Aspergillus fumigatus and infections with intrinsically resistant non-Aspergillus molds, the need for newer antifungals with novel mechanisms of action becomes ever more pressing.

Identification of Potent Zika Virus NS5 RNA-Dependent RNA Polymerase Inhibitors Combining Virtual Screening and Biological Assays

The Zika virus (ZIKV) epidemic poses a significant threat to human health globally. Thus, there is an urgent need for developing effective anti-ZIKV agents. ZIKV non-structural protein 5 RNA-dependent RNA polymerase (RdRp), a viral enzyme for viral replication, has been considered an attractive drug target. In this work, we screened an anti-infection compound library and a natural product library by virtual screening to identify potential candidates targeting RdRp. Then, five selected candidates were further applied for RdRp enzymatic analysis, cytotoxicity, and binding examination by SPR. Finally, posaconazole (POS) was confirmed to effectively inhibit both RdRp activity with an IC₅₀ of 4.29 μM and the ZIKV replication with an EC₅₀ of 0.59 μM. Moreover, POS was shown to reduce RdRp activity by binding with the key amino acid D666 through molecular docking and site-directed mutation analysis. For the first time, our work found that POS could inhibit ZIKV replication with a stronger inhibitory activity than chloroquine. This work also demonstrated fast anti-ZIKV screening for inhibitors of RdRp and provided POS as a potential anti-ZIKV agent.

Blastomycosis: A Review of Mycological and Clinical Aspects

Blastomycosis is caused by a thermally dimorphic fungus that thrives in moist acidic soil. Blastomyces dermatitidis is the species responsible for most infections in North America and is especially common in areas around the Great Lakes, the St. Lawrence Seaway, and in several south-central and southeastern United States. Other Blastomyces species have more recently been discovered to cause disease in distinct geographic regions around the world. Infection almost always occurs following inhalation of conidia produced in the mold phase. Acute pulmonary infection ranges from asymptomatic to typical community-acquired pneumonia; more chronic forms of pulmonary infection can present as mass-like lesions or cavitary pneumonia. Infrequently, pulmonary infection can progress to acute respiratory distress syndrome that is associated with a high mortality rate. After initial pulmonary infection, hematogenous dissemination of the yeast form of Blastomyces is common. Most often this is manifested by cutaneous lesions, but osteoarticular, genitourinary, and central nervous system (CNS) involvement also occurs. The diagnosis of blastomycosis can be made by growth of the mold phase of Blastomyces spp. in culture or by histopathological identification of the distinctive features of the yeast form in tissues. Detection of cell wall antigens of Blastomyces in urine or serum provides a rapid method for a probable diagnosis of blastomycosis, but cross-reactivity with other endemic mycoses commonly occurs. Treatment of severe pulmonary or disseminated blastomycosis and CNS blastomycosis initially is with a lipid formulation of amphotericin B. After improvement, therapy can be changed to an oral azole, almost always itraconazole. With mild to moderate pulmonary or disseminated blastomycosis, oral itraconazole treatment is recommended.

Salvage Treatment for Invasive Aspergillosis and Mucormycosis: Challenges, Recommendations and Future Considerations

Invasive mold diseases are devastating systemic infections which demand meticulous care in selection, dosing, and therapy monitoring of antifungal drugs. Various circumstances regarding PK/PD properties of the applied drug, resistance/tolerance of the causative pathogen or host intolerability can lead to failure of the initial antifungal therapy. This necessitates treatment adaption in the sense of switching antifungal drug class or potentially adding another drug for a combination therapy approach. In the current state of drastically limited options of antifungal drug classes adaption of therapy remains challenging. Current guidelines provide restricted recommendations only and emphasize individual approaches. However, novel antifungals, incorporating innovative mechanisms of action, show promising results in late stage clinical development. These will expand options for salvage therapy in the future potentially as monotherapy or in combination with conventional or other novel antifungals. We outline current recommendations for salvage therapy including PK/PD considerations as well as elucidate possible future treatment options for invasive aspergillosis and mucormycosis.

An Integrated Population Pharmacokinetic Analysis for Posaconazole Oral Suspension, Delayed-Release Tablet, and Intravenous Infusion in Healthy Volunteers

BACKGROUND

Posaconazole is widely used for the prophylaxis and treatment of invasive fungal diseases. Because of the limited and variable absorption of the initially available oral suspension, a delayed-release tablet and intravenous formulation were developed.

OBJECTIVE

This study aimed to characterize the pharmacokinetics, including the absolute oral bioavailability, of all posaconazole formulations in healthy volunteers.

METHODS

Data from 182 healthy volunteers with 3898 densely sampled posaconazole concentrations were pooled from eight phase I clinical studies on the three formulations of various single and multiple dosage regimens between 50 and 400 mg. Analysis and simulations were performed using NONMEM 7.5.0. In the covariate analysis, the influence of food (fed vs fasted), nonlinearity, and for the delayed-release tablet, comedication (antacid, ranitidine, esomeprazole, and metoclopramide) were tested.

RESULTS

A two-compartment model with respectively, four and eight absorption transit compartments, best described the profiles of the oral suspension and delayed-release tablet. For the suspension, both a food effect and a dose-dependent nonlinear bioavailability were quantified, resulting in lower bioavailability when fasted or at a higher dose. The typical bioavailability of the suspension at 100 mg and 400 mg was derived to be respectively, 17.1% and 10.1% under fasted conditions and 59.1% and 49.2% under fed conditions. The absolute bioavailability of the delayed-release tablet was 58.8% (95% confidence interval 33.2-80.4) under fasted conditions and approached complete absorption under fed conditions for dosages up to 300 mg. Food intake reduced the absorption rate constant of the suspension by 52.2% (confidence interval 45.2-59.2). The impact of comedication on the absorption of the delayed-release tablet was not statistically significant. Model-based simulations indicate that under fed conditions, the licensed dosages of the three formulations yield a steady-state trough concentration ≥ 0.7 mg/L in over 90% of healthy volunteers. About 35% of healthy volunteers who receive the licensed 300-mg delayed-release tablet under fasted conditions do not achieve this target, while for the suspension this percentage varies between 55 and 85%, depending on the dose.

CONCLUSIONS

For both oral posaconazole formulations, we quantified bioavailability and absorption rate, including food effects, in healthy volunteers. The pharmacokinetic superiority of the delayed-release tablet was demonstrated under both fed and fasted conditions, compared with the oral suspension. The impact of food on the bioavailability of the delayed-release tablet was larger than anticipated, suggesting that administering the delayed-release tablet with food enhances absorption.

Formation and Characterisation of Posaconazole Hydrate Form

Posaconazole is an API added as Form I for the production of oral suspensions, but it is found as Form-S in the final formulation. In this study, it was found that this polymorphic conversion, which may affect the bioavailability, is due to an interaction with water. However, the relatively poor wettability of posaconazole Form I renders the complete wetting of its particles and production of pure Form-S challenging. Consequently, for its isolation, Form I should be dispersed in water followed by application of sonication for at least 10 min. Pure posaconazole Form-S was characterised using X-ray powder diffraction (XRPD), Raman spectroscopy, attenuated total reflection (ATR) spectroscopy, thermogravimetric analysis (TGA) and optical microscopy. From these techniques, posaconazole Form-S was characterised as a hydrate form, which includes three molecules of water per API molecule.

Pulmonary aspergillosis: diagnosis and treatment

Aspergillusspecies are the most frequent cause of fungal infections of the lungs with a broad spectrum of clinical presentations including invasive pulmonary aspergillosis (IPA) and chronic pulmonary aspergillosis (CPA). IPA affects immunocompromised populations, which are increasing in number and diversity with the advent of novel anti-cancer therapies. Moreover, IPA has emerged as a complication of severe influenza and coronavirus disease 2019 in apparently immunocompetent hosts. CPA mainly affects patients with pre-existing lung lesions and is recognised increasingly frequently among patients with long-term survival following cure of tuberculosis or lung cancer. The diagnosis of pulmonary aspergillosis is complex as it relies on the presence of clinical, radiological and microbiological criteria, which differ according to the type of pulmonary aspergillosis (IPA or CPA) and the type of patient population. The management of pulmonary aspergillosis is complicated by the limited number of treatment options, drug interactions, adverse events and the emergence of antifungal resistance.

Efficacy of Crushed Delayed-Release Posaconazole Tablets in Rhino-Orbito-Cerebral Mucormycosis

A significant proportion of patients with Rhino-orbito-cerebral mucormycosis (ROCM) develop oroantral fistulas. Due to the unclear efficacy of crushed delayed-release posaconazole tablets (DRPT) via nasogastric tube in this group of patients, clinicians often use inferior alternatives like posaconazole suspension. In this prospective study, we report good plasma concentrations (median, 2,639 ng/mL; interquartile range [IQR], 1,690 to 3,575 ng/mL; and range, 1,004 to 4,835ng/mL) and complete cure and survival at 3 and 6 months in 19 such patients.

Clinical research advances of isavuconazole in the treatment of invasive fungal diseases

Purpose

Invasive fungal diseases (IFD) are a major global public health concern. The incidence of IFD has increased the demand for antifungal agents. Isavuconazole (ISA) is a new triazole antifungal agent that has shown promising efficacy in the prophylaxis and treatment of invasive fungal diseases. The aim of this review is to summarize the recent real-world experiences of using ISA for the treatment and prevention of IFD.

Methods

We performed a comprehensive literature search of the MEDLINE, PubMed, Embase, and Cochrane databases for clinical applications of ISA in the real world. Tables and reference lists are presented for this systematic review.

Results

IFD poses a major threat to public health and causes high mortality rates. ISA may provide a good treatment. For example, the efficacy of ISA in the treatment of invasive aspergillosis (IA) is comparable to that of voriconazole, and its efficacy in the treatment of invasive mucormycosis (IM) is similar to that of liposomal amphotericin B (L-AmB); therefore, ISA is recommended as the first-line treatment for IA and IM. ISA can also achieve good efficacy in the treatment of invasive candidiasis (IC) and can be used as an alternative to de-escalation therapy after first-line drug therapy. In addition, most studies have shown the efficacy and safety of ISA for the prophylaxis of IFD.

Conclusion

Taken together, ISA are expected to become a new choice for the treatment and prevention of IFD because of their good tolerability, high bioavailability, and few drug interactions.

A Physiologically-Based Pharmacokinetic Model of Ruxolitinib and Posaconazole to Predict CYP3A4-Mediated Drug-Drug Interaction Frequently Observed in Graft versus Host Disease Patients

Ruxolitinib (RUX) is approved for the treatment of steroid-refractory acute and chronic graft versus host disease (GvHD). It is predominantly metabolized via cytochrome P450 (CYP) 3A4. As patients with GvHD have an increased risk of invasive fungal infections, RUX is frequently combined with posaconazole (POS), a strong CYP3A4 inhibitor. Knowledge of RUX exposure under concomitant POS treatment is scarce and recommendations on dose modifications are inconsistent. A physiologically based pharmacokinetic (PBPK) model was developed to investigate the drug-drug interaction (DDI) between POS and RUX. The predicted RUX exposure was compared to observed concentrations in patients with GvHD in the clinical routine. PBPK models for RUX and POS were independently set up using PK-Sim^® Version 11. Plasma concentration-time profiles were described successfully and all predicted area under the curve (AUC) values were within 2-fold of the observed values. The increase in RUX exposure was predicted with a DDI ratio of 1.21 (C_max) and 1.59 (AUC). Standard dosing in patients with GvHD led to higher RUX exposure than expected, suggesting further dose reduction if combined with POS. The developed model can serve as a starting point for further simulations of the implemented DDI and can be extended to further perpetrators of CYP-mediated PK-DDIs or disease-specific physiological changes.

A Review of Population Pharmacokinetic Models of Posaconazole

Posaconazole is often used for the prophylaxis and treatment of invasive fungal infections (IFI). However, intra- and inter-individual differences and drug interactions affect the efficacy and safety of posaconazole. Precision dosing of posaconazole based on the population pharmacokinetic (PopPK) model may assist in making significant clinical decisions. This review aimed to comprehensively summarize the published PopPK models of posaconazole and analyze covariates that significantly influence posaconazole exposure. Articles published until May 2022 for PopPK analysis of posaconazole were searched in PubMed and EMBASE databases. Demographic characteristics, model characteristics, and results of PopPK analysis were extracted from the selected articles. In addition, the steady-state pharmacokinetic profiles of posaconazole were simulated at different covariate levels and dosing regimens. Out of the 13 studies included in our review, nine studies included adults, three included children, and one included both adults and children. All oral administration models were one-compartment models, and all intravenous administration models were two-compartment models. Body weight, proton pump inhibitors, and incidence of diarrhea were found to be important covariates. Clinically, the potential impact of factors such as patient physiopathologic characteristics and comorbid medications on posaconazole pharmacokinetics should be considered. Dose adjustment in combination with TDM or replacement with a tablet or intravenous formulation with higher exposure may be an effective way to ensure drug efficacy as well as to reduce fungal resistance. Meanwhile, published models require further external evaluation to examine extrapolation.

Antifungal prophylactic effectiveness and intrapulmonary concentrations of voriconazole versus posaconazole in lung transplant recipients

Invasive fungal diseases (IFDs) are one of the leading causes of death in lung transplant recipients. This study aimed to compare the antifungal prophylactic effectiveness, intrapulmonary and plasma levels of voriconazole with posaconazole in lung transplant recipients. This retrospective cohort study analyzed adult recipients who underwent lung transplantation between June 2017 and December 2020. Voriconazole oral tablets or posaconazole oral suspension were used for prophylaxis against posttransplant IFD. Drug concentrations in bronchoalveolar lavage fluid (BALF) and plasma were measured by using liquid chromatography-mass spectrometry. The 182 recipients included 142 in the voriconazole group and 40 in the posaconazole group. The trough plasma levels were comparable between voriconazole and posaconazole (1.65 ± 0.09 vs. 1.69 ± 0.03 μg/ml, p = 0.55). However, the BALF levels were significantly higher for posaconazole than voriconazole (17.47 ± 11.51 vs. 0.56 ± 0.49 μg/ml, p < 0.001). There was no significant difference in the total incidence of breakthrough IFDs between the voriconazole and posaconazole groups (10.6% vs. 7.5%, p = 0.77). The intrapulmonary concentrations of posaconazole were significantly higher than voriconazole. The two agents had comparable antifungal prophylactic effectiveness.

Population pharmacokinetics of posaconazole in Chinese pediatric patients with acute leukaemia: effect of food on bioavailability and dose optimization

This study aimed to investigate the effect of food on the pharmacokinetics of posaconazole suspension in pediatric patients with acute leukaemia and to recommend optimal dosing strategies. This single-site, prospective, open-label, observational study was conducted in 42 patients and included 186 plasma concentrations of posaconazole. Sparse data were analyzed using population pharmacokinetic modeling. Monte Carlo simulations were conducted to predict the morning trough concentrations at steady-state with the proposed dose of 2-7 mg/kg three times daily (tid) or four times daily (qid) for bodyweights of 10-36 kg. The target concentrations were 700 ng/mL for prophylaxis and 1000 ng/mL for treatment. Dosage regimens with percentage of target attainment (PTA) ≥70% were recommended. A one-compartment model with allometric scaling adequately described the pharmacokinetic profile. The apparent clearance was 9.05 L/h (95% confidence interval [CI] 7.14-11.09) and the apparent volume of distribution was 283 L (95% CI 168-491) for a typical individual of 17.5 kg. The relative bioavailability with high-fat diet was as high as 1.95-fold compared with regular food. Following the intake of regular meals, 4 mg/kg qid was adequate with a PTA ≥ 71.8% for prophylaxis. A dosage of 6 mg/kg qid under a regular diet reached a PTA ≥ 73.4% for treatment. The recommended dosage of posaconazole for prophylaxis and treatment could be predicted by the pharmacokinetic model based on bodyweight and diet type in pediatric patients.

COVID-19-Associated Pulmonary Mucormycosis

COVID-19-associated mucormycosis (CAM) emerged as an epidemic in certain parts of the world amidst the global COVID-19 pandemic. While rhino–orbital mucormycosis was well reported during the pandemic, in the absence of routine diagnostic facilities including lower airway sampling, pulmonary mucormycosis was probably under-recognized. In this review, we have focused on the epidemiology and management of COVID-19-associated pulmonary mucormycosis (CAPM). CAPM is a deadly disease and mortality can be as high as 80% in the absence of early clinical suspicion and treatment. While histopathological examination of tissue for angio-invasion and cultures have remained gold standard for diagnosis, there is an increasing interest in molecular and serological methods to facilitate diagnosis in critically ill patients and often, immune-suppressed hosts who cannot readily undergo invasive sampling. Combined medical and surgical treatment offers more promise than standalone medical therapy. Maintaining adequate glycemic control and prudent use of steroids which can be a double-edged sword in COVID-19 patients are the key preventative measures. We would like to emphasize the urgent need for the development and validation of reliable biomarkers and molecular diagnostics to facilitate early diagnosis.

High-Dose Oral Posaconazole for the Treatment of Recalcitrant Fungal Keratitis

PURPOSE

To report the successful treatment of 3 cases of recalcitrant fungal keratitis (FK) with high-dose oral posaconazole.

METHODS

This is a series of 3 patients from a single academic center with a culture-positive FK who were treated with oral posaconazole after failing to respond to conventional treatments.

RESULTS

All 3 patients had a history of contact lens wear. Two of the 3 cases were culture positive for Fusarium and the other for Paecilomyces . The infections of all 3 failed to respond to conventional antifungal therapies including varying combinations of topical, systemic, and intraocular antifungal therapies. All 3 cases rapidly responded to high-dose oral posaconazole ranging from 500 to 600 mg once daily. In 1 case, multiple courses of high-dose therapy were required to treat delayed recurrences of a latent infection. There were no significant adverse effects with the elevated dose, and treatment was administered with the guidance of an infectious disease specialist.

CONCLUSIONS

In cases of recalcitrant FK failing to respond to conventional therapies, high-dose posaconazole, in the delayed-release tablet formulation, can be an effective treatment option.

Multicenter Registry of Patients Receiving Systemic Mold-Active Triazoles for the Management of Invasive Fungal Infections

Introduction

‘Real-world’ data for mold-active triazoles (MATs) in the treatment of invasive fungal infections (IFIs) are lacking. This study evaluated usage of MATs in a disease registry for the management of IFIs.

Methods

Data were collected for this multicenter, observational, prospective study from 55 US centers, between March 2017 and April 2020. Eligible patients received isavuconazole, posaconazole, or voriconazole as MAT monotherapy (one MAT) or multiple/sequenced MAT therapy (more than one MAT) for prophylaxis or treatment. Patients were enrolled within 60 days of MAT initiation. The primary objective was to characterize patients receiving a MAT and their patterns of therapy. The full analysis set (FAS) included eligible patients for the relevant enrollment protocol, and the safety analysis set (SAF) included patients who received ≥ 1 MAT dose.

Results

Overall, 2009 patients were enrolled in the SAF. The FAS comprised 1993 patients (510 isavuconazole; 540 posaconazole; 491 voriconazole; 452 multiple/sequenced MAT therapies); 816 and 1177 received treatment and prophylaxis at study index/enrollment, respectively. Around half (57.8%) of patients were male, and median age was 59 years. Among patients with IFIs during the study, the most common pathogens were Aspergillus fumigatus in the isavuconazole (18.2% [10/55]) and voriconazole (25.5% [12/47]) groups and Candida glabrata in the posaconazole group (20.9% [9/43]); the lungs were the most common infection site (58.2% [166/285]). Most patients were maintained on MAT monotherapy (77.3% [1541/1993]), and 79.4% (1520/1915) completed their MAT therapies. A complete/partial clinical response was reported in 59.1% (591/1001) of patients with a clinical response assessment. Breakthrough IFIs were reported in 7.1% (73/1030) of prophylaxis patients. Adverse drug reactions (ADRs) were reported in 14.7% (296/2009) of patients (3.9% [20/514] isavuconazole; 11.3% [62/547] posaconazole; 14.2% [70/494] voriconazole).

Conclusions

In this ‘real-world’ study, most patients remained on their initial therapy and completed their MAT therapy. Over half of patients receiving MATs for IFIs had a successful response, and most receiving prophylaxis did not develop breakthrough IFIs. ADRs were uncommon.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-022-00661-5.

Does the Freeze-Thaw Technique Affect the Properties of the Alginate/Chitosan Glutamate Gels with Posaconazole as a Model Antifungal Drug?

Hydrogels are semi-solid systems with high flexibility, which, due to holding large amounts of water, are similar to natural tissues and are very useful in the field of biomedical applications. Despite the wide range of polymers available to form hydrogels, novel techniques utilized to obtain hydrogels with adequate properties are still being developed. The aim of this study was to evaluate the impact of the freeze–thaw technique on the properties of cryogels based on sodium alginate and chitosan glutamate with posaconazole as a model antifungal substance. The effect of the freezing and thawing process on the physicochemical, rheological, textural and bioadhesive properties of prepared cryogels was examined. Additionally, the antifungal activity against Candida albicans, Candida parapsilosis and Candida krusei of designed formulations was examined. It was shown that the freeze–thaw technique significantly improved viscosity, bioadhesiveness, textural properties and prolonged the in vitro posaconazole release. Moreover, alginate/chitosan glutamate cryogels exhibited higher values of inhibition zone in C. parapsilosis culture than traditional hydrogel formulations.

In Vitro Activity of Nitroxoline in Antifungal-Resistant Candida Species Isolated from the Urinary Tract

Infections by drug-resistant fungi are increasingly reported worldwide; however, only few novel antifungals are being developed. The old antimicrobial nitroxoline is currently repurposed for oral treatment of bacterial urinary tract infections (UTI). Previously, antifungal activity has been demonstrated and in contrast to many antifungals nitroxoline reaches high urinary concentrations. In this study, the activity of nitroxoline was assessed in vitro in a collection of yeasts from the German National Reference Centre for Invasive Fungal Infections. Susceptibility was determined by broth microdilution (BMD) and disk diffusion (DD). The collection comprised 45 Candida isolates originating from the urinary tract. MICs of amphotericin, anidulafungin and azoles were analyzed using EUCAST BMD. Among the collection isolates, resistance to antifungals was common, e.g., for fluconazole the MIC_50/90 was 16/>64 mg/L; in contrast MIC_50/90 of nitroxoline was 2/2 mg/L (MIC range 0.25-4 mg/L), which is at least two dilutions below the EUCAST breakpoint for uncomplicated UTI defined for E. coli (susceptible ≤ 16mg/L). Activity of nitroxoline was high irrespective of resistance to other agents. As BMD is labor-intensive, DD was investigated as an alternative method using three different agars. Nitroxoline disks produced large inhibition zones on all agars (≥19mm), but the correlation of MICs and zone diameters was low, with the highest correlation recorded for the CLSI recommended agar for antifungal DD (Pearson's r = -0,52). In conclusion, isolates of different Candida species are highly susceptible to nitroxoline, which could be a promising antimicrobial to treat candiduria caused by multidrug resistant yeasts.

Active Surveillance Program to Increase Awareness on Invasive Fungal Diseases: the French RESSIF Network (2012 to 2018)

The French National Reference Center for Invasive Mycoses and Antifungals leads an active and sustained nationwide surveillance program on probable and proven invasive fungal diseases (IFDs) to determine their epidemiology in France. Between 2012 and 2018, a total of 10,886 IFDs were recorded. The incidence increased slightly over time (2.16 to 2.36/10,000 hospitalization days, P = 0.0562) in relation with an increase of fungemia incidence (1.03 to 1.19/10,000, P = 0.0023), while that of other IFDs remained stable. The proportion of ≥65-year-old patients increased from 38.4% to 45.3% (P < 0.0001). Yeast fungemia (n = 5,444) was due mainly to Candida albicans (55.6%) with stable proportions of species over time. Echinocandins became the main drug prescribed (46.7% to 61.8%), but global mortality rate remained unchanged (36.3% at 1 month). Pneumocystis jirovecii pneumonia (n = 2,106) was diagnosed mostly in HIV-negative patients (80.7%) with a significantly higher mortality than in HIV-positive patients (21.9% versus 5.4% at 1 month, P < 0.0001). Invasive aspergillosis (n = 1,661) and mucormycosis (n = 314) were diagnosed mostly in hematology (>60% of the cases) with a global mortality rate of 42.5% and 59.3%, respectively, at 3 months and significant changes in diagnosis procedure over time. More concurrent infections were also diagnosed over time (from 5.4% to 9.4% for mold IFDs, P = 0.0115). In conclusion, we observed an aging of patients with IFD with a significant increase in incidence only for yeast fungemia, a trend toward more concurrent infections, which raises diagnostic and therapeutic issues. Overall, global survival associated with IFDs has not improved despite updated guidelines and new diagnostic tools.

Definition, diagnosis, and management of COVID-19-associated pulmonary mucormycosis: Delphi consensus statement from the Fungal Infection Study Forum and Academy of Pulmonary Sciences, India

COVID-19-associated pulmonary mucormycosis (CAPM) remains an underdiagnosed entity. Using a modified Delphi method, we have formulated a consensus statement for the diagnosis and management of CAPM. We selected 26 experts from various disciplines who are involved in managing CAPM. Three rounds of the Delphi process were held to reach consensus (≥70% agreement or disagreement) or dissensus. A consensus was achieved for 84 of the 89 statements. Pulmonary mucormycosis occurring within 3 months of COVID-19 diagnosis was labelled CAPM and classified further as proven, probable, and possible. We recommend flexible bronchoscopy to enable early diagnosis. The experts proposed definitions to categorise dual infections with aspergillosis and mucormycosis in patients with COVID-19. We recommend liposomal amphotericin B (5 mg/kg per day) and early surgery as central to the management of mucormycosis in patients with COVID-19. We recommend response assessment at 4–6 weeks using clinical and imaging parameters. Posaconazole or isavuconazole was recommended as maintenance therapy following initial response, but no consensus was reached for the duration of treatment. In patients with stable or progressive disease, the experts recommended salvage therapy with posaconazole or isavuconazole. CAPM is a rare but under-reported complication of COVID-19. Although we have proposed recommendations for defining, diagnosing, and managing CAPM, more extensive research is required.