Pharmacokinetic/pharmacodynamic profile of voriconazole

Mass spectrometric methods for evaluation of voriconazole avian pharmacokinetics and the inhibition of its cytochrome P450-induced metabolism

Invasive fungal aspergillosis is a leading cause of morbidity and mortality in many species including avian species such as common ravens (Corvus corax). Methods were developed for mass spectral determination of voriconazole in raven plasma as a means of determining pharmacokinetics of this antifungal agent. Without further development, GC/MS/MS (gas chromatography-tandem quadrupole mass spectrometry) proved to be inferior to LC/MS/MS (liquid chromatography-tandem quadrupole mass spectrometry) for measurement of voriconazole levels in treated raven plasma owing to numerous heat-induced breakdown products despite protection of voriconazole functional groups with trimethylsilyl moieties. LC/MS/MS measurement revealed in multi-dosing experiments that the ravens were capable of rapid or ultrarapid metabolism of voriconazole. This accounted for the animals' inability to raise the drug into the therapeutic range regardless of dosing regimen unless cytochrome P450 (CYP) inhibitors were included. Strategic selection of CYP inhibitors showed that of four selected compounds including cimetidine, enrofloxacin and omeprazole, only ciprofloxacin (Cipro) was able to maintain voriconazole levels in the therapeutic range until the end of the dosing period. The optimal method of administration involved maintenance doses of voriconazole at 6 mg/kg and ciprofloxacin at 20 mg/kg. Higher doses of voriconazole such as 18 mg/kg were also tenable without apparent induction of toxicity. Although most species employ CYP2C19 to metabolize voriconazole, it was necessary to speculate that voriconazole might be subject to metabolism by CYP1A2 in the ravens to explain the utility of ciprofloxacin, a previously unknown enzymatic route. Finally, despite its widespread catalog of CYP inhibitions including CYP1A2 and CYP2C19, cimetidine may be inadequate at enhancing voriconazole levels owing to its known effects on raising gastric pH, a result that may limit voriconazole solubility.

Silver(I) complexes with voriconazole as promising anti-Candida agents

Recognizing that metal ions play an important role in modifying the pharmacological properties of known organic-based drugs, the present manuscript addresses the complexation of the antifungal agent voriconazole (vcz) with the biologically relevant silver(I) ion as a strategy for the development of new antimycotics. The synthesized silver(I) complexes with vcz were characterized by mass spectrometry, IR, UV-Vis and NMR spectroscopy and single-crystal X-ray diffraction analysis. The crystallographic results showed that complexes {[Ag(vcz)(H2O)]CH3SO3}n (1), {[Ag(vcz)2]BF4}n (2) and {[Ag(vcz)2]PF6}n (3) have polymeric structures in the solid state, in which silver(I) ions have a distorted tetrahedral geometry. On the other hand, DFT calculations revealed that the investigated silver(I) complexes 1-3 in DMSO exist as linear [Ag(vcz-N2)(vcz-N19)]+ (1a), [Ag(vcz-N2)(vcz-N4)]+ (2a) and [Ag(vcz-N4)2]+ (3a) species, respectively. The evaluated complexes showed an enhanced anti-Candida activity compared to the parent drug with minimal inhibitory concentration (MIC) values in the range of 0.02-1.05 μM. In comparison with vcz, the corresponding silver(I) complexes showed better activity in prevention hyphae and biofilm formation of C. albicans, indicating that they could be considered as promising agents against Candida that significantly inhibit its virulence. Also, these complexes are much better inhibitors of ergosterol synthesis in the cell membrane of C. albicans at the concentration of 0.5 × MIC. This is also confirmed by a molecular docking, which revealed that complexes 1a - 3a showed better inhibitory activity than vcz against the sterol 14α-demethylase enzyme cytochrome P450 (CYP51B), which plays a crucial role in the formation of ergosterol.

Effectiveness and safety of the simulation-based first-dose design of voriconazole

BACKGROUND

We investigated whether the initial voriconazole (VRCZ) dosing design, as determined using simulation software with a population pharmacokinetic model of Japanese patients, impacts the effectiveness and safety when compared with VRCZ initiation according to the package insert.

METHODS

In this single-center retrospective observational study, we employed records from Tosei General Hospital (a 633-bed hospital), dated April 2017 to September 2023. Eligible patients were divided into the software-based simulation group, comprising patients administered initial VRCZ dosage adjustment by pharmacists using software-based simulation, and the standard therapy group, whose dosage was administered by a physician following the package insert recommendations without simulation. The primary objective of this study was to determine the efficacy of VRCZ first-dose design in reducing the incidence of hepatotoxicity and visual symptoms.

RESULTS

The median ages of enrolled participants (n = 93) were 75 (68-79) and 72 (65-78) years in the software-based simulation and standard therapy groups, respectively. Regardless of formulation, initial trough concentrations were lower in the VRCZ software-based first dosage adjustment group and higher rate within the appropriate range (1-4 μg/mL). The incidence of all-grade hepatotoxicity or visual symptoms was significantly lower in the software-based simulation group. The log-rank test revealed a significant impact on the occurrence of ≥grade 2 hepatotoxicity in the software-based first dosage adjustment group compared to that in the standard therapy group.

CONCLUSIONS

The initial VRCZ dosing design using simulation software improved the achievement of appropriate initial trough concentrations and resulted in fewer occurrences of hepatotoxicity (≥grade 2) when compared with the standard therapy.

Pharmacogenetic implementation for CYP2C19 and pharmacokinetics of voriconazole in children with malignancy or inborn errors of immunity

BACKGROUND

Voriconazole pharmacokinetics (PK) are known to be affected by genetic polymorphisms of drug-metabolizing enzymes such as CYP2C19; however, such information is limited for the pediatric population. The primary aim of this study is to establish a voriconazole PK model incorporating CYP2C19 phenotypes in Japanese children with malignancy or inborn errors of immunity.

METHODS

CYP2C19 genotypes were assessed by whole-genome genotyping and defined as follows: *17/*17: ultrarapid metabolizer (URM), *1/*17: rapid metabolizer (RM), *1/*1:normal metabolizer (NM), *1/*2, *1/*3, *2/*17:intermediate metabolizer (IM), and *2/*2, *2/*3, *3/*3: poor metabolizer (PM). Population PK analysis was performed. The voriconazole serum concentration profile was described by a two-compartment model with first-order absorption, mixed linear and nonlinear (Michaelis-Menten) elimination.

RESULTS

Voriconazole concentration data were available from 60 patients with a median age of 5.3 years. The phenotypes predicted from CYP2C19 genotypes were RM in 1 (2 %), NM in 21 (35 %) patients, IM in 27 (45 %) patients, and PM in 11 (18 %) patients. Underlying diseases included 38 (63%) patients with hematological malignancy and 18 (30 %) patients with inborn errors of immunity. Among the CYP2C19 phenotypes, PM was predicted to show complete inhibition (the degree of Vmax inhibition [Vmax, inh] = 100 %; Vmax = 0). The estimated parameters of Vmax,inh were +0.8 higher in patients with gamma-glutamyl transpeptidase (γ-GTP) Grade 2 or higher and +2.7 higher when C-reactive protein (CRP) levels were 2.0 mg/dL or higher.

CONCLUSION

CYP2C19 genetic polymorphisms, γ-GTP, and CRP affect Vmax,inh of voriconazole in children with malignancy or inborn errors of immunity.

Evaluation of Anticholinesterase Activity of the Fungicides Mefentrifluconazole and Pyraclostrobin

Triazoles are compounds with various biological activities, including fungicidal action. They became popular through cholinesterase studies after the successful synthesis of the dual binding femtomolar triazole inhibitor of acetylcholinesterase (AChE, EC 3.1.1.7) by Sharpless et al. via in situ click chemistry. Here, we evaluate the anticholinesterase effect of the first isopropanol triazole fungicide mefentrifluconazole (Ravystar®), developed to overcome fungus resistance in plant disease management. Mefentrifluconazole is commercially available individually or in a binary fungicidal mixture, i.e., with pyraclostrobin (Ravycare®). Pyraclostrobin is a carbamate that contains a pyrazole ring. Carbamates are known inhibitors of cholinesterases and the carbamate rivastigmine is already in use for the treatment of Alzheimer's disease. We tested the type and potency of anticholinesterase activity of mefentrifluconazole and pyraclostrobin. Mefentrifluconazole reversibly inhibited human AChE and BChE with a seven-fold higher potency toward AChE (Ki = 101 ± 19 μM). Pyraclostrobin (50 μM) inhibited AChE and BChE progressively with rate constants of (t1/2 = 2.1 min; ki = 6.6 × 103 M-1 min-1) and (t1/2 = 1.5 min; ki = 9.2 × 103 M-1 min-1), respectively. A molecular docking study indicated key interactions between the tested fungicides and residues of the lipophilic active site of AChE and BChE. Additionally, the physicochemical properties of the tested fungicides were compared to values for CNS-active drugs to estimate the blood-brain barrier permeability. Our results can be applied in the design of new molecules with a lesser impact on humans and the environment.

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.

Updated antimicrobial dosing recommendations for obese patients

The prevalence of obesity has increased considerably in the last few decades. Pathophysiological changes in obese patients lead to pharmacokinetic (PK) and pharmacodynamic (PD) alterations that can condition the correct exposure to antimicrobials if standard dosages are used. Inadequate dosing in obese patients can lead to toxicity or therapeutic failure. In recent years, additional antimicrobial PK/PD data, extended infusion strategies, and studies in critically ill patients have made it possible to obtain data to provide a better dosage in obese patients. Despite this, it is usually difficult to find information on drug dosing in this population, which is sometimes contradictory. This is a comprehensive review of the dosing of different types of antimicrobials (antibiotics, antifungals, antivirals, and antituberculosis drugs) in obese patients, where the literature on PK and possible dosing strategies in obese adults was critically assessed.

Combined impact of hypoalbuminemia and pharmacogenomic variants on voriconazole trough concentration: data from a real-life clinical setting in the Chinese population

Voriconazole (VRC) displays highly variable pharmacokinetics impacting treatment efficacy and safety. To provide evidence for optimizing VRC therapy regimens, the authors set out to determine the factors impacting VRC steady-state trough concentration (Cmin) in patients with various albumin (Alb) level. A total of 275 blood samples of 120 patients and their clinical characteristics and genotypes of CYP2C19, CYP3A4, CYP3A5, CYP2C9, FMO3, ABCB1, POR, NR1I2 and NR1I3 were included in this study. Results of multivariate linear regression analysis demonstrated that C-reactive protein (CRP) and total bilirubin (T-Bil) were predictors of the VRC Cmin adjusted for dose in patients with hypoalbuminemia (Alb < 35 g/L) (R2 = 0.16, P < 0.001). Additionally, in patients with normal albumin level (Alb ≥ 35 g/L), it resulted in a significant model containing factors of the poor metabolizer (PM) CYP2C19 genotype and CRP level (R2 = 0.26, P < 0.001). Therefore, CRP and T-Bil levels ought to receive greater consideration than genetic factors in patients with hypoalbuminemia.

Impact of CYP2C19, CYP2C9, CYP3A4, and FMO3 Genetic Polymorphisms and Sex on the Pharmacokinetics of Voriconazole after Single and Multiple Doses in Healthy Chinese Subjects

Voriconazole is the first-line treatment for invasive aspergillosis. Its pharmacokinetics exhibit considerable inter- and intra-individual variability. The purpose of this study was to investigate the effects of CYP2C19, CYP2C9, CYP3A4, and FMO3 genetic polymorphisms and sex on the pharmacokinetics of voriconazole in healthy Chinese adults receiving single-dose and multiple-dose voriconazole, to provide a reference for its clinical individualized treatment. A total of 123 healthy adults were enrolled in the study, with 108 individuals and 15 individuals in the single-dose and multiple-dose doses, respectively. Plasma voriconazole concentrations were measured using a validated LC-MS/MS method, and pharmacokinetics parameters were calculated using the non-compartmental method with WinNonlin 8.2. CYP2C19, CYP2C9, CYP3A4, and FMO3 single-nucleotide polymorphisms were sequenced using the Illumina Hiseq X-Ten platform. The results suggested that CYP2C19 genetic polymorphisms significantly affected the pharmacokinetics of voriconazole at single doses of 4, 6, and 8 mg/kg and multiple doses of voriconazole. CYP3A4 rs2242480 had a significant effect on AUC0-∞ (area under the plasma concentration-time curve from time 0 to infinity) and MRT (mean residence time) of voriconazole at a single dose of 4 mg/kg in CYP2C19 extensive metabolizer. Regardless of the CYP2C19 genotype, CYP2C9 rs1057910 and FMO3 rs2266780 were not associated with the pharmacokinetics of voriconazole at three single-dose levels or multiple doses. No significant differences in most voriconazole pharmacokinetics parameters were noted between male and female participants after single and multiple dosing. For patients receiving voriconazole treatment, CYP2C19 genetic polymorphisms should be genotyped for its precision administration. In contrast, based on our study of healthy Chinese adults, it seems unnecessary to consider the effects of CYP2C9, CYP3A4, and FMO3 genetic polymorphisms on voriconazole pharmacokinetics.

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.

Physiologically based pharmacokinetic modeling to predict the clinical effect of azole antifungal agents as CYP3A inhibitors on azelnidipine pharmacokinetics

In this study, a physiologically based pharmacokinetic (PBPK) model of the cytochrome P450 3A (CYP3A) substrate azelnidipine was developed using in vitro and clinical data to predict the effects of azole antifungals on azelnidipine pharmacokinetics. Modeling and simulations were conducted using the Simcyp™ PBPK simulator. The azelnidipine model consisted of a full PBPK model and a first-order absorption model. CYP3A was assumed as the only azelnidipine elimination route, and CYP3A clearance was optimized using the pharmacokinetic profile of single-dose 5-mg azelnidipine in healthy participants. The model reproduced the results of a clinical drug-drug interaction study and met validation criteria. PBPK model simulations using azole antifungals (itraconazole, voriconazole, posaconazole, fluconazole, fosfluconazole) and azelnidipine or midazolam (CYP3A index substrate) were performed. Increases in the simulated area under the plasma concentration-time curve from time zero extrapolated to infinity with inhibitors were comparable between azelnidipine (range, 2.11-6.47) and midazolam (range, 2.26-9.22), demonstrating that azelnidipine is a sensitive CYP3A substrate. Increased azelnidipine plasma concentrations are expected when co-administered with azole antifungals, potentially affecting azelnidipine safety. These findings support the avoidance of azole antifungals in patients taking azelnidipine and demonstrate the utility of PBPK modeling to inform appropriate drug use.

Factors influencing voriconazole plasma level in intensive care patients

Background

In clinical routine, voriconazole plasma trough levels (Cmin) out of target range are often observed with little knowledge about predisposing influences.

Objectives

To determine the distribution and influencing factors on voriconazole blood levels of patients treated on intensive- or intermediate care units (ICU/IMC).

Patients and methods

Data were collected retrospectively from patients with at least one voriconazole trough plasma level on ICU/IMC (n = 153) to determine the proportion of sub-, supra- or therapeutic plasma levels. Ordinal logistic regression analysis was used to assess factors hindering patients to reach voriconazole target range.

Results

Of 153 patients, only 71 (46%) reached the target range at the first therapeutic drug monitoring, whereas 66 (43%) patients experienced too-low and 16 (10%) too-high plasma levels. Ordinal logistic regression analysis identified the use of extra corporeal membrane oxygenation (ECMO), low international normalized ratio (INR) and aspartate-aminotransferase (AST) serum levels as predictors for too-low plasma levels.

Conclusion

Our data highlight an association of ECMO, INR and AST levels with voriconazole plasma levels, which should be considered in the care of critically ill patients to optimize antifungal therapy with voriconazole.

Standardization and validation of a high-efficiency liquid chromatography with a diode-array detector (HPLC-DAD) for voriconazole blood level determination

INTRODUCTION

A specialized service for antifungal blood level determination is not available in Colombia. This service is essential for the proper follow-up of antifungal therapies.

OBJECTIVE

To standardize and validate a simple, sensitive, and specific protocol based on high-performance liquid chromatography with a diode array detector for voriconazole blood level quantification.

MATERIALS AND METHODS

We used an Agilent HPLC™ series-1200 equipment with a UVdiode array detector with an analytical column Eclipse XDB-C18 and pre-column Eclipse- XDB-C18 (Agilent). We used voriconazole as the primary control and posaconazole as an internal control. We performed the validation following the Food and Drug Administration (FDA) recommendations.

RESULTS

The best chromatographic conditions were: Column temperature of 25°C, UV variable wavelength detection at 256 nm for voriconazole and 261 nm for posaconazole (internal standard); 50 μl of injection volume, 0,8 ml/min volume flow, 10 minutes of run time, and mobile phase of acetonitrile:water (60:40). Finally, retention times were 3.13 for voriconazole and 5.16 minutes for posaconazole. Quantification range varied from 0.125 μg/ml to 16 μg/ml.

CONCLUSION

The selectivity and chromatographic purity of the obtained signal, the detection limits, and the standardized quantification make this method an excellent tool for the therapeutic monitoring of patients treated with voriconazole.

Therapeutic Drug Monitoring of Voriconazole in Patients with End-Stage Liver Disease

BACKGROUND

This study aimed to identify the factors that influence voriconazole (VCZ) plasma concentrations and optimize the doses of VCZ in patients with end-stage liver disease (ESLD).

METHODS

Patients with ESLD who received a VCZ maintenance dose of 100 mg twice daily (group A, n = 57) or the VCZ maintenance dose of 50 mg twice daily (group B, n = 37), orally or intravenously, were enrolled in this study. Trough plasma concentrations (Cmin) of VCZ between 1 and 5 mg/L were considered within the therapeutic target range.

RESULTS

The VCZ Cmin was determined in 94 patients with ESLD. The VCZ Cmin of patients in group A was remarkably higher than those in group B (4.85 ± 2.53 mg/L vs 2.75 ± 1.40 mg/L; P < 0.001). Compared with group A, fewer patients in group B had VCZ Cmin outside the therapeutic target (23/57 vs. 6/37, P = 0.021). Univariate and multivariate analyses suggested that both body weight and Model for End-Stage Liver Disease scores were closely associated with the VCZ Cmin in group B.

CONCLUSIONS

These data indicate that dose optimization based on body weight and Model for End-Stage Liver Disease scores is required to strike an efficacy-safety balance during VCZ treatment in patients with ESLD.

Population pharmacokinetics and covariate-based dosing individualization of voriconazole in lung transplant recipients

This study aimed to explore pharmacokinetics of voriconazole and its covariates in lung transplant recipients using population approach in order to propose dosing individualization. Data from routine therapeutic drug monitoring in adult lung transplant recipients treated with oral voriconazole were analysed with a three-stage population pharmacokinetic model using nonlinear mixed-effects modelling. Monte Carlo simulations based on final voriconazole pharmacokinetic model were used to generate the theoretical distribution of pharmacokinetic profiles at various dosing regimens. A total of 78 voriconazole serum concentrations collected from 40 patients were included in pharmacokinetic analysis. The only significant covariate was age for voriconazole clearance. Population voriconazole apparent clearance started at 32.26 L/h and decreased by 0.021 L/h with each year of patient's age, while population apparent volume of distribution was 964.46 L. Based on this model, we have proposed an easy-to-use dosing regimen consisting of a loading dose of 400 mg every 12 h for the first 48 h of treatment followed by maintenance dose of 300 mg every 12 h in patients aged up to 59 years, or by maintenance dose of 200 mg every 12 h in patients aged above 59 years.

Voriconazole plus flucytosine is not superior to amphotericin B deoxycholate plus flucytosine as an induction regimen for cryptococcal meningitis treatment

BACKGROUND

The efficacy and side effects of voriconazole plus 5-flucytosine (Vori + 5-FC) versus amphotericin B deoxycholate plus 5-flucytosine (AmBd + 5-FC) as an induction treatment for cryptococcal meningitis are unknown.

METHODS

Forty-seven patients treated with Vori + 5-FC and 92 patients treated with AmBd + 5-FC were included in the current study after propensity score matching (PSM) at a ratio of 1:2. Two-week laboratory test results and 90-day mortality were compared between the two groups.

RESULTS

After 2 weeks of induction treatment, the CSF Cryptococcus sterile culture rate was 57.1% in the Vori + 5-FC group and 76.5% in the AmBd + 5-FC group (p = .026). No difference was found in the normalization of CSF indicators (glucose, total protein, intracranial pressure and India ink sterile rate) between the two groups. Both the Vori + 5FC regimen and AmBd + 5-FC regimen obviously decreased haemoglobin concentrations, platelet counts and serum potassium levels (all p ≤ .010). Notably, the Vori + 5FC regimen did not influence serum creatinine levels (p = .263), while AmBd + 5FC increased serum creatinine levels (p = .019) after 2-week induction treatment. The Vori + 5-FC group and AmBd + 5-FC group had similar 90-day cumulative survival rates (89.9% vs. 87.8%, p = .926).

CONCLUSION

The Vori + 5-FC regimen was associated with low 2-week CSF sterile culture and was not superior to AmBd + 5-FC as induction therapy in terms of the 90-day cumulative survival rate of CM patients.

Myelodysplastic syndrome-like response after voriconazole treatment of systemic lupus erythematosus complicated with fungal infection: a case report

Background

Voriconazole is mainly used to treat progressive and potentially life-threatening infections in immunocompromised patients. The adverse drug reactions related to voriconazole are varied. In some rare cases, the use of voriconazole can result in myelodysplastic syndrome (MDS)-like adverse reactions.

Case presentation

Here, we present a rare case of systemic lupus erythematosus patient with a fungal infection that developed MDS-like adverse reactions after treatment with voriconazole. The patient was admitted to the hospital because of 3 days of chest tightness and dyspnea. After the admission, the patient's sputum culture showed Candida albicans infection, and voriconazole was prescribed to be taken orally. After using voriconazole, drug-related adverse reactions such as visual impairment, nausea, vomiting, hiccup, middle and lower abdominal pain, disorders of consciousness, delirium, hallucination, slow response, and subcutaneous ecchymosis appeared, as well as the gradually increased serum creatinine, oliguria, and aggravated lower limb edema. In addition, there was a decrease in peripheral blood cells, and MDS-like changes in bone marrow were indicated by bone marrow biopsy. After discontinuing voriconazole, drug-related adverse symptoms disappeared, and hematocytopenia and the changes in MDS were significantly improved, which was confirmed by a subsequent bone marrow puncture at a 6 months interval.

Conclusion

This case reminded us that when using voriconazole for treatment, individual differences in patients should be considered, and the blood concentration of voriconazole should be closely monitored. Otherwise, potential drugs that affect voriconazole metabolism should be noted, and related adverse symptoms of patients should be closely observed during medication to reduce the occurrence of adverse drug events.

Optimal timing for therapeutic drug monitoring of voriconazole to prevent adverse effects in Japanese patients

BACKGROUND

The optimal timing for therapeutic drug monitoring (TDM) of voriconazole in Asians, who have higher rates of poor metabolisers than non-Asians, is unclear. This can cause unexpectedly high concentrations and delays in reaching steady-state levels.

OBJECTIVES

To determine the appropriate timing of TDM in Japanese patients receiving voriconazole.

PATIENTS/METHODS

Trough levels (Cmin ) were measured on days 3-5 (recommended timing, RT) and days 6-14 (delayed timing, DT) after starting voriconazole in patients receiving an appropriate dosage. Considering bioavailability, Cmin was only compared in patients receiving oral voriconazole.

RESULTS

A total of 289 and 186 patients were included in the safety and pharmacokinetic analyses, respectively. There was a significant difference in Cmin measured no later than and after day 5 (3.59 ± 2.12 [RT] vs. 4.77 ± 3.88 μg/mL [DT], p = .023), whereas no significant difference was observed on cutoff day 6 (3.91 ± 2.60 vs. 4.40 ± 3.94 μg/mL, p = .465), suggesting that Cmin close to the steady-state was achieved after day 5. DT causes a delay in achieving the therapeutic range. The hepatotoxicity rates were 21.5% and 36.8% in the RT and DT groups, respectively (p = .004); DT was an independent risk factor for hepatotoxicity.

CONCLUSION

Although steady-state concentrations may not be achieved by day 5, early dose optimisation using RT can prevent hepatotoxicity in Japanese patients. TDM should be performed on days 3-5 to ensure safety. However, subsequent TDM may be necessary due to a possible further increase in Cmin .

Pharmacogenetic and clinical predictors of voriconazole concentration in hematopoietic stem cell transplant recipients receiving CYP2C19-guided dosing

CYP2C19-guided voriconazole dosing reduces pharmacokinetic variability, but many patients remain subtherapeutic. The aim of this study was to evaluate the effect of candidate genes and a novel CYP2C haplotype on voriconazole trough concentrations in patients receiving CYP2C19-guided dosing. This is a retrospective candidate gene study in allogeneic hematopoietic cell transplant (HCT) patients receiving CYP2C19-guided voriconazole dosing. Patients were genotyped for ABCB1, ABCG2, CYP2C9, CYP3A4, CYP3A5, and the CYP2C haplotype. Of 185 patients, 36% were subtherapeutic (of which 79% were normal or intermediate metabolizers). In all patients, CYP2C19 (p < 0.001), age (p = 0.018), and letermovir use (p = 0.001) were associated with voriconazole concentrations. In the subset receiving 200 mg daily (non-RM/UMs), CYP2C19 (p = 0.004) and ABCG2 (p = 0.015) were associated with voriconazole concentrations; CYP2C19 (p = 0.028) and letermovir use (p = 0.001) were associated with subtherapeutic status. CYP2C19 phenotype and letermovir use were significantly associated with subtherapeutic voriconazole concentrations and may be used to improve voriconazole precision dosing, while further research is needed to clarify the role of ABCG2 in voriconazole dosing.

Septic Obturation of a Knee Endoprosthesis Caused by Aspergillus clavatus

Aspergillus clavatus is a rare opportunistic fungal pathogen that can be isolated from various environmental sources, including soil and animal feces. Although infrequent, infections caused by A. clavatus can be severe in immunocompromised patients. Here, we present a case of a prosthetic joint infection (PJI) in a 74-year-old female patient caused by A. clavatus. The patient presented with left knee pain, and septic loosening of the left knee endoprosthesis was diagnosed. She underwent surgical revision with the implantation of an antibiotic spacer and microbiologic testing. The results came back positive for both Staphylococcus lugdunensis and A. clavatus (which is found in only a fraction of a percent of PJIs). She was treated with oral antimicrobials for 3 months postoperatively. This case report vividly illustrates a clinical scenario that underscores the significance of rigorous microbiologic testing procedures, accurate pathogen identification, unwavering vigilance in testing protocols, and a cautious approach that avoids succumbing to the seductive simplicity of Occam's razor.

Voriconazole-induced psychosis in rhino-orbital invasive aspergillosis

Aspergillosis is a challenging fungal infection. Voriconazole is an antifungal drug belonging to the triazole group, commonly used for treating invasive aspergillosis, Cryptococcus neoformans and candida infections. We present a case of a man in his late 70s diagnosed with rhino-orbital invasive aspergillosis who developed voriconazole-induced psychosis as an idiosyncratic, adverse drug reaction (ADR); however, he responded to the cessation of intravenous voriconazole and, after starting on an oral antipsychotic, haloperidol. Clinicians need to be cognizant of this rare, idiosyncratic and iatrogenic ADR to voriconazole.

Towards Model-Informed Precision Dosing of Voriconazole: Challenging Published Voriconazole Nonlinear Mixed-Effects Models with Real-World Clinical Data

BACKGROUND AND OBJECTIVES

Model-informed precision dosing (MIPD) frequently uses nonlinear mixed-effects (NLME) models to predict and optimize therapy outcomes based on patient characteristics and therapeutic drug monitoring data. MIPD is indicated for compounds with narrow therapeutic range and complex pharmacokinetics (PK), such as voriconazole, a broad-spectrum antifungal drug for prevention and treatment of invasive fungal infections. To provide guidance and recommendations for evidence-based application of MIPD for voriconazole, this work aimed to (i) externally evaluate and compare the predictive performance of a published so-called 'hybrid' model for MIPD (an aggregate model comprising features and prior information from six previously published NLME models) versus two 'standard' NLME models of voriconazole, and (ii) investigate strategies and illustrate the clinical impact of Bayesian forecasting for voriconazole.

METHODS

A workflow for external evaluation and application of MIPD for voriconazole was implemented. Published voriconazole NLME models were externally evaluated using a comprehensive in-house clinical database comprising nine voriconazole studies and prediction-/simulation-based diagnostics. The NLME models were applied using different Bayesian forecasting strategies to assess the influence of prior observations on model predictivity.

RESULTS

The overall best predictive performance was obtained using the aggregate model. However, all NLME models showed only modest predictive performance, suggesting that (i) important PK processes were not sufficiently implemented in the structural submodels, (ii) sources of interindividual variability were not entirely captured, and (iii) interoccasion variability was not adequately accounted for. Predictive performance substantially improved by including the most recent voriconazole observations in MIPD.

CONCLUSION

Our results highlight the potential clinical impact of MIPD for voriconazole and indicate the need for a comprehensive (pre-)clinical database as basis for model development and careful external model evaluation for compounds with complex PK before their successful use in MIPD.

Treatment of Invasive Aspergillosis: How It's Going, Where It's Heading

Despite improvements in treatment and diagnostics over the last two decades, invasive aspergillosis (IA) remains a devastating fungal disease. The number of immunocompromised patients and hence vulnerable hosts increases, which is paralleled by the emergence of a rise in IA cases. Increased frequencies of azole-resistant strains are reported from six continents, presenting a new challenge for the therapeutic management. Treatment options for IA currently consist of three classes of antifungals (azoles, polyenes, echinocandins) with distinctive advantages and shortcomings. Especially in settings of difficult to treat IA, comprising drug tolerance/resistance, limiting drug-drug interactions, and/or severe underlying organ dysfunction, novel approaches are urgently needed. Promising new drugs for the treatment of IA are in late-stage clinical development, including olorofim (a dihydroorotate dehydrogenase inhibitor), fosmanogepix (a Gwt1 enzyme inhibitor), ibrexafungerp (a triterpenoid), opelconazole (an azole optimized for inhalation) and rezafungin (an echinocandin with long half-life time). Further, new insights in the pathophysiology of IA yielding immunotherapy as a potential add-on therapy. Current investigations show encouraging results, so far mostly in preclinical settings. In this review we discuss current treatment strategies, give an outlook on possible new pharmaceutical therapeutic options, and, lastly, provide an overview of the ongoing research in immunotherapy for IA.

Pharmacokinetics in Penguins Compared to Other Avian Species: A Review of Enrofloxacin and Voriconazole

Australasia is home to unique and endangered avian species. Drug administration to this group of animal patients for prophylaxis and treatment is challenging from a number of different perspectives. A key limitation for optimal drug dosing in birds is the lack of published pharmacokinetic studies to guide dose requirements. The aim of this review was to systematically investigate published literature on pharmacokinetics in penguin species and compare that with the pharmacokinetics of other avian species with a focus on two drugs: enrofloxacin and voriconazole. The review was conducted following PRISMA guidelines. A systematic literature search was performed in Pubmed, Embase, Scopus, and Web of Science databases. A key finding is that penguin pharmacokinetics differs from other avian species, with weight-adjusted AUC and Cmax values higher than most other avian species (e.g., for enrofloxacin, the AUC in the African penguin is 85.7 μg h/mL, which is more than double the other bird species). Doses for some avian species may be successfully extrapolated from other avian species; however, it appears important to consider factors other than just body weight (e.g., clearance mechanism and drug physicochemical characteristics). Consequently, there is an important need for robust pharmacokinetic data in wildlife species to ensure optimal therapy for this special group of patients. As part of this review, we identify key aspects that should be considered when estimating dose in species for which there is limited pharmacokinetic information available.

CYP3A and CYP2C19 Activity Determined by Microdosed Probe Drugs Accurately Predict Voriconazole Clearance in Healthy Adults

BACKGROUND AND OBJECTIVE

Voriconazole is an important broad-spectrum anti-fungal drug with nonlinear pharmacokinetics. The aim of this single centre fixed-sequence open-label drug-drug interaction trial in healthy participants (N = 17) was to determine whether microdosed probe drugs for CYP3A and CYP2C19 reliably predict voriconazole clearance (CLVRZ).

METHODS

At baseline, a single oral microdose of the paradigm substrates midazolam (CYP3A) and omeprazole (CYP2C19) were given to estimate their clearances (CL). Thereafter, a single oral dose of voriconazole was administered (50, 100, 200 or 400 mg), followed by the microdosed probe drugs.

RESULTS

The clearances of midazolam (CLMDZ 790-2790 mL/min at baseline; 248-1316 mL/min during voriconazole) and omeprazole (CLOMZ 66.4-2710 mL/min at baseline; 30.1-1420 mL/min during voriconazole) were highly variable. CLMDZ [geometric mean ratio (GMR) 0.586 at 50 mg voriconazole decreasing to GMR 0.196 at 400 mg voriconazole] and CLOMZ (GMR 0.590 at 50 mg decreasing to GMR 0.166 at 400 mg) were reduced with higher voriconazole doses. CLMDZ was linearly correlated with CLVRZ (slope 1.458; adjusted R2 0.528) as was CLOMZ (slope 0.807; adjusted R2 0.898). Multiple linear regression resulted in an adjusted R2 of 0.997 for the relationship CLVRZ ~ log CLOMZ + log CLMDZ using data during voriconazole treatment and an adjusted R2 of 0.997 for the relationship CLVRZ ~ log CLOMZ + log CLMDZ + voriconazole dose, using baseline data for CLMDZ and CLOMZ.

CONCLUSION

Microdosed midazolam and omeprazole accurately described and predicted total CLVRZ TRIAL REGISTRATION: EudraCT No: 2020-001017-20, registered on March 5th, 2020. DRKS: DRKS00022547, registered on August 6th, 2020.

It cuts both ways: A single-center retrospective review describing a three-way interaction between flucloxacillin, voriconazole and tacrolimus

AIM

Tacrolimus is a CYP3A4 substrate with a narrow therapeutic index that requires dose adjustment when used with voriconazole, a recognized CYP3A4 inhibitor. Interactions involving flucloxacillin and tacrolimus or voriconazole individually have been shown to result in decreased concentrations of the latter two drugs. Tacrolimus concentrations have been reported to be unaffected by flucloxacillin when voriconazole is administered; however, this has not been extensively investigated.

METHODS

Retrospective review of voriconazole and tacrolimus concentrations and subsequent dose adjustment following flucloxacillin administration.

RESULTS

Eight transplant recipients (five lung, two re-do lung, one heart) received concurrent flucloxacillin, voriconazole and tacrolimus. Voriconazole trough concentrations were measured before flucloxacillin initiation in three of eight patients and all trough concentrations were therapeutic. Following flucloxacillin initiation, all eight patients exhibited subtherapeutic concentrations of voriconazole (median concentration 0.15 mg/L [interquartile range (IQR) 0.10-0.28]). In five patients, voriconazole concentrations remained subtherapeutic despite dose increases, and treatment for two patients was changed to alternative antifungal agents. All eight patients required tacrolimus dose increases to maintain therapeutic concentrations after flucloxacillin initiation. Median total daily dose prior to flucloxacillin treatment was 3.5 mg [IQR 2.0-4.3] and this increased to 13.5 mg [IQR 9.5-20] (P=0.0026) during flucloxacillin treatment. When flucloxacillin was ceased, the median tacrolimus total daily dose reduced to 2.2 mg [IQR 1.9-4.7]. Supra-therapeutic tacrolimus concentrations were observed in seven patients after flucloxacillin discontinuation (median concentration 19.7 μg/L [IQR 17.9-28.0]).

CONCLUSION

A significant three-way interaction was shown between flucloxacillin, voriconazole and tacrolimus, resulting in subtherapeutic voriconazole concentrations, and requiring substantial tacrolimus dose increases. Administration of flucloxacillin to patients receiving voriconazole should be avoided. Tacrolimus concentrations should be closely monitored, and dosing adjusted during and after flucloxacillin administration.

Prediction of plasma trough concentration of voriconazole in adult patients using machine learning

OBJECTIVE

Plasma trough concentration of voriconazole (VCZ) was associated with its toxicity and efficacy. However, the nonlinear pharmacokinetic characteristics of VCZ make it difficult to determine the relationship between clinical characteristics and its concentration. We intended to present a machine learning (ML)-based method to predict toxic plasma trough concentration of VCZ (>5 μg/mL).

METHODS

A single center retrospective study was conducted. Three ML algorithms were used to estimate the concentration in adult patients, including random forest (RF), gradient boosting (GB), and extreme gradient boosting (XGBoost). The importance of variables was recognized by the SHapley Additive exPlanations (SHAP) method. In addition, an external validation set was used to validate the robustness of models.

RESULTS

A total of 1318 VCZ plasma concentration were included, with 33 variables enrolled in the model. Nine classification models were developed using the RF, GB, and XGBoost algorithms. Most models performed well for both the training set and test set, with an average balanced accuracy (BA) of 0.704 and an average accuracy (ACC) of 0.788. In addition, the average Matthews correlation coefficient value reached 0.484, which indicated the predicted values are meaningful. Based on the average BA and ACC values, the predictive ability of the models can be ranked from best to worst as follows: younger adult models > mixed models > elderly models, and XGBoost models > GBT models > RF models. The SHAP results showed that the top five influencing factors in younger adult patients (<60 years) were albumin, total bile acid (TBA), platelets count, age, and inflammation, while the top five influencing factors in elderly patients were albumin, TBA, aspartate aminotransferase, creatinine, and alanine aminotransferase. Furthermore, the prediction of external validation set for VCZ concentrations verified the high reliability of the models, for the ACC value of 0.822 by the best model.

CONCLUSIONS

The ML models can be reliable tools for predicting toxic concentration exposure of VCZ. The SHAP results may provide useful guidelines for dosage adjustment of VCZ.

Lower Prealbumin and Higher CRP Increase the Risk of Voriconazole Overexposure and Adverse Reactions

BACKGROUND

Voriconazole (VRZ) is a commonly used antifungal drug. However, the drug has nonlinear metabolic kinetic characteristics. Many factors can affect the plasma drug concentration, thus affecting the safety and effectiveness of VRZ.

OBJECTIVE

The aim of this study is to characterize the correlation between prealbumin (PA) or CRP and VRZ overexposure and adverse reactions.

METHODS

Patients who received VRZ as a treatment and performed therapeutic drug monitoring (TDM) were included. Biomarkers and combined medications were analyzed to find out factors that were related to VRZ trough concentrations (Cmin) and overexposure (Cmin >5.0 mg/L). Receiver operating characteristic (ROC) curves were used to determine the cut-off levels. Patients were divided into three groups according to different PA and CRP levels. Then, the incidence rate of VRZ adverse reactions between groups was analyzed.

RESULTS

A total of 123 patients were included in the study. PA was negatively correlated, while CRP was positively correlated with VRZ concentrations. Lower PA or higher CRP was related to VRZ overexposure with a cut-off level of 145.5 mg/L and 102.23 mg/L, respectively. Patients in Group 2 (PA <145.5 mg/L and CRP >102.23 mg/L) had an incidence rate of adverse reactions up to 70.27%, while the incidence rates in Group 1 (PA >145.5 mg/L and CRP <102.23 mg/L) and Group 3 (PA <145.5 mg/L and CRP <102.23 mg/L or PA >145.5 mg/L and CRP >102.23 mg/L) were 15.38% and 32.43%, respectively.

CONCLUSIONS

PA and CRP were both related to VRZ concentrations and overexposure. The risk of VRZ overexposure and adverse reactions significantly increased in patients with PA <145.5 mg/L and CRP >102.23 mg/L at the same time.

The impact of gene polymorphism and hepatic insufficiency on voriconazole dose adjustment in invasive fungal infection individuals

Voriconazole (VRZ) is a broad-spectrum antifungal medication widely used to treat invasive fungal infections (IFI). The administration dosage and blood concentration of VRZ are influenced by various factors, posing challenges for standardization and individualization of dose adjustments. On the one hand, VRZ is primarily metabolized by the liver, predominantly mediated by the cytochrome P450 (CYP) 2C19 enzyme. The genetic polymorphism of CYP2C19 significantly impacts the blood concentration of VRZ, particularly the trough concentration (Ctrough), thereby influencing the drug's efficacy and potentially causing adverse drug reactions (ADRs). Recent research has demonstrated that pharmacogenomics-based VRZ dose adjustments offer more accurate and individualized treatment strategies for individuals with hepatic insufficiency, with the possibility to enhance therapeutic outcomes and reduce ADRs. On the other hand, the security, pharmacokinetics, and dosing of VRZ in individuals with hepatic insufficiency remain unclear, making it challenging to attain optimal Ctrough in individuals with both hepatic insufficiency and IFI, resulting in suboptimal drug efficacy and severe ADRs. Therefore, when using VRZ to treat IFI, drug dosage adjustment based on individuals' genotypes and hepatic function is necessary. This review summarizes the research progress on the impact of genetic polymorphisms and hepatic insufficiency on VRZ dosage in IFI individuals, compares current international guidelines, elucidates the current application status of VRZ in individuals with hepatic insufficiency, and discusses the influence of CYP2C19, CYP3A4, CYP2C9, and ABCB1 genetic polymorphisms on VRZ dose adjustments and Ctrough at the pharmacogenomic level. Additionally, a comprehensive summary and analysis of existing studies' recommendations on VRZ dose adjustments based on CYP2C19 genetic polymorphisms and hepatic insufficiency are provided, offering a more comprehensive reference for dose selection and adjustments of VRZ in this patient population.

Voriconazole-Induced Hepatotoxicity in a Patient with Pulmonary Aspergillosis: A Case Report

Voriconazole is the therapy of choice for aspergillosis. However, hepatotoxicity is the most common reason for the discontinuation of voriconazole. In contrast, posaconazole is well tolerated, with a low incidence of hepatotoxicity. In most cases, hepatotoxicity is associated with high voriconazole trough concentration influenced mainly by cytochrome P450 (CYP) 2C19 gene polymorphism. Compared with normal metabolizers, intermediate and poor metabolizers generally have higher voriconazole trough concentrations with an increased risk of hepatotoxicity. Here, we describe changes in hepatotoxicity throughout azole therapy in a patient with pulmonary aspergillosis (PA). Nevertheless, the patient with the normal metabolism genotype of CYP2C19 developed severe hepatotoxicity caused by voriconazole but tolerated posaconazole well, with a lack of direct cross-hepatotoxicity between the both. Interestingly, the patient had a high risk of hepatotoxicity at a low voriconazole trough concentration. Fortunately, elevated liver enzymes declined to the baselines with posaconazole treatment.

Antifungal prophylaxis and pre-emptive therapy: When and how?

The growing pool of critically ill or immunocompromised patients leads to a constant increase of life-threatening invasive infections by fungi such as Aspergillus spp., Candida spp. and Pneumocystis jirovecii. In response to this, prophylactic and pre-emptive antifungal treatment strategies have been developed and implemented for high-risk patient populations. The benefit by risk reduction needs to be carefully weighed against potential harm caused by prolonged exposure against antifungal agents. This includes adverse effects and development of resistance as well as costs for the healthcare system. In this review, we summarise evidence and discuss advantages and downsides of antifungal prophylaxis and pre-emptive treatment in the setting of malignancies such as acute leukaemia, haematopoietic stem cell transplantation, CAR-T cell therapy, and solid organ transplant. We also address preventive strategies in patients after abdominal surgery and with viral pneumonia as well as individuals with inherited immunodeficiencies. Notable progress has been made in haematology research, where strong recommendations regarding antifungal prophylaxis and pre-emptive treatment are backed by data from randomized controlled trials, whereas other critical areas still lack high-quality evidence. In these areas, paucity of definitive data translates into centre-specific strategies that are based on interpretation of available data, local expertise, and epidemiology. The development of novel immunomodulating anticancer drugs, high-end intensive care treatment and the development of new antifungals with new modes of action, adverse effects and routes of administration will have implications on future prophylactic and pre-emptive approaches.

Pharmacokinetic interaction of voriconazole and clarithromycin in Pakistani healthy male volunteers: a single dose, randomized, crossover, open-label study

Background: Voriconazole an antifungal drug, has a potential for drug-drug interactions (DDIs) with administered drugs. Clarithromycin is a Cytochromes P450 CYP (3A4 and 2C19) enzyme inhibitor, and voriconazole is a substrate and inhibitor of these two enzymes. Being a substrate of the same enzyme for metabolism and transport, the chemical nature and pKa of both interacting drugs make these drugs better candidates for potential pharmacokinetic drug-drug interactions (PK-DDIs). This study aimed to evaluate the effect of clarithromycin on the pharmacokinetic profile of voriconazole in healthy volunteers. Methods: A single oral dose, open-label, randomized, crossover study was designed for assessing PK-DDI in healthy volunteers, consisting of 2 weeks washout period. Voriconazole, either alone (2 mg × 200 mg, tablet, P/O) or along with clarithromycin (voriconazole 2 mg × 200 mg, tablet + clarithromycin 500 mg, tablet, P/O), was administered to enrolled volunteers in two sequences. The blood samples (approximately 3 cc) were collected from volunteers for up to 24 h. Plasma concentrations of voriconazole were analyzed by an isocratic, reversed-phase high-performance-liquid chromatography ultraviolet-visible detector (RP HPLC UV-Vis) and a non-compartmental method. Results: In the present study, when voriconazole was administered with clarithromycin versus administered alone, a significant increase in peak plasma concentration (Cmax) of voriconazole by 52% (geometric mean ratio GMR: 1.52; 90% CI 1.04, 1.55; p = 0.000) was observed. Similarly, the area under the curve from time zero to infinity (AUC^0-∞) and the area under the concentration-time curve from time zero to time-t (AUC^0-t) of voriconazole also significantly increased by 21% (GMR: 1.14; 90% CI 9.09, 10.02; p = 0.013), and 16% (GMR: 1.15; 90% CI 8.08, 10.02; p = 0.007), respectively. In addition, the results also showed a reduction in the apparent volume of distribution (Vd) by 23% (GMR: 0.76; 90% CI 5.00, 6.20; p = 0.051), and apparent clearance (CL) by 13% (GMR: 0.87; 90% CI 41.95, 45.73; p = 0.019) of voriconazole. Conclusion: The alterations in PK parameters of voriconazole after concomitant administration of clarithromycin are of clinical significance. Therefore, adjustments in dosage regimens are warranted. In addition, extreme caution and therapeutic drug monitoring are necessary while co-prescribing both drugs. Clinical Trial Registration: clinicalTrials.gov, Identifier NCT05380245.

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.

IFISTRATEGY: Spanish National Survey of Invasive Fungal Infection in Hemato-Oncologic Patients

Recent advances in the treatment of hematologic malignancies have improved the overall survival rate, but the number of patients at risk of developing an invasive fungal infection (IFI) has increased. Invasive infections caused by non-Candida albicans species, non-Aspergillus molds, and azole-resistant Aspergillus fumigatus have been increasingly reported in recent years. We developed a cross-sectional multicenter survey which involved a total of 55 hematologists and infectious disease specialists from a total of 31 Spanish hospitals, to determine the most frequent strategies used for the management of IFIs. Data collection was undertaken through an online survey which took place in 2022. Regarding key strategies, experts usually prefer early treatment for persistent febrile neutropenia, switching to another broad-spectrum antifungal family if azole-resistant Aspergillus is suspected, broad-spectrum azoles and echinocandins as prophylactic treatment in patients receiving midostaurin or venetoclax, and liposomal amphotericin B for breakthrough IFIs after prophylaxis with echinocandins in patients receiving new targeted therapies. For antifungals failing to reach adequate levels during the first days and suspected invasive aspergillosis, the most appropriate strategy would be to associate an antifungal from another family.

Pharmacokinetics of Voriconazole in Peritoneal Fluid of Critically Ill Patients

Data on the distribution of voriconazole (VRC) in the human peritoneal cavity are sparse. This prospective study aimed to describe the pharmacokinetics of intravenous VRC in the peritoneal fluid of critically ill patients. A total of 19 patients were included. Individual pharmacokinetic curves, drawn after single (first dose on day 1) and multiple (steady-state) doses, displayed a slower rise and lower fluctuation of VRC concentrations in peritoneal fluid than in plasma. Good but variable penetration of VRC into the peritoneal cavity was observed, and the median (range) peritoneal fluid/plasma ratios of the area under the concentration-time curve (AUC) were 0.54 (0.34 to 0.73) and 0.67 (0.63 to 0.94) for single and multiple doses, respectively. Approximately 81% (13/16) of the VRC steady-state trough concentrations (Cmin,ss) in plasma were within the therapeutic range (1 to 5.5 μg/mL), and the corresponding Cmin,ss (median [range]) in peritoneal fluid was 2.12 (1.39 to 3.72) μg/mL. Based on the recent 3-year (2019 to 2021) surveillance of the antifungal susceptibilities for Candida species isolated from peritoneal fluid in our center, the aforementioned 13 Cmin,ss in peritoneal fluid exceeded the MIC90 of C. albicans, C. glabrata, and C. parapsilosis (0.06, 1.00, and 0.25 μg/mL, respectively), which supported VRC as a reasonable choice for initial empirical therapies against intraabdominal candidiasis caused by these three Candida species, prior to the receipt of susceptibility testing results.

Individual dose recommendations for drug interaction between tacrolimus and voriconazole in adult liver transplant recipients: A semiphysiologically based population pharmacokinetic modeling approach

The magnitude of drug-drug interaction between tacrolimus and voriconazole is highly variable, and individually tailoring the tacrolimus dose when concomitantly administered with voriconazole remains difficult. This study aimed to develop a semiphysiologically based population pharmacokinetic (semi-PBPK) model and a web-based dashboard to identify the dynamic inhibition of tacrolimus metabolism caused by voriconazole and provide individual tacrolimus regimens for Chinese adult liver transplant recipients. A total of 264 tacrolimus concentrations and 146 voriconazole concentrations were prospectively collected from 32 transplant recipients. A semi-PBPK model with physiological compartments including the gut wall, portal vein, and liver was developed using the nonlinear mixed-effects modeling software NONMEM (version 7.4). A web-based dashboard was established in R software (version 3.6.1) to recommend the individual tacrolimus regimens when concomitantly administered with voriconazole. The reversible inhibition of tacrolimus metabolism caused by voriconazole was investigated in both the liver and the gut wall. Moreover, voriconazole could highly inhibit the CYP3A activity in the gut wall more than in the liver. BMI and postoperative days were identified as significant covariates on intrinsic intestinal and hepatic clearance of tacrolimus, respectively. Age and postoperative days were identified as significant covariates on the volume of distribution of voriconazole. The individual tacrolimus regimens when concomitantly administered with voriconazole could be recommended in the dashboard (https://tac-vor-ddi.shinyapps.io/shinyapp3/). In conclusion, the semi-PBPK model successfully described the dynamic inhibition process between tacrolimus and voriconazole, and the web-based dashboard could provide individual tacrolimus regimens when concomitantly administered with voriconazole.

Impact of Inflammation on Voriconazole Exposure in Critically ill Patients Affected by Probable COVID-19-Associated Pulmonary Aspergillosis

(1) Background: To explore the impact of the degree of inflammation on voriconazole exposure in critically ill patients affected by COVID-associated pulmonary aspergillosis (CAPA); (2) Methods: Critically ill patients receiving TDM-guided voriconazole for the management of proven or probable CAPA between January 2021 and December 2022 were included. The concentration/dose ratio (C/D) was used as a surrogate marker of voriconazole total clearance. A receiving operating characteristic (ROC) curve analysis was performed by using C-reactive protein (CRP) or procalcitonin (PCT) values as the test variable and voriconazole C/D ratio > 0.375 (equivalent to a trough concentration [C_min] value of 3 mg/L normalized to the maintenance dose of 8 mg/kg/day) as the state variable. Area under the curve (AUC) and 95% confidence interval (CI) were calculated; (3) Results: Overall, 50 patients were included. The median average voriconazole C_min was 2.47 (1.75-3.33) mg/L. The median (IQR) voriconazole concentration/dose ratio (C/D) was 0.29 (0.14-0.46). A CRP value > 11.46 mg/dL was associated with the achievement of voriconazole C_min > 3 mg/L, with an AUC of 0.667 (95% CI 0.593-0.735; p < 0.001). A PCT value > 0.3 ng/mL was associated with the attainment of voriconazole C_min > 3 mg/L (AUC 0.651; 95% CI 0.572-0.725; p = 0.0015). (4) Conclusions: Our findings suggest that in critically ill patients with CAPA, CRP and PCT values above the identified thresholds may cause the downregulation of voriconazole metabolism and favor voriconazole overexposure, leading to potentially toxic concentrations.

Management of Invasive Infections in Diabetes Mellitus: A Comprehensive Review

Patients with diabetes often have more invasive infections, which may lead to an increase in morbidity. The hyperglycaemic environment promotes immune dysfunction (such as the deterioration of neutrophil activity, antioxidant system suppression, and compromised innate immunity), micro- and microangiopathies, and neuropathy. A greater number of medical interventions leads to a higher frequency of infections in diabetic patients. Diabetic individuals are susceptible to certain conditions, such as rhino-cerebral mucormycosis or aspergillosis infection. Infections may either be the primary symptom of diabetes mellitus or act as triggers in the intrinsic effects of the disease, such as diabetic ketoacidosis and hypoglycaemia, in addition to increasing morbidity. A thorough diagnosis of the severity and origin of the infection is necessary for effective treatment, which often entails surgery and extensive antibiotic use. Examining the significant issue of infection in individuals with diabetes is crucial. Comprehensive research should examine why infections are more common amongst diabetics and what the preventive treatment strategies could be.

Quantitative determination of voriconazole by thionine reduction and its potential application in a pharmaceutical and clinical setting

Voriconazole (VCZ) is a triazolic drug used to treat serious fungal infections and invasive mycosis and has also been more recently used as a generic antifungal treatment. However, VCZ therapies can cause undesirable side effects and doses must be carefully monitored before administration to avoid or reduce severe toxic effects. Analytical techniques used to quantify VCZ are mostly based on HPLC/UV and often associated with multiple technical steps as well as expensive equipment. The present work aimed to develop an accessible and affordable spectrophotometric technique in the visible range (λ = 514 nm) for the simple quantification of VCZ. The technique was based on VCZ-induced reduction of thionine (TH, red) to leucothionine (LTH, colorless) under alkaline conditions. The reaction showed a linear correlation over the range of 1.00 μg mL^-1 to 60.00 μg mL^-1 at room temperature, the limits of detection and quantification being 1.93 μg mL^-1 and 6.45 μg mL^-1, respectively. VCZ degradation products (DPs) according to ¹H and ¹³C-NMR spectrometric determinations not only showed good agreement with the ones previously reported (DP1 and DP2 - T. M. Barbosa, G. A. Morris, M. Nilsson, R. Rittner and C. F. Tormena, RSC Adv., 2017, DOI: 10.1039/c7ra03822d), but also revealed a new degradation product (DP3). Mass spectrometry not only confirmed the presence of LTH as a result of the VCZ DP-induced TH reduction, but also revealed the formation of a novel and stable Schiff base as a reaction product between DP1 and LTH. The latter finding became significant as it stabilizes the reaction for quantification purposes, by hindering LTH ↔TH redox reversibility. This analytical method was then validated according to the ICH Q2 (R1) guidelines, and additionally, it could be demonstrated as applicable for the reliable VCZ quantification in commercially available tablets. Importantly, it also represents a useful tool for detecting toxic threshold concentrations in human plasma from VCZ-treated patients, alerting when these risky limits are exceeded. In this way, this technique independent from sophisticated equipment, highly qualifies as a low-cost, reproducible, trustable, and non-laborious alternative method for VCZ measurements from different matrices.

Factors Influencing Blood Concentration of Voriconazole and Therapeutic Drug Monitoring in Patients with Child–Pugh Class C Cirrhosis

What Is Known and Objective. CYP2C19 is an important influencing factor for voriconazole trough plasma concentration (Cmin); however, it is not verified in Child–Pugh C (CP-C) cirrhosis patients, and no voriconazole dosage regimen is recommended for these patients in the package insert. This retrospective study identified CYP2C19 and other factors influencing voriconazole Cmin for CP-C cirrhosis, and obtained an appropriate method of application of voriconazole for them. Methods. A total of 66 patients with CP-C cirrhosis who accepted voriconazole therapy were involved. The voriconazole Cmin, clinical characteristics, CYP2C19 genotype, and adverse effects (AEs) were recorded and analyzed. Results. Unlike other research studies, voriconazole Cmin was not different among normal metabolizers (NMs), intermediate metabolizers (IMs), and poor metabolizers (PMs) of the CYP2C19 enzyme in CP-C cirrhosis ( $P$  > 0.05). The maintenance dose regimen for voriconazole was the only independent influencing factor for Cmin ( $P$  = 0.045; OR = 3.753; 95% CI, 1.029–13.694). At about 1/3 of the recommended maintenance dose, only 16.7% (8/48) had Cmin >5.5 μg/mL, 4.5% (3/48) had Cmin <1 μg/mL, and only one AE happened. There were four voriconazole-related AEs that happened in this study, and three AEs occurred (3/4, 75%) when the maintenance dose was not adjusted with therapeutic drug monitoring (TDM). What Is New and Conclusion. Voriconazole Cmin did not significantly vary according to CYP2C19 enzyme metabolization status (being an NM, IM, or PM) in CP-C cirrhosis. Reducing the maintenance dose of voriconazole to approximately 1/3 the standard maintenance dose and administering in combination with TDM in patients with CP-C cirrhosis are recommended.

Factors influencing plasma concentration of voriconazole and voriconazole- N-oxide in younger adult and elderly patients

Background: Voriconazole (VCZ) metabolism is influenced by many factors. Identifying independent influencing factors helps optimize VCZ dosing regimens and maintain its trough concentration (C₀) in the therapeutic window. Methods: We conducted a prospective study investigating independent factors influencing VCZ C₀ and the VCZ C₀ to VCZ N-oxide concentration ratio (C₀/C_N) in younger adults and elderly patients. A stepwise multivariate linear regression model, including the IL-6 inflammatory marker, was used. The receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive effect of the indicator. Results: A total of 463 VCZ C₀ were analyzed from 304 patients. In younger adult patients, the independent factors that influenced VCZ C₀ were the levels of total bile acid (TBA) and glutamic-pyruvic transaminase (ALT) and the use of proton-pump inhibitors. The independent factors influencing VCZ C₀/C_N were IL-6, age, direct bilirubin, and TBA. The TBA level was positively associated with VCZ C₀ (ρ = 0.176, p = 0.019). VCZ C₀ increased significantly when the TBA levels were higher than 10 μmol/L (p = 0.027). ROC curve analysis indicated that when the TBA level ≥4.05 μmol/L, the incidence of a VCZ C₀ greater than 5 μg/ml (95% CI = 0.54-0.74) (p = 0.007) increased. In elderly patients, the influencing factors of VCZ C₀ were DBIL, albumin, and estimated glomerular filtration rate (eGFR). The independent factors that affected VCZ C₀/C_N were eGFR, ALT, γ-glutamyl transferase, TBA, and platelet count. TBA levels showed a positive association with VCZ C₀ (ρ = 0.204, p = 0.006) and C₀/C_N (ρ = 0.342, p < 0.001). VCZ C₀/C_N increased significantly when TBA levels were greater than 10 μmol/L (p = 0.025). ROC curve analysis indicated that when the TBA level ≥14.55 μmol/L, the incidence of a VCZ C₀ greater than 5 μg/ml (95% CI = 0.52-0.71) (p = 0.048) increased. Conclusion: TBA level may serve as a novel marker for VCZ metabolism. eGFR and platelet count should also be considered when using VCZ, especially in elderly patients.

Voriconazole exposure is influenced by inflammation: A population pharmacokinetic model

BACKGROUND

Voriconazole is an antifungal drug used for the treatment of invasive fungal infections. Due to highly variable drug exposure, therapeutic drug monitoring (TDM) has been recommended. TDM may be helpful to predict exposure accurately, but covariates, such as severe inflammation, that influence the metabolism of voriconazole have not been included in the population pharmacokinetic (popPK) models suitable for routine TDM.

OBJECTIVES

To investigate whether the effect of inflammation, reflected by C-reactive protein (CRP), could improve a popPK model that can be applied in clinical care.

PATIENTS AND METHODS

Data from two previous studies were included in the popPK modelling. PopPK modelling was performed using Edsim++. Different popPK models were compared using Akaike Information Criterion and goodness-of-fit plots.

RESULTS

In total, 1060 voriconazole serum concentrations from 54 patients were included in this study. The final model was a one-compartment model with non-linear elimination. Only CRP was a significant covariate, and was included in the final model and found to affect the maximum rate of enzyme activity (V_max). For the final popPK model, the mean volume of distribution was 145 L [coefficient of variation percentage (CV%)=61%], mean Michaelis-Menten constant was 5.7 mg/L (CV%=119%), mean V_max was 86.4 mg/h (CV%=99%) and mean bioavailability was 0.83 (CV%=143%). Internal validation using bootstrapping resulted in median values close to the population parameter estimates.

CONCLUSIONS

This one-compartment model with non-linear elimination and CRP as a covariate described the pharmacokinetics of voriconazole adequately.

Impact of polymorphisms in CYP and UGT enzymes and ABC and SLCO1B1 transporters on the pharmacokinetics and safety of desvenlafaxine

Venlafaxine pharmacokinetic variability and pharmacotherapy outcomes are well known to be related to CYP2D6 pharmacogenetic phenotype. In contrast, scarce pharmacogenetic information is available nowadays concerning desvenlafaxine, its active metabolite first marketed in 2012. The aim of this study was to evaluate the impact of 29 alleles in 12 candidate genes (e.g., CYP enzymes like CYP2D6, CYP3A4, or CYP2C19; ABC transporters like ABCB1; SLCO1B1; and UGT enzymes like UGT1A1) on desvenlafaxine pharmacokinetic variability and tolerability. Pharmacokinetic parameters and adverse drug reaction (ADR) incidence obtained from six bioequivalence clinical trials (n = 98) evaluating desvenlafaxine formulations (five with single dose administration and one with multiple-dose administration) were analyzed. No genetic polymorphism was related to pharmacokinetic variability or ADR incidence. Volunteers enrolled in the multiple-dose clinical trial also showed a higher incidence of ADRs, e.g., xerostomia or appetite disorders. Volunteers experiencing any ADR showed a significantly higher area under the time-concentration curve (AUC) than those not experiencing any ADR (5115.35 vs. 4279.04 ng*h/mL, respectively, p = 0.034). In conclusion, the strong dose-dependent relationship with the occurrence of ADRs confirms that the mechanism of action of desvenlafaxine is essentially dose-dependent.

Therapeutic drug monitoring-guided treatment versus standard dosing of voriconazole for invasive aspergillosis in haematological patients: a multicentre, prospective, cluster randomised, crossover clinical trial

OBJECTIVES

Voriconazole therapeutic drug monitoring (TDM) is recommended based on retrospective data and limited prospective studies. This study aimed to investigate whether TDM-guided voriconazole treatment is superior to standard treatment for invasive aspergillosis.

METHODS

A multicentre (n = 10), prospective, cluster randomised, crossover clinical trial was performed in haematological patients aged ≥18 years treated with voriconazole. All patients received standard voriconazole dose at the start of treatment. Blood/serum/plasma was periodically collected after treatment initiation of voriconazole and repeated during treatment in both groups. The TDM group had measured voriconazole concentrations reported back, with dose adjustments made as appropriate, while the non-TDM group had voriconazole concentrations measured only after study completion. The composite primary endpoint included response to treatment and voriconazole treatment discontinuation due to an adverse drug reaction related to voriconazole within 28 days after treatment initiation.

RESULTS

In total, 189 patients were enrolled in the study. For the composite primary endpoint, 74 patients were included in the non-TDM group and 68 patients in the TDM group. Here, no significant difference was found between both groups (P = 0.678). However, more trough concentrations were found within the generally accepted range of 1-6 mg/L for the TDM group (74.0%) compared with the non-TDM group (64.0%) (P < 0.001).

CONCLUSIONS

In this trial, TDM-guided dosing of voriconazole did not show improved treatment outcome compared with standard dosing. We believe that these findings should open up the discussion for an approach to voriconazole TDM that includes drug exposure, pathogen susceptibility and host defence.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov registration no. NCT00893555.

Association of CYP2C19, CYP3A4 and ABCC2 polymorphisms and voriconazole plasma concentrations in Uygur pediatric patients

Aim: To evaluate the association between CYP2C19, CYP3A4 and ABCC2 polymorphisms and voriconazole plasma concentrations in Uygur pediatric patients with allogeneic hematopoietic stem cell transplantation. Materials & methods: High performance liquid chromatography-mass spectrometry was employed to monitor voriconazole concentrations. First-generation sequencing was performed to detect gene polymorphisms. Results: Voriconazole concentrations of normal metabolizers were significantly higher than those of intermediate (p < 0.05) and ultrafast (p < 0.001) metabolizers. Patients with ABCC2 GG and GA genotypes exhibited significantly lower voriconazole concentrations compared with patients with the AA genotype (p < 0.05). Conclusion: These results demonstrate a significant association between voriconazole concentrations and the CYP2C19 phenotype in Uygur pediatric patients with allogeneic hematopoietic stem cell transplantation.

Nanotechnology-Based Approaches for Voriconazole Delivery Applied to Invasive Fungal Infections

Invasive fungal infections increase mortality and morbidity rates worldwide. The treatment of these infections is still limited due to the low bioavailability and toxicity, requiring therapeutic monitoring, especially in the most severe cases. Voriconazole is an azole widely used to treat invasive aspergillosis, other hyaline molds, many dematiaceous molds, Candida spp., including those resistant to fluconazole, and for infections caused by endemic mycoses, in addition to those that occur in the central nervous system. However, despite its broad activity, using voriconazole has limitations related to its non-linear pharmacokinetics, leading to supratherapeutic doses and increased toxicity according to individual polymorphisms during its metabolism. In this sense, nanotechnology-based drug delivery systems have successfully improved the physicochemical and biological aspects of different classes of drugs, including antifungals. In this review, we highlighted recent work that has applied nanotechnology to deliver voriconazole. These systems allowed increased permeation and deposition of voriconazole in target tissues from a controlled and sustained release in different routes of administration such as ocular, pulmonary, oral, topical, and parenteral. Thus, nanotechnology application aiming to delivery voriconazole becomes a more effective and safer therapeutic alternative in the treatment of fungal infections.

Trends in Implementation of Loading Dose of Voriconazole from 2010 to 2019 and Influencing Factors of Loading Dose Based on a Japanese Administrative Claim Database: A Retrospective Cohort Study

A loading dose of voriconazole (VRCZ) is recommended to increase its blood concentration at an early stage. However, the trends in the implementation of the loading dose in VRCZ in Japan has not yet been clarified. In addition, although pharmacists play many important roles in antimicrobial stewardship, the effect of pharmacist intervention on the implementation of a loading dose of VRCZ has not yet been reported. Therefore, this study aimed to clarify the implementation of loading dose of VRCZ and the influencing factors of loading dose. This study used an administrative claims database that included patients who received injectable VRCZ between 2010 and 2019. The implementation of loading doses in the VRCZ was evaluated annually. Multivariate logistic regression analysis was performed to identify the factors influencing loading dose. Overall, 2197 patients were included. The implementation rate of the loading dose remained below 65% throughout the study period. Among medical fees that can be calculated through pharmacist intervention, only the infection prevention and control premium significantly increased the implementation of loading dose of VRCZ (odds ratio: 1.587, 95% confidence interval: 1.053-2.392). In conclusion, antifungal stewardship may have been promoted at medical institutions that established infection prevention and control. In the future, pharmacists will need to intervene more actively from the beginning of VRCZ administration.

Central Nervous System Toxicity of Voriconazole: Risk Factors and Threshold - A Retrospective Cohort Study

Purpose

Voriconazole (VRC) is an antifungal agent which is used for treatment and prophylaxis of invasive fungal infections. The common clinical adverse reactions mainly include central nervous system (CNS) toxicity and abnormal liver function. These adverse reactions limit the clinical use of voriconazole to a certain extent. Therefore, the aim of this study was to analyze the risk factors of voriconazole neurotoxic side effects and to determine the plasma trough concentration (C _min) threshold of voriconazole-induced CNS toxicity, so as to improve the safety of voriconazole treatment.

Patients and Methods

This study retrospectively collected the clinical data of 165 patients who received voriconazole and underwent therapeutic drug monitoring (TDM). CNS toxicity was defined using the National Cancer Institute (NCI) criteria, logistic regression was used to analyze the risk factors of CNS toxicity, classification and Regression tree (CART) model was used to determine the C _min threshold for CNS toxicity.

Results

Voriconazole-related CNS toxicity occurred during treatment in 34 of 165 patients (20.6%) and the median time from administration to onset of CNS toxicity was 6 days (range, 2-19 days). The overall incidence of CNS toxicity was 20.6% (34/165), including visual disturbances in 4.8% (8/165) and nervous system disorders in 15.8% (26/165). C _min significantly affects the occurrence of CNS toxicity and the threshold of C _min for voriconazole CNS toxicity was determined to be 4.85 mg/L, when C _min >4.85 mg/L and ≤4.85 mg/L, the incidence of CNS was 32.9% and 11.6%, respectively.

Conclusion

Voriconazole trough concentration of C _min is an independent risk factor for CNS toxicity, and the threshold of C _min for CNS toxicity is 4.85mg/L. TDM should be routinely performed in patients with clinical use of voriconazole to reduce the occurrence of CNS toxicity of voriconazole.

Statistical optimization of voriconazole nanoparticles loaded carboxymethyl chitosan-poloxamer based in situ gel for ocular delivery: In vitro, ex vivo, and toxicity assessment

The research study reflects the development of novel voriconazole (VCZ) loaded nanoparticles (NPs) for prolonged delivery for the management of ocular diseases. The in situ ophthalmic gel was prepared by incorporating NPs into carboxymethyl chitosan (CMCh) and poloxamer. The central composite design was used to optimize the process for the preparation of nanoparticles by the o/w solvent evaporation method. The developed nanoparticles were evaluated for the encapsulation efficiency (89.6 ± 1.2%), particle size (219.3 ± 1.8 nm), polydispersity index (PDI, 0.1), zeta potential (- 21.1 ± 1.12 mV), saturation solubility, DSC study, and drug release. The etherification process grafts carboxyl surface functional groups, on chitosan, and was confirmed by FTIR and NMR studies. The developed CMCh-poloxamer based gelling system was found to be clear and transparent with gelation temperature varying from 33 to 40 °C. The nanoparticle-loaded gel containing CMCh demonstrated enhanced antifungal activity against Candida albicans. The optimized batch containing CMCh showed improved mucoadhesion by 2.86-fold compared to VCZ nanosuspension. The drug release was prolonged up to 8 h with an ex vivo study suggesting the enhanced permeation across goat cornea estimated via fluorescent microscope. The hen's egg chorioallantoic membrane study revealed that the formulation was non-irritant and tolerated by the chorioallantoic membrane. The present study concludes that the VCZ loaded nanoparticulate in situ ophthalmic gel using CMCh may act as a potential alternative for traditional eye drops.