Influence of C-reactive protein on the pharmacokinetics of voriconazole in relation to the CYP2C19 genotype: a population pharmacokinetics analysis

Voriconazole is a broad-spectrum triazole antifungal agent. A number of studies have revealed that the impact of C-reactive protein (CRP) on voriconazole pharmacokinetics was associated with the CYP2C19 phenotype. However, the combined effects of CYP2C19 genetic polymorphisms and inflammation on voriconazole pharmacokinetics have not been considered in previous population pharmacokinetic (PPK) studies, especially in the Chinese population. This study aimed to analyze the impact of inflammation on the pharmacokinetics of voriconazole in patients with different CYP2C19 genotypes and optimize the dosage of administration. Data were obtained retrospectively from adult patients aged ≥16 years who received voriconazole for invasive fungal infections from October 2020 to June 2023. Plasma voriconazole levels were measured via high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). CYP2C19 genotyping was performed using the fluorescence in situ hybridization method. A PPK model was developed using the nonlinear mixed-effect model (NONMEM). The final model was validated using bootstrap, visual predictive check (VPC), and normalized prediction distribution error (NPDE). The Monte Carlo simulation was applied to evaluate and optimize the dosing regimens. A total of 232 voriconazole steady-state trough concentrations from 167 patients were included. A one-compartment model with first order and elimination adequately described the data. The typical clearance (CL) and the volume of distribution (V) of voriconazole were 3.83 L/h and 134 L, respectively. The bioavailability was 96.5%. Covariate analysis indicated that the CL of voriconazole was substantially influenced by age, albumin, gender, CRP, and CYP2C19 genetic variations. The V of voriconazole was significantly associated with body weight. An increase in the CRP concentration significantly decreased voriconazole CL in patients with the CYP2C19 normal metabolizer (NM) and intermediate metabolizer (IM), but it had no significant effect on patients with the CYP2C19 poor metabolizer (PM). The Monte Carlo simulation based on CRP levels indicated that patients with high CRP concentrations required a decreased dose to attain the therapeutic trough concentration and avoid adverse drug reactions in NM and IM patients. These results indicate that CRP affects the pharmacokinetics of voriconazole and is associated with the CYP2C19 phenotype. Clinicians dosing voriconazole should consider the patient's CRP level, especially in CYP2C19 NMs and IMs.

Clinical application of voriconazole in pediatric patients: a systematic review

The purpose of this study was to review the literature on the clinical use of voriconazole (VRC) in pediatric patients. MEDLINE, Embase, PubMed, Web of Science, and Cochrane Library were searched from January 1, 2000, to August 15, 2023 for relevant clinical studies on VRC use in pediatric patients. Data were collected based on inclusion and exclusion criteria, and a systematic review was performed on recent research related to the use of VRC in pediatric patients. This systematic review included a total of 35 observational studies among which there were 16 studies investigating factors influencing VRC plasma trough concentrations (Ctrough) in pediatric patients, 14 studies exploring VRC maintenance doses required to achieve target range of Ctrough, and 11 studies focusing on population pharmacokinetic (PPK) research of VRC in pediatric patients. Our study found that the Ctrough of VRC were influenced by both genetic and non-genetic factors. The optimal dosing of VRC was correlated with age in pediatric patients, and younger children usually required higher VRC doses to achieve target Ctrough compared to older children. Establishing a PPK model for VRC can assist in achieving more precise individualized dosing in children.

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.

The cost-utility analysis of antifungal prophylaxis for invasive fungal infections in acute myeloid leukaemia patients receiving chemotherapy: a study from a middle-income country

BACKGROUND

Invasive fungal infections (IFIs) contribute to morbidity and mortality during acute myeloid leukaemia (AML) treatment. Without prophylaxis, IFI rate during AML treatment in Thailand is high and results in a high mortality rate and a prolonged hospital stay.

AIM

To evaluate the cost-utility of antifungal therapy (AFT) prophylaxis during AML treatment.

METHODS

We assessed the cost-utility of AFT available in Thailand, including posaconazole (solution), itraconazole (solution and capsule), and voriconazole. A hybrid model consisting of a decision tree and the Markov model was established.

RESULTS

The costs to prevent overall IFI using any AFT were all lower than the treatment cost of a non-prophylaxis group, resulting in a saving of 808-1507 USD per patient. Prevention with voriconazole prophylaxis showed the highest quality-adjusted life years (QALYs = 3.51, incremental QALYs = 0.23), followed by posaconazole (QALYs = 3.46, incremental QALY = 0.18) and itraconazole solution (QALYs = 3.45, incremental QALYs = 0.17). Itraconazole capsule reduced QALY in the model. For invasive aspergillosis prevention, posaconazole and voriconazole both resulted in better QALYs and life year savings compared with no prophylaxis. However, posaconazole prophylaxis was the only cost-saving option (976 USD per patient).

CONCLUSION

Posaconazole, itraconazole solution and voriconazole were all cost saving compared with no prophylaxis for overall IFI prophylaxis, with voriconazole being the most cost-effective option. Posaconazole and voriconazole were both cost effective for invasive aspergillosis prevention but only posaconazole was cost saving. A change in reimbursement policy for the use of AFT prophylaxis during intensive AML treatment could provide both clinical benefits to patients and substantial economic benefits to healthcare systems.

Factors affecting voriconazole concentration to dose ratio changes according to route of administration

BACKGROUND

Voriconazole (VRCZ) is commonly used as oral and intravenous (IV) formulations. Few studies have comprehensively analysed the variation factors for the weight-corrected VRCZ serum concentration/dose (C/D) ratio based on the administration route. We retrospectively investigated the risk factors that influence the VRCZ C/D ratio in patients treated with oral or IV formulations.

METHODS

A total of 325 patients were divided into two groups (IV and oral groups). Propensity score matching was performed and linear regression analyses were used to identify the risk factors that affect the VRCZ C/D ratio according to the administration route. Receiver operating characteristic (ROC) curves were also used to assess the predictive potential for VRCZ trough concentration >5 µg/mL.

RESULTS

The VRCZ C/D ratio in the oral group was significantly lower than that in the IV group (p<0.001). Propensity score matching resulted in 65 in the IV group matched with 65 in the oral group. Multivariate analysis showed that age (p=0.039), aspartate aminotransferase (AST) (p=0.016) and total bilirubin (TBIL) (p=0.041) levels were independent influencing factors of the VRCZ C/D ratio in the oral group. ROC curves showed that the predicted probability of combined age, AST and TBIL had maximal area under the curve (AUC) of 0.901 for VRCZ trough level >5 µg/mL. Meanwhile, the ratio of TBIL (p=0.005) and single dose (p=0.015) were independent factors in the IV group with ROCAUC of 0.781.

CONCLUSIONS

To obtain optimal VRCZ efficacy and safety, dose adjustment is required based on multiple factors that may cause the observed difference in the VRCZ C/D ratio and trough levels between oral and IV administration.

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.

Population pharmacokinetics of voriconazole and the role of CYP2C19 genotype on treatment optimization in pediatric patients

The aim of this study was to evaluate factors that impact on voriconazole (VRC) population pharmacokinetic (PPK) parameters and explore the optimal dosing regimen for different CYP2C19 genotypes in Chinese paediatric patients. PPK analysis was used to identify the factors contributing to the variability in VRC plasma trough concentrations. A total of 210 VRC trough concentrations from 91 paediatric patients were included in the study. The median VRC trough concentration was 1.23 mg/L (range, 0.02 to 8.58 mg/L). At the measurement of all the trough concentrations, the target range (1.0~5.5 mg/L) was achieved in 52.9% of the patients, while subtherapeutic and supratherapeutic concentrations were obtained in 40.9% and 6.2% of patients, respectively. VRC trough concentrations were adjusted for dose (Ctrough/D), with normal metabolizers (NMs) and intermediate metabolizers (IMs) having significantly lower levels than poor metabolizers (PMs) (PN-P < 0.001, PI-P = 0.039). A one-compartment model with first-order absorption and elimination was suitable to describe the VRC pharmacokinetic characteristics. The final model of VRC PPK analysis contained CYP2C19 phenotype as a significant covariate for clearance. Dose simulations suggested that a maintenance dose of 9 mg/kg orally or 8 mg/kg intravenously twice daily was appropriate for NMs to achieve the target concentration. A maintenance dose of 9 mg/kg orally or 5 mg/kg intravenously twice daily was appropriate for IMs. Meanwhile, PMs could use lower maintenance dose and an oral dose of 6 mg/kg twice daily or an intravenous dose of 5mg/kg twice daily was appropriate. To increase the probability of achieving the therapeutic range and improving efficacy, CYP2C19 phenotype can be used to predict VRC trough concentrations and guide dose adjustments in Chinese pediatric patients.

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.

A review of prophylactic regimens to prevent invasive fungal infections in hematology patients undergoing chemotherapy or stem cell transplantation

INTRODUCTION

The recent introduction of targeted therapies, including monoclonal antibodies, tyrosine-kinase inhibitors, and immunotherapies has improved the cure rate of hematologic patients. The implication of personalized treatment on primary antifungal prophylaxis will be discussed.

AREAS COVERED

We reviewed the literature for clinical trials reporting the rate of invasive fungal infections during targeted and cellular therapies and stem cell transplant, and the most recent international guidelines for primary antifungal prophylaxis.

EXPERT OPINION

As the use of personalized therapies is growing, the risk of invasive fungal infection has emerged in various clinical settings. Therefore, it is possible that the use of mold-active antifungal prophylaxis would spread in the next years and the risk of breakthrough infections would increase. The introduction of new antifungal agents in the clinical armamentarium is expected to reduce clinical unmet needs concerning the management of primary antifungal prophylaxis and improve outcome of patients.

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.

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.

Population pharmacokinetics of voriconazole and initial dosage optimization in patients with talaromycosis

The high variability and unpredictability of the plasma concentration of voriconazole (VRC) pose a major challenge for clinical administration. The aim of this study was to develop a population pharmacokinetics (PPK) model of VRC and identify the factors influencing VRC PPK in patients with talaromycosis. Medical records and VRC medication history of patients with talaromycosis who were treated with VRC as initial therapy were collected. A total of 233 blood samples from 69 patients were included in the study. A PPK model was developed using the nonlinear mixed-effects models (NONMEM). Monte Carlo simulation was applied to optimize the initial dosage regimens with a therapeutic range of 1.0–5.5 mg/L as the target plasma trough concentration. A one-compartment model with first-order absorption and elimination adequately described the data. The typical voriconazole clearance was 4.34 L/h, the volume of distribution was 97.4 L, the absorption rate constant was set at 1.1 h^-1, and the bioavailability was 95.1%. Clearance was found to be significantly associated with C-reactive protein (CRP). CYP2C19 polymorphisms had no effect on voriconazole pharmacokinetic parameters. ‏Monte Carlo simulation based on CRP levels showed that a loading dose of 250 mg/12 h and a maintenance dose of 100 mg/12 h are recommended for patients with CRP ≤ 96 mg/L, whereas a loading dose of 200 mg/12 h and a maintenance dose of 75 mg/12 h are recommended for patients with CRP > 96 mg/L. The average probability of target attainment of the optimal dosage regimen in CRP ≤ 96 mg/L and CRP > 96 mg/L groups were 61.3% and 13.6% higher than with empirical medication, and the proportion of C_min > 5.5 mg/L decreased by 28.9%. In conclusion, the VRC PPK model for talaromycosis patients shows good robustness and predictive performance, which can provide a reference for the clinical individualization of VRC. Adjusting initial dosage regimens based on CRP may promote the rational use of VRC.

Systematic Evaluation of Voriconazole Pharmacokinetic Models without Pharmacogenetic Information for Bayesian Forecasting in Critically Ill Patients

Voriconazole (VRC) is used as first line antifungal agent against invasive aspergillosis. Model-based approaches might optimize VRC therapy. This study aimed to investigate the predictive performance of pharmacokinetic models of VRC without pharmacogenetic information for their suitability for model-informed precision dosing. Seven PopPK models were selected from a systematic literature review. A total of 66 measured VRC plasma concentrations from 33 critically ill patients was employed for analysis. The second measurement per patient was used to calculate relative Bias (rBias), mean error (ME), relative root mean squared error (rRMSE) and mean absolute error (MAE) (i) only based on patient characteristics and dosing history (a priori) and (ii) integrating the first measured concentration to predict the second concentration (Bayesian forecasting). The a priori rBias/ME and rRMSE/MAE varied substantially between the models, ranging from −15.4 to 124.6%/−0.70 to 8.01 mg/L and from 89.3 to 139.1%/1.45 to 8.11 mg/L, respectively. The integration of the first TDM sample improved the predictive performance of all models, with the model by Chen (85.0%) showing the best predictive performance (rRMSE: 85.0%; rBias: 4.0%). Our study revealed a certain degree of imprecision for all investigated models, so their sole use is not recommendable. Models with a higher performance would be necessary for clinical use.

Development of Physiology Based Pharmacokinetic Model to Predict the Drug Interactions of Voriconazole and Venetoclax

PURPOSE

Venetoclax (VEN), an anti-tumor drug that is a substrate of cytochrome P450 3A enzyme (CYP3A4), is used to treat leukemia. Voriconazole (VCZ) is an antifungal medication that inhibits CYP3A4. The goal of this study is to predict the effect of VCZ on VEN exposure.

METHOD

Two physiological based pharmacokinetics (PBPK) models were developed for VCZ and VEN using the bottom-up and top-down method. VCZ model was also developed to describe the effect of CYP2C19 polymorphism on its pharmacokinetics (PK). The reversible inhibition constant (Ki) of VCZ for CYP3A4 was calibrated using drug-drug interaction (DDI) data of midazolam and VCZ. The clinical verified VCZ and VEN model were used to predict the DDI of VCZ and VEN at clinical dosing scenario.

RESULT

VCZ model predicted VCZ exposure in the subjects of different CYP2C19 genotype and DDI related fold changes of sensitive CYP3A substrate with acceptable prediction error. VEN model can capture PK of VEN with acceptable prediction error. The DDI PBPK model predicted that VCZ increased the exposure of VEN by 4.5-9.6 fold. The increase in VEN exposure by VCZ was influenced by subject's CYP2C19 genotype. According to the therapeutic window, VEN dose should be reduced to 100 mg when co-administered with VCZ.

CONCLUSION

The PBPK model developed here could support individual dose adjustment of VEN and DDI risk assessment. Predictions using the robust PBPK model confirmed that the 100 mg dose adjustment is still applicable in the presence of VCZ with high inter-individual viability.

External evaluation of population pharmacokinetic models for voriconazole in Chinese adult patients with hematological malignancy

OBJECTIVES

Patients with hematological malignancies are prone to invasive fungal disease due to long-term chemotherapy or radiotherapy. Voriconazole is a second-generation triazole broad-spectrum antibiotic used to prevent or treat invasive fungal infections. Many population pharmacokinetic (pop PK) models have been published for voriconazole, and various diagnostic methods are available to validate the performance of these pop PK models. However, most of the published models have not been strictly evaluated externally. The purpose of this study is to evaluate these models externally and assess their predictive capabilities.

METHODS

The external dataset consists of adults receiving voriconazole treatment at Fujian Medical University Union Hospital. We re-established the published models based on their final estimated values in the literature and used our external dataset for initial screening. Each model was evaluated based on the following outcomes: prediction-based diagnostics, prediction- and variability-corrected visual predictive check (pvcVPC), normalized prediction distribution errors (NPDE), and Bayesian simulation results with one to two prior observations.

RESULTS

A total of 237 samples from 166 patients were collected as an external dataset. After screening, six candidate models suitable for the external dataset were finally obtained for comparison. Among the models, none demonstrated excellent predictive performance. Bayesian simulation shows that all models' prediction precision and accuracy were significantly improved when one or two prior concentrations were given.

CONCLUSIONS

The published pop PK models of voriconazole have significant differences in prediction performance, and none of the models could perfectly predict the concentrations of voriconazole for our data. Therefore, extensive evaluation should precede the adoption of any model in clinical practice.

Application of Population Pharmacokinetic Analysis to Characterize CYP2C19 Mediated Metabolic Mechanism of Voriconazole and Support Dose Optimization

Purpose: The aims of this study were to establish a joint population pharmacokinetic model for voriconazole and its N-oxide metabolite in immunocompromised patients, to determine the extent to which the CYP2C19 genetic polymorphisms influenced the pharmacokinetic parameters, and to evaluate and optimize the dosing regimens using a simulating approach.

Methods: A population pharmacokinetic analysis was conducted using the Phoenix NLME software based on 427 plasma concentrations from 78 patients receiving multiple oral doses of voriconazole (200 mg twice daily). The final model was assessed by goodness of fit plots, non-parametric bootstrap method, and visual predictive check. Monte Carlo simulations were carried out to evaluate and optimize the dosing regimens.

Results: A one-compartment model with first-order absorption and mixed linear and concentration-dependent-nonlinear elimination fitted well to concentration-time profile of voriconazole, while one-compartment model with first-order elimination well described the disposition of voriconazole N-oxide. Covariate analysis indicated that voriconazole pharmacokinetics was substantially influenced by the CYP2C19 genetic variations. Simulations showed that the recommended maintenance dose regimen would lead to subtherapeutic levels in patients with different CYP2C19 genotypes, and elevated daily doses of voriconazole might be required to attain the therapeutic range.

Conclusions: The joint population pharmacokinetic model successfully characterized the pharmacokinetics of voriconazole and its N-oxide metabolite in immunocompromised patients. The proposed maintenance dose regimens could provide a rationale for dosage individualization to improve clinical outcomes and minimize drug-related toxicities.

Real-World Use of Isavuconazole as Primary Therapy for Invasive Fungal Infections in High-Risk Patients with Hematologic Malignancy or Stem Cell Transplant

(1) Introduction: Invasive fungal infections (IFIs) are a major cause of morbidity and mortality among immunocompromised patients with hematologic malignancies (HM) and stem cell transplants (SCT). Isavuconazole was approved by FDA as a primary therapy for Invasive Aspergillosis (IA) and Mucormycosis. The aim of this study is to look at the real-world use of Isavuconazole in patients with HM and evaluate their clinical outcomes and safety. (2) Methods: We conducted a retrospective study of HM patients at MD Anderson Cancer Center who had definite, probable or possible mold infections between 1 April 2016 and 31 January 2020 and were treated with Isavuconazole for a period of at least 7 days. Clinical and radiological findings were assessed at baseline and at 6 and 12 weeks of follow up. (3) Results: We included 200 HM patients with IFIs that were classified as definite (11), probable (63) and possible (126). Aspergillus spp was the most commonly isolated pathogen. The majority of patients (59%) received prophylaxis with anti-mold therapy and Isavuconazole was used as a primary therapy in 43% of patients, and as salvage therapy in 58%. The switch to Isavuconazole was driven by the failure of the primary therapy in 66% of the cases and by adverse effects in 29%. Isavuconazole was used as monotherapy in 30% of the cases and in combination in 70%. Adverse events possibly related to Isavuconazole were reported in eight patients (4%) leading to drug discontinuation. Moreover, a favorable response with Isavuconazole was observed in 40% at 6 weeks and in 60% at 12 weeks. There was no significant difference between isavuconazole monotherapy and combination therapy (p = 0.16 at 6 weeks and p = 0.06 at 12 weeks). Finally, there was no significant difference in outcome when Isavuconazole was used after failure of other anti-mold prophylaxis or treatment versus when used de novo as an anti-mold therapy (p = 0.68 at 6 weeks and p = 0.25 at 12 weeks). (4) Conclusions: Whether used as first-line therapy or after the failure of other azole and non-azole prophylaxis or therapies, isavuconazole seems to have a promising clinical response and a good safety profile as an antifungal therapy in high-risk cancer patients with hematologic malignancies. Moreover, combination therapy did not improve the outcome compared to Isavuconazole therapy.

Predictive Value of C-Reactive Protein and Albumin for Temporal Within-Individual Pharmacokinetic Variability of Voriconazole in Pediatric Hematopoietic Cell Transplant Patients

Voriconazole is a widely used antifungal agent in immunocompromised patients, but its utility is limited by its variable exposure and narrow therapeutic index. Population pharmacokinetic (PK) models have been used to characterize voriconazole PK and derive individualized dosing regimens. However, determinants of temporal within-patient variability of voriconazole PK were not well-established. We aimed to characterize temporal variability of voriconazole PK within individuals and identify predictive clinical factors. This study was conducted as a part of a single-institution, phase I study of intravenous voriconazole in children undergoing HCT (NCT02227797). We analyzed voriconazole PK study data collected at week 1 and again at week 2 after the start of voriconazole therapy in 59 pediatric HCT patients (age <21 years). Population PK analysis using nonlinear mixed effect modeling was performed to analyze temporal within-individual variability of voriconazole PK by incorporating a between-occasion variability term in the model. A two-compartment linear elimination model incorporating body weight and CYP2C19 phenotype described the data. Ratio of individual voriconazole clearance between weeks 1 to 2 ranged from 0.11 to 3.3 (-9.1 to +3.3-fold change). Incorporation of covariate effects by serum C-reactive protein (CRP) and albumin levels decreased between-occasion variability of clearance (coefficient of variation: from 59.5% to 41.2%) and improved the model fit (p<0.05). As significant covariates on voriconazole PK, CRP and albumin concentrations may potentially serve as useful biomarkers as part of therapeutic drug monitoring. This article is protected by copyright. All rights reserved.

A Large Sample Retrospective Study on the Distinction of Voriconazole Concentration in Asian Patients from Different Clinical Departments

Voriconazole (VRZ) is widely used to prevent and treat invasive fungal infections; however, there are a few studies examining the variability and influencing the factors of VRZ plasma concentrations across different clinical departments. This study aimed to evaluate distinction of VRZ concentrations in different clinical departments and provide a reference for its reasonable use. From 1 May 2014 to 31 December 2020, VRZ standard rates and factors affecting the VRZ trough concentration were analyzed, and a multiple linear regression model was constructed. The standard rates of VRZ in most departments were above 60%. A total of 676 patients with 1212 VRZ trough concentrations using a dosing regimen of 200 mg q12h from seven departments were enrolled in the correlation analysis. The concentration distribution varied significantly among different departments (p < 0.001). Fifteen factors, including department, CYP2C19 phenotype, and gender, correlated with VRZ concentration. A multiple linear regression model was established as follows: VRZ trough concentration = 5.195 + 0.049 × age + 0.007 × alanine aminotransferase + 0.010 × total bilirubin − 0.100 × albumin − 0.004 × gamma-glutamyl transferase. According to these indexes, we can predict possible changes in VRZ trough concentration and adjust its dosage precisely and individually.

Effects of Letermovir and/or Methylprednisolone Coadministration on Voriconazole Pharmacokinetics in Hematopoietic Stem Cell Transplantation: A Population Pharmacokinetic Study

Objective

The aim of this study was to identify factors affecting blood concentrations of voriconazole following letermovir coadministration using population pharmacokinetic (PPK) analysis in allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients.

Methods

The following data were retrospectively collected: voriconazole trough levels, patient characteristics, concomitant drugs, and laboratory information. PPK analysis was performed with NONMEM^® version 7.4.3, using the first-order conditional estimation method with interaction. We collected data on plasma voriconazole steady-state trough concentrations at 216 timepoints for 47 patients. A nonlinear pharmacokinetic model with the Michaelis–Menten equation was applied to describe the relationship between steady-state trough concentration and daily maintenance dose of voriconazole. After stepwise covariate modeling, the final model was evaluated using a goodness-of-fit plot, case deletion diagnostics, and bootstrap methods.

Results

The maximum elimination rate (V_max) of voriconazole in patients coadministered letermovir and methylprednisolone was 1.72 and 1.30 times larger than that in patients not coadministered these drugs, respectively, resulting in decreased voriconazole trough concentrations. The developed PPK model adequately described the voriconazole trough concentration profiles in allo-HSCT recipients. Simulations clearly showed that increased daily doses of voriconazole were required to achieve an optimal trough voriconazole concentration (1–5 mg/L) when patients received voriconazole with letermovir and/or methylprednisolone.

Conclusions

The development of individualized dose adjustment is critical to achieve optimal voriconazole concentration, especially among allo-HSCT recipients receiving concomitant letermovir and/or methylprednisolone.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40268-021-00365-0.

Nanomaterial-Based Antifungal Therapies to Combat Fungal Diseases Aspergillosis, Coccidioidomycosis, Mucormycosis, and Candidiasis

Over the last years, invasive infections caused by filamentous fungi have constituted a serious threat to public health worldwide. Aspergillus, Coccidioides, Mucorales (the most common filamentous fungi), and Candida auris (non-filamentous fungus) can cause infections in humans. They are able to cause critical life-threatening illnesses in immunosuppressed individuals, patients with HIV/AIDS, uncontrolled diabetes, hematological diseases, transplantation, and chemotherapy. In this review, we describe the available nanoformulations (both metallic and polymers-based nanoparticles) developed to increase efficacy and reduce the number of adverse effects after the administration of conventional antifungals. To treat aspergillosis and infections caused by Candida, multiple strategies have been used to develop new therapeutic alternatives, such as incorporating coating materials, complexes synthesized by green chemistry, or coupled with polymers. However, the therapeutic options for coccidioidomycosis and mucormycosis are limited; most of them are in the early stages of development. Therefore, more research needs to be performed to develop new therapeutic alternatives that contribute to the progress of this field.

PLASMA VORICONAZOLE CONCENTRATIONS FOLLOWING SINGLE- AND MULTIPLE-DOSE SUBCUTANEOUS INJECTIONS IN WESTERN POND TURTLES (ACTINEMYS MARMORATA)

A recently characterized fungal pathogen, Emydomyces testavorans, has been associated with ulcerative shell disease and significant morbidity in Western pond turtles. Voriconazole is a second-generation triazole antifungal medication that prevents fungal growth through disruption of ergosterol synthesis, causing abnormalities in the fungal cell membrane. Preliminary reports of minimum inhibitory concentrations (MIC) indicate that voriconazole is effective in vitro against E. testavorans. Ultraperformance liquid chromatography was used to measure voriconazole plasma concentrations in blood samples from healthy Western pond turtles after administration of a single SC injection of 10 mg/kg and after multiple doses (10 mg/kg SC q48h for seven doses). The data were analyzed using a naïve pooled approach. Mean (SE) observed time to maximum concentration was 2 (0.18) h for a single dose and 50 (2.2) h for multiple doses; the multiple-dose trial observed mean (SE) maximum concentration was 12.4 (2.2) µg/ml, and observed mean (SE) trough concentration was 1.7 (0.7) µg/ml. Multifocal skin sloughing following the single-dose trial was observed in one turtle and there was a significant increase in polychromatophilic cells amongst the study turtles after the multiple-dose voriconazole trial. No other adverse effects were observed. When voriconazole was administered at 10 mg/kg SC q48h, observed trough plasma concentrations were consistently higher than reported E. testavorans MIC concentrations. Further study is needed to determine the clinical safety and in vivo efficacy of this dose in Western pond turtles.

Bacteroides Fragilis Polysaccharide A Ameliorates Abnormal Voriconazole Metabolism Accompanied With the Inhibition of TLR4/NF-κB Pathway

The antifungal agent voriconazole (VRC) exhibits extreme inter-individual and intra-individual variation in terms of its clinical efficacy and toxicity. Inflammation, as reflected by C-reactive protein (CRP) concentrations, significantly affects the metabolic ratio and trough concentrations of voriconazole. Bacteroides fragilis (B. fragilis) is an important component of the human intestinal microbiota. Clinical data have shown that B. fragilis abundance is comparatively higher in patients not presenting with adverse drug reactions, and inflammatory cytokine (IL-1β) levels are negatively correlated with B. fragilis abundance. B. fragilis natural product capsular polysaccharide A (PSA) prevents various inflammatory disorders. We tested the hypothesis that PSA ameliorates abnormal voriconazole metabolism by inhibiting inflammation. Germ-free animals were administered PSA intragastrically for 5 days after lipopolysaccharide (LPS) stimulation. Their blood and liver tissues were collected to measure VRC concentrations. PSA administration dramatically improved the resolution phase of LPS-induced hepatic VRC metabolism and inflammatory factor secretion. It reversed inflammatory lesions and alleviated hepatic pro-inflammatory factor secretion. Both in vitro and in vivo data demonstrate that PSA reversed LPS-induced IL-1β secretion, downregulated the TLR4/NF-κB signaling pathway and upregulated CYP2C19 and P-gp. To the best of our knowledge, this study is the first to show that PSA from the probiotic B. fragilis ameliorates abnormal voriconazole metabolism by inhibiting TLR4-mediated NF-κB transcription and regulating drug metabolizing enzyme and transporter expression. Thus, PSA could serve as a clinical adjunct therapy.

Using Child-Pugh Class to Optimize Voriconazole Dosage Regimens and Improve Safety in Patients with Liver Cirrhosis: Insights from a Population Pharmacokinetic Model-based Analysis

BACKGROUND

Cirrhotic patients are at a high risk of fungal infections. Voriconazole is widely used as prophylaxis and in the treatment of invasive fungal disease. However, the safety, pharmacokinetics, and optimal regimens of voriconazole are currently not well defined in cirrhotic patients.

DESIGN

Retrospective pharmacokinetics study.

SETTING

Two large, academic, tertiary-care medical center.

PATIENTS

Two hundred nineteen plasma trough concentrations (C_min ) from 120 cirrhotic patients and 83 plasma concentrations from 11 non-cirrhotic patients were included.

METHODS

Data pertaining to voriconazole were collected retrospectively. A population pharmacokinetics analysis was performed and model-based simulation was used to optimize voriconazole dosage regimens.

RESULTS

Voriconazole-related adverse events (AEs) developed in 29 cirrhotic patients, and the threshold C_min for AE was 5.12 mg/L. A two-compartment model with first-order elimination adequately described the data. The Child-Pugh class and body weight were the significant covariates in the final model. Voriconazole clearance in non-cirrhotic, Child-Pugh class A and B cirrhotic (CP-A/B) and Child-Pugh class C cirrhotic (CP-C) patients was 7.59, 1.86, and 0.93 L/hour, respectively. The central distribution volume and peripheral distribution volume was 100.8 and 55.2 L, respectively. The oral bioavailability was 91.6%. Model-based simulations showed that a loading dose regimen of 200 mg/12 hours intravenously or orally led to 65.0-75.7% of voriconazole C_min in therapeutic range on day 1, and the appropriate maintenance dosage regimens were 75 mg/12 hours and 150 mg/24 hours intravenously or orally for CP-A/B patients, and 50 mg/12 hours and 100 mg/24 hours intravenously or orally for CP-C patients. The predicted probability of achieving the therapeutic target concentration for optimized regimens at steady-state was 66.8-72.3% for CP-A/B patients and 70.3-74.0% for CP-C patients.

CONCLUSIONS

These results recommended that the halved loading dose regimens should be used, and voriconazole maintenance doses in cirrhotic patients should be reduced to one-fourth for CP-C patients and to one-third for CP-A/B patients compared to that for patients with normal liver function.

Influence of switching from intravenous to oral administration on serum voriconazole concentration

WHAT IS KNOWN AND OBJECTIVE

While bioavailability of oral voriconazole is known to be >90%, several reports have observed much lower oral bioavailability. The aim of the present study was to assess the oral bioavailability of voriconazole in clinical use by evaluating the change in serum voriconazole concentration in patients who received intravenous-to-oral switch therapy with the same dose of voriconazole.

METHODS

A single-centre, retrospective cohort study was conducted at the 614-bed Gifu University Hospital in Japan. Patients who received intravenous-to-oral switch therapy with the same dose of voriconazole between 1 January 2011 and 31 December 2018 were enrolled in the present study. We evaluated changes in serum voriconazole concentration before and after switch therapy.

RESULTS

Voriconazole trough concentrations significantly decreased following oral compared to intravenous treatment (2.5 ± 1.5 µg/mL vs 3.3 ± 2.0 µg/mL, p = 0.021). The median change rate of serum concentration by switching the route of administration was 82.7%, with wide inter-individual variability (range 27.2-333.3%). Further, concomitant glucocorticoid administration was a significant protective factor for reducing serum concentration (OR 0.16, 95% CI 0.03-0.79, p = 0.025).

WHAT IS NEW AND CONCLUSION

Switching from intravenous to oral treatment resulted in a significant decline in voriconazole trough concentrations with wide inter-individual variability. Therefore, measurement of serum concentration for dose adjustment should be performed after switching to the oral form.

Role and Interpretation of Antifungal Susceptibility Testing for the Management of Invasive Fungal Infections

Invasive fungal infections (IFIs) are associated with high mortality rates and timely appropriate antifungal therapy is essential for good outcomes. Emerging antifungal resistance among Candida and Aspergillus spp., the major causes of IFI, is concerning and has led to the increasing incorporation of in vitro antifungal susceptibility testing (AST) to guide clinical decisions. However, the interpretation of AST results and their contribution to management of IFIs remains a matter of debate. Specifically, the utility of AST is limited by the delay in obtaining results and the lack of pharmacodynamic correlation between minimal inhibitory concentration (MIC) values and clinical outcome, particularly for molds. Clinical breakpoints for Candida spp. have been substantially revised over time and appear to be reliable for the detection of azole and echinocandin resistance and for outcome prediction, especially for non-neutropenic patients with candidemia. However, data are lacking for neutropenic patients with invasive candidiasis and some non-albicans Candida spp. (notably emerging Candida auris). For Aspergillus spp., AST is not routinely performed, but may be indicated according to the epidemiological context in the setting of emerging azole resistance among A. fumigatus. For non-Aspergillus molds (e.g., Mucorales, Fusarium or Scedosporium spp.), AST is not routinely recommended as interpretive criteria are lacking and many confounders, mainly host factors, seem to play a predominant role in responses to antifungal therapy. This review provides an overview of the pre-clinical and clinical pharmacodynamic data, which constitute the rationale for the use and interpretation of AST testing of yeasts and molds in clinical practice.

Population Pharmacokinetics of Voriconazole in Patients With Invasive Aspergillosis: Serum Albumin Level as a Novel Marker for Clearance and Dosage Optimization

BACKGROUND

Voriconazole (VRCZ) is an antifungal triazole recommended as an effective first-line agent for treating invasive aspergillosis.

OBJECTIVES

To develop a population pharmacokinetic model of VRCZ and trough concentration-based dosing simulation for dynamic patient conditions.

METHODS

The authors combined plasma VRCZ data from intensive sampling, and retrospective trough concentration monitoring for analysis. Nonlinear mixed-effects modeling with subsequent model validation was performed. The recommended dosage regimens were simulated based on the developed model.

RESULTS

The study participants included 106 patients taking oral VRCZ. A linear one-compartment model with first-order elimination and absorption best described the observed data. The CYP2C19 phenotypes did not influence the pharmacokinetic parameters. Serum albumin (SA) levels and gamma-glutamyl transferase significantly correlated with the VRCZ clearance rate, whereas the actual body weight influenced the volume. A visual predictive check showed good consistency with the observed data, whereas SA levels across the treatment course correlated with linear clearance, irrespective of the CYP2C19 phenotype. Patients with SA levels ≤30 g/L had lower linear clearance than that in patients with SA levels >30 g/L. Dosing simulation based on the developed model indicated that patients with SA levels of ≤30 g/L required a lower daily maintenance dose to attain the therapeutic trough level.

CONCLUSIONS

SA level was identified as a novel marker associated with VRCZ clearance. This marker may be a practical choice for physicians to perform therapeutic drug monitoring and optimize VRCZ dosage.

Predictors of Adverse Events and Determinants of the Voriconazole Trough Concentration in Kidney Transplantation Recipients

Voriconazole is the mainstay for the treatment of invasive fungal infections in patients who underwent a kidney transplant. Variant CYP2C19 alleles, hepatic function, and concomitant medications are directly involved in the metabolism of voriconazole. However, the drug is also associated with numerous adverse events. The purpose of this study was to identify predictors of adverse events using binary logistic regression and to measure its trough concentration using multiple linear modeling. We conducted a prospective analysis of 93 kidney recipients cotreated with voriconazole and recorded 213 trough concentrations of it. Predictors of the adverse events were voriconazole trough concentration with the odds ratios (OR) of 2.614 (P = 0.016), cytochrome P450 2C19 (CYP2C19), and hemoglobin (OR 0.181, P = 0.005). The predictive power of these three factors was 91.30%. We also found that CYP2C19 phenotypes, hemoglobin, platelet count, and concomitant use of ilaprazole had quantitative relationships with voriconazole trough concentration. The fit coefficient of this regression equation was R²  = 0.336, demonstrating that the model explained 33.60% of interindividual variability in the disposition of voriconazole. In conclusion, predictors of adverse events are CYP2C19 phenotypes, hemoglobin, and voriconazole trough concentration. Determinants of the voriconazole trough concentration were CYP2C19 phenotypes, platelet count, hemoglobin, concomitant use of ilaprazole. If we consider these factors during voriconazole use, we are likely to maximize the treatment effect and minimize adverse events.

Population pharmacokinetics, safety and dosing optimization of voriconazole in patients with liver dysfunction: A prospective observational study

AIMS

Voriconazole is a broad-spectrum antifungal agent for the treatment of invasive fungal infections. There is limited information about the pharmacokinetics and appropriate dosage of voriconazole in patients with liver dysfunction. This study aimed to explore the relationship between voriconazole trough concentration (C_trough ) and toxicity, identify the factors significantly associated with voriconazole pharmacokinetic parameters and propose an optimised voriconazole dosing regimen for patients with liver dysfunction.

METHODS

The study prospectively enrolled 51 patients with 272 voriconazole concentrations. Receiver operating characteristic curves were used to explore the relationship between voriconazole C_trough and toxicity. The pharmacokinetic data was analysed with nonlinear mixed-effects method. Dosing simulations stratified by total bilirubin (TBIL, TBIL-1: TBIL < 51 μmol/L; TBIL-2: 51 μmol/L ≤ TBIL < 171 μmol/L; TBIL-3: TBIL ≥ 171 μmol/L) were performed.

RESULTS

Receiver operating characteristic curve analysis revealed that voriconazole C_trough of ≤ 5.1 mg/L were associated with significantly lower the incidence of adverse events. A 1-compartment pharmacokinetic model with first-order absorption and elimination was used to describe the data. Population pharmacokinetic parameters of clearance, volume of distribution and oral bioavailability were 0.88 L/h, 148.8 L and 88.4%, respectively. Voriconazole clearance was significantly associated with TBIL and platelet count. The volume of distribution increased with body weight. Patients with TBIL-1 could be treated with a loading dose of 400 mg every 12 hours (q12h) for first day, followed by a maintenance dose of 100 mg q12h administered orally or intravenously. TBIL-2 and TBIL-3 patients could be treated with a loading dose of 200 mg q12h and maintenance doses of 50 mg q12h or 100 mg once daily and 50 mg once daily orally or intravenously, respectively.

CONCLUSIONS

Lower doses and longer dosing intervals should be considered for patients with liver dysfunction. TBIL-based dosing regimens provide a practical strategy for achieving voriconazole therapeutic range and therefore maximizing treatment outcomes.

Predictive Value of FMO3 Variants on Plasma Disposition and Adverse Reactions of Oral Voriconazole in Febrile Neutropenia

BACKGROUND AND OBJECTIVES

With the increasing number of patients with febrile neutropenia (FN), voriconazole (VRC) has been widely used in hospitals for first-line treatment of FN. The study was designed for evaluating the influence of FMO3 mutation on the plasma disposition and adverse reactions of VRC in FN.

MATERIALS AND METHODS

A single-center observational study was conducted in the inpatient ward for 4 years. The genotypes of FMO3 and cytochrome P450 (CYP) 2C19 were detected by PCR-restriction fragment length polymorphism. Patients with neutropenia were screened according to the CYP2C19 metabolic phenotype and other inclusion criteria. Five days after empirical administration of VRC, blood concentrations of VRC and nitrogen oxides in patients' blood were determined by liquid chromatography-electrospray tandem mass spectrometry (LC-ESI MS/MS). Serum parameters and clinical adverse reaction symptoms in the medical records were collected and statistically analyzed.

RESULTS

A total of 165 patients with neutropenia with the intermediate metabolic phenotype of CYP2C19 were screened. At the initial stage of oral VRC treatment, patients with the FMO3 E308G genotype had a poorer plasma disposal ability to VRC than those with the wide type of FMO3 (WT) genotype (p = 0.0005). Moreover, patients with the FMO3 E308G genotype were more likely to have adverse drug reactions and abnormal serum parameters after receiving VRC treatment. For example, the serum potassium level in the FMO3 E308G genotype group was significantly lower than that in the WT group (p = 0.028), the abnormal level of total bilirubin in the FMO3 E308G genotype group was significantly higher than that in the WT group (p = 0.049), and the aspartate aminotransferase level in the E308G group was significantly higher than that in the WT group (p = 0.05). The incidence of atopic dermatitis and visual impairment in the FMO3 E308G genotype group was 67 and 75%, respectively, and the incidences of peripheral neuroedema, headache, and diarrhea were 57, 50, and 60%, respectively, which were significantly different from those in the WT group.

CONCLUSION

FMO3 E308G reduces the activity of the FMO3 enzyme by decreasing the metabolic ability of VRC, which increases the plasma concentration of VRC and may also lead to adverse reactions in patients with FN.

Impact of Albumin and Omeprazole on Steady-State Population Pharmacokinetics of Voriconazole and Development of a Voriconazole Dosing Optimization Model in Thai Patients with Hematologic Diseases

This study aimed to identify factors that significantly influence the pharmacokinetics of voriconazole in Thai adults with hematologic diseases, and to determine optimal voriconazole dosing regimens. Blood samples were collected at steady state in 65 patients (237 concentrations) who were taking voriconazole to prevent or treat invasive aspergillosis. The data were analyzed using a nonlinear mixed-effects modeling approach. Monte Carlo simulation was applied to optimize dosage regimens. Data were fitted with the one-compartment model with first-order absorption and elimination. The apparent oral clearance (CL/F) was 3.43 L/h, the apparent volume of distribution (V/F) was 47.6 L, and the absorption rate constant (Ka) was fixed at 1.1 h⁻¹. Albumin and omeprazole ≥ 40 mg/day were found to significantly influence CL/F. The simulation produced the following recommended maintenance doses of voriconazole: 50, 100, and 200 mg every 12 h for albumin levels of 1.5–3, 3.01–4, and 4.01–4.5 g/dL, respectively, in patients who receive omeprazole ≤ 20 mg/day. Patients who receive omeprazole ≥ 40 mg/day and who have serum albumin level 1.5–3 and 3.01–4.5 g/dL should receive voriconazole 50 and 100 mg, every 12 h, respectively. Albumin level and omeprazole dosage should be carefully considered when determining the appropriate dosage of voriconazole in Thai patients.

Pharmacokinetic/Pharmacodynamic Analysis of Voriconazole Against Candida spp. and Aspergillus spp. in Allogeneic Stem Cell Transplant Recipients

BACKGROUND

To evaluate the adequacy of different dosing regimens of voriconazole for the prophylaxis of invasive candidiasis and aspergillosis in adult allogeneic stem cell transplant recipients by means of population pharmacokinetic (PK) modelling and simulation.

METHODS

Allogeneic stem cell transplant recipients receiving voriconazole were included in this observational study. A population PK model was developed. Three oral voriconazole-dosing regimens were simulated: 200, 300, and 400 mg twice daily. The pharmacodynamic target was defined as fAUC0-24/0.7. A probability of target attainment ≥90% was considered optimal. The cumulative fraction of response was defined as the fraction of patients achieving the pharmacodynamic target when a population of simulated patients is matched with a simulated population of different Candida spp. and Aspergillus spp. The percentage of patients with trough plasma concentrations at steady state (Ctrough) within the reference range (1-5.5 mg/L) was also calculated.

RESULTS

A 2-compartment PK model was developed using data from 40 patients, which contributed 237 voriconazole plasma samples, including trough and maximum concentrations. Voriconazole 200, 300, and 400 mg twice daily achieved probability of target attainment ≥90% for minimal inhibitory concentration values ≤0.25, ≤0.38, and ≤0.50 mg/L, respectively. The cumulative fraction of response for A. niger, A. versicolor, and A. flavus increased >10% when increasing voriconazole dose from 200 to 400 mg twice daily (from 72.5% to 89.5% for A. niger; from 77.7% to 88.7% for A. versicolor; and from 82.4% to 94.9% for A flavus). The percentage of patients with Ctrough within the reference range increased 15% when voriconazole dose was increased from 200 to 300 mg twice daily.

CONCLUSIONS

The PK simulations in this study suggest that transplant recipients on voriconazole prophylaxis against invasive candidiasis or aspergillosis are likely to achieve the target concentrations associated with the desired treatment outcomes if the maintenance dose is 200 mg twice daily. However, Aspergillus spp. with high minimal inhibitory concentrations could require higher maintenance doses.

Review of influenza-associated pulmonary aspergillosis in ICU patients and proposal for a case definition: an expert opinion

PURPOSE

Invasive pulmonary aspergillosis is increasingly reported in patients with influenza admitted to the intensive care unit (ICU). Classification of patients with influenza-associated pulmonary aspergillosis (IAPA) using the current definitions for invasive fungal diseases has proven difficult, and our aim was to develop case definitions for IAPA that can facilitate clinical studies.

METHODS

A group of 29 international experts reviewed current insights into the epidemiology, diagnosis and management of IAPA and proposed a case definition of IAPA through a process of informal consensus.

RESULTS

Since IAPA may develop in a wide range of hosts, an entry criterion was proposed and not host factors. The entry criterion was defined as a patient requiring ICU admission for respiratory distress with a positive influenza test temporally related to ICU admission. In addition, proven IAPA required histological evidence of invasive septate hyphae and mycological evidence for Aspergillus. Probable IAPA required the detection of galactomannan or positive Aspergillus culture in bronchoalveolar lavage (BAL) or serum with pulmonary infiltrates or a positive culture in upper respiratory samples with bronchoscopic evidence for tracheobronchitis or cavitating pulmonary infiltrates of recent onset. The IAPA case definitions may be useful to classify patients with COVID-19-associated pulmonary aspergillosis (CAPA), while awaiting further studies that provide more insight into the interaction between Aspergillus and the SARS-CoV-2-infected lung.

CONCLUSION

A consensus case definition of IAPA is proposed, which will facilitate research into the epidemiology, diagnosis and management of this emerging acute and severe Aspergillus disease, and may be of use to study CAPA.

Saliva for Precision Dosing of Antifungal Drugs: Saliva Population PK Model for Voriconazole Based on a Systematic Review

Precision dosing for many antifungal drugs is now recommended. Saliva sampling is considered as a non-invasive alternative to plasma sampling for therapeutic drug monitoring (TDM). However, there are currently no clinically validated saliva models available. The aim of this study is firstly, to conduct a systematic review to evaluate the evidence supporting saliva-based TDM for azoles, echinocandins, amphotericin B, and flucytosine. The second aim is to develop a saliva population pharmacokinetic (PK) model for eligible drugs, based on the evidence. Databases were searched up to July 2019 on PubMed® and Embase®, and 14 studies were included in the systematic review for fluconazole, voriconazole, itraconazole, and ketoconazole. No studies were identified for isavuconazole, posaconazole, flucytosine, amphotericin B, caspofungin, micafungin, or anidulafungin. Fluconazole and voriconazole demonstrated a good saliva penetration with an average S/P ratio of 1.21 (± 0.31) for fluconazole and 0.56 (± 0.18) for voriconazole, both with strong correlation (r = 0.89-0.98). Based on the evidence for TDM and available data, population PK analysis was performed on voriconazole using Nonlinear Mixed Effects Modeling (NONMEM 7.4). 137 voriconazole plasma and saliva concentrations from 11 patients (10 adults, 1 child) were obtained from the authors of the included study. Voriconazole pharmacokinetics was best described by one-compartment PK model with first-order absorption, parameterized by clearance of 4.56 L/h (36.9% CV), volume of distribution of 60.7 L, absorption rate constant of 0.858 (fixed), and bioavailability of 0.849. Kinetics of the voriconazole distribution from plasma to saliva was identical to the plasma kinetics, but the extent of distribution was lower, modeled by a scale factor of 0.5 (4% CV). A proportional error model best accounted for the residual variability. The visual and simulation-based model diagnostics confirmed a good predictive performance of the saliva model. The developed saliva model provides a promising framework to facilitate saliva-based precision dosing of voriconazole.

Long-term Outcomes of Patients With Fungal Infections Associated With Contaminated Methylprednisolone Injections

Background

The largest health care–associated infection outbreak in the United States occurred during 2012–2013. Following injection of contaminated methylprednisolone, 753 patients developed infection with a dematiaceous mold, Exserohilum rostratum. The long-term outcomes of these infections have not been described.

Methods

This retrospective cohort study of 440 of a total of 753 patients with proven or probable Exserohilum infection evaluated clinical and radiographic findings, antifungal therapy and associated adverse effects, and outcomes at 6 weeks, 3, 6, 9, and 12 months after diagnosis. Patients were grouped into 4 disease categories: meningitis with/without stroke, spinal or paraspinal infections, meningitis/stroke plus spinal/paraspinal infections, and osteoarticular infections.

Results

Among the 440 patients, 223 (51%) had spinal/paraspinal infection, 82 (19%) meningitis/stroke, 123 (28%) both, and 12 (3%) osteoarticular infection. Of 82 patients with meningitis/stroke, 18 (22%) died; among those surviving, 87% were cured at 12 months. Only 7 (3%) of 223 patients with spinal/paraspinal infection died, but at 12 months, 68% had persistent or worsening pain and only 47% were cured. For the 123 patients with both meningitis/stroke and spinal/paraspinal infection, 10 (8%) died, pain persisted in 72%, and 52% were cured at 12 months. Only 37% of those with osteoarticular infection were cured at 12 months. Adverse events from antifungal therapy were noted at 6 weeks in 71% of patients on voriconazole and 81% on amphotericin B.

Conclusions

Fungal infections related to contaminated methylprednisolone injections culminated in death in 8% of patients. Persistent pain and disability were seen at 12 months in most patients with spinal/paraspinal infections.

Treatment of invasive fungal diseases in cancer patients-Revised 2019 Recommendations of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO)

BACKGROUND

Invasive fungal diseases remain a major cause of morbidity and mortality in cancer patients undergoing intensive cytotoxic therapy. The choice of the most appropriate antifungal treatment (AFT) depends on the fungal species suspected or identified, the patient's risk factors (eg length and depth of granulocytopenia) and the expected side effects.

OBJECTIVES

Since the last edition of recommendations for 'Treatment of invasive fungal infections in cancer patients' of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO) in 2013, treatment strategies were gradually moving away from solely empirical therapy of presumed or possible invasive fungal diseases (IFDs) towards pre-emptive therapy of probable IFD.

METHODS

The guideline was prepared by German clinical experts for infections in cancer patients in a stepwise consensus process. MEDLINE was systematically searched for English-language publications from January 1975 up to September 2019 using the key terms such as 'invasive fungal infection' and/or 'invasive fungal disease' and at least one of the following: antifungal agents, cancer, haematological malignancy, antifungal therapy, neutropenia, granulocytopenia, mycoses, aspergillosis, candidosis and mucormycosis.

RESULTS

AFT of IFDs in cancer patients may include not only antifungal agents but also non-pharmacologic treatment. In addition, the armamentarium of antifungals for treatment of IFDs has been broadened (eg licensing of isavuconazole). Additional antifungals are currently under investigation or in clinical trials.

CONCLUSIONS

Here, updated recommendations for the treatment of proven or probable IFDs are given. All recommendations including the levels of evidence are summarised in tables to give the reader rapid access to key information.

Antimicrobial therapeutic drug monitoring in critically ill adult patients: a Position Paper

Purpose

This Position Paper aims to review and discuss the available data on therapeutic drug monitoring (TDM) of antibacterials, antifungals and antivirals in critically ill adult patients in the intensive care unit (ICU). This Position Paper also provides a practical guide on how TDM can be applied in routine clinical practice to improve therapeutic outcomes in critically ill adult patients.

Methods

Literature review and analysis were performed by Panel Members nominated by the endorsing organisations, European Society of Intensive Care Medicine (ESICM), Pharmacokinetic/Pharmacodynamic and Critically Ill Patient Study Groups of European Society of Clinical Microbiology and Infectious Diseases (ESCMID), International Association for Therapeutic Drug Monitoring and Clinical Toxicology (IATDMCT) and International Society of Antimicrobial Chemotherapy (ISAC). Panel members made recommendations for whether TDM should be applied clinically for different antimicrobials/classes.

Results

TDM-guided dosing has been shown to be clinically beneficial for aminoglycosides, voriconazole and ribavirin. For most common antibiotics and antifungals in the ICU, a clear therapeutic range has been established, and for these agents, routine TDM in critically ill patients appears meritorious. For the antivirals, research is needed to identify therapeutic targets and determine whether antiviral TDM is indeed meritorious in this patient population. The Panel Members recommend routine TDM to be performed for aminoglycosides, beta-lactam antibiotics, linezolid, teicoplanin, vancomycin and voriconazole in critically ill patients.

Conclusion

Although TDM should be the standard of care for most antimicrobials in every ICU, important barriers need to be addressed before routine TDM can be widely employed worldwide.

Electronic supplementary material

The online version of this article (10.1007/s00134-020-06050-1) contains supplementary material, which is available to authorized users.

Genetic polymorphisms of transient receptor potential melastatin 1 correlate with voriconazole-related visual adverse events

BACKGROUND

Causes of voriconazole-related visual adverse events (VVAE) remained controversial.

OBJECTIVES

We aimed to explore the relationship between voriconazole serum concentrations and VVAE as well as the potential influence of transient receptor potential melastatin 1 (TRPM1) on VVAE.

PATIENTS/METHODS

This prospective observational cohort study was done in two stages. Patients who received voriconazole for invasive fungal diseases were consecutively enrolled. Correlations between voriconazole trough levels and VVAE were explored in 76 patients. Genotyping was further conducted for 17 tag SNPs of TRPM1 in a larger population of 137 patients. Genotype distributions were compared between patients with and without VVAE.

RESULT

Of the 76 patients, a total of 229 steady-state voriconazole trough levels were evaluated, 69.9% of which were within the target range (1-5.5 mg/L). No correlations were found between voriconazole trough levels and VVAE. Of the total 137 patients, VVAE occurred in 37 (27.0%) patients, including visual hallucination (13.9%, 19/137) and visual disturbances (19.0%, 26/137). Significant difference in TRPM1 genotype distribution was only observed in patients with visual hallucination but not with visual disturbances. We found that rs890160 G/T genotype was under-presented (OR, 0.11; 95% CI, 0.01-0.84; P = .011) and rs1378847 C/C genotype was more frequently detected (OR, 8.89; 95% CI, 1.14-69.02; P = .013) in patients with visual hallucination when compared with those without.

CONCLUSION

Transient receptor potential melastatin 1 was genetically associated with voriconazole-related visual hallucination. The correlation was failed to found between voriconazole trough levels and VVAE.

How to design a study to evaluate therapeutic drug monitoring in infectious diseases?

BACKGROUND

Therapeutic drug monitoring (TDM) is a tool to personalize and optimize dosing by measuring the drug concentration and subsequently adjusting the dose to reach a target concentration or exposure. The evidence to support TDM is however often ranked as expert opinion. Limitations in study design and sample size have hampered definitive conclusions of the potential added value of TDM.

OBJECTIVES

We aim to give expert opinion and discuss the main points and limitations of available data from antibiotic TDM trials and emphasize key elements for consideration in design of future clinical studies to quantify the benefits of TDM.

SOURCES

The sources were peer-reviewed publications, guidelines and expert opinions from the field of TDM.

CONTENT

This review focuses on key aspects of antimicrobial TDM study design: describing the rationale for a TDM study, assessing the exposure of a drug, assessing susceptibility of pathogens and selecting appropriate clinical endpoints. Moreover we provide guidance on appropriate study design.

IMPLICATIONS

This is an overview of different aspects relevant for the conduct of a TDM study. We believe that this paper will help researchers and clinicians to design and conduct high-quality TDM studies.

Determination of voriconazole in human plasma by liquid chromatography-tandem mass spectrometry and its application in therapeutic drug monitoring in Chinese patients

OBJECTIVE

To develop a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of voriconazole in human plasma, and to evaluate its application in clinical therapeutic drug monitoring.

METHOD

Plasma samples were obtained from Chinese patients receiving voriconazole, precipitated with methanol (using fluconazole as an internal standard), and then subjected to LC-MS/MS using an SB C18 column with a methanol and water mobile phase at a flow rate of 0.4 mL/minute. Quantification was performed by multiple-reaction monitoring using the precursor and product ion pair m/z 350-280.9 for voriconazole and m/z 307-219.9 for fluconazole.

RESULTS

The calibration curve was linear over a range of 0.1-10.0 µg/mL (R2 = 0.9995). The inter-day and intra-day relative standard deviations were <7.68% and <8.97%, respectively. Extraction recovery, matrix effect, and stability were also validated. Sixty-eight plasma samples from 42 patients were analyzed, and the voriconazole concentrations in 25 samples (36.8%) were outside the optimal range of 1.5-4.5 µg/mL.

CONCLUSIONS

We developed a simple and accurate method of drug monitoring, which could improve the efficacy and prevent adverse reactions of voriconazole.

Pharmacokinetics of intravenous voriconazole in patients with liver dysfunction: A prospective study in the intensive care unit

OBJECTIVES

To characterize the pharmacokinetics (PK) of intravenous voriconazole (VRC) in critically ill patients with liver dysfunction.

METHODS

Patients with liver dysfunction in the intensive care unit (ICU) were included prospectively. The Child-Pugh score was used to categorize the degree of liver dysfunction. The initial intravenous VRC dosing regimen comprised a loading dose of 300 mg every 12 h for the first 24 h, followed by 200 mg every 12 h. The first PK curves (PK curve 1) were drawn within one dosing interval of the first dose for 17 patients; the second PK curves (PK curve 2) were drawn within one dosing interval after a minimum of seven doses for 12 patients. PK parameters were estimated by non-compartmental analysis.

RESULTS

There were good correlations between the area under the curve (AUC_0-12) of PK curve 2 and the corresponding trough concentration (C₀) and peak concentration (C_max) (r² = 0.951 and 0.963, respectively; both p < 0.001). The median half-life (t_1/2) and clearance (CL) of patients in Child-Pugh class A (n = 3), B (n = 5), and C (n = 4) of PK curve 2 were 24.4 h and 3.31 l/h, 29.1 h and 2.54 l/h, and 60.7 h and 2.04 l/h, respectively. In the different Child-Pugh classes, the CL (median) of PK curve 2 were all lower than those of PK curve 1. The apparent steady-state volume of distribution (V_ss) of PK curve 1 was positively correlated with actual body weight (r² = 0.450, p = 0.004). The median first C₀ of 17 patients determined on day 5 was 5.27 (2.61) μg/ml, and 29.4% of C₀ exceeded the upper limit of the therapeutic window (2-6 μg/ml).

CONCLUSIONS

The CL of VRC decreased with increasing severity of liver dysfunction according to the Child-Pugh classification, along with an increased t_1/2, which resulted in high plasma exposure of VRC. Adjusted dosing regimens of intravenous VRC should be established based on Child-Pugh classes for these ICU patients, and plasma concentrations should be monitored closely to avoid serious adverse events.

Therapeutic Drug Monitoring of Antifungal Drugs: Another Tool to Improve Patient Outcome?

Introduction

This study aimed to examine the relationship among adequate dose, serum concentration and clinical outcome in a non-selected group of hospitalized patients receiving antifungals.

Methods

Prospective cross-sectional study performed between March 2015 and June 2015. Dosage of antifungals was considered adequate according to the IDSA guidelines, whereas trough serum concentrations (determined with HPLC) were considered adequate as follows: fluconazole > 11 µg/ml, echinocandins > 1 µg/ml, voriconazole 1–5.5 µg/ml and posaconazole > 0.7 µg/ml.

Results

During the study period, 84 patients (65.4% male, 59.6 years) received antifungals for prophylaxis (40.4%), targeted (31.0%) and empirical therapy (28.6%). The most frequent drug was micafungin (28/84; 33.3%) followed by fluconazole (23/84; 27.4%), voriconazole (15/84; 17.9%), anidulafungin (8/84; 9.5%), posaconazole (7/84; 8.3%) and caspofungin (3/84; 3.6%). Considerable interindividual variability was observed for all antifungals with a large proportion of the patients (64.3%) not attaining adequate trough serum concentrations, despite receiving an adequate antifungal dose. Attaining the on-target serum antifungal level was significantly associated with a favorable clinical outcome (OR = 0.02; 95% CI 0.01–0.64; p = 0.03), whereas the administration of an adequate antifungal dosage was not.

Conclusions

With the standard antifungal dosage, a considerable proportion of patients have low drug concentrations, which are associated with poor clinical outcome.

Population Pharmacokinetics of Voriconazole in Chinese Patients with Hematopoietic Stem Cell Transplantation

BACKGROUND AND OBJECTIVE

Voriconazole is widely recommended for the prevention and treatment of invasive fungal infections in hematopoietic stem cell transplantation patients. However, its use is limited by a narrow therapeutic range and large inter-individual variability. This study aimed to characterize the pharmacokinetics of voriconazole in Chinese hematopoietic stem cell transplantation patients, to explore factors affecting its pharmacokinetic parameters, and to provide recommendations for its optimal dosing regimens.

METHODS

A total of 121 serum concentration samples from 23 patients were retrospectively included. Voriconazole concentrations were detected, and patient clinical data were recorded. Population pharmacokinetic analysis was performed by a non-linear, mixed-effect modeling approach. Goodness-of-fit plots, bootstrap method, prediction-corrected visual predictive check and external validation by an independent group of seven patients were performed to evaluate the final model.

RESULTS

A one-compartment model with first-order elimination successfully described the data. The absorption rate constant was fixed at 1.1 h^-1 and bioavailability was fixed at 0.895. The typical values for voriconazole clearance and distribution volume were 9.52 L/h and 155 L, respectively. CYP2C19*2 genotype and mycophenolate mofetil combination presented a significant impact on the clearance. Compared with CYP2C19*2 carriers, voriconazole clearance was proven to be higher in CYP2C19*1/*1 patients.

CONCLUSIONS

A population pharmacokinetic model of voriconazole was successfully established in Chinese hematopoietic stem cell transplantation patients. Based on the final model, CYP2C19*2 genotyping coupled with therapeutic drug monitoring seems to be useful to guide voriconazole dosing and to explain subtherapeutic concentrations in clinical practice.

Tacrolimus Concentration after Letermovir Initiation in Hematopoietic Stem Cell Transplantation Recipients Receiving Voriconazole: A Retrospective, Observational Study

Letermovir (LMV) is a new antiviral drug used to prevent cytomegalovirus infection in hematopoietic stem cell transplantation (HSCT) recipients. It has been reported to increase tacrolimus (TAC) exposure and decrease voriconazole (VRCZ) exposure in healthy participants. However, VRCZ inhibits the metabolism of TAC. Thus, the effects of LMV on TAC exposure in patients receiving VRCZ are unknown. This retrospective, observational, single-center study was conducted between May 2018 and April 2019. The TAC concentration/dose (C/D) ratio, VRCZ concentration, and VRCZ C/D ratio for 7 days before and for the first and second 7-day periods after the initiation of LMV administration were evaluated. Fourteen HSCT recipients receiving VRCZ were enrolled. There was no significant difference in the TAC C/D ratio for 7 days before and for the first and second 7-day periods after initiating LMV administration (median: 866 [IQR: 653-953], 842 [IQR: 636-1031], and 906 [IQR: 824-1210] [ng/mL]/[mg/kg], respectively). In contrast, the VRCZ C/D ratio and concentration for the first and second 7-day periods after LMV initiation were significantly lower than those before initiating LMV administration (mean 1.11 ± 0.07, 0.12 ± 0.08, and 0.22 ± 0.12 [μg/mL]/[mg/kg] and 0.7 ± 0.5, 0.8 ± 0.5, and 1.3 ± 0.7 μg/mL, respectively; n = 12). This can be explained by the increase in TAC concentration caused by CYP3A4 inhibition due to LMV and by the decrease in TAC concentration ascribed to the decrease in VRCZ concentration by CYP2C19 induction due to LMV. These results suggest that it is unnecessary to adjust the dose of TAC based on LMV initiation; however, it is necessary to adjust the dose of TAC based on conventional TAC concentration measurements.

Novel insights into the complex pharmacokinetics of voriconazole: a review of its metabolism

Voriconazole, a second-generation triazole frequently used for the prophylaxis and treatment of invasive fungal infections, undergoes complex metabolism mainly involving various (polymorphic) cytochrome P450 enzymes in humans. Although high inter- and intraindividual variability in voriconazole pharmacokinetics have been observed and the therapeutic range for this compound is relatively narrow, the metabolism of voriconazole has not been fully elucidated yet. The available literature data investigating the multiple different pathways and metabolites are extremely unbalanced and thus the absolute or relative contribution of the different pathways and enzymes involved in the metabolism of voriconazole remains uncertain. Furthermore, other factors such as nonlinear pharmacokinetics caused by auto-inhibition or -induction and polymorphisms of the metabolizing enzymes hinder safe and effective voriconazole dosing in clinical practice and have not yet been studied sufficiently. This review aimed at amalgamating the available literature on the pharmacokinetics of voriconazole in vitro and in vivo, with a special focus on metabolism in adults and children, in order to congregate an overall landscape of the current body of knowledge and identify knowledge gaps, opening the way towards further research in order to foster the understanding, towards better therapeutic dosing decisions.

ESCMID-ECMM guideline: diagnosis and management of invasive aspergillosis in neonates and children

SCOPE

Presenting symptoms, distributions and patterns of diseases and vulnerability to invasive aspergillosis (IA) are similar between children and adults. However, differences exist in the epidemiology and underlying conditions, the usefulness of newer diagnostic tools, the pharmacology of antifungal agents and in the evidence from interventional phase 3 clinical trials. Therefore, the European Society for Clinical Microbiology and Infectious Diseases (ESCMID) and the European Confederation of Medical Mycology (ECMM) have developed a paediatric-specific guideline for the diagnosis and management of IA in neonates and children.

METHODS

Review and discussion of the scientific literature and grading of the available quality of evidence was performed by the paediatric subgroup of the ESCMID-ECMM-European Respiratory Society (ERS) Aspergillus disease guideline working group, which was assigned the mandate for the development of neonatal- and paediatric-specific recommendations.

QUESTIONS

Questions addressed by the guideline included the epidemiology of IA in neonates and children; which paediatric patients may benefit from antifungal prophylaxis; how to diagnose IA in neonates and children; which antifungal agents are available for use in neonates and children; which antifungal agents are suitable for prophylaxis and treatment of IA in neonates and children; what is the role of therapeutic drug monitoring of azole antifungals; and which management strategies are suitable to be used in paediatric patients. This guideline provides recommendations for the diagnosis, prevention and treatment of IA in the paediatric population, including neonates. The aim of this guideline is to facilitate optimal management of neonates and children at risk for or diagnosed with IA.