Efficacy and safety of voriconazole and CYP2C19 polymorphism for optimised dosage regimens in patients with invasive fungal infections

A Real-world Pharmacovigilance Study Of FDA Adverse Event Reporting System (FAERS) Events For Gender Of Voriconazole Drugs

To detect the gender variations in adverse events (AEs) of voriconazole, promote personalised medicine.A normalized dataset from Q1 2004 to Q4 2022 from the US Food and Drug Administration's Adverse Event Reporting System (FAERS) was analyses. The reporting odds ratio (ROR), proportional reporting ratio (PRR), and P value were used to examine data from the FAERS database to detect risk signals and quantify the presence and extent of gender variations in voriconazole adverse events.A total of 7670 cases (female/male (2785/4885)) of adverse reactions to voriconazole were analysed, and drug interaction (ROR 1.30 (1.10,1.54)), death and sudden death (ROR 1.31 (1.06,1.61)), actinic keratosis (ROR 1.98 (1.10,3.57)) were found to be significantly more frequent in male patients than in female patients.We found that gender was a determinant in voriconazole-related AEs using FAERS. Our results require future validation due to the inherent limits of this open data source, but they also identify potential contributing elements for a customised side effect profiling.

Voriconazole in the management of invasive pulmonary aspergillosis in patients with severe liver disease: balancing efficacy and hepatotoxicity

Patients with severe liver disease (SLD) are prone to developing invasive pulmonary aspergillosis (IPA) due to immunodeficiency and microbial translocation, leading to high mortality rates. Although voriconazole is the first-line treatment for IPA, its use in patients with SLD is challenging due to the risk of hepatotoxicity. In this population, reduced hepatic blood flow and enzyme activity, compromised bile excretion, and increased intestinal permeability collectively affect voriconazole metabolism, resulting in a prolonged half-life, drug accumulation, and higher incidence of adverse events (AEs). Therapeutic drug monitoring (TDM) is essential to optimize voriconazole therapy, ensuring plasma concentrations within the therapeutic range (1.0-5.0 mg/L) while minimizing toxicity risks. This review highlights the risk factors for IPA in patients with SLD, the mechanisms of voriconazole-induced hepatotoxicity, its pharmacokinetics in this population, and current research on dose optimization. We emphasize the necessity of closely monitoring voriconazole plasma concentration, liver function, and inflammatory markers during treatment. For patients with SLD, we recommend a loading dose of 200 mg every 12 hours, with subsequent maintenance doses reduced to 1/4-1/3 of the standard dose, though the evidence remains limited. We call for large-scale clinical trials to define optimal dosing, efficacy, and safety of voriconazole for IPA in patients with SLD, providing clinicians with clearer treatment guidelines and improving patient outcomes.

A preliminary exploration of liver microsomes and PBPK to uncover the impact of CYP3A4/5 and CYP2C19 on tacrolimus and voriconazole drug-drug interactions

Solid transplant recipients are at increased risk for invasive aspergillosis. Tacrolimus and Voriconazole is one of the most frequently utilized treatments for those recipients with invasive fungal infections. However, it is difficult to use them properly due to the interaction between them. This study aimed to investigate the potential drug-drug interaction between Tacrolimus and Voriconazole by multiple methods, including in vitro liver microsome method and the PBPK(Physiologically Based Pharmacokinetic) model. Midazolam and testosterone were used as probe substrates to evaluate individual differences in CYP3A4/5 metabolic activity. A comprehensive interaction analysis was also conducted based on the STITCH database and the DD-Inter system. Furthermore, a PBPK model was constructed by the data from the literature to simulate the real metabolic process in vivo. The research employed multiple methodologies to demonstrate that the co-administration of Voriconazole significantly enhances Tacrolimus concentrations, considering genotypes and the activity of CYP3A4/5 genotypes. The findings indicated a decrease in the relative percentages of midazolam and testosterone metabolites with increasing Voriconazole concentration. Moreover, the results for residual Tacrolimus in the 30-minute incubation group revealed that Voriconazole exerts a mild inhibitory effect on the in vitro metabolism of Tacrolimus. The STITCH database and DD-Inter system analysis also suggested that Tacrolimus and Voriconazole share a strong association in liver metabolism, most likely interacting with CYP3A4/5 and CYP2C19. Furthermore, the result of PBPK analysis indicated that Tacrolimus AUC increases with Voriconazole co-therapy. Moreover, the AUC of Tacrolimus in intermediate CYP2C19 metabolizers (IM) was the highest at 10.1 µmol·min/L, followed by poor metabolizers (PM) at 8.13 µmol·min/L, and extensive metabolizers (EM) at 2.18 µmol·min/L. And the genotype of CYP3A5 poor metabolizer (PM) had AUC of Tacrolimus at 3.13µmol·min/L and extensive metabolizer (EM) at 2.18µmol·min/L. Microsomal studies, PBPK models, and multiple other analyses have comprehensively elucidated the impact of Voriconazole on Tacrolimus concentrations. These findings can serve as a valuable point of reference for concurrently administering these two medications. These findings also indicate that the genotypes of CYP2C19 play an important role in the development of DDI during concurrent Tacrolimus and Voriconazole treatment, which may have some guidance for clinical medication.

1-methylnicotinamide modulates IL-10 secretion and voriconazole metabolism

Background

Inflammatory diseases impair the hepatic metabolism of voriconazole (VRC). 1-Methylnicotinamide (1-MNA), a common final metabolite of nicotinamide in the liver, has demonstrated anti-inflammatory effects in recent studies. This study investigated the impact of 1-MNA on VRC metabolism in the liver.

Method

Mice with a systemic inflammatory response induced by lipopolysaccharide (LPS) were intragastrically administered 1-MNA, and their VRC metabolic capacity was evaluated. Kupffer cells and primary hepatocytes were isolated, and flow cytometry along with molecular knockdown experiments were performed to explore the molecular mechanisms underlying improved drug metabolism. IL-10 knockout (IL-10-/-) mice were used to validate the role of IL-10 in enhancing hepatocyte VRC metabolism under inflammatory conditions.

Results

1-MNA promoted M2 polarization of liver Kupffer cells, stimulated IL-10 secretion, upregulated CYP2C38 expression in primary hepatocytes, and enhanced VRC metabolism. The mechanism by which IL-10 upregulated CYP2C38 appears to involve the inhibition of the nuclear transcription factor NF-κB (p65) in hepatocytes.

Conclusions

1-MNA regulated Kupffer cell polarization in an LPS-induced inflammatory environment, reduced the inflammatory inhibition of CYP2C38 expression in hepatocytes, and promoted VRC metabolism.

Stability and Analytical Characterization of Voriconazole as Measured by Immunoassay

BACKGROUND

Voriconazole is a broad-spectrum triazole antifungal agent recommended for invasive fungal diseases, including invasive aspergillosis. Therapeutic drug monitoring via voriconazole target trough concentration is important to ensure efficacy while preventing toxicity. Our aim was to determine the stability of voriconazole as adapted and measured by an immunoassay.

METHODS

Plasma from patient samples (n = 45) evaluated by a liquid chromatography with tandem mass spectrometry (LC-MS/MS) method was compared against an ARK immunoassay method, adapted and optimized on the Abbott Alinity c analyzer. Stability of voriconazole and analytical performance of ARK immunoassay was assessed, including functional sensitivity, limit of blank (LoB), limit of detection (LoD), and limit of quantification (LoQ), linearity, and precision.

RESULTS

ARK voriconazole immunoassay was highly correlated (Pearson R = 0.988) to the LC-MS/MS method, with an average bias of 0.09 mg/L (2%). CV at LoQ of 0.5 mg/L was 3.7% while the functional sensitivity was established at 0.05 mg/L. Overall imprecision with liquid quality control material obtained from ARK was 5.0%, 6.3%, and 5.9% at 1 mg/L, 5 mg/L, and 10 mg/L, respectively. Limit of blank and LoD were 0.02 mg/L and 0.05 mg/L, respectively. Voriconazole in lithium heparin plasma separator tube declines over time, with a decrease that is more evident near or above toxic concentrations.

CONCLUSION

Voriconazole collected in gel separation tubes declines over time, possibly due to absorptive properties. Voriconazole measurements by immunoassay and LC-MS/MS demonstrated acceptable comparability with sufficient level of sensitivity and precision.

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.

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.

Characterization and real-live results of nebulized voriconazole: A single-center observational study

OBJECTIVE

Pulmonary administration of voriconazole involves advantages, including optimization of lung penetration and reduction of adverse effects and interactions. However, there is scarce evidence about its use and there are no commercial presentations for nebulization. We aim to characterize a compounded voriconazole solution for nebulization and describe its use in our center.

METHOD

This is a retrospective observational study including patients who received nebulized voriconazole to treat fungal lung diseases (infection or colonization). Voriconazole solution was prepared from commercial vials for intravenous administration.

RESULTS

The pH and osmolarity of voriconazole solutions were adequate for nebulization. Ten patients were included, nine adults and a child. The dosage was 40 mg in adults and 10 mg in the pediatric patient, diluted to a final concentration of 10 mg/ml, administered every 12-24 hours. The median duration of treatment was 139 (range: 26-911) days. There were no reported adverse effects and the drug was not detected in plasma when nebulized only.

CONCLUSION

Voriconazole nebulization is well tolerated and it is not absorbed into the systemic circulation; further research is needed to assess its efficacy.

Characterization and real-live results of nebulized voriconazole: A single-center observational study

OBJECTIVE

Pulmonary administration of voriconazole involves advantages, including optimization of lung penetration and reduction of adverse effects and interactions. However, there is scarce evidence about its use and there are no commercial presentations for nebulization. We aim to characterize a compounded voriconazole solution for nebulization and describe its use in our center.

METHOD

This is a retrospective observational study including patients who received nebulized voriconazole to treat fungal lung diseases (infection or colonization). Voriconazole solution was prepared from commercial vials for intravenous administration.

RESULTS

The pH and osmolarity of voriconazole solutions were adequate for nebulization. Ten patients were included, 9 adults and a child. The dosage was 40 mg in adults and 10 mg in the pediatric patient, diluted to a final concentration of 10 mg/ml, administered every 12-24 h. The median duration of treatment was 139 (range: 26-911) days. There were no reported adverse effects and the drug was not detected in plasma when nebulized only.

CONCLUSION

Voriconazole nebulization is well-tolerated and it is not absorbed into the systemic circulation; further research is needed to assess its efficacy.

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.

Establishment of a mathematical prediction model for voriconazole stable maintenance dose: a prospective study

Background

In patients with invasive fungal infection (IFI), the steady-state serum trough concentration (C min) of voriconazole (VCZ) is highly variable and can lead to treatment failure (C min < 0.5 mg/L) and toxicity (C min ≥ 5.0 mg/L). However, It remains challenging to determine the ideal maintenance dose to achieve the desired C min level quickly.

Aims

This randomized, prospective observational single-center study aimed to identify factors affecting VCZ-C min and maintenance dose and create an algorithmic model to predict the necessary maintenance dose. MeThe study enrolled 306 adult IFI patients, split into two groups: non-gene-directed (A) (where CYP2C19 phenotype is not involved in determining VCZ dose) and gene-directed (B) (where CYP2C19 phenotype is involved in determining VCZ dose).

Results

Results indicated that CYP2C19 genetic polymorphisms might significantly impact VCZ loading and maintenance dose selection. CYP2C19 phenotype, C-reaction protein (CRP), and average daily dose/body weight were significant influencers on VCZ-C min, while CYP2C19 phenotype, CRP, and body weight significantly impacted VCZ maintenance dose. A feasible predictive formula for VCZ stable maintenance dose was derived from the regression equation as a maintenance dose (mg) =282.774-0.735×age (year)+2.946×body weight(Kg)-19.402×CYP2C19 phenotype (UM/RM/NM:0, IM:1, PM:2)-0.316×CRP (mg/L) (p < 0.001).

Discussion

DiThis formula may serve as a valuable supplement to the Clinical Pharmacogenetics Implementation Consortium (CPIC®) guideline for CYP2C19 and VCZ therapy, especially for IFI patients with highly variable inflammatory cytokines during VCZ therapy.

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.

Isavuconazole for the Treatment of Invasive Mold Disease in Solid Organ Transplant Recipients: A Multicenter Study on Efficacy and Safety in Real-life Clinical Practice

BACKGROUND

Isavuconazole has theoretical advantages over other mold-active triazoles for the treatment of invasive aspergillosis and mucormycosis after solid organ transplantation (SOT). The available clinical experience, nevertheless, is scarce.

METHODS

We performed a retrospective study including all adult SOT recipients with proven or probable invasive mold disease (IMD) that received isavuconazole for ≥24 h as first-line or salvage therapy at 10 Spanish centers between September 2017 and November 2021. The primary efficacy outcome was clinical response (complete or partial resolution of attributable symptoms and findings) by weeks 6 and 12. Safety outcomes included the rates of treatment-emergent adverse events and premature isavuconazole discontinuation.

RESULTS

We included 81 SOT recipients that received isavuconazole for a median of 58.0 days because of invasive aspergillosis (n = 71) or mucormycosis (n = 10). Isavuconazole was used as first-line (72.8%) or salvage therapy due because of previous treatment-emergent toxicity (11.1%) or refractory IMD (7.4%). Combination therapy was common (37.0%), mainly with an echinocandin or liposomal amphotericin B. Clinical response by weeks 6 and 12 was achieved in 53.1% and 54.3% of patients, respectively, and was more likely when isavuconazole was administered as first-line single-agent therapy. At least 1 treatment-emergent adverse event occurred in 17.3% of patients, and 6.2% required premature discontinuation. Daily tacrolimus dose was reduced in two-thirds of patients by a median of 50.0%, although tacrolimus levels remained stable throughout the first month of therapy.

CONCLUSIONS

Isavuconazole is a safe therapeutic option for IMD in SOT recipients, with efficacy comparable to other patient groups.

Evaluation of Pharmacokinetics and Safety With Bioequivalence of Voriconazole Injection of 2 Formulations in Chinese Healthy Volunteers: Bioequivalence Study

Voriconazole is a first-line medicine for treating invasive aspergillosis. We aimed to evaluate the bioequivalence (BE) of voriconazole injection in Chinese healthy volunteers (HVs). In this single-center, randomized, single-dose, 2-cycle, fasting-dose BE study, HVs (n = 24) were 1:1 divided into 2 groups (test [T]-reference [R] and R-T) and received 6 mg/kg of voriconazole intravenously with a 7-day washout. The plasma was collected for up to 72 hours at the time point after dosing on day 1/day 8. The plasma concentration of voriconazole was measured by liquid chromatography-tandem mass spectrometry. Pharmacokinetic parameters were ascertained on the basis of a noncompartmental model. In the BE study, the geometric mean ratios of the maximum concentration, area under the concentration-time curve from time 0 to the last measurable plasma concentration, and area under the concentration-time curve from time 0 to infinity were 101.1%, 105.6%, and 105.5%, respectively, and the 90%CI fell within 80%-125%. Adverse events were observed in 26.1% of subjects in the T formulation stage and 17.4% in the R formulation stage. Under the BE study, voriconazole values from T and R formulations were bioequivalent.

Contribution of voriconazole N-oxide plasma concentration measurements to voriconazole therapeutic drug monitoring in patients with invasive fungal infection

BACKGROUND

Voriconazole (VRC), a widely used triazole antifungal, exhibits significant inter- and intra-individual pharmacokinetic variability. The main metabolite voriconazole N-oxide (NOX) can provide information on the patient's drug metabolism capacity.

OBJECTIVES

Our objectives were to implement routine measurement of NOX concentrations and to describe the metabolic ratio (MR), and the contribution of the MR to VRC therapeutic drug monitoring (TDM) by proposing a suggested dosage-adjustment algorithm.

PATIENTS AND METHODS

Sixty-one patients treated with VRC were prospectively included in the study, and VRC and NOX levels were assayed by LC-MS/MS. A mixed logistic model on repeated measures was implemented to analyse risk factors for the patient's concentration to be outside the therapeutic range.

RESULTS

Based on 225 measurements, the median and interquartile range were 2.4 μg/ml (1.2; 4.2), 2.1 μg/ml (1.5; 3.0) and 1.0 (0.6; 1.9) for VRC, NOX and the MR, respectively. VRC C_min <2 μg/ml were associated with a higher MR during the previous visit. MR values >1.15 and <0.48 were determined to be the best predictors for having a VRC C_min lower than 2 μg/ml and above 5.5 μg/ml, respectively, at the next visit.

CONCLUSIONS

Measurement of NOX resulted useful for TDM of patients treated with VRC. The MR using NOX informed interpretation and clinical decision-making and is very interesting for complex patients. VRC phenotyping based on the MR is now performed routinely in our institution. A dosing algorithm has been suggested from these results.

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.

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.

Dosage optimization of voriconazole in children with haematological malignancies based on population pharmacokinetics

WHAT IS KNOWN AND OBJECTIVES

Voriconazole has a complex pharmacokinetic profile and exhibits different pharmacokinetic characteristics in adults and children. Nevertheless, few studies have been conducted on the population pharmacokinetics (PPK) of voriconazole in children with haematological malignancies. This study aims to build a PPK model and propose a suitable voriconazole treatment scheme for children with haematological malignancies.

METHODS

We retrospectively collected 146 samples from 67 children aged from 1.08 to 17.92 years. The PPK model was established using nonlinear mixed effects modelling (NONMEM). Dosage simulations were conducted on the basis of the final model's covariates.

RESULTS AND DISCUSSION

Data were fully characterized by a one-compartment model with first-order absorption and elimination. The weight (WT), CYP2C19 phenotype, and Albumin (ALB) were notable covariates for clearance (CL). The typical values of CL, the volume of distribution (V), and oral bioavailability (F) were 2.29 L/h, 76 L, and 0.902, respectively. The proposed doses for different CYP2C19 genotypes were presented in this ranking: EM (extensive metabolizer) > IM (intermediate metabolizer) > PM (poor metabolizer). Furthermore, higher dosages for light WT patients were recommended while lower ALB levels required lower doses. The probability of achieving the target (PTA) for the recommended doses ranged from 72.2% to 99%.

WHAT IS NEW AND CONCLUSION

We successfully built a voriconazole PPK model for children with hematologic malignancies. Dosing regimens were developed for different patients based on the final model, which could enhance the rational use of voriconazole in children with haematological malignancies.

Voriconazole therapeutic drug monitoring and hepatotoxicity in critically ill patients: A nationwide multi-centre retrospective study

OBJECTIVES

To characterize trough concentrations (C_min) of voriconazole and associated hepatotoxicity, and to determine predictors of hepatotoxicity and identify high-risk groups in critically ill patients.

METHODS

This was a nationwide, multi-centre, retrospective study. C_min and hepatotoxicity were studied from 2015 to 2020 in 363 critically ill patients who received voriconazole treatment. Logistic regression and classification and regression tree (CART) models were used to identify high-risk patients.

RESULTS

Large interindividual variability was observed in initial voriconazole C_min and concentrations ranged from 0.1 mg/L to 18.72 mg/L. Voriconazole-related grade ≥2 hepatotoxicity developed in 101 patients, including 48 patients with grade ≥3 hepatotoxicity. The median time to hepatotoxicity was 3 days (range 1-24 days), and 83.2% of cases of hepatotoxicity occurred within 7 days of voriconazole initiation. Voriconazole C_min was significantly associated with hepatotoxicity. The CART model showed that significant predictors of grade ≥2 hepatotoxicity were C_min >3.42 mg/L, concomitant use of trimethoprim-sulfamethoxazole or tigecycline, and septic shock. The model predicted that the incidence of grade ≥2 hepatotoxicity among these high-risk patients was 48.3-63.4%. Significant predictors of grade ≥3 hepatotoxicity were C_min >6.87 mg/L, concomitant use of at least three hepatotoxic drugs, and septic shock; the predictive incidence among these high-risk patients was 22.7-36.8%.

CONCLUSION

Higher voriconazole C_min, septic shock and concomitant use of hepatotoxic drugs were the strongest predictors of hepatotoxicity. Plasma concentrations of voriconazole should be monitored early (as soon as steady state is achieved) to avoid hepatotoxicity.

Therapeutic drug monitoring and safety evaluation of voriconazole in the treatment of pulmonary fungal diseases

Aims:

The gene polymorphism of voriconazole metabolism–related liver enzyme is notable in East Asia population. It casts a significant influence on the rational use of voriconazole. We conducted this study to investigate the relationship between steady-state voriconazole trough concentration (C_trough) and adverse effects (AEs), especially hepatotoxicity.

Methods:

We conducted a real-world study in the Jinling Hospital from January 2015 to June 2020. A total of 140 patients receiving voriconazole were enrolled in this study. The determination and scoring of voriconazole-associated hepatotoxicity were performed according to the Roussel Uclaf Causality Assessment Method scoring scale and the severity of hepatotoxicity was graded according to the Common Terminology Criteria for Adverse Events (CTCAE).

Results:

Elevated steady-state voriconazole C_trough with concomitant AEs are the most common reason for dose adjustments during treatment. Compared with the group without any AEs, voriconazole C_trough was significantly higher in the hepatotoxicity and neurotoxicity groups, and the incidence of both events showed an overall increasing trend with increasing voriconazole C_trough. Hepatotoxicity occurred in 66.7% of patients within 7 days of the first dose of voriconazole and 94.4% within 15 days of the dose. Steady-state voriconazole C_trough >3.61 mg/l was associated with an increased incidence of hepatotoxicity (area under the curve = 0.645, p = 0.047). Logistic regression analysis showed that timely voriconazole dose adjustment was a predictor of attenuated hepatotoxicity after adjustment for confounders, but hepatotoxicity was not associated with voriconazole C_trough measured at a single time point.

Conclusion:

Hepatotoxicity and neurotoxicity correlate with voriconazole C_trough, and dose reduction in patients with elevated steady-state voriconazole C_trough may prevent hepatotoxicity. In patients with early occurrence of hepatotoxicity, initial therapeutic drug monitoring (TDM) might predict the risk of hepatotoxicity. Follow-up TDM may be necessary to predict late onset hepatotoxicity.

Plain Language Summary

Safety of voriconazole for the treatment of pulmonary fungal diseases

Introduction: Several studies have suggested an association between the concentration of voriconazole in the blood and liver damage, but the evidence is weak. This study aimed to investigate relationships between voriconazole drug concentration and side effects and to analyze the factors affecting liver damage caused by voriconazole.

Methods: We conducted a study at the Jinling Hospital from January 2015 to June 2020, in which a total of 140 patients were finally enrolled.

Results: Voriconazole doses were adjusted in 44 patients due to abnormal voriconazole drug concentration or side effects, 32 patients reduced the dose and 8 patients increased the dose. An elevated liver enzyme level was the most common cause for dose adjustment. After the first dose adjustment, most patients achieved the target drug concentration. A total of 18 patients were determined as probable or highly probable to have drug-induced liver injury from voriconazole. Voriconazole drug concentration was significantly higher in the liver damage and nervous system damage groups as compared with the group without any side effects, and most liver damage events occurred within 14 days of the first dose. Voriconazole drug concentration >3.61 mg/l was associated with an increased incidence of liver damage.

Conclusion: In this study, approximately one-third of patients with pulmonary fungal disease needed to adjust their dose after the standard dose of voriconazole treatment. The incidence of liver damage and nervous system damage showed an overall increasing trend with increasing voriconazole baseline concentrations. Initial therapeutic drug monitoring may be predictive of liver damage. Follow-up monitoring of liver enzymes may be needed.

Real-World Comparison of Isavuconazole and Voriconazole in Terms of the Need for Dosage Adjustments Guided by Clinical Pharmacological Advice During Primary Prophylaxis of Invasive Fungal Infections in Pediatric Patients with Hemato-Oncological Malignancies

BACKGROUND

Limited evidence concerning optimal azole dosing regimens currently exists for antifungal prophylaxis in hemato-oncological pediatric patients.

METHODS

Hemato-oncological children receiving intravenous or oral isavuconazole or voriconazole for primary antifungal prophylaxis at IRCCS Azienda Ospedaliero-Universitaria of Bologna during November 2020 to October 2021 and undergoing CPA programs based on real-time therapeutic drug monitoring (TDM) were retrospectively analyzed. CPAs for isavuconazole and voriconazole and the number of dosage adjustments were collected. Normalized trough concentrations [(C min )/dose/kg] were calculated for both drugs at each TDM assessment, and the coefficient of variation was determined. The efficacy and safety of the drugs were evaluated.

RESULTS

Sixteen hemato-oncological pediatric patients received azole prophylaxis (mean age and weight: 9.1 ± 4.9 years and 32.6 ± 16.0 kg; 6 isavuconazole and 10 voriconazole). Sixty and 89 CPAs were delivered as isavuconazole and voriconazole, respectively. Dosage adjustments were needed in 3.3% of cases for isavuconazole and 53.9% of cases for voriconazole ( P < 0.001). At first TDM, achievement of the desired target during standard dosing regimens was higher for isavuconazole (83.3%) than for voriconazole (10.0%; P = 0.008). Dispersion of normalized concentrations was higher for voriconazole (CV = 139.1% vs. CV = 79.4%). Elevation of ALT and aspartate aminotransferase levels between baseline and the third month was higher in patients receiving voriconazole (median, 28 vs. 90 U/L; P = 0.038, and 19 vs. 65.5 U/L; P = 0.002).

CONCLUSIONS

Our findings suggest that there is limited variability in isavuconazole exposure in hemato-oncological pediatric patients receiving azole prophylaxis , resulting in a low need for CPA-guided dosage adjustments.

High-Performance Liquid Chromatography for Ultra-Simple Determination of Plasma Voriconazole Concentration

Voriconazole is an antifungal drug used to treat invasive aspergillosis. Voriconazole exhibits nonlinear behavior and considerable individual variability in its pharmacokinetic profile. Invasive aspergillosis has a poor prognosis, and failure of treatment owing to low voriconazole blood levels is undesirable. Thus, therapeutic drug monitoring (TDM) of voriconazole is recommended. However, plasma voriconazole concentration is rarely measured in hospitals, and the TDM of voriconazole is not widely practiced in Japan. We aimed to develop an ultra-simple method to measure plasma voriconazole concentration. Ten microliters of plasma sample was extracted, and proteins were precipitated using methanol extraction. Voriconazole and ketoconazole (internal standard) were separated using high-performance liquid chromatography. A calibration curve was prepared, which was linear over plasma voriconazole concentrations of 0.125−12.5 µg/mL, with a coefficient of determination of 0.9999. The intra-day and inter-day validation coefficients were 0.9−2.2% and 1.3−6.1%, respectively. The assay accuracy was −4.2% to 1.6%, and recovery was >97.8%. Our ultra-simple, sensitive, and inexpensive high-performance liquid chromatography ultraviolet method to determine plasma voriconazole concentration will help improve the voriconazole TDM implementation rate and contribute to effective and safe voriconazole use.

Impact of cytochrome P450 2C19 polymorphisms on the clinical efficacy and safety of voriconazole: an update systematic review and meta-analysis

OBJECTIVE

To assess the impact of cytochrome P450 (CYP) 2C19 polymorphisms on the clinical efficacy and safety of voriconazole.

METHODS

We systematically searched PubMed, EMBASE, CENTRAL, ClinicalTrials.gov, and three Chinese databases from their inception to 18 March 2021 using a predefined search algorithm to identify relevant studies. Studies that reported voriconazole-treated patients and information on CYP2C19 polymorphisms were included. The efficacy outcome was success rate. The safety outcomes included overall adverse events, hepatotoxicity, and neurotoxicity.

RESULTS

A total of 20 studies were included. Intermediate metabolizers (IMs) and poor metabolizers (PMs) were associated with increased success rates compared with normal metabolizers (NMs) [risk ratio (RR), 1.18; 95% confidence interval (CI), 1.03-1.34; I2 = 0%; P = 0.02; RR, 1.28; 95% CI, 1.06-1.54; I2 = 0%; P = 0.01]. PMs were at increased risk of overall adverse events in comparison with NMs and IMs (RR, 2.18; 95% CI, 1.35-3.53; I2 = 0%; P = 0.001; RR, 1.80; 95% CI, 1.23-2.64; I2 = 0%; P = 0.003). PMs demonstrated a trend towards an increased incidence of hepatotoxicity when compared with NMs (RR, 1.60; 95% CI, 0.94-2.74; I2 = 27%; P = 0.08), although there was no statistically significant difference. In addition, there was no significant association between CYP2C19 polymorphisms and neurotoxicity.

CONCLUSION

IMs and PMs were at a significant higher success rate in comparison with NMs. PMs were significantly associated with an increased incidence of all adverse events compared with NMs and IMs. Researches are expected to further confirm these findings. Additionally, the relationship between hepatotoxicity and CYP2C19 polymorphisms deserves clinical attention.

Physiologically based pharmacokinetic modeling of brivaracetam and its interactions with rifampin based on CYP2C19 phenotypes

Brivaracetam (BRV), a third-generation antiepileptic drug (AED), is primarily metabolized through amidase hydrolysis and CYP2C19-mediated hydroxylation in vivo. This study utilized physiologically based pharmacokinetic (PBPK) modeling to explore the pharmacokinetics of BRV and drug interactions between BRV and rifampin (RIF), a CYP2C19 inducer, based on CYP2C19 genetic polymorphisms. A PBPK model of BRV was developed in the general population and in individuals with different CYP2C19 phenotypes by adjusting catalytic rate constants (k_cat), and the model was validated with observed clinical data. The model was then extrapolated to predict BRV steady-state plasma concentration in individuals with different CYP2C19 phenotypes, with or without coadministration of RIF. The developed model adequately described BRV exposure in the abovementioned populations. The predicted steady-state area under the curve (AUC_τ-ss) increases by 20% in heterozygous extensive metabolizers (hEMs) and 55% in poor metabolizers (PMs), compared to homozygous extensive metabolizer (EMs). When coadministered with RIF, the model predicted the most significant magnitude of drug-drug interaction (DDI) in EMs, while the exposure change of BRV was minimal in PMs. Referencing the recommended concentration for therapeutic drug monitoring (TDM), we concluded that the current clinical maintenance dose of BRV is acceptable regardless of CYP2C19 polymorphisms and coadministration with RIF.

Dose Optimisation of Posaconazole and Therapeutic Drug Monitoring in Pediatric Patients

Experience in the clinical use of posaconazole (PCZ) in pediatric patients is limited, and no specific dose recommendations exist. This study aimed to investigate an appropriate dosing regimen, and assess the exposure-response relationships of PCZ in children. We reviewed the medical records of inpatients aged <18 years who subjected to PCZ concentrations monitoring. Clinical data, PCZ dosing and monitoring data were collected. A total of 375 PCZ trough concentrations (C _min) from 105 pediatric patients were included. For children receiving PCZ for prophylaxis, the median doses required to achieve the therapeutic range at the ages of <6, 6-12 and >12 years were 14.80, 14.52 and 12.90 mg/kg/day, respectively (p = 0.001); and for those receiving PCZ for treatment, the median doses were 23.50, 20.96 and 15.38 mg/kg/day, respectively (p = 0.001). Among children taking PCZ for prophylaxis, 12% developed a proven or probable breakthrough IFIs; the median PCZ concentrations were significantly lower than those children with successful treatment response (0.43 versus 1.20 μg mL^-1; p < 0.001). 79.2% patients taking PCZ for treatment had a positive clinical response, and the median PCZ concentrations were significantly higher than those children with disease progression (1.06 versus 0.53 μg mL^-1; p = 0.024). No association between C _min values and hepatotoxicity was observed. Factors such as age, CRP, ALT and co-administration with proton pump inhibitors exhibited significant effects on PCZ C _min. It is necessary to adjust the dosing regimens based on PCZ C _min to individualize antifungal therapy and provide guidelines for dose adjustment in children.

Invasive Pulmonary Aspergillosis in Acute-on-Chronic Liver Failure Patients: Short-Term Outcomes and Antifungal Options

INTRODUCTION

Acute-on-chronic liver failure (ACLF) patients are susceptible to invasive fungal infections. We evaluated the prognosis and antifungal options in ACLF patients with invasive pulmonary aspergillosis (IPA).

METHODS

ACLF patients with IPA from 15 hospitals were retrospectively screened from 2011 to 2018, and 383 ACLF patients without lung infections were included from a prospective cohort (NCT02457637). Demographic, laboratory, clinical data, and 28-day outcomes were documented in the two cohorts.

RESULTS

ACLF patients with probable IPA (n = 145) had greater 28-day mortality (33.6% vs. 15.7%, p < 0.001) than those without (n = 383). The respiratory failure-associated 28-day mortality was greater in ACLF patients with IPA than in those without before (17.1% vs. 0.3%, p < 0.001) and after (16.0% vs. 0.0%, p < 0.001) propensity score matching in 116 pairs. IPA patients with lung injury had greater 28-day all-cause mortality (66.5% vs. 24.2%, p < 0.001) and IPA-associated mortality (45.8% vs. 8.1%, p < 0.001) than patients without lung injury (PaO2/FiO2 ≥ 400 mmHg). Antifungal therapy was prescribed to 139 of 145 patients, and 102 patients were treated with voriconazole alone (n = 59) or sequential/combined therapy (n = 43) with varying loading doses (100-800 mg) and daily maintenance doses (0-800 mg). A proposed optimal voriconazole regimen (loading dose, 200 mg twice daily; daily maintenance dose, 100 mg) achieved comparable short-term survival and optimal trough drug concentrations (1-5 μg/mL) on therapeutic drug monitoring in 26 patients.

CONCLUSION

Presence of IPA increases the short-term mortality of ACLF patients mainly due to respiratory failure. An optimal voriconazole regimen is needed for such critical patients.

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.

Recent Advances in Therapeutic Drug Monitoring of Voriconazole, Mycophenolic Acid, and Vancomycin: A Literature Review of Pediatric Studies

The review includes studies dated 2011-2021 presenting the newest information on voriconazole (VCZ), mycophenolic acid (MPA), and vancomycin (VAN) therapeutic drug monitoring (TDM) in children. The need of TDM in pediatric patients has been emphasized by providing the information on the differences in the drugs pharmacokinetics. TDM of VCZ should be mandatory for all pediatric patients with invasive fungal infections (IFIs). Wide inter- and intrapatient variability in VCZ pharmacokinetics cause achieving and maintaining therapeutic concentration during therapy challenging in this population. Demonstrated studies showed, in most cases, VCZ plasma concentrations to be subtherapeutic, despite the updated dosages recommendations. Only repeated TDM can predict drug exposure and individualizing dosing in antifungal therapy in children. In children treated with mycophenolate mofetil (MMF), similarly as in adult patients, the role of TDM for MMF active form, MPA, has not been well established and is undergoing continued debate. Studies on the MPA TDM have been carried out in children after renal transplantation, other organ transplantation such as heart, liver, or intestine, in children after hematopoietic stem cell transplantation or cord blood transplantation, and in children with lupus, nephrotic syndrome, Henoch-Schönlein purpura, and other autoimmune diseases. MPA TDM is based on the area under the concentration-time curve; however, the proposed values differ according to the treatment indication, and other approaches such as pharmacodynamic and pharmacogenetic biomarkers have been proposed. VAN is a bactericidal agent that requires TDM to prevent an acute kidney disease. The particular group of patients is the pediatric one. For this group, the general recommendations of the dosing may not be valid due to the change of the elimination rate and volume of distribution between the subjects. The other factor is the variability among patients that concerns the free fraction of the drug. It may be caused by both the patients' population and sample preconditioning. Although VCZ, MMF, and VAN have been applied in pediatric patients for many years, there are still few issues to be solve regarding TDM of these drugs to ensure safe and effective treatment. Except for pharmacokinetic approach, pharmacodynamics and pharmacogenetics have been more often proposed for TDM.

Analysis of Combined Effect of CYP2C19 Genetic Polymorphism and Proton Pump Inhibitors Coadministration on Trough Concentration of Voriconazole

Purpose

To analyze the combined effect of CYP2C19 genetic polymorphism and PPIs coadministration on voriconazole trough concentration (VCZ-C_trough) in Chinese patients with hematological disorders.

Patients and Methods

A prospective observational study involved 250 plasma samples from 114 adult patients receiving voriconazole with or without PPIs were analyzed. Demographics and clinical characteristics were obtained from patient’s records. A validated LC-MS/MS was used to quantify the plasma VCZ-C_trough. Genotyping for CYP2C19*2 and CYP2C19*3 variant alleles was performed by PCR-RFLP followed by DNA sequencing. The combined total score (from 2 to 5) was calculated for each patient. The higher the score, the lesser the metabolism of the patient.

Findings

Fifty percent of patients administered with voriconazole were coadministered with PPIs, predominantly omeprazole or esomeprazole. Patients exhibiting CYP2C19 poor metabolizer phenotype showed a significantly higher median VCZ-C_trough, (4.31µg/mL [IQR, 1.64µg/mL–7.36µg/mL]) than patients with normal metabolizer (1.38µg/mL, [IQR, 0.79µg/mL–2.14µg/mL], p < 0.0001). Similarly, patients co-administration with PPIs had higher median VCZ-C_trough (2.86µg/mL [IQR 1.33µg/mL–4.66µg/mL]), than PPIs non-users (1.71µg/mL, [IQR, 0.86µg/mL–3.48µg/mL], p = 0.001). However, we noted that the median VCZ-C_trough for each factor was ranging within the normal recommended therapeutic range in the Chinese population (0.5µg/mL–5µg/mL). But when the two factors were combined, the median VCZ-C_trough was steadily increasing as the metabolic capacity (reflected by combined total score) was increasing. Importantly, the median VCZ-C_trough in PM/PPIs user (total score 5) was significantly elevated to supra-therapeutic levels compared to NM/PPI non-user group (total score 2) (5.83µg/mL [IQR, 2.19µg/mL–9.51µg/mL] versus 1.13µg/mL [IQR, 0.67µg/mL–1.82µg/mL]), respectively, P < 0.0001. Furthermore, we observed that the elevation of median VCZ-C_trough to supra-therapeutic levels was largely contributed by omeprazole or esomeprazole compared to lansoprazole or pantoprazole.

Conclusion

Coadministration with PPIs significantly increased voriconazole trough concentrations and there was an additive effect in CYP2C19 PMs, who were most likely to have supra-therapeutic levels.

Experience of a Strategy Including CYP2C19 Preemptive Genotyping Followed by Therapeutic Drug Monitoring of Voriconazole in Patients Undergoing Allogenic Hematopoietic Stem Cell Transplantation

Many factors have been described to contribute to voriconazole (VCZ) interpatient variability in plasma concentrations, especially CYP2C19 genetic variability. In 2014, Hicks et al. presented data describing the correlation between VCZ plasma concentrations and CYP2C19 diplotypes in immunocompromised pediatric patients and utilized pharmacokinetic modeling to extrapolate a more suitable VCZ dose for each CYP2C19 diplotype. In 2017, in our hospital, a clinical protocol was developed for individualization of VCZ in immunocompromised patients based on preemptive genotyping of CYP2C19 and dosing proposed by Hicks et al., Clinical Pharmacogenetics Implementation Consortium (CPIC) clinical guidelines, and routine therapeutic drug monitoring (TDM). We made a retrospective review of a cohort of 28 immunocompromised pediatric patients receiving VCZ according to our protocol. CYP2C19 gene molecular analysis was preemptively performed using PharmArray^®. Plasma trough concentrations were measured by immunoassay analysis until target concentrations (1–5.5 μg/ml) were reached. Sixteen patients (57.14%) achieved VCZ trough target concentrations in the first measure after the initial dose based on PGx. This figure is similar to estimations made by Hicks et al. in their simulation (60%). Subdividing by phenotype, our genotyping and TDM-combined strategy allow us to achieve target concentrations during treatment/prophylaxis in 90% of the CYP2C19 Normal Metabolizers (NM)/Intermediate Metabolizers (IM) and 100% of the Rapid Metabolizers (RM) and Ultrarapid Metabolizers (UM) of our cohort. We recommended modifications of the initial dose in 29% (n = 8) of the patients. In RM ≥12 years old, an increase of the initial dose resulted in 50% of these patients achieving target concentrations in the first measure after initial dose adjustment based only on PGx information. Our experience highlights the need to improve VCZ dose predictions in children and the potential of preemptive genotyping and TDM to this aim. We are conducting a multicenter, randomized clinical trial in patients with risk of aspergillosis in order to evaluate the effectiveness and efficiency of VCZ individualization: VORIGENIPHARM (EudraCT: 2019-000376-41).

Predictors of Voriconazole Trough Concentrations in Patients with Child-Pugh Class C Cirrhosis: A Prospective Study

This prospective observational study aimed to clinically describe voriconazole administrations and trough concentrations in patients with Child–Pugh class C and to investigate the variability of trough concentration. A total of 144 voriconazole trough concentrations from 43 Child–Pugh class C patients were analyzed. The majority of patients (62.8%) received adjustments. The repeated measured trough concentration was higher than the first and final ones generally (median, 4.33 vs. 2.99, 3.90 mg/L). Eight patients with ideal initial concentrations later got supratherapeutic with no adjusted daily dose, implying accumulation. There was a significant difference in concentrations among the six groups by daily dose (p = 0.006). The bivariate correlation analysis showed that sex, CYP2C19 genotyping, daily dose, prothrombin time activity, international normalized ratio, platelet, and Model for end-stage liver disease score were significant factors for concentration. Subsequently, the first four factors mentioned above entered into a stepwise multiple linear regression model (variance inflation factor <5), implying that CYP2C19 testing makes sense for precision medicine of Child–Pugh class C cirrhosis patients. The equation fits well and explains the 34.8% variety of concentrations (R² = 0.348). In conclusion, it needs more cautious administration clinically due to no recommendation for Child–Pugh class C patients in the medication label. The adjustment of the administration regimen should be mainly based on the results of repeated therapeutic drug monitoring.

Fungal pneumonia in kidney transplant recipients

Fungal pneumonia is a dreaded complication encountered after kidney transplantation, complicated by increased mortality and often associated with graft failure. Diagnosis can be challenging because the clinical presentation is non-specific and diagnostic tools have limited sensitivity and specificity in kidney transplant recipients and must be interpreted in the context of the clinical setting. Management is difficult due to the increased risk of dissemination and severity, multiple comorbidities, drug interactions and reduced immunosuppression which should be applied as an important adjunct to therapy. This review will focus on the main causes of fungal pneumonia in kidney transplant recipients including Pneumocystis, Aspergillus, Cryptococcus, mucormycetes and Histoplasma. Epidemiology, clinical presentation, laboratory and radiographic features, specific characteristics will be discussed with an update on diagnostic procedures and treatment.

The influence of CYP2C19 polymorphisms on voriconazole trough concentrations: Systematic review and meta-analysis

BACKGROUND

Voriconazole primary metabolism is catalysed by CYP2C19. A large variability of trough concentrations in patients with invasive fungal infection treated with voriconazole has been observed in clinical practice. It remains controversial whether the CYP2C19 polymorphisms are responsible for voriconazole metabolism in the individual variation.

OBJECTIVES

The primary aim of this study was to assess the effect of CYP2C19 polymorphisms on voriconazole trough concentrations.

METHODS

Following a systematic literature review, we performed a meta-analysis for mean differences (MD) of voriconazole trough concentrations (C_min ), voriconazole dosage adjusted trough concentrations (C_min /D) and for risk ratio (RR) of the proportion of patients in the target therapeutic range between pairwise comparisons of CYP2C19 phenotypes.

RESULTS

Compared with normal metabolisers (NMs), intermediate metabolisers (IMs) (MD: 0.82, 95% CI: 0.57 to 1.07, I²  = 44%, p < .00001) or poor metabolisers (PMs) (MD: 1.59, 95% CI: 1.14 to 2.05, I²  = 46%, p < .00001) had significantly higher voriconazole C_min (μg·ml^-1 ), while rapid metabolisers (RMs) had significantly lower voriconazole C_min (MD: -0,87, 95% CI: -1.35 to -0.38, I²  = 0%, p = .0004). In addition, IMs had significantly lower C_min than PMs (MD: -0.59, 95% CI: -0.97 to -0.20, I²  = 22%, p = .003). Similarly, the C_min /D (μg·kg·ml^-1 ·mg^-1 ) was significantly higher in IMs (MD: 0.13, 95% CI: 0.05 to 0.22, I²  = 0%, p = .002) and PMs (MD: 0.20, 95% CI: 0.07 to 0.34, I²  = 0%, p = .003) than that in NMs, and also, IMs had significantly lower C_min /D than PMs (MD: -0.11, 95% CI: -0.14 to -0.08, I²  = 0%, p < .00001). Furthermore, PMs had a significantly higher proportion of the target therapeutic range than NMs (RR: 1.34, 95% CI: 1.09 to 1.64, I²  = 50%, p = .005).

CONCLUSIONS

Compared to NMs, IMs and PMs had higher voriconazole trough concentrations, especially in Asians, while RMs had lower voriconazole trough concentrations. In addition, PMs had a higher proportion of the target therapeutic range than NMs, especially in Asians. CYP2C19 genotyping is expected to be used to preemptively guide the individualisation of voriconazole in clinical practice.

Favorable Effects of Voriconazole Trough Concentrations Exceeding 1 μg/mL on Treatment Success and All-Cause Mortality: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis examined the optimal trough concentration of voriconazole for adult patients with invasive fungal infections. We used stepwise cutoffs of 0.5-2.0 μg/mL for efficacy and 3.0-6.0 μg/mL for safety. Studies were included if they reported the rates of all-cause mortality and/or treatment success, hepatotoxicity, and nephrotoxicity according to the trough concentration. Twenty-five studies involving 2554 patients were included. The probability of mortality was significantly decreased using a cutoff of ≥1.0 μg/mL (odds ratio (OR) = 0.34, 95% confidence interval (CI) = 0.15-0.80). Cutoffs of 0.5 (OR = 3.48, 95% CI = 1.45-8.34) and 1.0 μg/mL (OR = 3.35, 95% CI = 1.52-7.38) also increased the treatment success rate. Concerning safety, significantly higher risks of hepatotoxicity and neurotoxicity were demonstrated at higher concentrations for all cutoffs, and the highest ORs were recorded at 4.0 μg/mL (OR = 7.39, 95% CI = 3.81-14.36; OR = 5.76, 95% CI 3.14-10.57, respectively). Although further high-quality trials are needed, our findings suggest that the proper trough concentration for increasing clinical success while minimizing toxicity is 1.0-4.0 μg/mL for adult patients receiving voriconazole 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.

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.

Impact of CYP2C19, CYP3A4, ABCB1, and FMO3 genotypes on plasma voriconazole in Thai patients with invasive fungal infections

Voriconazole is the first-line antifungal choice in the treatment of invasive fungal infections (IFIs). Single nucleotide polymorphisms (SNPs) in drug-metabolizing and transporter genes may affect voriconazole pharmacokinetics. This study aimed to determine the frequency of the CYP2C19 rs4244285, rs4986893, rs72552267, and rs12248560, CYP3A4 rs4646437, ABCB1 rs1045642, and FMO3 rs2266782 alleles and determine the association between these genetic variants and voriconazole concentrations in Thai patients with invasive fungal infections. The study comprised 177 Thai patients with IFIs in whom seven SNPs in CYP2C19, CYP3A4, ABCB1, and FMO3 were genotyped using TaqMan real-time polymerase chain reaction (RT-PCR) 5´ nuclease assays, and voriconazole plasma concentrations were measured by high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). Of the 177 patients included, 31 were <12 years and 146 were ≥12 years. The CYP2C19 allele frequencies were 0.29 for *2, 0.060 for *3, 0.003 for *6, and 0.008 for *17. The allele frequency of CYP3A4 (rs4646437) was 0.26, ABCB1 (rs1045642) was 0.36, and FMO3 (rs2266782) was 0.16. The median voriconazole dose/weight was significantly lower in patients aged ≥12 years when compared to the patients aged <12 years (P < .001). Patients aged <12 years with CYP2C19*1/*2 exhibited significantly higher median voriconazole plasma concentrations than those with the CYP2C19*1/*1 (P = .038). However, there were no significant differences in median voriconazole plasma concentrations among the CYP2C19 genotypes in the patients aged ≥12 years. There was a lack of association observed among the CYP3A4, ABCB1, and FMO3 genotypes on the plasma voriconazole concentrations in both groups of patients. Our findings indicate that voriconazole plasma concentrations are affected by the CYP2C19*2 allele in patients aged <12 years but not in patients aged ≥12 years.

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.

Deciphering the Relationship Between the Trough Concentration of Posaconazole and Its Efficacy and Safety in Chinese Patients With Hematological Disorders

Posaconazole (PCZ) is effective in preventing and salvage treatment invasive fungal infections in patients with hematologic disorders. However, PCZ displays highly variable individual pharmacokinetics affecting its efficacy and safety. To investigate the correlation between PCZ concentration and efficacy and safety, the following key influencing factors were explored. A total of 285 trough plasma concentrations (C_min) of 81 Chinese patients receiving PCZ oral suspension for prophylaxis or treatment of invasive fungal infections were collected in this study. The relationships between C_min values and clinical response and hepatotoxicity were investigated as well as the incidence of clinical response under different C_min values of PCZ with a logistic regression model. The concentration of PCZ showed remarkable differences among patients with haematologic disorders. PCZ C_min values of 0.76 and 1.0 µg/mL were both associated with an over 80% probability of successful response to prophylaxis and treatment of fungal infections, respectively. No association between C_min values and hepatotoxicity was noted (P > 0.05). Gender, albumin, and co-administration of proton pump inhibitor (PPI) were identified as independent factors influencing PCZ C_min by multiple linear regression analysis. Furthermore, patients’ C-reactive protein (CRP), albumin, and co-administration of PPI exhibited significant effects on the therapeutic window of patients receiving PCZ for prophylaxis. The plasma concentration is closely associated with therapeutic efficacy of PCZ. It is necessary to adjust the dosing regimens based on PCZ C_min to obtain an optimal therapeutic response.

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.

Effect of CYP2C19 polymorphism on the plasma voriconazole concentration and voriconazole-to-voriconazole-N-oxide concentration ratio in elderly patients

BACKGROUND

Effects of CYP2C19 polymorphism on voriconazole concentration (C0 ), dose-adjusted trough concentrations (C0 /dose) and voriconazole-to-voriconazole-N-oxide concentration ratio (C0 /CN ) have not been fully investigated.

OBJECTIVES

To investigate correlations of CYP2C19 polymorphisms with plasma concentrations of voriconazole and the major metabolite voriconazole-N-oxide in elderly patients.

METHODS

A prospective, multi-centre, non-intervention, open clinical study was conducted within Southwestern Chinese patients clinically diagnosed with invasive fungal infections, to investigate the associations of CYP2C19∗2 (681G > A), CYP2C19∗3 (636G > A) and CYP2C19∗17 (-806C > T) genetic polymorphisms with voriconazole C0 , C0 /dose and C0 /CN .

RESULTS

The study included 131 adult patients, of which 72 were elderly (≥60 years) and 59 were adults (<60 years). The allele frequencies of CYP2C19∗2, ∗3 and ∗17 in the elderly cohort were 61.1%, 29.9% and 7.6%, respectively, which were similar to those in the adult cohort (66.9%, 29.7% and 2.5%, respectively; P > .05). The median voriconazole C0 (C0 ), C0 /dose and C0 /CN ratio in patients with the CYP2C19∗1/∗2 and CYP2C19∗2/∗2 genotypes were significantly higher than those in patients with the CYP2C19∗1/∗1 genotype in the adult cohort (P < .05). The C0 and C0 /dose in patients with the CYP2C19∗1/∗3 and CYP2C19∗2/∗2 genotypes, and the C0 /CN ratio for patients with the CYP2C19∗1/∗2 genotype were numerically higher than those in patients with the CYP2C19∗1/∗1 genotype in the elderly cohort, but this difference was not statistically significant (P > 0.05). The C0 , C0 /dose and C0 /CN in patients with poor metaboliser phenotypes were higher than in those with normal metaboliser phenotypes and C0 in patients with intermediate metaboliser phenotypes were significantly higher than in those with normal metaboliser phenotypes in the adult cohort (P < .05). However, there were no significant differences in the C0 , C0 /dose and C0 /CN among different CYP2C19-predicted metabolic phenotypes in the elderly cohort.

CONCLUSIONS

Voriconazole C0 , C0 /dose and C0 /CN ratio are not significantly affected by the CYP2C19∗2/∗3 polymorphisms in the elderly patients.

Impact of CYP2C19 Genotype and Drug Interactions on Voriconazole Plasma Concentrations: A Spain Pharmacogenetic-Pharmacokinetic Prospective Multicenter Study

BACKGROUND

Voriconazole, a first-line agent for the treatment of invasive fungal infections, is mainly metabolized by cytochrome P450 (CYP) 2C19. A significant portion of patients fail to achieve therapeutic voriconazole trough concentrations, with a consequently increased risk of therapeutic failure.

OBJECTIVE

To show the association between subtherapeutic voriconazole concentrations and factors affecting voriconazole pharmacokinetics: CYP2C19 genotype and drug-drug interactions.

METHODS

Adults receiving voriconazole for antifungal treatment or prophylaxis were included in a multicenter prospective study conducted in Spain. The prevalence of subtherapeutic voriconazole troughs was analyzed in the rapid metabolizer and ultra-rapid metabolizer patients (RMs and UMs, respectively), and compared with the rest of the patients. The relationship between voriconazole concentration, CYP2C19 phenotype, adverse events (AEs), and drug-drug interactions was also assessed.

RESULTS

In this study 78 patients were included with a wide variability in voriconazole plasma levels with only 44.8% of patients attaining trough concentrations within the therapeutic range of 1 and 5.5 µg/ml. The allele frequency of *17 variant was found to be 29.5%. Compared with patients with other phenotypes, RMs and UMs had a lower voriconazole plasma concentration (RM/UM: 1.85 ± 0.24 µg/ml vs other phenotypes: 2.36 ± 0.26 µg/ml). Adverse events were more common in patients with higher voriconazole concentrations (p<0.05). No association between voriconazole trough concentration and other factors (age, weight, route of administration, and concomitant administration of enzyme inducer, enzyme inhibitor, glucocorticoids, or proton pump inhibitors) was found.

CONCLUSION

These results suggest the potential clinical utility of using CYP2C19 genotype-guided voriconazole dosing to achieve concentrations in the therapeutic range in the early course of therapy. Larger studies are needed to confirm the impact of pharmacogenetics on voriconazole pharmacokinetics.

Effect of Therapeutic Drug Monitoring and Cytochrome P450 2C19 Genotyping on Clinical Outcomes of Voriconazole: A Systematic Review

Objectives

To examine current knowledge on the clinical utility of therapeutic drug monitoring (TDM) in voriconazole therapy, the impact of CYP2C19 genotype on voriconazole plasma concentrations, and the role of CYP2C19 genotyping in voriconazole therapy.

Data Sources

Three literature searches were conducted for original reports on (1) TDM and voriconazole outcomes and (2) voriconazole and CYP2C19 polymorphisms. Searches were conducted through EMBASE, MEDLINE/PubMed, Scopus, and Cochrane Central Register of Controlled Trials from inception to June 2020.

Study Selection and Data Extraction

Randomized controlled trials, cohort studies, and case series with ≥10 patients were included. Only full-text references in English were eligible.

Data Synthesis

A total of 63 studies were reviewed. TDM was recommended because of established concentration and efficacy/toxicity relationships. Voriconazole trough concentrations ≥1.0 mg/L were associated with treatment success; supratherapeutic concentrations were associated with increased neurotoxicity; and hepatotoxicity associations were more prevalent in Asian populations. CYP2C19 polymorphisms significantly affect voriconazole metabolism, but no relationship with efficacy/safety were found. Genotype-guided dosing with TDM was reported to increase chances of achieving therapeutic range.

Relevance to Patient Care and Clinical Practice

Genotype-guided dosing with TDM is a potential solution to optimizing voriconazole efficacy while avoiding treatment failures and common toxicities.

Conclusions

Voriconazole plasma concentrations and TDM are treatment outcome predictors, but research is needed to form a consensus target therapeutic range and dosage adjustment guidelines based on plasma concentrations. CYP2C19 polymorphisms are a predictor of voriconazole concentrations and metabolism, but clinical implications are not established. Large-scale, high-methodological-quality trials are required to investigate the role for prospective genotyping and establish CYP2C19-guided voriconazole dosing recommendations.

Voriconazole therapeutic drug monitoring in critically ill patients improves efficacy and safety of antifungal therapy

Since voriconazole plasma trough concentration (VPC) is related to its efficacy and adverse events, therapeutic drug monitoring (TDM) is recommended to perform. However, there is no report about the data of voriconazole TDM in critically ill patients in China. This retrospective study was performed to determine whether voriconazole TDM was associated with treatment response and/or voriconazole adverse events in critically ill patients, and to identify the potential risk factors associated with VPC. A total of 216 critically ill patients were included. Patients were divided into two groups: those underwent voriconazole TDM (TDM group, n = 125) or did not undergo TDM (non-TDM group, n = 91). The clinical response and adverse events were recorded and compared. Furthermore, in TDM group, multivariate logistic regression analysis was performed to identify the possible risk factors resulting in the variability in initial VPC. The complete response in the TDM group was significantly higher than that in the non-TDM group (P = .012). The incidence of adverse events strongly associated with voriconazole in the non-TDM group was significantly higher than that in the TDM group (19.8% vs 9.6%; P = .033). The factors, including age (OR 0.934, 95% CI: 0.906-0.964), male (OR 5.929, 95% CI: 1.524-23.062), serum albumin level (OR 1.122, 95% CI: 1.020-1.234), diarrhoea (OR 4.953, 95% CI: 1.495-16.411) and non-intravenous administration (OR 4.763, 95% CI: 1.576-14.39), exerted the greatest effects on subtherapeutic VPC (VPC < 1.5 mg/L) in multivariate analysis. Intravenous administration (OR 7.657, 95% CI: 1.957-29.968) was a significant predictor of supratherapeutic VPC (VPC > 4.0 mg/L). TDM can result in a favourable clinical efficacy and a lower incidence of adverse events strongly associated with voriconazole in critically ill patients. Subtherapeutic VPC was closely related to younger age, male, hyperalbuminaemia, diarrhoea and non-intravenous administration, and intravenous administration was a significant predictor of supratherapeutic VPC.

Effect of proton pump inhibitors on voriconazole concentrations in Chinese patients with malignant hematological diseases

PURPOSE

To evaluate the influence of three proton pump inhibitors (PPIs) on plasma voriconazole (VOR) concentrations and characterize potential drug-drug interactions (DDIs) between VOR and three PPIs (omeprazole, lansoprazole, and pantoprazole) in Chinese patients with malignant hematological diseases.

METHODS

A simple and reliable 2D-HPLC with internal quality control method was used to ensure accurate concentration measurements. A total of 194 patients in this retrospective study were divided into control (N = 59), omeprazole (OME, N = 57), lansoprazole (LAN, N = 26), and pantoprazole (PAN, N = 52) groups for comparison of plasma VOR trough concentrations. To further validate our retrospective analysis of clinical data, we used molecular docking simulation to analyze the binding affinity of PPIs to the cytochrome P450 2C19 (CYP2C19) and cytochrome P450 3A4 (CYP3A4) enzymes that are integral to the metabolism of PPIs and VOR.

RESULTS

Our findings indicated that VOR trough concentrations were significantly higher in patient on PPIs compared with those who were not (P = 0.012). Patients on LAN (P < 0.01) or OME (P < 0.05) had significantly elevated VOR concentrations compared with the control group, whereas those on PAN did not. Although VOR trough concentrations were not significantly elevated with PAN, more patients in the PAN group reached therapeutic VOR concentrations than in any other group.

CONCLUSION

In conclusion, our retrospective data analysis and molecular docking simulations results indicate that LAN and OME interact with VOR via CYP2C19 and CYP3A4 to increase VOR plasma concentrations. This study helps with selection of PPIs in Chinese patients with malignant hematological cancer administered VOR.

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.