Standardization and validation of a high-efficiency liquid chromatography with a diode-array detector (HPLC-DAD) for voriconazole blood level determination. / Estandarización y validación de un método de cromatografía líquida de alta eficiencia con detector de arreglo de diodos (HPLC-DAD) para la determinación de niveles sanguíneos de voriconazol

INTRODUCTION: A specialized service for antifungal blood level determination is not available in Colombia. This service is essential for the proper follow-up of antifungal therapies. OBJECTIVE: To standardize and validate a simple, sensitive, and specific protocol based on high-performance liquid chromatography with a diode array detector for voriconazole blood level quantification. MATERIALS AND METHODS: We used an Agilent HPLC™ series-1200 equipment with a UVdiode array detector with an analytical column Eclipse XDB-C18 and pre-column Eclipse- XDB-C18 (Agilent). We used voriconazole as the primary control and posaconazole as an internal control. We performed the validation following the Food and Drug Administration (FDA) recommendations. RESULTS: The best chromatographic conditions were: Column temperature of 25°C, UV variable wavelength detection at 256 nm for voriconazole and 261 nm for posaconazole (internal standard); 50 µl of injection volume, 0,8 ml/min volume flow, 10 minutes of run time, and mobile phase of acetonitrile:water (60:40). Finally, retention times were 3.13 for voriconazole and 5.16 minutes for posaconazole. Quantification range varied from 0.125 µg/ml to 16 µg/ml. CONCLUSION: The selectivity and chromatographic purity of the obtained signal, the detection limits, and the standardized quantification make this method an excellent tool for the therapeutic monitoring of patients treated with voriconazole.

Introducción. Hasta la fecha, Colombia no cuenta con un servicio especializado de medición de niveles séricos de antifúngicos, procedimiento esencial para el adecuado seguimiento del tratamiento de infecciones fúngicas invasoras. Objetivo. Estandarizar y validar un protocolo ­simple, sensible y específico­ basado en la aplicación de cromatografía líquida de alta eficiencia acoplada con un detector de arreglo de diodos para la cuantificación de los niveles séricos de voriconazol. Materiales y métodos. Se usó un equipo HPLC-Agilent™, serie-1200, con un detector UVDAD, una columna analítica Eclipse-XDB-C18 y una pre-columna Eclipse-XDB-C18, ambas de la marca Agilent. Como control primario se utilizó voriconazol y como control interno, posaconazol. La validación se hizo cumpliendo todos los criterios de aceptación recomendados por la Food and Drug Administration (FDA). Resultados. Las mejores condiciones cromatográficas se obtuvieron con los siguientes parámetros: temperatura de la columna de 25 °C, detección UV-VWD de 261 nm, volumen de inyección de 50 µl, flujo de 0,8 ml/minuto y un tiempo de corrido de 10 minutos. La fase móvil usada fue acetonitrilo:agua (60:40) y los tiempos finales de retención fueron de 3,13 para voriconazol y de 5,16 minutos para posaconazol. El rango de cuantificación fue desde 0,125 µg/ml hasta 16 µg/ml. Conclusiones. La selectividad y la pureza de la señal cromatográfica, así como los límites de detección y cuantificación estandarizados hacen de esta metodología una excelente herramienta para el seguimiento terapéutico de pacientes tratados con voriconazol o en profilaxis con este fármaco.

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.

Development of a therapeutic drug-monitoring algorithm for outpatients receiving voriconazole: A multicentre retrospective study.

AIMS: Although therapeutic drug monitoring (TDM) of voriconazole is performed in outpatients to prevent treatment failure and toxicity, whether TDM should be performed in all or only selected patients remains controversial. This study evaluated the association between voriconazole trough concentrations and clinical events. METHODS: We investigated the aggravation of clinical symptoms, incidence of hepatotoxicity and visual disturbances, change in co-medications and interaction between voriconazole and co-medications in outpatients receiving voriconazole between 2017 and 2021 in three facilities. Abnormal trough concentrations were defined as <1.0 mg/L (low group) and >4.0 mg/L (high group). RESULTS: A total of 141 outpatients (578 concentration measurements) met the inclusion criteria (treatment, 37 patients, 131 values; prophylaxis, 104 patients, 447 values). The percentages of patients with abnormal concentrations were 29.0% and 31.5% in the treatment and prophylaxis groups, respectively. Abnormal concentrations showed 50% of the concentrations at the first measurement in both therapies. Aggravation of clinical symptoms was most frequently observed in the low treatment group (18.2%). Adverse events were most common in the high group for both therapies (treatment, hepatotoxicity 6.3%, visual disturbance 18.8%; prophylaxis, hepatotoxicity 27.9%). No differences were found in changes to co-medications and drug interactions. In the prophylaxis group, prescription duration in the presence of clinical events tended to be longer than in their absence (47.4 ± 23.4 days vs 39.7 ± 21.9 days, P = .1132). CONCLUSIONS: We developed an algorithm based on clinical events for appropriate implementation of TDM in outpatients. However, future interventions based on this algorithm should be validated.

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 Pharmacokinetic Effect of Itraconazole and Voriconazole on Ripretinib in Beagle Dogs by UPLC-MS/MS Technique.

BACKGROUND: A new UPLC-MS/MS technique for the determination of ripretinib in beagle dog plasma was developed, and the pharmacokinetic effects of voriconazole and itraconazole on ripretinib in beagle dogs were studied. METHODS: After extraction with ethyl acetate under alkaline conditions, ripretinib was detected using avapritinib as the internal standard (IS). The mobile phases were 0.1% formic acid-acetonitrile. The scanning method was multi-reaction monitoring using ESI+ source, and the ion pairs for ripretinib and IS were m/z 509.93→416.85 and 499.1→482.09, respectively. This animal experiment adopted a three period self-control experimental design. In the first period, ripretinib was orally administered to six beagle dogs at a dose of 5 mg/kg. In the second period, the same six beagle dogs were orally given itraconazole at a dose of 7 mg/kg, after 30 min, ripretinib was orally given. In the third period, voriconazole at a dose of 7 mg/kg was given orally, and then ripretinib was orally given. At different time points, the blood samples were collected. The concentration of ripretinib was detected, and the pharmacokinetic parameters of ripretinib were calculated. RESULTS: Ripretinib had a good linear relationship in the range of 1-1000 ng/mL. The precision, accuracy, recovery, matrix effect and stability met the requirements of the guiding principles. After erdafitinib combined with itraconazole, the Cmax and AUC0→t of ripretinib increased by 38.35% and 36.36%, respectively, and the t1/2 was prolonged to 7.53 h. After ripretinib combined with voriconazole, the Cmax and AUC0→t of ripretinib increased by 37.44% and 25.52%, respectively, and the t1/2 was prolonged to 7.33 h. CONCLUSION: A new and reliable UPLC-MS/MS technique was fully optimized and developed to detect the concentration of ripretinib in beagle dog plasma. Itraconazole and voriconazole could inhibit the metabolism of ripretinib in beagle dogs and increase the plasma exposure of ripretinib.

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.

Rare Infant Case of Pulmonary Aspergilloma Highlighting Common Challenges With Voriconazole Dosing.

We describe a 6-week-old male-term infant with a pulmonary aspergilloma diagnosed following lobectomy for suspected pleuropulmonary blastoma, with characteristic histopathologic findings and Aspergillus detected by polymerase chain reaction. Intensive testing did not reveal primary or secondary immunodeficiency. During 5 weeks treatment with voriconazole including regular therapeutic drug monitoring and dose adjustment, a level in the target range was never achieved. When the patient developed photosensitivity, treatment was stopped without relapse over 12 months follow-up. Voriconazole dosing is notoriously challenging in children. We review the cumulative published experience with voriconazole use in infants to highlight even greater difficulty in infants. Pulmonary aspergillosis is typically a disease affecting immunocompromised or critically ill patients. In children, it is well described in those with chronic granulomatous disease (CGD) as a complication of immunosuppressive antineoplastic chemotherapy and rarely in extremely- or very-low birthweight premature neonatal intensive care patients. The diagnosis is extremely rare in children without underlying risk factors. To our knowledge, this is the first report of a pulmonary aspergilloma in an immunocompetent infant.

Simultaneous quantification of plasma levels of 12 antimicrobial agents including carbapenem, anti-methicillin-resistant Staphylococcus aureus agent, quinolone and azole used in intensive care unit using UHPLC-MS/MS method.

OBJECTIVES: Critically ill patients in intensive care unit (ICU) are susceptible to infectious diseases, thus empirical therapy is recommended. However, the therapeutic effect in ICU patients is difficult to predict due to fluctuation in pharmacokinetics because of various factors. This problem can be solved by developing personalized medicine through therapeutic drug monitoring. However, when different measurement systems are used for various drugs, measurements are complicated and time consuming in clinical practice. In this study, we aimed to develop an assay using ultra-high performance liquid chromatography coupled with tandem mass spectrometry for simultaneous quantification of 12 antimicrobial agents commonly used in ICU: doripenem, meropenem, linezolid, tedizolid, daptomycin, ciprofloxacin, levofloxacin, pazufloxacin, fluconazole, voriconazole, voriconazole N-oxide which is a major metabolite of voriconazole, and posaconazole. DESIGN & METHODS: Plasma protein was precipitated by adding acetonitrile and 50% MeOH containing standard and labeled IS. The analytes were separated with an ACQUITY UHPLC CSH C18 column, under a gradient mobile phase consisting of water and acetonitrile containing 0.1% formic acid and 2 mM ammonium formate. RESULTS: The method fulfilled the criteria of US Food and Drug Administration for assay validation. The recovery rate was more than 84.8%. Matrix effect ranged from 79.1% to 119.3%. All the calibration curves showed good linearity (back calculation of calibrators: relative error ≤ 15%) over wide concentration ranges, which allowed determination of Cmax and Ctrough. Clinical applicability of the novel method was confirmed. CONCLUSIONS: We have developed an assay for simultaneous quantification of 12 antimicrobial agents using a small sample volume of 50 µL with a short assay time of 7 min. Our novel method may contribute to simultaneous calculation of pharmacokinetic and pharmacodynamic parameters.

Correlation between enzyme multiplied immunoassay technique and high-performance liquid chromatography in the quantification of voriconazole in a paediatric population.

The enzyme multiplied immunoassay technique (EMIT) is a new method for determining the plasma concentration of voriconazole (VRZ). This study aimed to investigate the correlation between EMIT and high-performance liquid chromatography/ultraviolet rays (HPLC/UV) in determining the plasma VRZ trough concentration in children, in China. A total of 419 blood samples were collected, and plasma VRZ concentrations were detected by the EMIT and HPLC methods. The results of 304 samples were analysed after excluding samples that were undetectable or beyond the quantification limit. A test result value of 0 was defined as undetectable, while concentrations outside the detection range (0.2 - 20.0 µg/ml for HPLC and 0.5 - 16.0 µg/ml for EMIT) were defined as beyond the quantification limit. Results from both methods were compared using the Passing Bablok regression, Bland-Altman plot analysis, and paired Wilcoxon test. The plasma VRZ concentrations determined by EMIT and HPLC showed a strong linear correlation through the linear regression equation YEMIT = 1.310 × HPLC +0.149 (R2 = 0.9082). The Bland-Altman plot analysis showed poor level consistency as measured by the two methods. The paired Wilcoxon-test showed a significant difference between the two methods (p < .0001). Compared to EMIT, HPLC accurately detected plasma VRZ concentration, making it suitable for VRZ therapeutic drug monitoring. The numerical values of the EMIT-measured levels were higher than those of HPLC, which may be related to VRZ metabolites interference and co-administrated drugs.

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.

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.

Potential voriconazole associated posterior reversible leukoencephalopathy in children with malignancies: Report of two cases.

INTRODUCTION: The fungal infection has become severe morbidity amongst patients with malignancy. Voriconazole, a new generation of triazole, has shown excellent results in treating invasive fungal infections. CASE REPORT: Herein, we report two cases of posterior reversible encephalopathy syndrome (PRES), which induced after voriconazole exposure.Management and outcome: Magnetic resonance imaging, and the serum level of voriconazole were investigated in both patients to assess toxicity. The role of methotrexate, as one of the possible causes of PRES, is weakened significantly through precise assessing diffusion-weighted images on magnetic resonance imaging. DISCUSSION: These unique cases emphasize that voriconazole can induce PRES even at therapeutic levels. Therefore, in the case of neurotoxicity, PRES must be considered, and voriconazole should discontinue. The prognosis seemed promising when voriconazole stopped immediately after clinical suspicion.

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.

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.

A Prospective Study on the Usefulness of Initial Voriconazole Dose Adjustment Based on CYP2C19 Gene Polymorphism Analysis.

Genetic polymorphism exists for CYP2C19, a dominant metabolic enzyme of voriconazole (VRCZ), and VRCZ pharmacokinetics has been shown to fluctuate according to the CYP2C19 phenotype. Although dosages for different phenotypes have been recommended in various retrospective studies, few reports have adjusted the initial VRCZ dose based on CYP2C19 phenotype determined prior to administration. In this study, we prospectively evaluated the usefulness of CYP2C19 polymorphism analysis in adjusting the initial VRCZ maintenance dose. The study enrolled 19 patients who underwent analysis of CYP2C19 polymorphism prior to VRCZ administration. Subjects were classified into 3 phenotype subgroups: extensive metabolizer (EM), intermediate metabolizer (IM), and poor metabolizer (PM). The initial VRCZ maintenance doses given twice daily were proposed as follows: approximately 8, 6, and 4 mg/kg/day for EM, IM and PM, respectively, according to previous reports. In EM, the initial maintenance dose was 8.0 ± 0.5 mg/kg/day, and trough level was 6.6 ± 2.4 µg/mL. By contrast, the initial maintenance doses in IM and PM were 5.5 ± 0.7 and 4.1 ± 0.3 mg/kg/day, and the initial trough concentrations were 2.9 ± 1.2 and 2.6 ± 0.4 µg/mL, respectively. The attainment rate of target trough concentration of 1-6 µg/mL was 50% in EM, and was 100% in IM and PM. Determining the initial dose of VRCZ only by phenotype based on CYP2C19 gene polymorphism was found to be challenging. However, decreasing the initial maintenance dose in IM and PM may be important for adjusting the initial trough level to target range.

Factors Associated With Voriconazole Concentration in Pediatric Patients.

BACKGROUND: Serum concentrations of voriconazole are difficult to predict, especially in pediatric patients, because of its complex pharmacokinetic characteristics. This study aimed to identify the factors associated with the concentration of voriconazole in pediatric patients. METHODS: This cohort study was based on retrospective data collection and involved the administration of voriconazole to pediatric patients younger than 18 years, between January 2010 and August 2017. Electronic medical records of the patients were reviewed to collect demographic characteristics, voriconazole treatment regimen, and factors that could potentially influence voriconazole trough concentrations. A voriconazole trough serum concentration of less than 1.0 mcg/mL or greater than 5.5 mcg/mL was defined as outside the therapeutic range and was set as the outcome of this study. RESULTS: Among the 114 patients enrolled, 61 patients were included in the analysis. Oral administration of a maintenance dose of voriconazole and C-reactive protein (CRP) level were significantly and independently associated with a low initial trough concentration of voriconazole (<1.0 mcg/mL). Alanine aminotransferase levels were a significant factor associated with a high initial trough concentration of voriconazole (>5.5 mcg/mL) after adjusting for sex, age, weight, and serum creatinine (odds ratio 5.42; 95% confidence interval 1.34-21.97). CONCLUSIONS: Considering the variability of voriconazole concentrations in pediatric patients, monitoring certain parameters and considering the route of administration could help determine the therapeutic range of voriconazole and subsequently avoid unwanted effects.

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.

Metabolomics analysis of plasma reveals voriconazole-induced hepatotoxicity is associated with oxidative stress.

Voriconazole is one of the most frequently used antifungal drugs for the initial treatment of invasive aspergillosis, but liver-related adverse events occur frequently and usually lead to drug discontinuation. Moreover, the mechanism of voriconazole-induced hepatotoxicity remains unsettled. A holistic understanding of its mechanism is critical to prevent liver-related adverse events. Metabolomics has been demonstrated to be a helpful strategy for investigating drug-induced toxicity. This study aimed to utilize human plasma samples to investigate the mechanism of voriconazole-induced hepatotoxicity through a metabolomics approach. Patients that were administered voriconazole were classified into a voriconazole-induced hepatotoxicity group and control group (n = 65, 18% hepatotoxicity). Plasma samples were analyzed by targeted metabolomics using ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry. The obtained peak areas for each metabolite were utilized for correlation analysis, fold change evaluation, and univariate statistical tests to identify metabolites associated with voriconazole-induced hepatotoxicity. This study showed a significantly lower glutamine-to-glutamate ratio (p = .04) and a higher ß-N-acetylglucosamine (p = .003) in the voriconazole-induced hepatotoxicity group, implying the presence of oxidative stress. Other significant metabolites also indicated several adaptive responses to oxidative stress in patients with voriconazole-induced toxicity, including cell repair, energy production, and alteration to bile acid hemostasis. Furthermore, a metabolite panel consisting of α-ketoglutarate, glycocholate, and ß-N-acetylglucosamine demonstrated better performance for detecting voriconazole-induced hepatotoxicity than conventional liver function tests. These metabolomics findings reveal that voriconazole-induced hepatotoxicity is associated with oxidative stress.

Preparation of magnetic metal organic framework and development of solid phase extraction method for simultaneous determination of fluconazole and voriconazole in rat plasma samples by HPLC.

Fluconazole and voriconazole are the two broad-spectrum triazole antifungals. The present work described the fabrication method for the synthesis of the amino-modified magnetic metal-organic framework. This material was applied as a pre-sample treatment sorbent for the selective extraction of fluconazole and voriconazole in rat plasma samples. The material was fabricated by the chemical bonding approach method and was characterized by different parameters. The factors which affect the extraction efficiency of the sorbent material were also optimized in this study. Due to the optimization of solid-phase extraction conditions, the nonspecific interaction was reduced and the extraction recoveries of target drugs were increased in plasma samples. The extraction method was combined with the HPLC-UV method for the analysis. Excellent linearity (0.1-25 µg/mL), detections (0.02, 0.03 µg/mL) and quantification limits (0.04, 0.05 µg/mL) were resulted for fluconazole and voriconazole respectively. The maximum recoveries from spiked plasma samples of fluconazole and voriconazole were 86.8% and 78.6% and relative standard deviation were 0.9-2.8% and 2.2-3.6% respectively. Moreover, this sorbent material was used multiple times which was an improvement over single-use commercial sorbent materials. This validated method has practical potential for the simultaneous determination of these drugs in therapeutic drug monitoring studies as well as for routine pharmacokinetic evaluations.

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.