RESUMO
Objective: Hepatotoxicity is an important cause of early withdrawal of voriconazole (VCZ). The role of the plasma trough concentration of VCZ (C0) in hepatotoxicity is confusion. VCZ N-oxide is the primary metabolite of VCZ in plasma. We investigated the role of VCZ C0 and plasma trough concentration of VCZ N-oxide (CN) in hepatotoxicity in adult patients. Materials and Methods: This was a prospective study. VCZ C0 and CN were measured using liquid chromatography-tandem mass spectrometry. Results: In total, 601 VCZ C0 and CN from 376 adult patients were included. The percentage of grade 1 or higher adverse events for ALP, ALT, AST, γ-GT, and TBIL were 35.4%, 21.0%, 30.1%, 56.2%, and 22.2%, respectively. Compared with younger adult patients, elderly patients (≥65 years) had a higher rate of grade 1 or higher adverse events of ALP. In the multivariate analysis, VCZ C0 was a risk factor for grade 1 or higher adverse events of AST in elderly patients and TBIL in younger adult patients, and VCZ CN was a risk factor for grade 1 or higher adverse events of ALT, AST, and TBIL. Results of the receiver operating characteristic curve analysis indicated that when the VCZ C0 was higher than 4.0 µg/mL, or the VCZ CN was lower than 1.7 µg/mL, the incidence of grade 1 or higher adverse events of AST and TBIL increased. Conclusion: VCZ C0 and CN were associated with liver function-related adverse events. Measurement of VCZ CN should be considered for VCZ therapeutic drug monitoring.
Assuntos
Antifúngicos , Doença Hepática Induzida por Substâncias e Drogas , Voriconazol , Humanos , Voriconazol/efeitos adversos , Voriconazol/sangue , Voriconazol/farmacocinética , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Estudos Prospectivos , Doença Hepática Induzida por Substâncias e Drogas/sangue , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Idoso , Antifúngicos/efeitos adversos , Antifúngicos/farmacocinética , Antifúngicos/sangue , Adulto Jovem , Espectrometria de Massas em Tandem , Idoso de 80 Anos ou mais , Monitoramento de MedicamentosRESUMO
Voriconazole is the cornerstone of the treatment and prevention of fungal infections. While there is a good correlation between CYP2C19 genotype and voriconazole exposure during prophylactic treatment, no correlation was found in patients with invasive aspergillosis. Proinflammatory cytokines result in inhibition of CYP2C19 enzyme activity (and may result in phenoconversion). Here we investigated the relationship between inflammation, CYP2C19 genotype-predicted-phenotype, and CYP2C19 activity in patients receiving voriconazole. Data were obtained from two prospective studies investigating voriconazole treatment (NCT02074462 and NCT00893555). Dose-corrected voriconazole plasma concentration and C-reactive protein (CRP) were used as proxies for CYP2C19 activity and inflammation, respectively. After data extraction and synthesis, data from 39 patients with paired voriconazole and CRP measurements were available. The distribution of CYP2C19 genotype-predicted metabolizer phenotypes was 31% intermediate (IM), 41% normal (NM), and 28% rapid metabolizer (RM). During inflammation, dose-corrected voriconazole levels were increased by 245%, 278%, and 486% for CYP2C19 NMs IMs and RMs, respectively. Patients with moderate or high CRP levels (>50 mg/L) were phenoconverted to a lower metabolizer phenotype irrespective of their CYP2C19 genotype. In a subgroup analysis of eight patients with longitudinal data available with and without inflammation, the pattern of the dose-corrected voriconazole and CRP measurements were similar, with CYP2C19 activity following decreasing or increasing CRP levels. In conclusion, voriconazole plasma concentrations increase during inflammation due to downregulation of CYP2C19 activity. While this effect appears largest for CYP2C19 RMs, no clinically relevant differences were observed between the CYP2C19 genotypes.
Assuntos
Antifúngicos , Proteína C-Reativa , Citocromo P-450 CYP2C19 , Genótipo , Inflamação , Voriconazol , Voriconazol/administração & dosagem , Voriconazol/farmacocinética , Voriconazol/sangue , Humanos , Citocromo P-450 CYP2C19/genética , Citocromo P-450 CYP2C19/metabolismo , Masculino , Feminino , Inflamação/tratamento farmacológico , Inflamação/genética , Pessoa de Meia-Idade , Antifúngicos/administração & dosagem , Antifúngicos/farmacocinética , Antifúngicos/sangue , Antifúngicos/efeitos adversos , Antifúngicos/farmacologia , Adulto , Proteína C-Reativa/análise , Proteína C-Reativa/metabolismo , Idoso , Estudos Prospectivos , Aspergilose/tratamento farmacológico , Aspergilose/genética , FenótipoRESUMO
OBJECTIVES: Both age and CYP2C19 genotypes affect voriconazole plasma concentration; the interaction of age and CYP2C19 genotypes on voriconazole plasma concentration remains unknown. This study aims to investigate the combined effects of age and CYP2C19 genotypes on voriconazole plasma concentration in Chinese patients. METHODS: A total of 480 patients who received voriconazole treatment were recruited. CYP2C19*2 (rs4244285) and CYP2C19*3 (rs4986893) polymorphisms were genotyped. Patients were divided into the young and the elderly groups by age of 60 years old. Influence of CYP2C19 genotype on steady-state trough concentration (C ss-min ) in overall patients and in age subgroups was analyzed. RESULTS: Voriconazole C ss-min correlated positively with age, and mean voriconazole C ss-min was significantly higher in the elderly group ( Pâ <â 0.001). CYP2C19 poor metabolizers showed significantly increased mean voriconazole C ss-min in the young but not the elderly group. The percentage of patients with subtherapeutic voriconazole C ss-min (<1.0â mg/l) was higher in the young group and that of supratherapeutic voriconazole C ss-min (>5.5â mg/l) was higher in the elderly patients. When the average C ss-min in the CYP2C19 normal metabolizer genotype was regarded as a reference, CYP2C19 genotypes showed greater impact on voriconazole C ss-min in the young group, while the influence of age on voriconazole C ss-min exceeded CYP2C19 genotypes in the elderly. CONCLUSION: CYP2C19 genotypes affects voriconazole exposure is age dependent. Influence of CYP2C19 poor metabolizer genotype on increased voriconazoleexposure is prominent in the young, while age is a more important determinant factor for increased voriconazole exposure in the elderly patients.
Assuntos
Antifúngicos , Povo Asiático , Citocromo P-450 CYP2C19 , Genótipo , Voriconazol , Humanos , Voriconazol/farmacocinética , Voriconazol/sangue , Voriconazol/administração & dosagem , Citocromo P-450 CYP2C19/genética , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Adulto , Fatores Etários , Antifúngicos/farmacocinética , Antifúngicos/sangue , Povo Asiático/genética , Polimorfismo de Nucleotídeo Único/genética , Adulto Jovem , Idoso de 80 Anos ou mais , China , População do Leste AsiáticoRESUMO
OBJECTIVE: Individual differences challenge the treatment of vancomycin, linezolid and voriconazole in severe infections. This study aimed to build a simple and economical method for simultaneous determination of the three antibiotics in human plasma by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and provided a reference for therapeutic drug monitoring (TDM) of infected patients. METHODS: The plasma samples were precipitated by acetonitrile and detected and separated on a shim-pack GIST C18 column following the gradient elution within 5 min. Mass quantification was performed on multiple reaction monitoring mode under positive electrospray ionization. RESULTS: The linear ranges of vancomycin, linezolid and voriconazole were 1.00-100.00, 0.10-15.00 and 0.10-20.00 µg·mL-1, respectively, with good linearity (R2 > 0.99). The accuracy and precision, matrix effect, extraction recovery and stability were validated, and the results all meet the acceptance criteria of China Food and Drug Administration (CFDA) guidelines. CONCLUSION: The UHPLC-MS/MS method was established and validated for the simultaneous determination of vancomycin, linezolid and voriconazole in human plasma and successfully applied to routine TDM for individualized treatment.
Assuntos
Monitoramento de Medicamentos , Linezolida , Espectrometria de Massas em Tandem , Vancomicina , Voriconazol , Humanos , Voriconazol/sangue , Linezolida/sangue , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas em Tandem/métodos , Vancomicina/sangue , Vancomicina/farmacocinética , Monitoramento de Medicamentos/métodos , Reprodutibilidade dos Testes , Modelos Lineares , Limite de DetecçãoRESUMO
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.
Assuntos
Antifúngicos , Triazóis , Voriconazol , Voriconazol/sangue , Cromatografia Líquida de Alta Pressão/métodos , Antifúngicos/sangue , Humanos , Triazóis/sangue , Triazóis/análise , Reprodutibilidade dos Testes , Monitoramento de Medicamentos/métodos , Monitoramento de Medicamentos/instrumentação , Monitoramento de Medicamentos/normas , Limite de DetecçãoRESUMO
Voriconazole is the first-line treatment for invasive aspergillosis. Its pharmacokinetics exhibit considerable inter- and intra-individual variability. The purpose of this study was to investigate the effects of CYP2C19, CYP2C9, CYP3A4, and FMO3 genetic polymorphisms and sex on the pharmacokinetics of voriconazole in healthy Chinese adults receiving single-dose and multiple-dose voriconazole, to provide a reference for its clinical individualized treatment. A total of 123 healthy adults were enrolled in the study, with 108 individuals and 15 individuals in the single-dose and multiple-dose doses, respectively. Plasma voriconazole concentrations were measured using a validated LC-MS/MS method, and pharmacokinetics parameters were calculated using the non-compartmental method with WinNonlin 8.2. CYP2C19, CYP2C9, CYP3A4, and FMO3 single-nucleotide polymorphisms were sequenced using the Illumina Hiseq X-Ten platform. The results suggested that CYP2C19 genetic polymorphisms significantly affected the pharmacokinetics of voriconazole at single doses of 4, 6, and 8 mg/kg and multiple doses of voriconazole. CYP3A4 rs2242480 had a significant effect on AUC0-∞ (area under the plasma concentration-time curve from time 0 to infinity) and MRT (mean residence time) of voriconazole at a single dose of 4 mg/kg in CYP2C19 extensive metabolizer. Regardless of the CYP2C19 genotype, CYP2C9 rs1057910 and FMO3 rs2266780 were not associated with the pharmacokinetics of voriconazole at three single-dose levels or multiple doses. No significant differences in most voriconazole pharmacokinetics parameters were noted between male and female participants after single and multiple dosing. For patients receiving voriconazole treatment, CYP2C19 genetic polymorphisms should be genotyped for its precision administration. In contrast, based on our study of healthy Chinese adults, it seems unnecessary to consider the effects of CYP2C9, CYP3A4, and FMO3 genetic polymorphisms on voriconazole pharmacokinetics.
Assuntos
Antifúngicos , Povo Asiático , Citocromo P-450 CYP2C19 , Citocromo P-450 CYP2C9 , Citocromo P-450 CYP3A , Oxigenases , Polimorfismo de Nucleotídeo Único , Voriconazol , Humanos , Voriconazol/farmacocinética , Voriconazol/sangue , Voriconazol/administração & dosagem , Masculino , Feminino , Citocromo P-450 CYP2C19/genética , Oxigenases/genética , Adulto , Citocromo P-450 CYP2C9/genética , Citocromo P-450 CYP3A/genética , Citocromo P-450 CYP3A/metabolismo , Antifúngicos/farmacocinética , Antifúngicos/administração & dosagem , Antifúngicos/sangue , Adulto Jovem , Povo Asiático/genética , Fatores Sexuais , Voluntários Saudáveis , Genótipo , População do Leste AsiáticoRESUMO
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 0.09â mg/L (2%). CV at LoQ of 0.5â mg/L was 3.7% while the functional sensitivity was established at 0.05â mg/L. Overall imprecision with liquid quality control material obtained from ARK was 5.0%, 6.3%, and 5.9% at 1â mg/L, 5â mg/L, and 10â mg/L, respectively. Limit of blank and LoD were 0.02â mg/L and 0.05â 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.
Assuntos
Antifúngicos , Monitoramento de Medicamentos , Espectrometria de Massas em Tandem , Voriconazol , Voriconazol/sangue , Humanos , Imunoensaio/métodos , Imunoensaio/normas , Espectrometria de Massas em Tandem/métodos , Antifúngicos/sangue , Antifúngicos/análise , Monitoramento de Medicamentos/métodos , Cromatografia Líquida/métodos , Estabilidade de Medicamentos , Limite de Detecção , Reprodutibilidade dos TestesRESUMO
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.
Assuntos
Algoritmos , Antifúngicos , Interações Medicamentosas , Monitoramento de Medicamentos , Pacientes Ambulatoriais , Voriconazol , Humanos , Voriconazol/efeitos adversos , Voriconazol/administração & dosagem , Voriconazol/uso terapêutico , Voriconazol/farmacocinética , Voriconazol/sangue , Monitoramento de Medicamentos/métodos , Masculino , Feminino , Estudos Retrospectivos , Antifúngicos/efeitos adversos , Antifúngicos/administração & dosagem , Pessoa de Meia-Idade , Idoso , Adulto , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Doença Hepática Induzida por Substâncias e Drogas/epidemiologia , Doença Hepática Induzida por Substâncias e Drogas/sangue , Adulto Jovem , Idoso de 80 Anos ou maisRESUMO
Background: Drug interactions (DI) in patients receiving hematopoietic stem cell transplantation (HSCT) are common and clinically significant, highlighting: anticonvulsants, voriconazole (VCZ) and cyclosporine (CsA), which require monitoring. Objective: To describe the interactions between CsA-VCZ in children undergoing HSCT. Methods: Retrospective, descriptive study in immunocompromised children hospitalized since January 2013 to December 2014 at Bone Marrow Transplant Unit, Hospital Dr. Luis Calvo Mackenna, who received CsA and VCZ. Results: The median age was 5 years (3-6) and the median weight was 20 kg (17-30). Sixtythree baseline drug levels were analyzed, of those, 27 were CsA drug levels obtained previous to using VCZ and 36 were CsA drug levels collected concomitantly with VCZ. In the group CsA previous to VCZ, the CsA dose was 4.6 ± 2.6 (mg/ kg/ day) and the CsA average level was 188.8 ± 84.1 (μg/ml). In the group of CsA concomitantly with VCZ, the dose of CsA was 5.5 ± 3.0 (mg/ kg/day) (p = 0.07) and CsA average level was significantly higher: 232.5 ± 106.7 (μg/ml) (p = 0.04). Conclusion: This study shows an increased level of CsA when it is used together with VCZ. Therapeutic drug monitoring could improve the management of the DI and optimize the co-administration of CsA and VCZ.
Introducción: Las interacciones medicamentosas (IM) en el trasplante de progenitores hematopoyéticos (TPH) son comunes y clínicamente significativas, especialmente en: anticonvulsivantes, voriconazol (VCZ) y ciclosporina (CsA). Objetivo: Describir las interacciones de CsA-VCZ en pacientes con TPH. Métodos: Estudio descriptivo, retrospectivo, en pacientes receptores de TPH entre enero de 2013 y diciembre de 2014 en la Unidad de Trasplante de Médula Ósea del Hospital Dr. Luis Calvo Mackenna, que recibieran CsA y VCZ. Resultados: Edad media: 5 años (3-6), peso promedio: 20 kg (17-30). Se analizaron 63 concentraciones plasmáticas de CsA, 27 eran concentraciones de CsA previas al uso de VCZ y 36 concentraciones plasmáticas de CsA concomitantes con VCZ. En el grupo de CsA previo a VCZ, la dosis de CsA fue 4,6 ± 2,6 (mg/kg/día) y la concentración media de CsA 188,8 ± 84,1 (μg/ml). En el grupo de CsA en forma concomitante con VCZ, la dosis de CsA fue de 5,5 ± 3,0 (mg/kg/día) (p 0,07) y la concentración media de CsA fue: 232,5 ± 106,7 (μg/ml) (p = 0,04). Conclusión: Se demostró un aumento de las concentraciones plasmáticas de CsA en IM con VCZ. La monitorización terapéutica podría mejorar el manejo de la IM y optimizar la coadministración de CsA y VCZ.
Assuntos
Humanos , Masculino , Pré-Escolar , Criança , Monitoramento de Medicamentos , Ciclosporina/administração & dosagem , Transplante de Células-Tronco Hematopoéticas/métodos , Voriconazol/administração & dosagem , Imunossupressores/administração & dosagem , Antifúngicos/administração & dosagem , Fatores de Tempo , Estudos Retrospectivos , Hospedeiro Imunocomprometido , Ciclosporina/sangue , Interações Medicamentosas , Voriconazol/sangue , Imunossupressores/sangue , Antifúngicos/sangueRESUMO
Background: Voriconazole (VCZ) serum drug levels (SDL) vary widely and are associated with increased mortality when they are below the therapeutic range for invasive aspergillosis (IA). Aim: To describe VCZ SDL in oncology pediatric patients in order to reach adequate concentrations for prophylaxis (≥ 0.5 mg/L) and treatment (≥ 1.0 y 2.0 mg/L) for IA and their relationship with toxicity. Patients and Methods: Retrospective analysis of VCZ SDL and toxicities recorded in oncology pediatric patients between February 2013 and November 2014. The daily dosage and SDLs were analyzed according to administration route: intravenous (IV) and oral (PO), type of therapy (prophylaxis and treatment) and patient age (< 12 y ≥ 12 years old). Results: 112 through levels from 26 patients were analyzed and the average age was 9.3 years-old. The SDL obtained from the IV route were 43.7%. There were more SDL ≥ 0.5 mg/L and ≥ 1.0 mg/L with the IV route than the PO route (p < 0.05). Patients younger than 12-years-old received a higher dosage than those ≥ 12 years old (median 18.6 and 9.2 mg/kg/d, respectively, p < 0.05). To reach SDL ≥ 0,5 mg/L with the PO route, a dosage of 200 mg every 12 hours showed the best results for all patients (80-100% SDL ≥ 0.5 mg/L). With an IV dosage between 14 and 20 mg/kg/day in patients > 12-years-old, 80% of the SDL were ≥ 1 mg/L and ≥ 2 mg/L. In patients younger than 12-year-old, dosages between 8-30 mg/ kg/day showed similar results (50-63% of SDL ≥ 1 mg/L and 36-40% of SDL ≥ 2 mg/L). Eight patients (30.8%) presented an adverse drug reaction and no relationship with the SDL was found. Conclusión: A VCZ standard dosage of 200 mg every 12 hours PO showed the best results for IA prophylaxis in all patients. Patients younger than 12-years-old would require higher dosages than the doses used in this study to attain adequate SDL for IA treatment. No relation with SDL and adverse reactions was found.
Introducción: Las concentraciones plasmáticas (CPs) de voriconazol (VCZ) son erráticas y en el caso de encontrarse bajo rango terapéutico para el tratamiento de aspergilosis invasora (AI) se asocian a un aumento de mortalidad. Objetivo: Analizar las CPs de VCZ obtenidas en pacientes pediátricos para alcanzar valores que se estiman efectivos para profilaxis (≥ 0,5 mg/L) y tratamiento (≥ 1,0 y 2,0 mg/L) de AI y su relación con toxicidades. Pacientes y Métodos: Análisis retrospectivo de CPs de VCZ y toxicidades asociadas obtenidas en pacientes oncológicos pediátricos desde febrero de 2013 hasta noviembre 2014. Se analizó la dosis diaria y CPs de acuerdo a la vía de administración: intravenosa (iv) u oral (vo), tipo de terapia (profilaxis y tratamiento) y edad (< 12 y ≥ 12 años). Resultados: Se analizaron 112 CPs valle de 26 pacientes, con una edad promedio de 9,3 años. El 43,7% de las CPs correspondió a administración iv. Se obtuvieron más CPs ≥ 0,5 mg/L y ≥ 1,0 mg/L con la vía iv en relación a vo (p < 0,05). Pacientes bajo 12 años de edad recibieron mayor dosis en comparación a los ≥ 12 años (medianas 18,6 y 9,2 mg/kg/día, respectivamente, p < 0,05). La dosis vo más efectiva para alcanzar CPs ≥ 0,5 mg/L fue de 200 mg cada 12 h en todos los pacientes (80-100% de CPs ≥ 0,5 mg/L). En pacientes ≥ 12 años con dosis iv entre 14 y 20 mg/kg/día, 80% de las CPs fueron ≥ 1 mg/L y ≥ 2 mg/L. En pacientes bajo 12 años de edad, dosis entre 8-30 mg/ kg/día generaron similares resultados (50-63% para CPs ≥ 1 mg/L y 36-40% para CPs ≥ 2 mg/L). Ocho pacientes (30,8%), tuvieron alguna reacción adversa al fármaco, no encontrándose relación con la CP alcanzada. Conclusión: Una dosis estándar vo de 200 mg c/12 h de VCZ mostró los mejores resultados para profilaxis de AI en todos los pacientes. Pacientes bajo 12 años de edad requerirían dosis mayores a las utilizadas en este estudio para obtener CPs efectivas para tratamiento de AI. No se encontró relación entre CPs tóxicas y reacciones adversas.