Levetiracetam prescription profile in children younger than 4 years treated at a tertiary care hospital in Chile. / Perfil de prescripción de levetiracetam en niños menores de cuatro años atendidos en un hospital de alta complejidad de Chile.

Introduction. Levetiracetam (LEV) is an antiepileptic drug approved by the Chilean Institute of Public Health as concomitant therapy for epileptic seizures in children older than 4 years of age. However, it is widely prescribed from the neonatal period, which makes it necessary to evaluate its off-label use. Objective. To determine the prescription-indication profile of LEV in the treatment of epileptic seizures in children younger than 4 years in a tertiary care hospital in southern Chile. Population and method. Observational, descriptive, and retrospective study. The medical records of patients who started treatment with LEV between 2014 and 2019 were reviewed, and data on sociodemographic, pharmacological, and clinical variables were collected. The analysis was based on the description of the profile of patients, prescriptions, follow-up, and safety. Results. A total of 68 patients were included: 40 (58.8%) were males, 49 (72.1%) were born at a gestational age ≥ 37 weeks. The main etiology of epilepsy was structural (35.3%); LEV was mostly used in children diagnosed with central nervous system malformation (17.6%), and monotherapy was the prevailing dosage (55.9%). LEV was used for focal seizures in 50% of cases. Five children (7.3%) had psychiatric disorders, classified as probable adverse drug reactions. Conclusion. LEV was used in children with various diagnoses, with a low rate of adverse events. The profile of drug use varied in the different age groups. Future studies are needed to identify effectiveness, especially in newborn infants and patients with refractory epilepsy.

Introducción. El levetiracetam (LEV) es un antiepiléptico aprobado por el Instituto de Salud Pública de Chile como terapia concomitante en crisis epilépticas en niños mayores de cuatro años. Sin embargo, es ampliamente indicado desde el periodo neonatal, lo que hace necesario evaluar su utilización fuera de ficha técnica. Objetivo. Determinar el perfil de prescripción-indicación de LEV en el tratamiento de las crisis epilépticas en menores de cuatro años en un hospital de alta complejidad del sur de Chile. Población y método. Estudio observacional, descriptivo y retrospectivo. Se revisaron las historias clínicas de quienes iniciaron tratamiento con LEV entre 2014 y 2019, y se recopilaron datos sobre variables sociodemográficas, farmacológicas y clínicas. El análisis se basó en la descripción del perfil de los pacientes, prescripción, seguimiento y seguridad. Resultados. Se incluyeron 68 pacientes: 40 (58,8 %) de sexo masculino, 49 (72,1 %) con edad gestacional ≥ 37 semanas. La etiología principal de la epilepsia fue de tipo estructural (35,3 %); el LEV se utilizó principalmente en niños diagnosticados con malformación del sistema nervioso central (17,6 %) y predominó la monoterapia (55,9 %). En el 50 % se usó LEV para crisis focales. Cinco niños (7,3 %) presentaron trastornos de tipo psiquiátrico clasificados como probables reacciones adversas al medicamento. Conclusión. El LEV se utilizó en niños con diferentes diagnósticos con baja frecuencia de eventos adversos. El perfil de utilización varió en los diferentes grupos etarios. Es necesario identificar en futuros estudios la efectividad especialmente en el recién nacido y en epilepsias refractarias.

Comparison of Viscoelastic Testing by Rotational Torsion and Harmonic Resonance Methods.

OBJECTIVES: To compare the performance of the TEG 5000 and TEG 6S Global Hemostasis cartridge. METHODS: We reviewed validation data of the TEG 5000 and TEG 6S Global Hemostasis cartridge. The specimens were analyzed in parallel according to the manufacturer's operating instructions. RESULTS: Fifty-four healthy donors and 13 donors with known hemostatic abnormalities were included. The correlations between instrument types were only moderate-the Spearman rank correlations were 0.55, 0.62, 0.64, and 0.72, respectively, for CK R, K, angle, and maximum amplitude (MA) parameters. Using the manufacturer's device-specific reference ranges to classify results as normal/abnormal, there was weak agreement in the qualitative interpretation of all parameters (Cohen's κ for agreement for CK R, K, angle, and MA was 0.418, 0.154, -0.083, and 0.127, respectively). This could lead to discordant transfusion decisions. CONCLUSIONS: These findings indicate that the TEG 5000 and TEG 6S may not be used interchangeably.

Functional Assessment of Platelet Dense Granule ATP Release.

OBJECTIVES: This study was undertaken to explore the feasibility of assessing platelet dense granule release in response to platelet stimuli, using less than 1 mL of whole blood (WB). METHODS: Optimization of the luciferin-luciferase (LL) assay for ATP release, together with additional modifications, was applied to 1:10 diluted WB. RESULTS: LL assay optimization using nonstirred 1:10 diluted WB resulted in dense granule ATP release in response to thrombin receptor-activating peptide (TRAP) of similar magnitude to that observed using stirred platelet-rich plasma. Stirring of the 1:10 diluted WB restored collagen-induced dense granule secretion. Addition of lyophilized, formalin-fixed platelets, together with stirring, restored dense granule secretion responsiveness to ADP. TRAP, ADP, and collagen all stimulated ATP release in 1:10 diluted WB under the optimized conditions of this study at levels close to those observed using platelet-rich plasma. Blood sample reconstitution experiments offer hope that this assay may prove robust down to WB platelet counts as low as 50 × 103/µL. CONCLUSIONS: Platelet dense granule release in response to a number of classic stimuli, including ADP, was accomplished from less than 1 mL WB with minimal specimen processing, using widely available reagents and instrumentation.

Development of a Nonradioactive Platelet Serotonin Uptake and Release Assay by Micro-Liquid Chromatography Tandem Mass Spectrometry Using Minimal Blood Volume.

OBJECTIVES: Analysis of platelet functional responses to stimuli is presently quite limited with respect to measurement of dense granule secretion. We sought to develop a nonradioactive assay of stimulated serotonin release using liquid chromatography tandem mass spectrometry (LC-MS/MS). METHODS: Citrated whole blood (200 µL) was incubated with deuterated serotonin (d45-HT). Following uptake by platelets, blood was diluted 10-fold and aliquots were incubated with platelet stimuli. Following stimulation, blood was further diluted, centrifuged, and supernatant was assayed for released d45-HT by micro-LC-MS/MS. RESULTS: This study demonstrated a broad linear range of 50 to 2,000 pg/mL d45-HT, with a total precision of less than 15.0% coefficient of variation at all quality control levels and a limit of quantitation of 50 pg/mL. CONCLUSIONS: Quantification of d45-HT by micro-LC-MS/MS assay offers a highly sensitive, nonradioactive methodology for quantitating platelet serotonin uptake and dense granule secretion, requiring only small volumes of patient blood.