biostudies-literatureUnknown12Xia Y<b>Background:</b> Valproic acid (VPA) is a widely used antiseizure medication and its dosing needs to be tailored individually through therapeutic drug monitoring (TDM) to avoid or prevent toxicity. Currently, immune-enzymatic assays such as Enzyme Multiplied Immunoassay Technique (EMIT), and Liquid Chromatography (LC)-based techniques, particularly coupled to Electrospray Ionization Tandem Mass Spectrometry (LC-ESI-MS/MS), resulting a potential lack of concordance between laboratories. <b>Methods:</b> In this study, plasma VPA concentrations were determined for 711 pediatric patients with epilepsy by a routine EMIT assay and by a validated in-house LC-ESI-MS/MS method on the same group of samples, aimed to address the aforementioned concern. Consistency between two assays was evaluated uFrontiers in pharmacology750744https://www.ebi.ac.uk/biostudies/studies/S-EPMC8650496biostudies-literatureSwitching Between LC-ESI-MS/MS and EMIT Methods for Routine TDM of Valproic Acid in Pediatric Patients With Epilepsy: What Clinicians and Researchers Need to Know.PMC8650496Xia YShen MYLong JYGuo HLChen FQiu JCDong NLu XPHu YHDing XSfalseSwitching Between LC-ESI-MS/MS and EMIT Methods for Routine TDM of Valproic Acid in Pediatric Patients With Epilepsy: What Clinicians and Researchers Need to Know.<b>Background:</b> Valproic acid (VPA) is a widely used antiseizure medication and its dosing needs to be tailored individually through therapeutic drug monitoring (TDM) to avoid or prevent toxicity. Currently, immune-enzymatic assays such as Enzyme Multiplied Immunoassay Technique (EMIT), and Liquid Chromatography (LC)-based techniques, particularly coupled to Electrospray Ionization Tandem Mass Spectrometry (LC-ESI-MS/MS), resulting a potential lack of concordance between laboratories. <b>Methods:</b> In this study, plasma VPA concentrations were determined for 711 pediatric patients with epilepsy by a routine EMIT assay and by a validated in-house LC-ESI-MS/MS method on the same group of samples, aimed to address the aforementioned concern. Consistency between two assays was evaluated u2021-01-01T00:00:00Z20212026-05-08T05:02:06.703Z2025-06-01T02:42:58.64ZS-EPMC86504963488775610.3389/fphar.2021.750744