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Therapeutic Drug Monitoring of Low Methotrexate Doses for Drug Exposure and Adherence Assessment-Pre-Analytical
Arkadiusz Kocur1, Aleksandra Mikulska2, Mateusz Moczulski2
1Department of Drug Chemistry, Pharmaceutical and Biomedical Analysis, Faculty of Pharmacy, Medical University of Warsaw, Banacha 1, 02-097 Warsaw, Poland.
Abstract:
Methotrexate (MTX) is an antifolic agent used in the first line of anti-inflammatory disease treatment and some oncologic issues. The metabolism of MTX is rapid, and the MTX concentration in the blood is not significant 24 h after administration. Unlike this, methotrexate polyglutamates (MTXPGs) can be informative biomarkers of drug exposure. It is widely concluded that MTXPG retention in red blood cells (RBCs) is related to appropriate efficacy, drug exposure, and toxicity during treatment. Therefore, the mentioned biomarker may be appropriately used for the PK/PD monitoring of low-dose MTX (LDMTX) treatment. The presented review study aimed to review published studies about MTX determination in clinical practice, including pre-analytical variability, bioanalytical considerations, and clinical applications of the methods for pharmacotherapy supporting target populations. In total, 14 papers from the field of bioanalytics have been included in the main review. For each phase of an analytical process, the best practises and main findings were defined as guidelines for proper analytical method optimisation, validation, and standard operation procedure implementation in clinical practice. The presented study is the first comprehensive review of MTX and its methods of metabolite determination to account for pre-analytical, analytical, and post-analytical phases concerning the TDM process.
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