Simultaneous Determination of Urine Methotrexate, 7-Hydroxy Methotrexate, Deoxyaminopteroic Acid, and 7-Hydroxy Deoxyaminopteroic Acid by UHPLC-MS/MS in Patients Receiving High-dose Methotrexate Therapy

Abstract

Nephrotoxicity, the most important toxicity in high dose methotrexate (MTX) therapy, is partly caused by the formation of crystal deposits in the kidney due to poor water solubility of MTX and its metabolites 7-hydroxy methotrexate (7-OH MTX), deoxyaminopteroic acid (DAMPA) and 7-hydroxy deoxyaminopteroic acid (7-OH DAMPA). Plasma MTX level guided urine alkalinization, leucovorin rescue and glucarpidase detoxification are common strategies to overcome MTX related nephrotoxicity. However, overestimation is a problem for MTX analysis by immunoassays due to cross-reactivity of MTX metabolites (7-OH MTX and DAMPA). An UHPLC-MS/MS method for simultaneous determination of MTX, 7-OH MTX, DAMPA and 7-OH DAMPA in human urine was developed, validated and applied in clinical practice.Samples were treated by one-step protein precipitation and analyzed within 3 min. The calibration range was 0.02 to 4 µmol/L for MTX and DAMPA, and 0.1 to 20 µmol/L for 7-OH MTX and 7-OH DAMPA. For all analytes, the intra-day and inter-day bias and imprecision were -8.0% to 7.6% and < 9.0%, the internal standard normalized recovery and matrix factor were 92.34% to 109.49% and < 20.68%. Plasma MTX and 7-OH MTX levels increased with urine drug levels, age, serum creatinine and alanine transaminase, but urine could not replace blood for MTX monitoring due to their poor correlation (R 2 , 0.16 to 0.51). Dose normalized urine and plasma MTX and 7-OH MTX levels were similar between different patient groups (urine pH < 7 or ≥ 7). Due to the large inter-individual variance of the analytes levels in both plasma and urine, these findings should be treated with caution.

Leucovorin (folinic acid) rescue for high‐dose methotrexate: A review

“…Excessive alkalinization increases the risk of an acid-base disturbance. 1,9,10 However, by using these strategies, nephrotoxicity still occurs in 2%-10% of patients. 8 Therefore, MTX plasma level-guided leucovorin rescue is used to overcome HDMTX-induced toxicities.…”

Effects of sampling rate and noise filter processing on repeatability assessment in UHPLC with ultraviolet detection based on the ISO 11843-7

“…Ultra-high performance liquid chromatography (UHPLC), which is equipped with an analytical column packed with sub 2 m porous particles, is an advance LC technique that offers a significantly short measurement time. [1][2][3][4][5][6][7] UHPLC with ultraviolet detection (UHPLC-UV) is one of the attractive methods for the quality control of medicines. [8][9][10][11] To accomplish the quality control of medicines based on highly precise results, a stable quantitative UHPLC-UV method with satisfactory precision must be used.…”

Simple, low-cost and sensitive electrochemical sensing of antineoplastic drug amethopterin based on a nanocarbon black modified electrode

“…Up to now, several methods mainly including UV-Vis spectrophotometry, high performance liquid chromatography, uorimetry, mass spectrometry and capillary electrophoresis have been proposed to monitor the ATP concentration in human blood. [8][9][10][11] Although the above methods can meet the demands of sensitivity and selectivity for ATP analysis, they generally need complex operation and sample pretreatment, excess organic solvent, long task and high cost. 12,13 Recently, the electrochemical technologies have received considerable attention and some related methods have been developed for sensing ATP based on their prominent advantages of simplicity, sensitivity, accuracy and ease of eld applications.…”