Lomerizine, trimetazidine and bis‐(4‐fluorophenyl)‐methylpiperazine in human urine after oral administration of lomerizine dihydrochloride: analysis by liquid chromatography‐high resolution‐tandem mass spectrometry

Abstract

In sports drugs testing, the differentiation between the abuse of the prohibited substance trimetazidine and that of the permitted drug lomerizine is required because trimetazidine is one of the metabolites of lomerizine. Therefore, it is important to identify a lomerizine-specific metabolite in urine that allows making the distinction.In this study, a simple dilute-and-shoot method employing liquid chromatographyhigh resolution-tandem mass spectrometry for the quantification of trimetazidine, lomerizine and the specific metabolite bis-(4-fluorophenyl)-methylpiperazine (M6) in urine was developed. An oral dose of 15 mg was administered to 10 male volunteers, after which urine samples collected during the following 276 hours were analyzed using the developed method, allowing for examination of the target analytes' excretion profile. The limit of detection of all target analytes was <0.02 ng/mL. In all volunteers, the metabolite M6 was detected up to 276 hours after administration. After more than 12 hours, all volunteers were found to have higher concentrations of the metabolite M6 than of trimetazidine. The concentrations of trimetazidine, lomerizine, M6, and the M6/trimetazidine ratio in the final sample collected after 276 hours were 0.2-0.9 ng/mL, <0.05-0.1 ng/mL, 14.1-38.3 ng/mL, and 28.8-122.9, respectively.The urinary excretion of trimetazidine, unchanged lomerizine, and the metabolite M6 within the first 276 hours was 0.64%, 0.006%, and 6.1%, respectively. Consequently, the absence of the metabolite M6 in doping control urine samples corroborates the conclusion that lomerizine is unlikely to be the source of trimetazidine.The results confirm that the M6 metabolite is the longest-lasting urinary metabolite of lomerizine currently known.

Doping control analyses during the Tokyo 2020 Olympic and Paralympic Games

“…Trimetazidine is excreted in the urine after the administration of the permitted drug lomerizine in the same manner as described above for 4-CPA detection. [29][30][31] Therefore, a lomerizinespecific metabolite (M6) was analyzed to confirm its origin. However, the estimated concentration of trimetazidine was lower than the LODs of lomerizine and the specific metabolite M6, resulting in the ATF being reported.…”

Annual banned‐substance review – Analytical approaches in human sports drug testing

“…Differentiating the source of urinary trimetazidine, i.e. the legitimate use of lomerizine or the prohibited use of trimetazidine, was accomplished by monitoring a characteristic urinary metabolite of lomerizine (Figure B), which was shown to be abundantly present in post‐administration urine samples collected after oral application of therapeutic amounts (15 mg) of lomerizine to 10 healthy male volunteers . A dilute‐and‐inject test method was established, utilizing a C‐18 analytical column (2.1 × 50 mm, 1.7 μm particle size) operated with 0.1% formic acid (solvent A), and methanol (solvent B), and a Q/Orbitrap‐based MS using targeted MS/MS experiments.…”

Analytical Approaches in Human Sports Drug Testing: Recent Advances, Challenges, and Solutions

“…Further for contamination scenarios and unexpected chemical reactions occurring in vesica, straightforward metabolic transformations need to be taken into consideration in sports drug testing. For some analytes, analytical strategies exist that enable the identification of a banned substance’s origin as being the result of a metabolic conversion of a permitted drug. , The migraine therapeutic lomerizine has been shown to produce the urinary metabolite trimetazidine, which is classified according to WADA’s Prohibited List as a metabolic modulator. In order to differentiate between the illicit use of trimetazidine and the permitted use of lomerizine, Okano et al , conducted elimination studies with lomerizine, which outlined the diagnostic properties of bis­(4-fluorophenyl)-methylpiperazine, a specific lomerizine metabolite, and its relative abundance compared to trimetazidine in postadministration urine samples.…”

“…For some analytes, analytical strategies exist that enable the identification of a banned substance’s origin as being the result of a metabolic conversion of a permitted drug. , The migraine therapeutic lomerizine has been shown to produce the urinary metabolite trimetazidine, which is classified according to WADA’s Prohibited List as a metabolic modulator. In order to differentiate between the illicit use of trimetazidine and the permitted use of lomerizine, Okano et al , conducted elimination studies with lomerizine, which outlined the diagnostic properties of bis­(4-fluorophenyl)-methylpiperazine, a specific lomerizine metabolite, and its relative abundance compared to trimetazidine in postadministration urine samples. Bis­(4-fluorophenyl)-methylpiperazine was found to be the longest-lasting metabolite of lomerizine and, consequently, the detection of trimetazidine in the absence of bis­(4-fluorophenyl)-methylpiperazine is considered consistent with the administration of the banned substance.…”