title: Confirming urinary excretion of mephentermine and phentermine following the ingestion of oxethazaine by gas chromatography-mass spectrometry analysis.
abstract: Mephentermine and phentermine, substances prohibited in sports by the World Anti-Doping Agency, were found for the first time in urine specimens following the administration of a therapeutic medication, oxethazaine. In a recent sporting event, a urine specimen donor who tested positive for mephentermine and phentermine claimed consumption of Mucaine((R)) for treating stomach pain was the reason for testing positive. Five volunteers were administrated oxethazaine (a topical anesthetic found in the multi-ingredient medication Mucaine and its generic equivalent, Stoin, both of which are available in Taiwan), mephentermine, and phentermine. Excretion profiles of mephentermine and phentermine following the administration of these drugs were found to be similar. However, the mephentermine/phentermine ratios found in urine specimens collected at different time points following the administration of oxethazine and mephentermine were found to be characteristically different.
authors.affiliation: Institute of Pharmacology and Toxicology, Tzu Chi University, Hualien, 970, Taiwan.
authors.forename: Wei-Hsun
authors.initials: WH
authors.lastname: Huang
authors.forename: Chin-Hung
authors.initials: CH
authors.lastname: Liu
authors.forename: Ray H
authors.initials: RH
authors.lastname: Liu
authors.forename: Ying Lung
authors.initials: YL
authors.lastname: Tseng
mesh_terms: D000089:Acetic Anhydrides; D000328:Adult; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism; D002138:Calibration; D004300:Doping in Sports; D004983:Ethanolamines / Q000008:administration & dosage* / Q000737:chemistry / Q000378:metabolism*; D005260:Female; D005463:Fluoroacetates; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008297:Male; D008616:Mephentermine / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism / Q000652:urine*; D010645:Phentermine / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism / Q000652:urine*; D015203:Reproducibility of Results; D015813:Substance Abuse Detection; D014269:Trifluoroacetic Acid / Q000737:chemistry
chemical_list: D000089:Acetic Anhydrides; D000779:Anesthetics, Local; D004983:Ethanolamines; D005463:Fluoroacetates; C017958:trifluoroacetic anhydride; D010645:Phentermine; D014269:Trifluoroacetic Acid; C100289:oxethazaine; D008616:Mephentermine