title: Identification and quantitative determination of fentanyl metabolites in patients by gas chromatography--mass spectrometry.
abstract: Although fentanyl has been used widely as a short-acting narcotic analgesic, its metabolism in humans has not been clarified. In this study, three fentanyl metabolites were identified in the urine of eight surgical patients receiving 0.3-0.5 mg of fentanyl intravenously. The metabolites 4-N-(N-propionylanilino)piperidine, 4-N-(N-hydroxypropionylanilino)piperidine and 1-(2-phenethyl)-4-N-(N-hydroxypropionylanilino)piperidine, and unchanged fentanyl were identified by GC-mass spectrometry in urine collected 6 h after administration. Fentanyl and its main metabolite, 4-N-(N-propionylanilino)piperidine, were determined quantitatively in the urine of five additional patients receiving 0.5 mg fentanyl intravenously. Urinary excretion of fentanyl and 4-N-(N-propionylanilino)-piperidine during the first 12 h after injection accounted for 0.3-4.0% and 26 to 55% of the dose, respectively.
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage / Q000652:urine*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D007275:Injections, Intravenous; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D013514:Surgical Procedures, Operative; D013997:Time Factors
chemical_list: D005283:Fentanyl