title: Identification of new oxycodone metabolites in human urine by capillary electrophoresis-multiple-stage ion-trap mass spectrometry.
abstract: Capillary electrophoresis-electrospray ionization multiple-stage ion-trap mass spectrometry (CE-MSn) and computer simulation of fragmentation are demonstrated to be effective tools to detect and identify phase I and phase II metabolites of oxycodone (OCOD) in human urine. OCOD is a strong analgesic used for the management of moderate to severe mainly postoperative or cancer-related pain whose metabolism in man is largely unknown. Using an aqueous pH 9 ammonium acetate buffer and CE-MSn (n < or = 5), OCOD and its phase I metabolites produced by O-demethylation, N-demethylation, 6-ketoreduction and N-oxidation (such as oxymorphone, noroxycodone, noroxymorphone, 6-oxycodol, nor-6-oxycodol, oxycodone-N-oxide and 6-oxycodol-N-oxide) and phase II conjugates with glucuronic acid of several of these compounds could be detected in alkaline solid-phase extracts of a patient urine that was collected during a pharmacotherapy episode with daily ingestion of 240-320 mg of OCOD chloride. The data for three known OCOD metabolites for which the standards had to be synthesized in-house, 6-oxycodol, nor-6-oxycodol and oxycodone-N-oxide, were employed to identify two new metabolites, the N-oxidized derivative of 6-oxycodol and an O-glucuronide of this compound. CE-MSn and computer simulation of fragmentation also led to the identification of the N-glucuronide of noroxymorphone, another novel OCOD metabolite for which no standard compound or mass spectra library data were available.
authors.affiliation: Department of Clinical Pharmacology, University of Berne, Berne, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Baldacci
authors.forename: J
authors.initials: J
authors.lastname: Caslavska
authors.forename: A B
authors.initials: AB
authors.lastname: Wey
authors.forename: W
authors.initials: W
authors.lastname: Thormann
mesh_terms: D000701:Analgesics, Opioid / Q000652:urine*; D019075:Electrophoresis, Capillary / Q000379:methods*; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D010098:Oxycodone / Q000652:urine*
chemical_list: D000701:Analgesics, Opioid; D010098:Oxycodone