title: In vivo tissue pharmacokinetics by fluorine magnetic resonance spectroscopy: a study of liver and muscle disposition of fleroxacin in humans.
abstract: Magnetic resonance spectroscopy of fluorine (19F) has been used to noninvasively study the in vivo pharmacokinetics of a model drug, fleroxacin (a fluoroquinolone antibiotic agent), in healthy human subjects. After oral administration, fleroxacin was detected in 19F magnetic resonance spectra from both liver and calf muscle and four magnetic resonance examinations were undertaken during a 24-hour period. By combining plasma analysis by high performance liquid chromatography with the magnetic resonance data, the following pharmacokinetic parameters (mean values) were obtained: tmax, 1.4, 4.6, and 5.6 hours in liver, plasma, and muscle, respectively; Cmax, 53, about 250, and about 60 mumol/L in plasma, liver, and muscle, respectively; t1/2, 4.4 hours (fast phase) and 10.8 hours (slow phase) in liver and 14.2 hours in plasma. The study documents for the first time the potential use of 19F magnetic resonance spectroscopy to noninvasively observe the time-related changes of a fluorine-containing drug in human tissues after oral administration.
authors.affiliation: Department of Pharmacology and Toxicology, Faculty of Medicine, University of Trondheim, Norway.
authors.forename: P
authors.initials: P
authors.lastname: Jynge
authors.forename: T
authors.initials: T
authors.lastname: Skjetne
authors.forename: I
authors.initials: I
authors.lastname: Gribbestad
authors.forename: C H
authors.initials: CH
authors.lastname: Kleinbloesem
authors.forename: H F
authors.initials: HF
authors.lastname: Hoogkamer
authors.forename: O
authors.initials: O
authors.lastname: Antonsen
authors.forename: J
authors.initials: J
authors.lastname: Krane
authors.forename: O E
authors.initials: OE
authors.lastname: Bakøy
authors.forename: K M
authors.initials: KM
authors.lastname: Furuheim
authors.forename: O G
authors.initials: OG
authors.lastname: Nilsen
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D002851:Chromatography, High Pressure Liquid; D002939:Ciprofloxacin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D016576:Fleroxacin; D005461:Fluorine; D006801:Humans; D008099:Liver / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D009132:Muscles / Q000378:metabolism*
chemical_list: D000890:Anti-Infective Agents; D005461:Fluorine; D002939:Ciprofloxacin; D016576:Fleroxacin