title: Age-related differences in norfloxacin pharmacokinetic behaviour following intravenous and oral administration in sheep.
abstract: The pharmacokinetics of norfloxacin after intravenous (i.v.) and oral (PO) administration in lambs (n = 5) and adult sheep (n = 5) were studied. After i.v. administration (10 mg.kg-1) plasma concentrations were best fitted by a three-compartment open model in both age groups. Distribution volumes were significantly larger in lambs (approximate 4.0 fold difference between 4 week old and adult sheep). There was no significant difference (p < 0.05) between the groups in terms of elimination halflife but plasma clearance was significantly higher in lambs. Norfloxacin was poorly absorbed after oral administration (60 mg.kg-1) in sheep (F = 4.04%). Mean oral bioavailability was 73.51% in lambs (30 mg.kg-1). Norfloxacin elimination was faster in lambs after oral administration. MRTt was significantly prolonged in both age groups when compared with the respective data for i.v. administration.
authors.affiliation: Cátedra de Farmacología, Facultad de Veterinaria, Universidad Complutense de Madrid, Spain.
authors.forename: F
authors.initials: F
authors.lastname: González
authors.forename: C
authors.initials: C
authors.lastname: Rodríguez
authors.forename: J
authors.initials: J
authors.lastname: Nieto
authors.forename: M L
authors.initials: ML
authors.lastname: De Vicente
authors.forename: M D
authors.initials: MD
authors.lastname: San Andrés
authors.forename: M I
authors.initials: MI
authors.lastname: San Andrés
mesh_terms: D000042:Absorption; D000284:Administration, Oral; D000375:Aging / Q000378:metabolism* / Q000502:physiology; D000818:Animals; D000890:Anti-Infective Agents / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*; D001682:Biological Availability; D018592:Cross-Over Studies; D005260:Female; D006207:Half-Life; D007275:Injections, Intravenous / Q000662:veterinary; D008297:Male; D009643:Norfloxacin / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*; D011897:Random Allocation; D012756:Sheep / Q000276:immunology / Q000378:metabolism* / Q000502:physiology
chemical_list: D000890:Anti-Infective Agents; D009643:Norfloxacin