title: Pharmacokinetics of intravenously and orally administered meloxicam in sheep.
abstract: OBJECTIVE
  To determine the pharmacokinetics of meloxicam after IV and PO administration to 6 healthy sheep.
  
  
  METHODS
  6 healthy adult Dorset cross sheep (5 males and 1 female).
  
  
  METHODS
  Meloxicam (0.5 mg/kg, IV, or 1.0 mg/kg, PO) was administered in a randomized crossover design with a 10-day washout period. Blood samples were collected at predetermined times over 96 hours. Serum drug concentrations were determined by high-pressure liquid chromatography with mass spectrometry. Computer software was used to estimate values of pharmacokinetic parameters through noncompartmental methods.
  
  
  RESULTS
  Following IV administration (n = 5), the geometric mean (range) elimination half-life was 14.0 hours (10.5 to 17.0 hours), volume of distribution was 0.204 L/kg (0.171 to 0.272 L/kg), and clearance was 0.17 mL/min/kg (0.12 to 0.27 mL/min/kg). Following oral administration (n = 6), maximum serum concentration was 1.72 μg/mL (1.45 to 1.93 μg/mL), time to maximum serum concentration was 19.0 hours (12.0 to 24.0 hours), clearance per bioavailability was 0.22 mL/min/kg (0.16 to 0.30 mL/min/kg), and terminal half-life was 15.4 hours (13.2 to 17.7 hours). Bioavailability of orally administered meloxicam was calculated as 72% (40% to 125%; n = 5). No adverse effects were evident following meloxicam administration via either route.
  
  
  CONCLUSIONS
  Meloxicam administered PO at 1.0 mg/kg has good bioavailability with slow elimination kinetics in sheep. These data suggested that meloxicam may be clinically useful, provided the safety and analgesic efficacy of meloxicam as well as feed-related influences on its pharmacokinetics are established in ruminants.
authors.affiliation: Department of Clinical Studies, School of Veterinary Medicine, New Bolton Center, University of Pennsylvania, Kennett Square, PA 19348, USA. mstock@iastate.edu
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Stock
authors.forename: Johann F
authors.initials: JF
authors.lastname: Coetzee
authors.forename: Butch
authors.initials: B
authors.lastname: KuKanich
authors.forename: Billy I
authors.initials: BI
authors.lastname: Smith
mesh_terms: D000284:Administration, Oral; D000818:Animals; D019540:Area Under Curve; D001682:Biological Availability; D005260:Female; D006207:Half-Life; D007275:Injections, Intravenous; D008297:Male; D000077239:Meloxicam; D012756:Sheep / Q000097:blood*; D013843:Thiazines / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D013844:Thiazoles / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D013843:Thiazines; D013844:Thiazoles; D000077239:Meloxicam