Objective: To determine the pharmacokinetics of meloxicam (1 mg/kg) in rabbits after oral administration of single and multiple doses.
Animals: 6 healthy rabbits.
Procedures: A single dose of meloxicam (1 mg/kg, PO) was administered to the rabbits. After a 10-day washout period, meloxicam (1 mg/kg, PO) was administered to rabbits every 24 hours for 5 days. Blood samples were obtained from rabbits at predetermined intervals during both treatment periods. Plasma meloxicam concentrations were determined, and noncompartmental pharmacokinetic analysis was performed.
Results: The mean peak plasma concentration and area under the plasma concentration-versus-time curve extrapolated to infinity after administration of a single dose of meloxicam were 0.83 μg/mL and 10.37 h•μg/mL, respectively. After administration of meloxicam for 5 days, the mean peak plasma concentration was 1.33 μg/mL, and the area under the plasma concentration-versus-time curve from the time of administration of the last dose to 24 hours after that time was 18.79 h•μg/mL. For single- and multiple-dose meloxicam experiments, the mean time to maximum plasma concentration was 6.5 and 5.8 hours and the mean terminal half-life was 6.1 and 6.7 hours, respectively.
Conclusions and clinical relevance: Plasma concentrations of meloxicam for rabbits in the present study were proportionally higher than those previously reported for rabbits receiving 0.2 mg of meloxicam/kg and were similar to those determined for animals of other species that received clinically effective doses. A dose of 1 mg/kg may be necessary to achieve clinically effective circulating concentrations of meloxicam in rabbits, although further studies are needed.