Pharmacokinetics of intravenous and oral meloxicam in ruminant calves.

The purpose of this study was to investigate the pharmacokinetics and oral bioavailability of meloxicam in ruminant calves. Six Holstein calves (145 to 170 kg) received meloxicam at 0.5 mg/kg IV or 1 mg/kg PO in a randomized crossover design with a 10-day washout period. Plasma samples collected up to 96 hours after administration were analyzed by liquid chromatography/mass spectrometry followed by noncompartmental pharmacokinetic analysis. A mean peak plasma concentration of 3.10 microg/ml (range, 2.64 to 3.79 microg/ml) was recorded at 11.64 hours (range, 10 to 12 hours) with a half-life of 27.54 hours (range, 19.97 to 43.29 hours) after oral meloxicam administration. The bioavailability of oral meloxicam corrected for dose was 1.00 (range, 0.64 to 1.66). These findings indicate that oral meloxicam administration might be an effective and convenient means of providing long-lasting analgesia to ruminant calves.