Pharmacokinetics of meloxicam following intravenous and oral administration in green iguanas (Iguana iguana).

Objective: To determine pharmacokinetics of meloxicam in healthy green iguanas following PO and IV administration and assess potential toxicity.

Animals: 21 healthy green iguanas (Iguana iguana).

Procedures: To assess pharmacokinetics, 13 iguanas were administered a single dose (0.2 mg/kg) of meloxicam PO and, 14 days later, the same dose IV. To assess potential toxicity, 4 iguanas were given meloxicam at a dosage of 1 or 5 mg/kg, PO, every 24 hours for 12 days, and results of histologic examination were compared with results for another 4 iguanas given a single dose of meloxicam (0.2 mg/kg).

Results: There were no significant differences between PO and IV administration with regard to terminal half-life (mean ± SD, 12.96 ± 8.05 hours and 9.93 ± 4.92 hours, respectively), mean area under the curve to the last measured concentration (5.08 ± 1.62 μg•h/mL and 5.83 ± 2.49 μg•h/mL), volume of distribution (745 ± 475 mL/kg and 487 ± 266 mL/kg), or clearance (40.17 ± 10.35 mL/kg/h and 37.17 ± 16.08 mL/kg/h). Maximum plasma concentration was significantly greater following IV (0.63 ± 0.17 μg/mL) versus PO (0.19 ± 0.07 μg/mL) administration. Time from administration to maximum plasma concentration and mean residence time were significantly longer following PO versus IV administration. Daily administration of high doses (1 or 5 mg/kg) for 12 days did not induce any histologic changes in gastric, hepatic, or renal tissues.

Conclusions And Clinical Relevance: Results suggested that administration of meloxicam at a dose of 0.2 mg/kg IV or PO in green iguanas would result in plasma concentrations > 0.1 μg/mL for approximately 24 hours.