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 mu g.h/mL and 5.83 +/- 2.49 mu g.h/mL), volume of distribution (745 +/- 475 mL/kg and 487 +/- 266 mL/kg), or clearance (40.17 +/- 10.35 mL/kg/h and 3717 +/- 16.08 mL/kg/h). Maximum plasma concentration was significantly greater following IV (0.63 +/- 0.17 mu g/mL) versus PO (0.19 +/- 0.07 mu g/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 mu g/mL for approximately 24 hours. (Am J Vet Res 2010;71:1277-1283)