Meloxicam has been reported as an alternate of diclofenac sodium which was banned for veterinary use during 2005-06, due to its relay toxicity associated with the catastrophic decline in vulture populations in Indian subcontinent. It is a preferential cyclooxygenase-2 (COX-2) inhibiter with higher therapeutic index as compared to diclofenac, indomethacin and piroxicam. The pharmacokinetics (PK) of a non-steroidal anti-inflammatory drug meloxicam was studied in dogs. Eight dogs used in the experiment were administered @ 0.2 mg/kg body weight as an intravenous (IV) bolus of meloxicam through cephalic vein. Blood samples (3-5 ml) were drawn pre medication and then up to 96 hours post-medication. Plasma concentrations of meloxicam were measured in triplicate by HPLC method developed and validated at laboratories of University of Veterinary and Animal Sciences and Lahore College for Women University, Lahore Pakistan. The plasma concentration versus time profile was prepared. Mean (+ SEM) values of pharmacokinetic parameters viz area under curve (AUC), steady state volume of distribution (V_Dss), half-life (t_1/2), mean residence time (MRT) and clearance (Cl) were 26.97 ± 0.256 μg.h/ml, 0.22 ± 0.002 L/Kg, 23.39 ± 0.4h, 33.69 ± 0.56h and 0.01 ± 0.003 L/h/Kg, respectively. These parameters of meloxicam in dogs were comparable to the reported values in dogs but different when compared with PK values in many other species like sheep, goats, horses, chicken, rabbits and rats. The pharmacokinetic parameters were put in different PK-equations for calculations of dose. We recommend a single IV dose of 0.2mg /Kg body weight of meloxicam in dogs.

Key words: Dog, HPLC, Meloxicam, Pharmacokinetics