ATCvet code: QM01AC06

Meloxicam is a Non-Steroidal Anti-Inflammatory Drug (NSAID) of the oxicam class which acts by inhibition of prostaglandin synthesis, thereby exerting anti-inflammatory, anti-exudative, analgesic and antipyretic effects. It reduces leukocyte infiltration into the inflamed tissue. To a minor extent it also inhibits collagen-induced thrombocyte aggregation. In vitro and in vivo studies demonstrated that meloxicam inhibits cyclooxygenase-2 (COX-2) to a greater extent than cyclooxygenase-1 (COX-1). Meloxicam also has anti-endotoxic properties because it has been shown to inhibit production of thromboxane B2 induced by E. coli endotoxin administration in calves and pigs.

Following subcutaneous administration, meloxicam is completely bioavailable and maximal mean plasma concentrations of 0.73 μg/ml in dogs and 1.1 µg/ml in cats were reached approximately 2.5 hours and 1.5 hours post administration, respectively.

After a single subcutaneous dose of 0.5 mg meloxicam/kg, Cmax values of 2.1 μg/ml were reached after 7.7 hours in young cattle.

Following single intramuscular doses of 0.4 mg meloxicam/kg, a Cmax value of 1.1-1.5 μg/ml was reached within 1 hour in pigs.

There is a linear relationship between the dose administered and plasma concentration observed in the therapeutic dose range in dogs and cats. More than 97% of meloxicam is bound to plasma proteins.

The volume of distribution is 0.3 l/kg in dogs and 0.09 l/kg in cats.

In cattle and pigs, the highest meloxicam concentrations are to be found in liver and kidney. Comparatively low concentrations are detectable in skeletal muscle and fat.

Meloxicam is predominantly found in plasma. For dogs, cats and cattle it is also a major biliary excretion product whereas urine contains only traces of the parent compound.

In cattle, meloxicam is also a major excretion product in milk. In pigs, bile and urine contain only traces of the parent compound.

Five major metabolites were detected all having been shown to be pharmacologically inactive. Meloxicam is metabolised to an alcohol, an acid derivative and to several polar metabolites. The main pathway of meloxicam biotransformation is oxidation.

In dogs and cats, Meloxicam is eliminated with a half-life of 24 hours. Approximately 75% of the administered dose is eliminated via faeces and the remainder via urine in dogs.

In cats, the detection of metabolites from the parent compound in urine and faeces, but not in plasma is indicative for their rapid excretion. 21% of the recovered dose is eliminated in urine (2% as unchanged meloxicam, 19% as metabolites) and 79% in the faeces (49% as unchanged meloxicam, 30% as metabolites).

Meloxicam is eliminated with a half-life of 26 hours after subcutaneous injection in young cattle. In pigs, after intramuscular administration, the mean plasma elimination half-life is approximately 2.5 hours. Approximately 50% of the administered dose is eliminated via urine and the remainder via faeces.