ATCvet code: QM01AH95 enflicoxib

Enflicoxib is a non-steroidal anti-inflammatory drug belonging to the coxib class and acting by selective inhibition of the enzyme cyclooxygenase 2. The cyclooxygenase enzyme (COX) is present in two isoforms. COX-1 is usually a constitutive enzyme expressed in tissues, which synthesize products responsible for normal physiologic functions (e.g. in the gastro-intestinal tract and kidneys), and COX-2 is mainly inducible and synthesized by macrophages and other inflammatory cells after stimulation by cytokines and other mediators of inflammation. COX-2 is involved in the production of mediators, including PGE2, that induce pain, exudation, inflammation and fever.

Enflicoxib is well absorbed after oral administration; bioavailability is high, and it is increased by 40-50% with food. The recommended dose is based on administration with food. After oral administration to fed dogs at the recommended loading dose of 8 mg/kg bw, enflicoxib is readily absorbed and reaches its maximal concentration of 1.8 (± 0.4) µg/ml (Cmax) after 2 hours (Tmax). The elimination half-life (t1/2) is 20 h. Enflicoxib is extensively transformed by the hepatic microsomal system into an active pyrazol metabolite, which reaches its maximal concentration of 1.3 (± 0.2) µg/ml (Cmax) after 6 days (Tmax). The elimination half-life (t1/2) is 17 days. Enflicoxib and its active metabolite are extensively bound to dog plasma proteins (98‒99%) and are mainly excreted in faeces by the biliary route and, to a lesser extent, in urine. After repeated administrations, systemic exposure to enflicoxib and its pyrazol metabolite rapidly reaches a plateau, with no evidence of time-dependent pharmacokinetics or over-accumulation for either compound.