Carprofen (Ridamyl) is a propionic acid derivate and nonsteroidal anti-inflammatory drug (NSAID) with anti-inflammatory, analgesic, and antipyretic activities.

Administration of 4 mg/kg Carprofen significantly elevated peak plasma concentrations in dogs. Compared to buprenorphine, Carprofen treatment resulted in marginally superior analgesic effects with reduced sedative action in canines. Preoperative administration of Carprofen in dogs yielded lower pain scores than other groups, with marked effectiveness observed 2 hours post-extubation. Carprofen provided sustained analgesia for 18 hours in treated canines without adverse side effects and notably improved the speed of recovery in limping birds.

Carprofen binds to human serum albumin (HSA) via fluorescence and equilibrium dialysis methods, with two sets of binding constants [K1=5.1 μM (fluorescence) and 3.7 μM (ED), K2=37 μM (fluorescence) and 13 μM (ED)]. It predominantly binds to site II, the benzodiazepine site, while site I, the Warfarin site, exhibits a lower affinity for Carprofen. The carboxyl group of Carprofen plays a significant role in its high-affinity binding with HSA. Additionally, Carprofen (S and R enantiomers) inhibits canine COX2 with an IC50 of 0.102 microM, primarily attributed to the S enantiomer (IC50, 0.0371 μM), which is approximately 200 times more potent than the R enantiomer (IC50, 5.97 microM).