The COX-1:COX-2 selectivity ratios generally are established by comparing the IC ₅₀ for COX-1 to the IC ₅₀ for COX-2. The IC ₈₀ value more closely resembles the steady-state plasma drug concentration than does the IC ₅₀ value.The selectivity ratio for Firocoxib based on the IC ₈₀ values is 121 (IC ₈₀ of 0.36 μM and 43.6 μM for COX-2 and COX-1, respectively), indicating that selectivity for COX-2 is not reduced at concentrations higher than the IC ₅₀ . Notably, Firocoxib concentrations that yield 80% to 95% inhibition of COX-2 produce < 20% inhibition of COX-1.

Firocoxib (0.75-1.5mg/kg; oral gavage; female domestic shorthair cats) treatment efficacious in attenuating fever when administered to cats 1 or 14 hours before LPS challenge.
Pharmacokinetic properties of Firocoxib are determined after i.v. (2 mg/kg) and oral (3 mg/kg) administration in male cats. Firocoxib has moderate to high oral bioavailability (54% to 70%), low plasma clearance (4.7 to 5.8 mL/min/kg), and an elimination half-life of 8.7 to 12.2 hours.