Summary
Pharmacokinetic values for flunixin meglumine (1 mg/kg of body weight) and phenylbutazone (4 mg/kg) dosages were determined after a single iv injection with and without concurrent intragastric administration of probenecid (50 mg/kg) in 6 healthy mares. Significant difference was not apparent in the pharmacokinetic values of flunixin meglumine with and without concurrent probenecid administration. Significant (P ≤ 0.05) increase was evident in the 12-hour mean concentration of phenylbutazone (11.45 ± 1.66 μg/ml without probenecid; 14.56 ± 1.20 μg/ml with probenecid) along with significant (P ≤ 0.05) reduction in its volume of distribution at steady state associated with concurrent probenecid administration (218.6 ± 11.52 ml/kg without probenecid; 169.4 ± 9.25 ml/kg with probenecid).