Effect of tolfenamic acid co-administration on pharmacokinetics of cefquinome following intramuscular administration in sheep

The pharmacokinetics of cefquinome (2 mg/kg) were studied following intramuscular administration of cefquinome alone, and co-administered with tolfenamic acid (2 mg/kg) in sheep. The plasma concentration of cefquinome was detected by High Performance Liquid Chromatography. Following a single dose intramuscular administration of cefquinome alone, the peak plasma concentration (C-max) was 4.36 +/- 0.10 mu g/mL obtained at 0.75 h. The absorption half-life (t(1/2K alpha)), volume of distribution (Vd(area)), total body clearance (Cl-B) and elimination half-life (t(1/2 beta)) of cefquinome were 0.61 +/- 0.10 h,2.07 +/- 0.36 L/kg, 0.12 +/- 0.01 L/h/kg and 12.29 +/- 2.62 h, respectively. Following intramuscular co-administration of tolfenamic acid, no significant changes were observed in most of the pharmacokinetic parameters of cefquinome, except C-max, and the absorption rate constant (K-a) were significantly increased, while t(1/2) (K alpha) was significantly reduced compared to cefquinome alone treatment of sheep. Cefquinome pharmacokinetic data (2 mg/kg) generated from the present study suggest that cefquinome may be administered with tolfenamic acid to treat bacterial infection with inflammatory conditions in sheep.