Single dose pharmacokinetic study of flumequine after intravenous, intraperitoneal and oral administration to Atlantic halibut ( Hippoglossus hippoglossus) held in seawater at 9 °C

• Published in: Aquaculture Vol. 158; no. 3; pp. 215 - 227
• Main Authors: Samuelsen, Ole Bent, Ervik, Arne
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.12.1997
• Subjects: Flumequine; Intraperitoneal; Intravenous; Intraperitoneal; Flumequine; Intravenous
• ISSN: 0044-8486; 1873-5622
• DOI: 10.1016/S0044-8486(97)00190-7

The pharmacokinetic properties of the antibacterial agent flumequine were studied after intravenous, intraperitoneal and oral administration to Atlantic halibut ( Hippoglossus hippoglossus) held in seawater at 9 °C and weighing 1.5-2.5 kg. Following intravenous injection the plasma drug concentration-time profile showed three distinct phases. The distribution half life ( t 1 2 α) was estimated to be 0.8 h and the terminal elimination half life ( t 1 2 γ) to be 43 h. Total body clearance (Cl T) was determined to be 0.052 1/kg h −1. The volume of distribution at steady state, V d( ss) , was estimated to be 2.3 1/kg indicating good tissue penetration of flumequine in Atlantic halibut. The peak plasma concentration ( C max) and the time to peak plasma concentrations ( T max) were estimated to be 2.7 and 6.1 μg/ml and 20 and 10 h, respectively, following oral administration of medicated feed or intraperitoneal injection. The bioavailabilities were calculated to be 31 and 69%, respectively, following oral or intraperitoneal administration. Only traces (< 10 ng/ml) of the metabolite 7-hydroxy-flumequine were found in a few of the plasma samples. Based on a minimum inhibitory concentration (MIC) of 0.0625 μg/ml for susceptible strains, a single intraperitoneal injection of 25 mg/kg of flumequine maintain plasma levels in excess of 0.25 μg/ml corresponding to 4 times the MIC-value, for approximately 10 d. The corresponding value for a single oral dose of 25 mg/kg of flumequine given as medicated feed, was 5 d.