These authors contributed equally to this work.
Pharmacokinetics of doxycycline in tilapia (Oreochromis aureus × Oreochromis niloticus) after intravenous and oral administration
Article first published online: 31 JAN 2014
© 2014 John Wiley & Sons Ltd
Journal of Veterinary Pharmacology and Therapeutics
Volume 37, Issue 4, pages 388–393, August 2014
How to Cite
Pharmacokinetics of doxycycline in tilapia (Oreochromis aureus × Oreochromis niloticus) after intravenous and oral administration. J. vet. Pharmacol. Therap. 37, 388–393., , ,
- Issue published online: 3 JUL 2014
- Article first published online: 31 JAN 2014
- Manuscript Accepted: 5 NOV 2013
- Manuscript Received: 25 JUL 2013
The pharmacokinetics of doxycycline was studied in plasma after a single dose (20 mg/kg) of intravenous or oral administration to tilapia (Oreochromis aureus × Oreochromis niloticus) reared in fresh water at 24 °C. Plasma samples were collected from six fish per sampling point. Doxycycline concentrations were determined by high-performance liquid chromatography with a 0.005 μg/mL limit of detection, then were subjected to noncompartmental analysis. Following oral administration, the double-peak phenomenon was observed, and the first (Cmax1) and second (Cmax2) peaks were 1.99 ± 0.43 μg/mL at 2.0 h and 2.27 ± 0.38 μg/mL at 24.0 h, respectively. After the intravenous injection, a Cmax2 (12.12 ± 1.97 μg/mL) was also observed, and initial concentration of 45.76 μg/mL, apparent elimination rate constant (λz) of 0.018 per h, apparent elimination half-life (t1/2λz) of 39.0 h, systemic total body clearance (Cl) of 41.28 mL/h/kg, volume of distribution (Vz) of 2323.21 mL/kg, and volume of distribution at steady-state (Vss) of 1356.69 mL/kg were determined, respectively. While after oral administration, the λz, t1/2λz, and bioavailability of doxycycline were 0.009 per h, 77.2 h, and 23.41%, respectively. It was shown that doxycycline was relatively slowly and incompletely absorbed, extensively distributed, and slowly eliminated in tilapia, in addition, doxycycline might undergo enterohepatic recycling in tilapia.