Pharmacokinetics of florfenicol in veal calves

• Published in: Journal of veterinary pharmacology and therapeutics Vol. 9; no. 4; p. 412
• Main Authors: Varma, K J, Adams, P E, Powers, T E, Powers, J D, Lamendola, J F
• Format: Journal Article
• Language: English
• Published: England 01-12-1986
• Subjects: Administration, Oral; Animals; Biological Availability; Cattle; Female; Injections, Intravenous; Intestinal Absorption; Kinetics; Metabolic Clearance Rate; Thiamphenicol - administration & dosage; Thiamphenicol - analogs & derivatives; Thiamphenicol - blood; Thiamphenicol - metabolism
• ISSN: 0140-7783
• DOI: 10.1111/j.1365-2885.1986.tb00062.x

The pharmacokinetic disposition of florfenicol was described in veal calves after administration of a single 22-mg/kg dose intravenously, orally after a 12-h fast and orally 5 min post feeding. Both serum concentrations and urinary excretion were studied. After intravenous administration the median elimination half-life was 171.9 min while the half-life of the distribution phase was 5.9 min. The median body clearance (Cl) and apparent volume of distribution (Vz) were 2.85 ml/kg/min and 0.78 l/kg, respectively. Following oral administration the median bio-availability (f) was 0.88 for calves dosed after a 12-h fast and 0.65 for calves dosed 5 min post feeding. Calves given the oral doses had a complex absorption pattern with delayed absorption. Slightly more than 50% of the administered dose both orally and intravenously was recovered as unchanged florfenicol in the urine by 30 h.