title: Pharmacokinetics of ceftriaxone in healthy horses.
abstract: Five healthy Equidae (4 horses and one pony) were given a single i.v. dose of ceftriaxone (50 mg/kg bwt) to determine the pharmacokinetics and concentration in cerebrospinal fluid (CSF). Blood was drawn from an i.v. jugular catheter and CSF from a pre-placed, intrathecal catheter. Serum and CSF concentrations were determined by high performance liquid chromatography. The mean serum concentration of ceftriaxone was 144.7 micrograms/ml 15 min after injection and declined to 0.3 microgram/ml 10 h after injection. The elimination rate constant (lambda 2) was 0.63 +/- s.e. 0.23/h, the elimination half-life (t 1/2) was 1.62 +/- s.e. 0.42 h and the apparent volume of distribution at steady state (Vd(ss)) was 330.8 +/- 11.8 ml/kg bwt. Clearance was 312.7 +/- 38 ml/h/kg bwt and mean residence time was 1.13 +/- 0.14 h. Mean CSF concentration was 0.60 +/- 0.14 microgram/ml at 3 h after injection and 0.4 +/- 0.31 microgram/ml at 8 h. Ceftriaxone may be useful in the treatment of bacterial infections in horses. Its ability to penetrate the CSF should make it effective in the treatment of bacterial meningitis.
authors.affiliation: College of Veterinary Medicine, Oregon State University, Corvallis 97331, USA.
authors.forename: N C
authors.initials: NC
authors.lastname: Ringger
authors.forename: E G
authors.initials: EG
authors.lastname: Pearson
authors.forename: R
authors.initials: R
authors.lastname: Gronwall
authors.forename: S J
authors.initials: SJ
authors.lastname: Kohlepp
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000097:blood / Q000134:cerebrospinal fluid / Q000493:pharmacokinetics*; D002443:Ceftriaxone / Q000097:blood / Q000134:cerebrospinal fluid / Q000493:pharmacokinetics*; D002851:Chromatography, High Pressure Liquid / Q000379:methods / Q000662:veterinary; D005260:Female; D006736:Horses / Q000378:metabolism*; D007275:Injections, Intravenous; D008297:Male; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D002443:Ceftriaxone