Dosage recommendations for cephalothin use in horses

Pharmacokinetic/pharmacodynamic analysis of cephalothin after intramuscular administration in Thoroughbred horses
J Equine Sci. 2023 Dec;34(4):111-114. doi: 10.1294/jes.34.111. Epub 2024 Jan 18.
Authors
Taisuke Kuroda 1 , Yohei Minamijima 2 , Hidekazu Niwa 1 , Hiroshi Mita 1 , Norihisa Tamura 1 , Kentaro Fukuda 1 , Minoru Ohta 1
Affiliations

1 Equine Research Institute, Japan Racing Association, Tochigi 329-0412, Japan.
2 Laboratory of Racing Chemistry, Tochigi 320-0851, Japan.

PMID: 38274556
PMCID: PMC10806359
DOI: 10.1294/jes.34.111

Abstract

A pharmacokinetic/pharmacodynamic (PK/PD) approach was used to determine a dosage regimen of cephalothin (CET) after intramuscular (IM) administration in horses. CET plasma concentrations were measured in eight horses after a single IM administration of 11 mg/kg bwt of CET. The data were modeled using a nonlinear mixed-effect model, and the probability of target attainment (PTA) of the PK/PD target was calculated for 5,000 horses generated by Monte Carlo simulations. IM administrations of CET at 11 mg/kg bwt q 8 hr and q 6 hr achieved a PTA of 90% against the MIC90 of S. zooepidemicus and S. aureus, respectively, and were considered to be effective dosage regimens. The total dose for the IM administration recommended in this study was lower than that for intravenous (IV) administration in previous studies.

Keywords: cephalosporins; gram-positive bacteria; intramuscular administration; pharmacokinetics.

©2023 The Japanese Society of Equine Science.