Yamanaka Takashi, Yamada Masayuki, Tsujimura Koji, Kondo Takashi, Nagata Shunichi, Hobo Seiji, Kurosawa Masahiko, Matsumura Tomio
Epizootic Research Center, Equine Research Institute, Japan Racing Association, Japan.
J Vet Med Sci. 2007 Mar;69(3):293-6. doi: 10.1292/jvms.69.293.
The aim of this study was to investigate the pharmacokinetics of oseltamivir carboxylate (OC) in horses (n=6) after oral administration of its prodrug oseltamivir. The binding rate of OC to horse plasma proteins was negligible (<1%). Oral administration of oseltamivir of 2 mg/kg body weight of oseltamivir to horses provided a plasma concentration of OC (mean maximum concentration: 257.9 ng/ml) above the inhibitory concentrations against equine influenza A viruses determined in vitro. However, because OC is rapidly eliminated from horse plasma (mean elimination half-life: 2.5 hr), administration intervals should be less than 10 hr to retain a suitable concentration when using a single dose of 2 mg/kg oseltamivir.
