Clinical pharmacokinetics of oseltamivir and its active metabolite oseltamivir carboxylate after oral administration in horses.
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.
Yamanaka
Takashi
T
Epizootic Research Center, Equine Research Institute, Japan Racing Association, Japan.
Yamada
Masayuki
M
Tsujimura
Koji
K
Kondo
Takashi
T
Nagata
Shunichi
S
Hobo
Seiji
S
Kurosawa
Masahiko
M
Matsumura
Tomio
T
D000284:Administration, Oral; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D006734:Horse Diseases / Q000188:drug therapy; D006736:Horses; D008297:Male; D015394:Molecular Structure; D009976:Orthomyxoviridae Infections / Q000188:drug therapy / Q000662:veterinary; D053139:Oseltamivir / Q000008:administration & dosage / Q000097:blood* / Q000378:metabolism / Q000493:pharmacokinetics*; D011355:Prodrugs / Q000008:administration & dosage / Q000378:metabolism / Q000493:pharmacokinetics*; D013997:Time Factors
D011355:Prodrugs; D053139:Oseltamivir