Pharmacokinetics of penciclovir after oral administration of its prodrug famciclovir to horses.
We investigated the pharmacokinetics of penciclovir after oral administration of its prodrug famciclovir to horses. Following an oral dose of famciclovir at 20 mg/kg, maximum plasma concentrations of penciclovir occurred between 0.75 and 1.5 hr (mean 0.94 + or - 0.38 hr) after dosing and were in the range 2.22 to 3.56 microg/ml (mean 2.87 + or - 0.61 microg/ml). The concentrations of penciclovir declined in a biphasic manner after the peak concentration was attained. The mean half-life of the rapid elimination phase was 1.73 + or - 0.34 hr whereas that of the slow elimination phase was 34.34 + or - 13.93 hr. These pharmacokinetic profiles observed were similar to those of another antiherpesvirus drug, acyclovir, previously reported in horses following oral dosing of its prodrug valacyclovir.
Tsujimura
Koji
K
Epizootic Research Center, Equine Research Institute, Japan Racing Association, 1400-4 Shiba, Shimotsuke, Tochigi 329-0412, Japan. koji_tsujimura@jra.go.jp
Yamada
Masayuki
M
Nagata
Shun-ichi
S
Yamanaka
Takashi
T
Nemoto
Manabu
M
Kondo
Takashi
T
Kurosawa
Masahiko
M
Matsumura
Tomio
T
D015075:2-Aminopurine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics; D000212:Acyclovir / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics; D000284:Administration, Oral; D000818:Animals; D000998:Antiviral Agents / Q000097:blood / Q000493:pharmacokinetics; D019540:Area Under Curve; D000077595:Famciclovir; D006147:Guanine; D006207:Half-Life; D006566:Herpesviridae Infections / Q000188:drug therapy / Q000662:veterinary; D004861:Herpesvirus 1, Equid / Q000187:drug effects; D006734:Horse Diseases / Q000188:drug therapy / Q000821:virology; D006736:Horses
D000998:Antiviral Agents; C053539:penciclovir; D015075:2-Aminopurine; D006147:Guanine; D000077595:Famciclovir; D000212:Acyclovir