title: Pharmacokinetics of doxycycline in sheep after intravenous and oral administration.
abstract: The pharmacokinetics of doxycycline were investigated in sheep after oral (PO) and intravenous (IV) administration. The IV data were best described using a 2- (n = 5) or 3- (n = 6) compartmental open model. Mean pharmacokinetic parameters obtained using a 2-compartmental model included a volume of distribution at steady-state (V(ss)) of 1.759+/-0.3149L/kg, a total clearance (Cl) of 3.045+/-0.5264mL/kg/min and an elimination half-life (t(1/2beta)) of 7.027+/-1.128h. Comparative values obtained from the 3-compartmental mean values were: V(ss) of 1.801+/-0.3429L/kg, a Cl of 2.634+/-0.6376mL/kg/min and a t(1/2beta) of 12.11+/-2.060h. Mean residence time (MRT(0-infinity)) was 11.18+/-3.152h. After PO administration, the data were best described by a 2-compartment open model. The pharmacokinetic parameter mean values were: maximum plasma concentration (C(max)), 2.130+/-0.950microg/mL; time to reach C(max) (t(max)), 3.595+/-3.348h, and absorption half-life (t(1)/(2k)(01)), 36.28+/-14.57h. Non-compartmental parameter values were: C(max), 2.182+/-0.9117microg/mL; t(max), 3.432+/-3.307h; F, 35.77+/-10.20%, and mean absorption time (MAT(0-infinity)), 25.55+/-15.27h. These results suggest that PO administration of doxycycline could be useful as an antimicrobial drug in sheep.
authors.affiliation: Pharmacology, Department of Biomedical Sciences, Veterinary Faculty, University of Leon, Spain.
authors.forename: Luis J
authors.initials: LJ
authors.lastname: Castro
authors.forename: Ana M
authors.initials: AM
authors.lastname: Sahagún
authors.forename: M José
authors.initials: MJ
authors.lastname: Diez
authors.forename: Nélida
authors.initials: N
authors.lastname: Fernández
authors.forename: Matilde
authors.initials: M
authors.lastname: Sierra
authors.forename: Juan J
authors.initials: JJ
authors.lastname: García
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics*; D019540:Area Under Curve; D018592:Cross-Over Studies; D004318:Doxycycline / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics*; D005260:Female; D006207:Half-Life; D007275:Injections, Intravenous; D012756:Sheep / Q000097:blood / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D004318:Doxycycline