Age-related changes in the pharmacokinetics of marbofloxacin after intravenous administration in goats.
The pharmacokinetics of marbofloxacin was studied in adult goats and 1-, 3- and 6-weeks-old kids after single dose i.v. dose of 2 mg/kg body weight. Drug concentration in plasma was determined by high-performance liquid chromatography (HPLC) and the data collected were subjected to compartmental kinetic analysis. Volume of distribution was relatively high in adult goats (Vss = 1.31 L/kg), and increased with age (Vss = 0.92 L/kg, 0.95 L/kg and 1.00 L/kg, in 1-, 3- and 6-weeks-old kids respectively). Total body clearance (Cl) also increased with age from 0.080 L/kg.h (1-week-old) to 0.097 L/kg.h (3-weeks-old), 0.18 L/kg.h (6-weeks-old) and 0.23 L/kg.h (adult goats). As a consequence of increased body Cl, area under the plasma concentration vs. time curve decreased with age (AUC = 27.46 microg.h/mL, 22.61 microg.h/mL, 11.86 microg.h/mL and 8.44 microg.h/mL in 1-, 3-, 6-weeks-old kids and adults, respectively) and a longer elimination half-life was found during the first 3 weeks of age (t1/2beta = 9.66 h, 8.25 h, 6.44 h and 7.18 h, in 1-, 3-, 6-weeks-old kids and adults, respectively). Mean residence time decreased with age from 11.86 h in 1-week-old kids to 9.63 h (3 weeks), 5.76 h (6 weeks) and 5.06 h in adult goats.
Department of Pharmacology, Veterinary Sciences Faculty, University of Buenos Aires, Buenos Aires, Argentina.
S
S
Waxman
M D
MD
San Andrés
F
F
González
M I
MI
San Andrés
J J
JJ
De Lucas
C
C
Rodríguez
D000375:Aging; D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism; D019540:Area Under Curve; D002851:Chromatography, High Pressure Liquid; D004791:Enzyme Inhibitors / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D005260:Female; D024841:Fluoroquinolones / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D006041:Goats / Q000378:metabolism*; D007275:Injections, Intravenous / Q000662:veterinary; D015363:Quinolones / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D059005:Topoisomerase II Inhibitors
D004791:Enzyme Inhibitors; D024841:Fluoroquinolones; D015363:Quinolones; D059005:Topoisomerase II Inhibitors; C080260:marbofloxacin