Pharmacokinetics of ceftiofur sodium after intramuscular or subcutaneous administration in green iguanas (Iguana iguana).
OBJECTIVE
To determine the pharmacokinetics of ceftiofur sodium after IM and SC administration in green iguanas.


METHODS
6 male and 4 female adult green iguanas.


METHODS
In a crossover design, 5 iguanas received a single dose of ceftiofur sodium (5 mg/kg) IM, and 5 iguanas received the same dose SC. Blood samples were taken at 0, 20, and 40 minutes and 1, 2, 4, 8, 24, 48, and 72 hours after administration. After a 10-week washout period, each iguana was given the same dose via the reciprocal administration route, and blood was collected in the same fashion. Ceftiofur free-acid equivalents were measured via high-performance liquid chromatography.


RESULTS
The first phase intercepts were significantly different between the 2 administration routes. Mean maximum plasma concentration was significantly higher with the IM (28.6 +/- 8.0 microg/mL) than the SC (18.6 +/- 8.3 microg/mL) administration route. There were no significant differences between terminal half-lives (harmonic mean via IM route, 15.7 +/- 4.7 hours; harmonic mean via SC route, 19.7 +/- 6.7 hours) and mean areas under the curve measured to the last time point (IM route, 11,722 +/- 7,907 microg x h/mL; SC route, 12,143 +/- 9,633 microg x h/mL). Ceftiofur free-acid equivalent concentrations were maintained > or = 2 microg/mL for > 24 hours via both routes.


CONCLUSIONS
A suggested dosing schedule for ceftiofur sodium in green iguanas for microbes susceptible at > 2 microg/mL would be 5 mg/kg, IM or SC, every 24 hours.
Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
Keith G
KG
Benson
Lisa A
LA
Tell
Lee A
LA
Young
Scott
S
Wetzlich
Arthur L
AL
Craigmill
D000818:Animals; D002511:Cephalosporins / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D005260:Female; D007076:Iguanas; D007273:Injections, Intramuscular; D007279:Injections, Subcutaneous; D007700:Kinetics; D008297:Male; D008657:Metabolic Clearance Rate
D002511:Cephalosporins; C053503:ceftiofur