Pharmacokinetics of florfenicol in North American elk (Cervus elaphus).
Florfenicol pharmacokinetics after administration of a single subcutaneous (s.c.) dose of 40 mg/kg of body weight in adult elk (Cervus elaphus) was investigated. Serum florfenicol concentrations were determined by a sensitive high-performance liquid chromatographic method with limit of quantification of 0.03 microg/mL. Florfenicol pharmacokinetic parameters in elk were estimated using a noncompartmental approach. After a single s.c. injection, florfenicol concentrations remained above 1 microg/mL for approximately 36 h and above 0.5 microg/mL for approximately 72 h. Following s.c. injection, florfenicol was absorbed rapidly with a mean maximum concentration (C(max)) of 3.7 microg/mL achieved at 4.2 h (T(max)). The C(max) value in elk is similar to values reported in cattle at the same dose, suggesting that the 40 mg/kg s.c. dose achieves therapeutic concentrations in elk. A mean elimination half-life (t(1/2)) of 44 h is shorter than that reported in cattle. The more rapid elimination half-life in elk suggests that elk may require a multiple dose regimen for therapeutic success with s.c. Nuflor. We recommend s.c. Nuflor be administered subcutaneously to elk every 24 h at a dose level of 40 mg/kg.
Alcorn
J
J
College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
Dowling
P
P
Woodbury
M
M
Killeen
R
R
D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D019540:Area Under Curve; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary; D003670:Deer / Q000378:metabolism*; D005260:Female; D007279:Injections, Subcutaneous / Q000662:veterinary; D013839:Thiamphenicol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics*
D000900:Anti-Bacterial Agents; C035534:florfenicol; D013839:Thiamphenicol