A series of in vivo, ex vivo, and in vitro studies in adult cats evaluated cefovecin, a third-generation cephalosporin that needs to be administered only every 2 weeks. The dosage used was 8 mg/kg. Bioavailability and pharmacokinetics were determined after intravenous and subcutaneous delivery. Protein binding was determined in vitro in feline plasma and ex vivo in transudate from cats surgically implanted with tissue chambers. The primary route of elimination is via the kidneys. Fourteen days after administration, the total concentration of cefovecin in plasma remained about the MIC90 for Pasteurella multocida and in urine above the MIC90 for Escherichia coli. The slow elimination and long-lasting free concentrations in extracellular fluid of cefovecin allow the long dosing interval of 14 days.

COMMENTARY: This third-generation cephalosporin, newly approved for use in cats, is formulated for administration as an aqueous solution via subcutaneous injection and has a broad spectrum of activity against gram-positive and gram-negative bacteria. Many pet owners find it difficult to give medicines at home, so a product that could be given in the veterinarian's office and be effective for 14 days would be very desirable.

Pharmacokinetics of cefovecin in cats. Stegemann MR, Sherington J, Coati N, et al.  J VET PHARMACOL THER 29:513-524, 2006.