Antibacterials for systemic use; amphenicols; florfenicol

Florfenicol is a broad-spectrum antibiotic which is active against both Gram-positive and Gram-negative bacteria isolated from domestic animals.

Florfenicol is a bacteriostatic antibiotic. Its activity is due to inhibition of protein synthesis and results from the binding of bacterial ribosomes in such a way as to prevent ongoing translation of mRNA into protein. In vitro studies have shown florfenicol to have a broad spectrum of activity which includes aerobic and anaerobic bacteria which are either Gram positive or Gram negative. Aeromonas salmonicida has been shown to be sensitive to florfenicol concentrations of 1.6 µg/ml or less.

Pharmacokinetic studies have been conducted with florfenicol following oral administration to Atlantic salmon. After oral administration florfenicol reached a peak plasma concentration of 4 µg/ml at 10.3 hours after administration. The drug was well distributed in body fluids and tissues as demonstrated by a volume of distribution of 0.9 L/kg. Florfenicol had an oral bioavailability of 96.5%.