Florfenicol pharmacokinetics in lactating cows after intravenous, intramuscular and intramammary administration

Abstract

Pharmacokinetics of florfenicol 30% injectable solution was determined in lactating cows after intravenous, intramammary and intramuscular administration. Serum concentration-time data generated in the present study were analysed by non-compartmental methods based on statistical moment theory. Florfenicol half-life was 176 min, mean residence time 129 min, volume of distribution at steady-state 0.35 L/kg, and total body clearance 2.7 mL/min.kg after intravenous administration at 20 mg/kg. The absorption after intramuscular administration appeared slow and the kinetic parameters and the serum concentration vs. time curve were characteristic of absorption rate-dependent elimination. The absorption after intramammary administration of florfenicol at 20 mg/kg was good (53.9%) and resulted in serum concentrations with apparent clinical significance. The intramammary administration resulted in serum florfenicol concentrations that were significantly higher than the respective serum concentrations following intravenous administration 4 h after administration and thereafter. Florfenicol absorption was faster from the mammary gland than from the muscle. The maximum serum concentrations (Cmax) were 6.9 micrograms/mL at 360 min after intramammary administration and 2.3 micrograms/mL at 180 min after intramuscular administration. The bioavailability of florfenicol was 54% and 38% after intramammary and intramuscular administration, respectively. The Cmax in milk was 5.4 micrograms/mL at 180 min after intravenous and 1.6 micrograms/mL at 600 min after intramuscular administration.

Pharmacokinetics and Distribution of Florfenicol in Bronchial Secretions of Healthy and Pasteurella multocida Infected Calves

“…injection was adequately described by a biexponential terms with a slow distribution and elimination phases. Our findings were similar to those reported in calves [12,26] and cattle [15,27].…”

“…The principle method for treating pneumonic pasteurellosis is antibiotic therapy [31]. Florfenicol has been suggested as an appropriate antimicrobial drug for the treatment of respiratory disease in cattle [15,27], the suggestion which is supported by the results of the present study.…”

Pharmacokinetics and Bioequivalence of Florfenicol Oral Solution Formulations (Flonicol® and Veterin®10%) in Broiler Chickens

“…In poultry, florfenicol is used extensively for the twreatment of respiratory and gastrointestinal bacterial infections, administered via drinking water [7,17,24]. It has been reported that florfenicol showed greater activity than chloramphenicol and thiamphenicol, especially against Pasteurella, Salmonella, E. coli and Staphylococcus aureus [28]. Moreover, Florfenicol has superior pharmacological and pharmacokinetics features over some other antimicrobials used in chicken industry [18,29,30].…”

Florfenicol concentrations in milk of lactating cows postreated by intramuscular or intramammary routes

“…Florfenicol, administered by intramuscular and intramammary routes, has good distribution in the bovine mammary gland (8,9). In addition, the bacterium Staphylococcus aureus has shown high susceptibility to phenicols (10,11) making florfenicol a good therapeutic option in S. aureus caused mastitis (12).…”