Basic Science Sector

Citation:

Ramadan, A., and A. A. M. El-Aty, "Pharmacokinetics and Distribution of Florfenicol in Bronchial Secretions of Healthy and Pasteurellamultocida Infected Calves", Pharmaceutica Analytica Acta, 2011.

Abstract:

Florfenicol was administered intravenously and intramuscularly at a dose rate of 20 g/kg bwt to determine itsconcentration in blood and bronchial secretions as well as kineticbehavior in healthy and diseased calves. Severacute bronchopneumonia was induced via inoculating the animals with Pasteurellamultocida. Following intravenous(i.v) administration, the serum concentration - time curve indicated a two compartment open model with a meanelimination half-lives (t1/2?) of 4.10 and 4.84 h in healthy and infected calves, respectively. The mean volumes ofdistribution at steady state (Vdss) were 0.68 and 0.63 L/kg and the total body clearances (Cltot) were 0.15 and0.11 L/kg/h with mean residence time (MRT) of 0.05 and 0.05 h, respectively. Florfenicol was slowly eliminatedfrom serum and bronchial secretions with elimination half-lives (t1/2el) of (12.43 and 17.23 h) and (13.74 and 22.46h), respectively, following intramuscular (i.m.) injection. The peak concentrations (Cmax) in serum and bronchialsecretions were (3.70 and 4.06 ?g/ml) and (6.88 and 7.62 ?g/ml) attained at (3.07 and 3.01 h) and (1.54 and 1.70h), respectively. The drug is extensively distributed to bronchial secretions with AUCbronchial secretion / AUCserum ratio of 1:2.53 and 1: 2.03, respectively. The clinical and hematological parameters in calves treated intramuscularly returnedto normal faster than those treated intravenously. These results suggest that i.m. injection of florfenicol could be usedfor treatment of acute P. multocidabronchopneumonia in calves.

Notes:

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