Administration Of Marbofloxacin Research Articles

Pharmacokinetic characteristics and tissue residues for marbofloxacin and its metabolite N-desmethyl-marbofloxacin in broiler chickens.

To determine pharmacokinetic characteristics of marbofloxacin after a single IV and oral administration and tissue residues after serial daily oral administration in chickens. 40 healthy broiler chickens. Two groups of chickens (groups A and B; 8 chickens/group) were administered a single IV and oral administration of marbofloxacin (2 mg/kg). Chickens of group C (n = 24) were given serial daily doses of marbofloxacin (2 mg/kg, PO, q 24 h for 3 days). Plasma (groups A and B) and tissue concentrations (group C) of marbofloxacin and its major metabolite N-desmethyl-marbofloxacin were determined by use of high-performance liquid chromatography. Residues of marbofloxacin and N-desmethylmarbofloxacin were measured in target tissues. Elimination half-life and mean residence time of marbofloxacin in plasma were 5.26 and 4.36 hours after IV administration and 8.69 and 8.55 hours after oral administration, respectively. Maximal plasma concentration was 1.05 microg/ml, and interval from oral administration until maximum concentration was 1.48 hours. Oral bioavailability of marbofloxacin was 56.82%. High concentrations of marbofloxacin and N-desmethyl-marbofloxacin were found in the kidneys, liver, muscles, and skin plus fat 24 hours after the final dose of marbofloxacin; however, marbofloxacin and N-desmethyl-marbofloxacin were detected in only hepatic (27.6 and 98.7 microg/kg, respectively) and renal (39.7 and 69.1 microg/kg, respectively) tissues 72 hours after termination of marbofloxacin treatment. Analysis of pharmacokinetic data obtained in this study reveals that a minimal therapeutic dose of 2 mg/kg, PO, every 24 hours should be appropriate for control of most infections in chickens.

Effect of experimental renal impairment on disposition of marbofloxacin and its metabolites in the dog.

The pharmacokinetics of marbofloxacin was studied in eight healthy female Beagle dogs before and after moderate renal impairment was induced experimentally. A single intravenous (i.v.) administration and repeated administration for 8 days (2 mg/kg, once-a-day) of marbofloxacin were studied. Renal impairment was induced by a right kidney nephrectomy and electrocoagulation of the left kidney. An increase (P < 0.001) in the plasma concentrations of urea (from 3.8+/-0.7 to 9.8+/-2.1 mmol/L) and creatinine (from 78.8+/-3.4 to 145.8+/-22.3 micromol/L), and a significant decrease (2.9+/-0.3 vs 1.5+/-0.2 mL/kg/min) (P < 0.001) in glomerular filtration rate were observed in the renal-impaired dogs. The clearance of marbofloxacin was slightly decreased after the induction of renal failure (1.6+/-0.2 to 1.4+/-0.1 mL/kg/min) (P < 0.05), but no significant variation of volume of distribution at steady state (Vss) and mean residence time (MRT) was observed after intravenous administration of marbofloxacin (P > 0.05). Following oral administration of marbofloxacin, an increase in total area under the concentration time curve (AUC) was observed after renal failure (from 10372+/-1710 to 11459+/-1119 mg x min/L) (P < 0.05), but indices of accumulation were not modified. An increase (P < 0.01) in the AUC of N-oxide-marbofloxacin was observed after surgery. In conclusion, renal impairment has no biologically relevant influence on marbofloxacin disposition and there is no need for dosage adjustment of marbofloxacin in dogs with mild renal impairment.