Flumequine in the Goat: Pharmacokinetics after Intravenous and Intramuscular Administration

The pharmacokinetics of flumequine, administered intravenously and intramuscularly at the single dose of 20 mg.kg-1, was investigated in healthy goats. After intravenous injection, flumequine distributed rapidly (t1/2 alpha = 0.87 ± 0.15 h) but was eliminated slowly (t1/2 beta = 7.12 ± 1.27 h), mean Clearance (Cl) and Volume of distribution (Vdss) were 0.32±0.03 (L.h-1.kg-1) and 1.22±029 (L.kg-1), respectively. After intramuscular administration, the peak serum concentration (Cmax = 7.40 ± 0.5 mcg.mL-1) was reached in about 1.5 h (Tmax) and bioavailability was about 93%. Estimated flumequine serum levels following repeated intramuscular administration of the aqueous suspension used in the study (7.23 ± 0.7 µg.mL-1 and 4.82 ± 0.47 µg.mL-1 at intervals of 8 and 12 hours, respectively) indicated that to maintain serum levels above MIC values for susceptible bacteria is necessary a dosage regimen of 20 mg.kg-1 every 12h by intramuscular route.