RESUMEN
The pharmacokinetics of moxifloxacin was studied following intravenous (IV) and subcutaneous (SC) administration of 5 mg/kg to healthy lactating goats (n = 6). Moxifloxacin concentrations were determined by high performance liquid chromatography assay with fluorescence detection. The moxifloxacin plasma concentration versus time data after IV administration could best be described by a two compartment open model. The disposition of SC administered moxifloxacin was best described by a one-compartment model. The plasma moxifloxacin clearance (Cl) for the IV route was 0.43 +/- 0.02 L/kg (mean +/- SE). The steady-state volume of distribution (Vss) was 0.79 +/- 0.08 L/kg. The terminal half-life (t1/2lambdaz) was 1.94 +/- 0.41 and 2.98 +/- 0.48 h after IV and SC administration, respectively. The absolute bioavailability was 96.87 +/- 10.27% after SC administration. Moxifloxacin penetration from blood to milk was quick for both routes of administration and the high AUCmilk/AUCplasma and Cmax-milk/Cmax-plasma ratios reached indicated a wide penetration of moxifloxacin into the milk. From these data, it appears that a 5 mg/kg SC dose of moxifloxacin would be effective in lactating goats against bacterial isolates with MIC < or = 0.20 microg/mL in plasma and MIC < or = 0.40 microg/mL in milk.
Asunto(s)
Antibacterianos/farmacocinética , Compuestos Aza/farmacocinética , Cabras/metabolismo , Leche/metabolismo , Quinolinas/farmacocinética , Animales , Antibacterianos/administración & dosificación , Antibacterianos/sangre , Compuestos Aza/administración & dosificación , Compuestos Aza/sangre , Femenino , Fluoroquinolonas , Cabras/sangre , Inyecciones Intravenosas , Inyecciones Subcutáneas , Lactancia , Moxifloxacino , Quinolinas/administración & dosificación , Quinolinas/sangreRESUMEN
OBJECTIVE: To investigate the disposition kinetics of ampicillin and sulbactam after IV and IM administration of an ampicillin-sulbactam (2:1) preparation and determine the bioavailability of the combined preparation after IM administration in turkeys. ANIMALS: 10 healthy large white turkeys. PROCEDURE: In a crossover study, turkeys were administered the combined preparation IV (20 mg/kg) and IM (30 mg/kg). Blood samples were collected before and at intervals after drug administrations. Plasma ampicillin and sulbactam concentrations were measured by use of high-performance liquid chromatography; plasma concentration-time curves were analyzed via compartmental pharmacokinetics and noncompartmental methods. RESULTS: The drugs were distributed according to an open 2-compartment model after IV administration and a 1-compartment model (first-order absorption) after IM administration. For ampicillin and sulbactam, the apparent volumes of distribution were 0.75+/-0.11 L/kg and 0.74+/-0.10 L/kg, respectively, and the total body clearances were 0.67+/-0.07 L x kg(-1) x h(-1) and 0.56+/-0.06 L x kg(-1) x h(-), respectively. The elimination half-lives of ampicillin after IV and IM administration were 0.78+/-0.12 hours and 0.89+/-0.17 hours, respectively, whereas the corresponding half-lives of sulbactam were 0.91+/-0.12 hours and 0.99+/-0.16 hours, respectively. Bioavailability after IM injection was 58.87+/-765% for ampicillin and 53.75+/-5.35% for sulbactam. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that a regimen of loading and maintenance doses of 300 mg of the ampicillin-sulbactam (2:1) combination/kg every 8 hours could be clinically useful in turkeys. This dosage regimen maintained plasma concentrations of ampicillin > 0.45 microg/mL in turkeys.