Farmakokinetika i doziranje levofloksacina u bivolje teladi nakon jednokratne potkožne primjene

The present study was conducted on six male buffalo calves to investigate the pharmacokinetics of levofloxacin following a single subcutaneous administration at the dose rate of 3 mg/kg body weight. Appreciable plasma concentration of levofloxacin (0.28 ± 0.01 μg/mL) was detected 2.5 min after injection and the peak plasma level of 2.94 ± 0.07 μg/mL was observed at 1 h. Drug levels of 0.28 ± 0.01 μg/mL in plasma were detected up to 12 h from administration. Rapid absorption of the drug was also evident by the high value of the absorption rate constant (2.53 ± 0.53 /h). The absolute bioavailability of levofloxacin after subcutaneous administration calculated on the basis of AUC (10.5 ± 0.11 μg/mL/h) and Ke (0.272 ± 0.009 /h) after a single intravenous injection in buffalo calves was 44.3 ± 1.76 per cent. The high value of AUC (8.02 ± 0.2 μg/mL/h) reflected major exposure in the buffalo calves. Extensive distribution of the drug into various body fluids and tissues was reflected by the high value of Vdarea (1.06 ± 0.04 L.kg-1). The elimination half-life and MRT were 4.43 ± 0.1 h and 6.71 ± 0.17 h, respectively. On the basis of the pharmacokinetic parameters, the calculated subcutaneous dosage regimen for levofloxacin in buffalo calves was 4.6 mg/kg at 24 h intervals.Farmakokinetika levofloksacina nakon njegove jednokratne supkutane primjene u dozi od 3 mg/kg tjelesne mase određivana je na šest muške bivolje teladi. Mjerljiva koncentracija levofloksacina u plazmi (0,28 ± 0,01 μg/mL) bila je ustanovljena 2,5 minute nakon primjene, a vršna razina od 2,94 ± 0,07 μg/mL ustanovljena je jedan sat nakon primjene. Razina lijeka od 0,28 ± 0,01 μg/mL bila je u plazmi dokazana do 12 sati nakon primjene. Brza apsorpcija lijeka očitovala se u visokoj vrijednosti stupnja apsorpcije (2,53 ± 0,53/h). Apsolutna biološka raspoloživost levofloksacina nakon supkutane primjene izračunana na osnovi AUC (10,5 ± 0,11 μg/mL/h) i Ke (0,272 ± 0,009 /h) nakon jednokratne intravenske primjene iznosila je 44,3 ± 1,76%. Visoka vrijednost AUC (8,02 ± 0,2 μg/mL/h) bila je posljedica velike količine primijenjenoga lijeka. Široka raspodjela lijeka u različitim tjelesnim tekućinama i tkivima očitovala se velikom vrijednošću Vdarea (1,06 ± 0,04 L/kg). Poluživot izlučivanja lijeka iznosio je 4,43 ± 0,1 h, a MRT 6,71 ± 0,17 h. Na osnovi farmakokinetičkih pokazatelja, izračunana supkutana doza levofloksacina u bivolje teladi iznosila je 4,6 mg/kg u razmacima od 24 sata