Faculty of Veterinary Medicine University of Zagreb
Abstract
The disposition kinetics of kanamycin was investigated following an injection of a single intravenous dose 5 mg/kg body mass in healthy adult female mules. Blood samples collected at various time intervals post-medication were analyzed for kanamycin by microbiological assay. The plasma drug concentration versus time data was best fitted by a biexponential expression. Macro-kinetic parameters were computed for a two-compartment open model. Values for distribution half-life (t1/2á)) and elimination half-life (t1/2 ß) were 0.18 ± 0.26 and 4.39 ± 0.68 h, respectively. The apparent volume of distribution (Vd) was 0.64 ± 0.17 L/kg. Total body clearance (ClB) of the drug was 1.66 ± 0.22 ml/min.kg. Existing dosage of 5 mg/kg body mass at 24 h intervals does not maintain the desired minimum inhibitory concentration (MIC) at the end of proposed dosing intervals. Calculated optimal dosage regimen for kanamycin in mules was 8.73 and 7.45 mg/kg body mass for priming and maintenance, respectively, for a dosage interval of 12 h to maintain the concentration of 2 μg/ml in blood.Istražena je farmakokinetika raspodjele kanamicina u zdravih, odraslih mula nakon jednokratne intravenske primjene u dozi 5 mg/kg tjelesne mase (t.m.) u zdravih odraslih mula. Uzorci krvi uzeti u različitim vremenskim razmacima bili su pretraženi na količinu kanamicina mikrobiološkim testom. Koncentracija lijeka u plazmi u odnosu na vrijeme najviše je odgovarala bieksponencijalnoj krivulji. Za izračunavanje farmakokinetièkih pokazatelja rabljen je dvoprostorni otvoreni model. Rezultati su pokazali da je poluvrijeme raspodjele lijeka (t1/2α) iznosilo 0.18 ± 0.26, a poluvrijeme eliminacije (t1/2β) 4.39 ± 0.68 sati. Prividni volumen raspodjele lijeka (Vd) bio je 0.64 ± 0.17 l/kg, a ukupni klirens (ClB) 1.66 ± 0.22 ml/min/kg. Dozom 5 mg/kg t.m. jedanput na dan nije postignuta željena minimalna inhibicijska koncentracija (MIC) na kraju doznog razmaka. Izračunato je da je optimalna udarna doza kanamicina za mule iznosila 8.73, a doza održavanja 7.45 mg/kg t.m. Pritom se lijek mora primjenjivati svakih 12 sati da bi se postigla koncentracija u krvi 2 mg/ml
