title: Comparative disposition kinetics and plasma protein binding of gentamicin sulphate in three juvenile animal species.
abstract: The pharmacokinetics of gentamicin was studied in lambs, calves and foals, respectively after single intravenous (i.v.) injections of 5 mg kg(-1) body weight. The plasma concentration-time curves of gentamicin sulphate were best fitted to follow a two-compartment open model in calves and foals and a three-compartment open model in lambs. Gentamicin showed high plasma level at 5 min post-injection. Then its concentration decreased gradually until its minimum detectable level at 10 and 12 h post-injection in foals and calves, respectively, was reached. In contrast, the plasma concentrations were much higher in lambs and persisted up to 48 h from the onset of injection. Values of pharmacokinetic parameters for gentamicin sulphate in different animals after i.v. injections were calculated. Pharmacokinetic data in lambs demonstrated a triphasic decline in plasma gentamicin concentration with slow terminal elimination phase (washout phase) with (t(1/2y)) of 7.7 h. Gentamicin showed a small volume of distribution Vd(ss) (80.3 ml kg(-1)) in lambs indicating that the drug is slightly distributed in extra-vascular tissues. The overall rate of total body clearance ClB in lambs was (0.46 ml kg(-1)) slower than in calves (1.5 ml kg(-1)) and foals (2.7 ml kg(-1)). In vitro protein binding per cent of gentamicin sulphate in plasma were 16.80, 11.03 and 7.98% in lambs, calves and foals. The results of this study emphasize the importance of determining the pharmacokinetics of gentamicin in each species of young animals separately.
authors.affiliation: Pharmacology Department, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt. kasooud@hotmail.com
authors.forename: K
authors.initials: K
authors.lastname: Abo El Sooud
mesh_terms: D000818:Animals; D000829:Animals, Domestic / Q000502:physiology*; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D019540:Area Under Curve; D001665:Binding Sites; D002417:Cattle; D005839:Gentamicins / Q000008:administration & dosage / Q000493:pharmacokinetics*; D006736:Horses; D007275:Injections, Intravenous; D011485:Protein Binding; D012756:Sheep; D013045:Species Specificity
chemical_list: D000900:Anti-Bacterial Agents; D005839:Gentamicins