Pharmacokinetics of tobramycin in ducks and sex-related differences.

Author(s): Dimitrova D, Moutafchieva R, Kanelov I, Dinev T, Lashev L

Affiliation(s): Department of Pharmacology, Physiology of Animals and Physiological Chemistry, Trakia University, Stara Zagora, Bulgaria.

Publication date & source: 2009-03, Vet J., 179(3):462-4. Epub 2007 Nov 19.

Publication type: Randomized Controlled Trial

The aims of the present study were to determine the disposition of tobramycin after single intravenous (IV) and intramuscular (IM) injections in ducks, and to establish any sex-related differences. Tobramycin sulfate was administered as a 2.5% water solution in a cross-over design at a dose of 5mg/kg to 12 healthy ducks (six males and six females). Concentrations of the drug in serum were determined by a microbiological assay. The serum pharmacokinetic values for tobramycin were best represented using a one- or two-compartment open model, depending on the method of administration. Non-compartment analysis was also performed after IV administration. Tobramycin had a low degree of distribution and a relatively fast elimination. The mean volume of distribution in ducks (males and females) was higher than that reported in pigeons but lower than in chickens, with a slower rate of elimination. The IM injection resulted in a fast and complete absorption. The rate of elimination after IM administration was about twice as slow as in other avian species. Sex-related variations in tobramycin pharmacokinetics were similar to those reported for kanamycin and apramycin in hens and roosters.