Amikacin plasmatic disposition in goats, after intramuscular single dose

Abstract

Amikacin is a semi-synthetic antimicrobial agent belonging to the aminoglycoside group. The main objective of the present study was to describe the pharmacokinetic behaviour of amikacin in goats, in order to obtain data for a correct intramuscular dosage thus, a 5 mg/kg intramuscular administration of amikacin was given. Amikacin plasma levels were determined by microbiological method, using Bacillus subtilis BGA as the microorganism test. Blood samples were taken at 5, 10, 15, 20, 25, 30 minutes and at 1, 2, 3, 4, 6, 8, 10 and 12 hours following the administration of the drug. The results were adjusted to a one compartment open model for statistical analysis. The plasma pharmacokinetic parameters obtained were: Amikacin average plasma level (Cp max) of 29.7 ± 5.1 mg/ml at 32.4 minutes. The elimination half-life (t_1/2) and total body clearance (Cl_t/f) were 3.09 ± 0.6 h and 0.66 ± 0.1 ml/min/kg, respectively. The distribution volume (V_d/f) of 0.162 ± 0.03 L/kg indicates the restricted tisular diffusion. The drug was quickly absorbed from the injection site, reaching effective concentrations that overcome the minimum inhibitory concentration (MIC) at least for 10 hours, for most of the pathogens of veterinary interest. Intramuscular administration of 4-5 mg/kg can be considered satisfactory for the treatment of pathologies produced by these microorganisms.