Amikacin sulfate in the cat: Serum, urine and uterine tissue concentrations

Abstract

Puerperal metritis and pyometra in non-breeding cats is frequently caused by gram-negative bacteria that are resistant to a variety of antibiotics. Amikacin has been found to be effective against pathogens associated with uterine infections in the mare and the woman, but its efficacy has not been studied in the cat. Serum concentrations of amikacin were determined in healthy adult cats (six male and six female) after administration of 5, 10, and 20 mg/kg body weight of amikacin sulfate, each dose given subcutaneously (s.c.), intramuscularly (i.m.) and intravenously (i.v.) to each of the cats using a repeat treatment design. In a subsequent experiment, the six females were given 10 mg/kg s.c. amikacin and samples of blood, urine and full-thickness uterine wall were taken at 40 and 120 minutes after treatment. Mean serum concentrations of amikacin peaked between 30 and 45 minutes after i.m. injection and between 45 and 60 minutes after s.c. injections. The serum amikacin concentration curves were similar regardless of dose or administration route except for a slightly longer retention time after the 20 mg/kg dose given i.m. and s.c. After s.c. injection of 10 mg/kg, the mean uterine concentration of amikacin at two hours after treatment was 4.1 ug/g; the concurrent mean serum concentration was 18.6 ug/ml.