Amikacin sulfate in mares: pharmacokinetics and body fluid and endometrial concentrations after repeated intramuscular administration.
Six mares were given 5 IM injections (at 12-hour intervals between doses) of amikacin sulfate at a dosage of 7 mg/kg of body weight. Serum amikacin concentrations were measured serially throughout the study; synovial, peritoneal, endometrial, and urine concentrations were determined after the last injection. Amikacin concentrations of the CSF were measured serially in 3 of the 6 mares; 1 of the 3 mares had septic meningitis. Mean serum amikacin concentrations peaked at 1 to 2 hours after IM injection. The highest mean serum concentration was 19.2 micrograms/ml (1.5 hours after the 5th injection). The highest mean synovial concentration was 10.8 micrograms/ml at 2 hours after the 5th injection; the highest mean peritoneal concentration was 16.2 micrograms/ml at 3 hours after the 5th injection. The mean endometrial amikacin concentration was 2.5 micrograms/g (1.5 hours after the 5th injection). Amikacin reached a CSF concentration of 0.97 micrograms/ml in the mare with meningitis, but amikacin was not detected in CSF of healthy mares. Urine concentrations reached 1,458 micrograms/ml. Pharmacokinetic values were estimated after the 1st injection (elimination rate constant = 0.31/hour; half-life = 2.3 hours; apparent volume of distribution = 0.26 L/kg), and after the 5th injection (elimination rate constant = 0.28/hour; half-life = 2.6 hours; apparent volume of distribution = 0.30 L/kg); significant differences were not observed.
D000583:Amikacin / Q000008:administration & dosage / Q000378:metabolism*; D000818:Animals; D001202:Ascitic Fluid / Q000378:metabolism; D001826:Body Fluids / Q000378:metabolism*; D004717:Endometrium / Q000378:metabolism*; D005260:Female; D006734:Horse Diseases / Q000378:metabolism; D006736:Horses / Q000378:metabolism*; D007273:Injections, Intramuscular / Q000662:veterinary; D007612:Kanamycin / Q000031:analogs & derivatives*; D008581:Meningitis / Q000378:metabolism / Q000662:veterinary; D011552:Pseudomonas Infections / Q000378:metabolism / Q000662:veterinary; D013582:Synovial Fluid / Q000378:metabolism
D007612:Kanamycin; D000583:Amikacin