PHARMACOKINETICS OF GENTAMICIN IN CATS GIVEN ESCHERICHIA-COLI ENDOTOXIN

  • 1 May 1988
    • journal article
    • research article
    • Vol. 49  (5) , 603-607
Abstract
Nineteen cats were given 3 mg of gentamicin sulfate/kg of body weight by rapid IV, SC, or IM injection for baseline values. Serum concentration of gentamicin vs time data were analyzed using a noncompartmental model based on statistical moment theory. One week later, each cat was given 0.5 .mu.g of Escherichia coli endotoxin/kg, IV. After cats had an increase in rectal temperature of at least 1 C, 3 mg of gentamicin/kg was administered by the same route used the previous week. Serum concentration of gentamicin vs time data were analyzed, and pharmacokinetic values were compared with base-line values. For IV studies, the half-life (t1/2) of gentamicin and the mean residence time were significantly different (P < 0.05) compared with base line, whereas the total body clearance and apparent volume of distribution at steady state were not. The harmonic mean .+-. pseudo SD for the t1/2 of gentamicin after IV administration was 76.8 .+-. 12.6 minutes for base line and was 65.2 .+-. 12.2 minutes in the same cats given endotoxin. The t1/2 of gentamicin after SC administration was 74.6 .+-. 6.2 minutes for base line and was 65.2 .+-. 13.6 minutes in the same cats given endotoxin. After IM administration, the t1/2 of gentamicin was 60.3 .+-. 10 minutes for base line and was 59.7 .+-. 13.6 minutes in the same cats given endotoxin. After IV administration of gentamicin, the arithmetic mean .+-. SD for the mean residence time was 102.4 .+-. 16.1 Minutes for base line vs 79.2 .+-. 18.4 minutes in the same cats given endotoxin. The volume of distribution at steady state was 0.20 .+-. 0.03 L/kg for base line and was 0.19 .+-. 0.02 L/kg in the same cats given endotoxin. Total body clearance was 2 .+-. 0.2 ml/min/kg for base line and 2.6 .+-. 0.7 ml/min/kg in the same cats given endotoxin. A recommended dosage of 3 mg of gentamicin/kg administered every 8 hours IV, IM, or SC was calculated on the basis of pharmacokinetic values.