Plasma disposition of ceftazidime in healthy neonatal foals following intravenous and intramuscular administration. Academic Article uri icon


  • Cephalosporin antimicrobials can be utilized for the treatment of sepsis in neonatal foals, particularly when an aminoglycoside is contraindicated. Some cephalosporins, however, are not utilized because of cost, sporadic availability, or uncertainty about efficacy. The plasma disposition of ceftazidime, a third-generation cephalosporin with a broad spectrum of activity against a wide variety of gram-negative bacteria and minimal renal side effects has not been reported in neonatal foals. In this study, the plasma disposition of single intravenous (IV) and intramuscular (IM) doses of ceftazidime in neonatal foals was determined. Six healthy one to two-day-old foals were given 25mg/kg of ceftazidime by IV and IM routes in a cross-over design, with a 48-h washout period between doses. Non-compartmental analysis was used to estimate plasma pharmacokinetic parameters. Median t1/2 was 2h and median AUC0-last was 364gh/ml for both IV and IM administration. Median Cmax after IM administration was 101g/ml, with a median Tmax of 0.7h. Relative bioavailability of IM injection was 90%. There were no statistically significant differences between estimated IV and IM pharmacokinetic parameters. Plasma concentrations remained above the human CLSI susceptible breakpoint for Enterobacteriaceae for over 8h following IV and IM administration.

published proceedings

  • J Vet Pharmacol Ther

author list (cited authors)

  • McNeal, C. D., Ryan, C. A., Berghaus, L. J., Credille, B. C., Lo, C., & Fajt, V. R.

citation count

  • 0

complete list of authors

  • McNeal, Christina D||Ryan, Clare A||Berghaus, Londa J||Credille, Brenton C||Lo, Chih-Ping||Fajt, Virginia R

publication date

  • July 2021