PHARMACOKINETICS OF INTRAMUSCULAR AND NEBULIZED CEFTRIAXONE IN CHICKENS

The cephalosporin antibiotic ceftriaxone was administered intramuscula rly (100 mg/kg) and by nebulization (I hr, with and without dimethyl s ulfoxide [DMSO]) to five adult chickens (Gallus domesticus) and by neb ulization (I hr, with DMSO) to 15 1-day-old chicks. Serum samples coll ected from the adult chickens at 30, 60, 90, 120, 180, 240, 360, 480 m in and at 24 hr and from chicks at 60, 90, and 120 min posttreatment w ere assayed by high-performance liquid chromatography for ceftriaxone concentrations. Thirty minutes after intramuscular injection, adult ch ickens had a mean serum concentration of 18.03 mug/ml, which declined to nondetectable levels at 4-6 hr posttreatment. No significant serum levels were obtained in adults or chicks after nebulization therapy, w ith or without DMSO. This project demonstrates that therapeutic levels of this antibiotic can be obtained in this species. It is likely that this regime would be effective in similar exotic bird species as well .