Tobramycin therapy for lethal sepsis in the dog

Antimicrobial effectiveness and effect on survival of single-dose vs. multiple-dose aminoglycoside antibiotic therapy (with and without steroid) for lethal sepsis were evaluated. Adult dogs of either sex were anesthetized, divided into five groups, and infused iv for one hour with Escherichia coli. Group A was given no drug. Group B was given a 45-mg/kg, 10-min iv injection of tobramycin (TOB) at 65 min. Group C was given a 3-mg/kg, 10-min TOB injection at 65 min, followed by an 8.25-mg/kg iv infusion for 285 min, and three 11.25-mg/kg intramuscular injections at 6, 12, and 18 h (total 45 mg/kg). Group D was given the same TOB regimen as B, plus a 30-mg/kg iv injection and 30-mg/kg iv infusion of methylprednisolone sodium succinate (MPSS) from 15 to 360 min. Group E was given the same TOB regimen as C, plus the same MPSS regimen as D. Treated dogs also received 11.25 mg/kg of TOB daily for 4 days. The percent surviving more than 7 days was 0, 0, 17%, 83%, and 83%, for groups A through E, respectively. By 4 h, TOB-treated groups had significantly (p less than .05) lower E. coli blood levels than group A. Also E. coli levels in group B were significantly (p less than .05) lower than those in groups C, D, or E. High trough serum TOB concentrations were associated with death and very low levels with recovery. Serum urea nitrogen and creatinine concentrations increased in all groups, but returned to normal by 7 days in survivors.(ABSTRACT TRUNCATED AT 250 WORDS)