Therapeutic efficacy of cefpiramide-ciprofloxacin combination in experimental Pseudomonas infections in neutropenic mice.

The therapeutic efficacy of cefpiramide and ciprofloxacin alone and in combination was investigated and compared with that of ticarcillin plus tobramycin against pseudomonal infections in mice made neutropenic by administration of cyclosphosphamide. Therapy with cefpiramide plus ciprofloxacin was significantly more effective than that by either antibiotic alone. These results were consistent with in-vitro synergistic effects. At a higher dose of ciprofloxacin (4 mg/kg) plus cefpiramide (50 mg/kg), the combination therapy protected all neutropenic mice from fatal bacteraemia, and was more protective than ticarcillin (200 mg/kg) plus tobramycin (1 mg/kg). The peak serum concentration of cefpiramide in infected neutropenic mice was 51 mg/l when they were given 50 mg/kg subcutaneously. Ciprofloxacin attained a peak serum concentration of 1.2 mg/l and a serum half-life of 34 min.