Treatment of acute bacterial peritonitis: a trial of imipenem/cilastatin against ampicillin-metronidazole-gentamicin.

Imipenem/cilastatin at a dose of 0.5 g six hourly was compared to conventional combination therapy with ampicillin 0.5 g six hourly, metronidazole 0.5 g eight hourly and gentamicin 80 mg eight hourly (with dose adjustment by trough and peak serum levels) in the treatment of severe intra-abdominal infections. All antibiotics were given intravenously. Forty-five patients entered the trial. Of the 19 evaluable patients in the imipenem/cilastatin group, 16 were clinically cured with five microbiological successes and two failures. Of 24 evaluable patients in the combination group, 22 were clinically cured with one microbiological success and one failure. One patient in each group suffered an adverse effect. Patients in the I/C group tended to be older with more women and more severe infections. The origin of peritonitis was similar. I/C did not differ from combination therapy in efficacy or safety and was comparable in cost. However, I/C was easier to administer than combination therapy and there was no need for serum concentration monitoring.