In a randomized, double-blind, multicenter trial, ciprofloxacin/metronidazole was compared with imipenem/cilastatin for treatment of complicated intra-abdominal infections. A secondary objective was to demonstrate the ability to switch responding patients from intravenous (IV) to oral (PO) therapy.
Intra-abdominal infections result in substantial morbidity, mortality, and cost. Antimicrobial therapy often includes a 7-to 10-day intravenous course. The use of oral antimicrobials is a recent advance due to the availability of agents with good tissue pharmacokinetics and potent aerobic gram-negative activity.
Patients were randomized to either ciprofloxacin plus metronidazole intravenously (CIP/MTZ IV) or imipenem intravenously (IMI IV) throughout their treatment course, or ciprofloxacin plus metronidazole intravenously and treatment with oral ciprofloxacin plus metronidazole when oral feeding was resumed (CIP/MTZ IV/PO).
Among 671 patients who constituted the intent-to-treat population, overall success rates were as follows: 82% for the group treated with CIP/MTZ IV; 84% for the CIP/MTZ IV/PO group; and 82% for the IMI IV group. For 330 valid patients, treatment success occurred in 84% of patients treated with CIP/MTZ IV, 86% of those treated with CIP/MTZ IV/PO, and 81% of the patients treated with IMI IV. Analysis of microbiology in the 30 patients undergoing intervention after treatment failure suggested that persistence of gram-negative organisms was more common in the IMI IV-treated patients who subsequently failed. Of 46 CIP/MTZ IV/PO patients (active oral arm), treatment success occurred in 96%, compared with 89% for those treated with CIP/MTZ IV and 89% for those receiving IMI IV. Patients who received intravenous/oral therapy were treated, overall, for an average of 8.6 ± 3.6 days, with an average of 4.0 ± 3.0 days of oral treatment.
These results demonstrate statistical equivalence between CIP/MTZ IV and IMI IV in both the intent-to-treat and valid populations. Conversion to oral therapy with CIP/MTZ appears as effective as continued intravenous therapy in patients able to tolerate oral feedings.
From the Department of Surgery, University of Cincinnati College of Medicine, * Cincinnati, Ohio; Medical Research, Anti-Infectives Group, Bayer Corporation (formerly Miles, Inc.), Pharmaceutical Division, † West Haven, Connecticut; the Department of Surgery, University of Washington School of Medicine, ‡ Seattle, Washington; the Department of Surgery, Wellesley Hospital, § Toronto, Ontario, Canada; the Department of Surgery, Toronto Hospital, and University of Toronto, ∥ Toronto, Ontario, Canada; the Department of Surgery, University of Florida College of Medicine, ¶ Gainesville, Florida; and the Department of Surgery, Rhode Island Hospital, Brown University, # Providence, Rhode Island
Presented in part at the 34th Interscience Conference on Antimicrobial Agents and Chemotherapy; October 1994; Orlando, Florida.
Supported by a research grant from Miles Inc., Pharmaceutical Division, West Haven, Connecticut.
Address reprint requests to Joseph S. Solomkin, M.D., University of Cincinnati College of Medicine, Department of Surgery, 231 Bethesda Avenue, Cincinnati, OH 45267-0558.