The role of oral antimicrobials for the management of intra-abdominal infections.

Abstract

Background: Oral therapy for patients with complicated intra-abdominal infections has been very limited because those patients are frequently ill and need surgery. In addition, at the time of diagnosis and initial treatment, the infection is often accompanied by ileus, gastrointestinal tract function is frequently unknown, and many patients cannot tolerate oral intake. The use of oral antimicrobials in this setting is a recent advance resulting from the availability of agents with good tissue pharmacokinetics and potent aerobic gram-negative activity. This is the first prospective blinded study of oral therapy to provide data on the characteristics of patients eligible for oral treatment and the consequences of such treatment.

Study design: In blinded fashion, patients with complicated intra-abdominal infections were randomized to either i.v. ciprofloxacin plus metronidazole or i.v. imipenem throughout their treatment course, or i.v. ciprofloxacin plus metronidazole and treatment with oral ciprofloxacin plus metronidazole when oral feeding was resumed (CIP/MTZ i.v./oral). Physicians could switch the patient to oral therapy between 3 and 8 days after the start of i.v. treatment.

Results: One hundred fifty-five of 330 (47%) patients were switched to active or placebo oral therapy. Patients who received i.v./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. Of 46 CIP/MTZ i.v./oral patients (active oral arm), treatment failure occurred in 2 patients (4%) compared with 41 patients (23%) who were not switched to oral agents. No patient or disease features, such as Acute Physiology and Chronic Health Evaluation II score, severity of illness at study entry, organ source of infection, or duration of treatment were identified as predictors of conversion to oral treatment.

Conclusions: In this first prospective examination of sequential i.v./oral therapy for complicated intra-abdominal infections, conversion to oral therapy with ciprofloxacin plus metronidazole appears as effective as continued i.v. therapy for patients able to tolerate oral feedings. Patients who can tolerate oral intake may be treated with appropriate oral antimicrobials and are not at any significant increased risk for failure.