Evaluation of an algorithm for switching from IV to PO therapy in clinical practice in patients with community-acquired pneumonia.

Background: In patients with community-acquired pneumonia (CAP), switching from IV to PO antibiotics offers advantages over IV therapy alone, including improved cost-effectiveness through reductions in the length of hospital stay and treatment costs.

Objective: The aim of this study was to determine whether a method for switching therapy in clinical practice could be used in patients with CAP and whether differences were found in the duration of IV treatment and length of hospital stay between the 5 risk classes of the Pneumonia Severity Index (PSI) after the therapy switch.

Methods: This was a prospective, observational study of patients aged >/=18 years presenting with CAP at our teaching hospital between December 1998 and November 2000. Microbiological and serological tests were performed, and signs and symptoms of CAP, C-reactive protein levels, and white blood cell counts were assessed throughout treatment and at the 1-month follow-up. Patients were stratified by PSI risk class. When the patient's temperature had been normalized for 72 hours and respiratory symptoms (dyspnea, coughing, and thoracal pain) had improved, patients were switched from IV to PO therapy (same drug).

Results: The study included 180 patients with CAP Clinical cure was seen in 174 (97%) patients. No significant difference between the 5 risk classes was found in duration of therapy. Patients in risk class V remained hospitalized for a significantly longer period than patients in risk classes I through IV (P < 0.001). Furthermore, after patients were switched to PO antibiotics, the level of C-reactive protein decreased in patients in all risk classes and was normalized by follow-up.

Conclusions: In the population studied, use of specific criteria (ie, absence of fever for 72 hours and reduction in respiratory symptoms) allowed successful switch from IV to PO antibiotic therapy for the treatment of CAP Duration of therapy was not affected by PSI risk class, but those in risk class V were hospitalized longer than other risk classes.