Intravenous to Oral Antibiotic Switch Therapy among Patients Hospitalized with Community-Acquired Pneumonia

Author Department

Medicine; Pulmonary/Critical Care Medicine; Infectious Diseases; Healthcare Quality

Document Type

Article, Peer-reviewed

Publication Date



Background: Community-acquired pneumonia (CAP) is a leading cause of hospital admissions and antimicrobial use. Clinical practice guidelines recommend switching from intravenous (IV) to oral antibiotics once patients are clinically stable.

Methods: We conducted a retrospective cohort study of adults admitted with CAP and initially treated with intravenous antibiotics at 642 US hospitals from 2010-2015. Switching was defined as discontinuation of IV and initiation of oral antibiotics without interrupting therapy. Patients switched by hospital day 3 were considered early switchers. We compared length-of-stay (LOS), in-hospital 14-day mortality, late deterioration (ICU transfer) and hospital costs between early switchers and others, controlling for hospital characteristics, patient demographics, comorbidities, initial treatments and predicted mortality.

Results: Of 378,041 CAP patients, 21,784 (6%) were switched early. Patients were most frequently switched to fluoroquinolones. Patients switched early had fewer days on IV antibiotics, shorter duration of inpatient antibiotic treatment, shorter LOS, and lower hospitalization cost. There were no significant differences in 14-day in-hospital mortality or late ICU admission between early switchers and others. Patients at higher predicted risk of mortality were less likely to be switched, but even in hospitals with relatively high switch rates <15% of very low risk patients were switched early.

Conclusions: Although early switching was not associated with worse outcomes and was associated with shorter LOS and fewer days on antibiotics, it occurred infrequently. Even in hospitals with high switch rates, <15% of very low risk patients were switched early. Our findings suggest many more patients could be switched early without compromising outcomes.

Keywords: IV to per oral; antimicrobial stewardship; community-acquired pneumonia; switch therapy.