Antibiotic Therapy in Community-Acquired Pneumonia: Switch and Step Down Therapy

Hugh A. Cassiere, MD, Winthrop University Hospital


Medscape General Medicine. 1998;1(3) 

In This Article

Conclusions That Can -- and Can't -- be Drawn

These studies suggest that patients hospitalized for community-acquired pneumonia can be switched to oral antimicrobials when there is evidence of clinical improvement on intravenous antibiotics and when risk factors associated with increased morbidity and mortality (Table I) are absent. This implies dynamic evaluation -- some risk factors may have been present on admission, but later disappeared, allowing the switch therapy to occur. However, several caveats are worth considering. Patients hospitalized for community-acquired pneumonia have varying coexisting medical diseases and are managed by physicians with different practice patterns. There is inherent variability in the patient-physician interaction resulting in a wide range of diagnostic approaches and initial antibiotic regimens. It is therefore impossible to establish a set formula for switch therapy. This concept is further complicated by the fact that not all patients are "created equal." Patients respond to therapy at different rates as influenced by the interaction of types and severity of preexisting morbidities, age, severity of pneumonia, and pathogen virulence. Factors that contribute to slowly resolving or nonresolving pneumonia are also significant because they impact on response to therapy (Table II). It seems likely that response assessment must be ongoing rather than static in its attempt to set predetermined time intervals for conversion to oral therapy. This hypothesis, however, remains to be tested.

Based upon the limited data available at this time, the author recommends that switch therapy be instituted if all of the following criteria are met: (1) improving cough, (2) improving respiratory distress, (3) absence of fever for > 24 hours, (4) absence of identified high-risk or resistant pathogens, ie, S aureus and gram-negative enteric rods, (5) absence of unstable coexisting medical disease, such as congestive heart failure, (6) absence of complications, such as empyema, (7) intact gastrointestinal absorption, and (8) improving leucocytosis (Table III).[38,39] These criteria are conservative because data they are based upon come from only a handful of studies.