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

Abstract and Introduction


The treatment of hospitalized patients with community-acquired pneumonia has traditionally been with intravenous antibiotics. The administration of intravenous antibiotics for community-acquired pneumonia is based upon the concept that to ensure eradication of the causative pathogen, a high concentration of antibiotic in the blood and tissue is initially required. Replacing intravenous antibiotics with effective oral antibiotics in the treatment of serious infections (community-acquired pneumonia, nosocomial pneumonia, and urinary tract infections) is known as "switch therapy." If the change is accomplished with the same antibiotic as that administered intravenously, then the change is labeled "step-down therapy." If a different drug is used (ie, as in a switch from an IV 3rd generation cephalosporin to oral erythromycin), the maneuver is labeled as "sequential therapy." Determining the type and duration of therapy, and deciding whether and when to switch to oral therapy, is complicated by the fact that the causative pathogen is not identified in the majority of patients with community-acquired pneumonia. In most cases, the physician chooses the therapy empirically, based on epidemiologic data. Recently, several studies have been published that shed some light on the subject of switch therapy for community-acquired pneumonia. Although these data are limited at this time, it seems clear that switching to oral antibiotics in selected low-risk patients may be feasible and safe.


Community-acquired pneumonia is a significant concern in the healthcare community and has been a recent focus of several clinical practice guidelines.[1,2] The medical and economic impact of pneumonia on society is great and is increasing. Pneumonia is the sixth leading cause of death in the US when combined with influenza, and its economic impact in 1985 dollars was in excess of $15 billion.[3,4,5] Even in active-duty Navy and Marine Corps personnel -- a population considered to be young and healthy, with minimal coexisting medical illness -- the crude mean annual rate of pneumonia hospitalization was 77.6 per 100,000.[6]

In our current healthcare environment, hospitals and physicians are challenged to provide a high standard of care in a cost-effective manner. An expert panel of the American Thoracic Society has confronted this challenge by formulating practice guidelines based on a review of data from the recent literature on community-acquired pneumonia.[1] These practice guidelines sought to improve clinical management by standardizing the care of patients with this disease.

Hospitals and other healthcare organizations have used these guidelines to streamline care and reduce cost. Recommended strategies include limiting such diagnostic procedures as routine Gram staining and fiberoptic bronchoscopy. The issues of duration of antibiotic therapy and timing of switch from intravenous to oral medications -- assuming antibiotics were initiated by intravenous route -- were left deliberately vague.

As the pressure for cost containment has increased, decisions concerning the appropriate duration of intravenous antibiotics, length of hospital stay, and the economics of antibiotic therapy have come under scrutiny. More data stressing innovative "nontraditional" approaches to the antibiotic management of community-acquired pneumonia, such as home intravenous treatment and therapy with oral antibiotics, are emerging.[7,8,9] It is becoming clear that a substantial portion of patients hospitalized with community-acquired pneumonia can be safely switched to oral antibiotics earlier in their hospital course without any adverse effects.