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

Data Suggest Potential Benefits

The clinical concept behind switch, step down and sequential therapy is, however, identical: switching from intravenous to oral antibiotics with similar or identical bacterial coverage. A common theme that underlies the successful implementation of changing to oral therapy is the need to identify "low risk" patients who are responding clinically to intravenous therapy (see below).

Data on this subject are still emerging and a standard of care has yet to be firmly established. Nevertheless, several investigators have shown that the institution of switch therapy may be safe and may have economic benefits as well.[35,36,37,38,39]

In addition, switch therapy may have clinical and psychological benefits for the patient. Among these are decreased incidence of nosocomial infection (urinary tract and catheter-related infections), decreased complications of intravenous therapy (thrombophlebitis and line sepsis), and shorter length of hospital stay. From the physicians point of view, switch therapy may allow for a more focused approach to patient care with an emphasis on clearly definable clinical endpoints (see below). Healthcare organizations may benefit from switch therapy by allowing the care of patients with community-acquired pneumonia to be standardized and streamlined. Clinical practice guidelines may be formulated which facilitate management of community-acquired pneumonia at reduced cost. These "potential" benefits need to be evaluated in further prospective studies.

Three studies summarized. Weingarten and colleagues[38] applied a switch therapy practice guideline retrospectively to 503 hospitalized patients with community-acquired pneumonia. The practice guideline was based upon three criteria which were used to categorize patients as low risk on hospital day three. Patients were considered low-risk if the following criteria were met: 1) no prevailing condition warranted continued hospitalization (for example, hypoxia or presence of a high-risk pneumonia), 2) no high-risk pathogens were identified (for example, Staphylococcus aureus), and 3) no life-threatening complications arose during hospitalization (such as, acute myocardial infarction). Based upon this practice guideline, these investigators reported that only 33% of patients met their criteria retrospectively at day 3 for switch to oral antibiotics. They reported that the quality-of-care would not have been affected in 98.2% of these patients had they been switched to oral therapy on day three. If these same patients were discharged from the hospital on day four (one day after the switch), 93.4% would have had no change in their quality-of-care. Adverse effects, as assessed by two physician-reviewers, would have occurred in 6.6% of patients who experienced the following complications: systolic hypotension, congestive heart failure (with one patient requiring transfer to the ICU), lung abscess, deep venous thrombosis, hemolytic anemia secondary to M pneumoniae-induced pneumonia, hypoxemia, and death (in the case of an 87-year-old patient with a complicated hospital course and a DNR order). However, given the retrospective application of the practice guideline, it is not possible to draw any definite conclusions from these data.[18]

In a study by Ramirez and colleagues,[37] 120 patients admitted to the hospital with community-acquired pneumonia were evaluated prospectively for switch therapy. In this study, patients were treated initially with either intravenous ceftizoxime, 1 gram every 12 hours, or intravenous ceftriaxone, 1 gram every 24 hours. Switch therapy with oral cefixime, 400 mg once daily, was initiated if patients met the following criteria: resolution of fever (defined as absence of fever on two measures at least 8 hours apart), improved cough and respiratory distress, improved leucocytosis, and presence of normal gastrointestinal tract absorption. Of the 120 patients studied, 45 (37%) were not considered candidates for switch therapy (Fig. 1). The 75 patients who met the criteria for switch therapy received intravenous antibiotics for a mean of 3 days prior to institution of oral therapy. There were no significant differences, in length of therapy or clinical outcome, between the different intravenous regimens in this study. Switch therapy failure rate necessitating readmission to the hospital was 1.3% (1 patient) indicating a 98.7% clinical cure rate.[37] Patients treated with this switch therapy protocol did not present with any adverse side effects, including the one patient readmitted to the hospital and treated with intravenous erythromycin with good response. The investigators also estimated that $104,524 were saved per patient because they remained hospitalized for four days rather than the usual six.

The reasons for the inability to initiate switch therapy. Adapted from Ramirez JA, Srinath L, Ahkee S, et al: Early switch from intravenous to oral cephalosporins in the treatment of hospitalized patients with community-acquired pneumonia. Arch Intern Med 155:1273-1276, 1995

Weingarten and colleagues,[39] prospectively applied the same practice guideline in a study with an alternative month design (ie, no intervention on the first month of the study, intervention on the second month of the study, no intervention on the third month of study, etc.). If patients were enrolled in the study during a non-interventional month (controls), data were collected but no active therapeutic intervention was initiated by the study team. If patients were enrolled in the study during an interventional month, data were also collected, but a team of case management nurses, pharmacists, and physicians were instructed to inform the attending physician of the guideline recommendations.[39]

Of the 717 hospitalized patients with a pneumonia-related diagnosis over the 22 month study period, 146 (20%) were considered low risk and therefore, candidates for the switch therapy practice guideline. Adherence to the practice guideline occurred in 76% of cases during the interventional months. Of considerable interest was the fact that during the non-interventional months (the times when control patients were enrolled), 69% of the cases adhered to the practice guideline. The investigators suggest that this occurred because physicians may have been sensitized to the practice guideline during both the interventional and non-interventional months. This study design may explain why there were no differences found between the two groups in terms of length of stay, hospital readmission rates, health-related quality-of-life, and patient satisfaction. The 30-day survival rate was 99.3%, with the only mortality being a 98-year-old with prostate cancer who died on day 11 post-discharge. The severity of pneumonia was relatively low as evidenced by the 30-day mortality rate of 0.7% (predicted from literature at 9%). This study suggests that switch therapy practice guidelines aimed at both early conversion from intravenous antibiotics to oral therapy and early hospital discharge are feasible and safe in carefully selected patients.[39]