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A chest X-ray indicates pneumonia.
Switch to oral therapy. The ability to achieve clinical stability has important implications for hospital length of stay. Most patients hospitalized with CAP initially are treated with intravenous (IV) antibiotics and require transition to oral therapy in anticipation of discharge. Several studies have found there is no advantage to continuing IV medication once a patient is deemed clinically stable and is able to tolerate oral medication.9,10 There are no specific guidelines regarding choice of oral antibiotics, but it is common practice, supported by the IDSA/ATS recommendations, to use the same agent as the IV antibiotic or a medication in the same drug class. For patients started on β-lactam and macrolide combination therapy, it usually is appropriate to switch to a macrolide alone.5 In cases in which a pathogen has been identified, antibiotic selection should be based on the susceptibility profile.
Once patients are switched to oral antibiotics, it is not necessary for them to remain in the hospital for further observation, provided they have no other active medical problems or social needs. A retrospective analysis of 39,232 patients hospitalized with CAP compared those who were observed overnight after switching to oral antibiotics with those who were not and found no difference in 14-day readmission rate or 30-day mortality rate.11 These findings, in conjunction with the strategy of an early switch to oral therapy, suggest hospital length of stay may be safely reduced for many patients with uncomplicated CAP.
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A chest X-ray indicates pneumonia.
Duration of therapy. After a patient becomes clinically stable and a decision is made to switch to oral medication and a plan for hospital discharge, the question becomes how long to continue the course of antibiotics. Historically, clinical practice has extended treatment for up to two weeks, despite lack of evidence for this duration of therapy. The IDSA/ATS guidelines offer some general recommendations, noting patients should be treated for a minimum of five days, in addition to being afebrile for 48 to 72 hours and meet other criteria for clinical stability.5
Li and colleagues conducted a systematic review evaluating 15 randomized controlled trials comparing short-course (less than seven days) with extended (more than seven days) monotherapy for CAP in adults.4 Overall, the authors found no difference in the risk of treatment failure between short-course and extended-course antibiotic therapy, and they found no difference in bacteriologic eradication or mortality. It is important to note the studies included in this analysis enrolled patients with mild to moderate CAP, including those treated as outpatients, which limits the ability to extrapolate to exclusively inpatient populations and more severely ill patients.
Another meta-analysis, published shortly thereafter, examined randomized controlled trials in outpatients and inpatients not requiring intensive care. It compared different durations of treatment with the same agent in the same dosage. The authors similarly found no difference in effectiveness or safety of short (less than seven days) versus longer (at least two additional days of therapy) courses.12 Table 3 (above) reviews selected trials of short courses of antibiotics, which have been studied in inpatient populations.
The trials summarized in these meta-analyses examined monotherapy with levofloxacin for five days; gemifloxacin for seven days, azithromycin for three to five days; ceftriaxone for five days; cefuroxime for seven days; amoxicillin for three days; or telithromycin for five to seven days. The variety of antibiotics in these studies contrasts the IDSA/ATS guidelines, which recommend only fluoroquinolones as monotherapy for inpatient CAP.
One important randomized, double-blind study of fluoroquinolones compared a five-day course of levofloxacin 750 mg daily, with a 10-day course of levofloxacin, 500 mg daily, in 528 patients with mild to severe CAP.13 The authors found no difference in clinical success or microbiologic eradication between the two groups, concluding high-dose levofloxacin for five days is an effective and well-tolerated alternative to a longer course of a lower dose, likely related to the drug’s concentration-dependent properties.