Associations Between Initial Antimicrobial Therapy and Medical Outcomes for Hospitalized Elderly Patients with Pneumonia

Abstract & Commentary

Synopsis: Initial treatment with a second-generation cephalosporin plus a macrolide, a nonpseudomonal third-generation cephalosporin plus a macrolide, or a fluoroquinolone alone was independently associated with a lower 30-day mortality.

Source: Gleason PP, et al. Arch Intern Med 1999;159:2562-2572.

Gleason and colleagues reviewed records for almost 13,000 Medicare inpatients with pneumonia. An association between initial therapy and 30-day mortality was assessed incorporating differences in baseline patient characteristics. A non-pseudomonal third-generation cephalosporin alone was the reference standard. Three regimens—a nonpseudomonal third-generation, a second-generation cephalosporin plus macrolide, or a fluroquinolone alone—were independently associated with a lower 30-day mortality. Use of a beta-lactam/beta-lactamase inhibitor plus macrolide and an aminoglycoside plus another agent were associated with an increased 30-day mortality.

Comment by Martin Lipsky, MD

Pneumonia remains one of the common problems encountered by internists and family physicians. Each year more than 4 million adults develop pneumonia, resulting in more than 1 million hospital admissions. Because of the substantial morbidity and mortality of this disease, optimal therapy is essential. Current guidelines are based on expert opinion without many studies that examine antibiotic choice and patient outcome.

These two studies shed some light on the outcomes associated with different antibiotic regimens. Both studies suggest there is benefit to either adding a macrolide to a cephalosporin as part of the initial therapy or that using a fluoroquinolone alone improves outcomes. Surprisingly, the commonly used regimen of a beta-lactam/beta-lactamase inhibitor or aminoglycoside in conjunction with another agent did not do as well.

Although further study is needed before there can be a firm recommendation about the best initial therapy, adding a macrolide to the initial therapy for elderly patients with pneumonia seems to reduce mortality. Although future controlled studies will be helpful to confirm what antibiotic regimen yields the best outcome, given the relative safety of macrolides and fluoroquinolones clinicians might consider using these agents as part of initial therapy now, while awaiting corroborating evidence. One caveat pointed out by Gleason et al, regarding the quinolones is that their advantages should be weighed against the risk of developing widespread resistance to these agents.

Which of the following is correct?

a. There is benefit to adding a macrolide to a cephalosporin as part of the initial therapy.

b. Using a fluoroquinolone alone does not improve outcomes.

c. There is no benefit to adding a macrolide to a cephalosporin as part of the initial therapy.

d. None of the above