Community-acquired pneumonia substantially affects patient morbidity and mortality, and has significant health care costs. This type of pneumonia has more impact on elderly patients, who tend to have longer hospital stays and a higher cost per stay compared with younger patients. Multiple published guidelines provide physicians with information about when to admit patients with community-acquired pneumonia, which antibiotic therapy is appropriate, how long to treat, and when it is suitable to discharge patients from the hospital. These treatment strategies do not take into account the emergence of resistant organisms and the poorly understood impact of community-acquired pneumonia on younger patients. Although various studies have looked at combination antibiotic therapy, they rarely have been comparative. Brown and colleagues examined the effect of initial antibiotic therapy for community-acquired pneumonia on selected clinical outcomes.

The authors analyzed a hospital database of adult patients with a diagnosis of community-acquired pneumonia. Outcomes assessed included 30-day mortality, total hospital costs, and length of stay. In addition, patients were stratified on the basis of severity of illness and age. Patients who received one antibiotic were divided into five monotherapy groups: ceftriaxone, “other” cephalosporins, fluoroquinolones, macrolides, or penicillin. Those who received dual therapy were divided into four groups: each of the above antibiotics plus a macrolide. Patients who were defined as severely ill were excluded from the study.

There were 44,814 patients who met the inclusion criteria for the study. Those who received monotherapy with macrolides had a lower mortality rate but also were considered less ill than the other monotherapy groups. Patients who received dual therapy generally had a shorter length of stay, lower hospital costs, and decreased mortality compared with patients who received monotherapy. Those who were younger than 65 years also had better outcomes with dual therapy. Patients who received ceftriaxone and macrolide therapy had a lower length of stay and lower total hospital charges compared with other therapies. In the sickest patients (based on risk stratification), dual therapy with fluoroquinolones resulted in the least improvement in length of stay and total hospital charges.

The authors conclude that dual therapy using a macrolide as the second agent decreases mortality, reduces length of hospital stay, and results in lower hospital charges in patients admitted for community-acquired pneumonia. These differences are true for patients younger and older than 65. The authors note that ceftriaxone plus a macrolide appears to provide the best outcome compared with other dual-therapy regimens.