Lower mortality among patients with community-acquired pneumonia treated with a macrolide plus a beta-lactam agent versus a beta-lactam agent alone

Abstract

A cohort of 1,391 patients with community acquired pneumonia of unknown etiology, atypical pneu monia, Legionella pneumophila pneumonia, viral pneumo nia, or pneumococcal pneumonia was studied according to a standard protocol to analyse whether the addition of a macrolide to β-lactam empirical treatment decreases mor tality rates. Patients admitted to the intensive care unit were excluded. Severity was assessed using the PORT score. An etiological diagnosis was achieved in 498 (35.8%) patients (292 infections due to Streptococcus pneumoniae). Treat ment was chosen by the attending physician according to his/her own criteria: β-lactam agent in 270 and β-lactam agent plus a macrolide in 918 cases. The mortality rate was 13.3% in the group treated with a β-lactam agent alone and 6.9% in the group treated with a β-lactam agent plus a macrolide (p=0.001). The percentage of PORT-group V patients was 32.6% in the group treated with a beta-lactam agent alone compared to 25.7% in the group who received a β-lactam agent plus a macrolide (p=0.02). After control ling for PORT score, the odds of fatal outcome was two times higher in patients treated with a beta-lactam agent alone than in those treated with a β-lactam agent plus a macrolide (adjusted OR = 2, 95%CI 1.24–3.23). The re sults suggest that the addition of a macrolide to an initial β-lactam-based antibiotic regimen is associated with lower mortality in patients with community-acquired pneumo nia, independent of severity of infection, thus supporting the recommendation of a β-lactam-agent plus a macrolide as empirical therapy.