β-Lactam Monotherapy vs β-Lactam-Macrolide Combination Treatment in Moderately Severe Community-Acquired Pneumonia A Randomized Noninferiority Trial

IMPORTANCE The clinical benefit of adding a macrolide to a beta-lactam for empirical treatment of moderately severe community-acquired pneumonia remains controversial. OBJECTIVE To test noninferiority of a beta-lactam alone compared with a beta-lactam and macrolide combination in moderately severe community-acquired pneumonia. DESIGN, SETTING, AND PARTICIPANTS Open-label, multicenter, noninferiority, randomized trial conducted from January 13, 2009, through January 31, 2013, in 580 immunocompetent adult patients hospitalized in 6 acute care hospitals in Switzerland for moderately severe community-acquired pneumonia. Follow-up extended to 90 days. Outcome assessors were masked to treatment allocation. INTERVENTIONS Patients were treated with a beta-lactam and a macrolide (combination arm) or with a beta-lactam alone (monotherapy arm). Legionella pneumophila infection was systematically searched and treated by addition of a macrolide to the monotherapy arm. MAIN OUTCOMES AND MEASURES Proportion of patients not reaching clinical stability (heart rate <100/min, systolic blood pressure >90 mm Hg, temperature <38.0 degrees C, respiratory rate <24/min, and oxygen saturation >90% on room air) at day 7. RESULTS After 7 days of treatment, 120 of 291 patients (41.2%) in the monotherapy arm vs 97 of 289 (33.6%) in the combination arm had not reached clinical stability (7.6% difference, P = .07). The upper limit of the 1-sided 90% CI was 13.0%, exceeding the predefined noninferiority boundary of 8%. Patients infected with atypical pathogens (hazard ratio [HR], 0.33; 95% CI, 0.13-0.85) or with Pneumonia Severity Index (PSI) category IV pneumonia (HR, 0.81; 95% CI, 0.59-1.10) were less likely to reach clinical stability with monotherapy, whereas patients not infected with atypical pathogens (HR, 0.99; 95% CI, 0.80-1.22) or with PSI category I to III pneumonia (HR, 1.06; 95% CI, 0.82-1.36) had equivalent outcomes in the 2 arms. There were more 30-day readmissions in the monotherapy arm (7.9% vs 3.1%, P = .01). Mortality, intensive care unit admission, complications, length of stay, and recurrence of pneumonia within 90 days did not differ between the 2 arms. CONCLUSIONS AND RELEVANCE We did not find noninferiority of beta-lactam monotherapy in patients hospitalized for moderately severe community-acquired pneumonia. Patients infected with atypical pathogens or with PSI category IV pneumonia had delayed clinical stability with monotherapy.