Survival Benefit Associated with Clarithromycin in Severe Community-acquired Pneumonia: A Matched Comparator Study

Although analysis of retrospective studies has documented survival benefit from the addition of a macrolide to the treatment regimen for community-acquired pneumonia (CAP), no data are available to determine if there is differential efficacy between members of the macrolide family. In order to investigate this, an analysis was undertaken of data from 1174 patients with CAP who met the new Sepsis-3 definitions and were enrolled prospectively in the data registry of the Hellenic Sepsis Study Group. Four well-matched treatment groups were identified with 130 patients per group: clarithromycin and β-lactam; azithromycin and β-lactam; respiratory fluoroquinolone and β-lactam monotherapy. The primary endpoint was comparison of the effects of clarithromycin with β-lactam monotherapy on 28-day mortality. The secondary endpoint was resolution of CAP. Mortality rates for the clarithromycin, azithromycin, respiratory fluoroquinolone and β-lactam groups were 20.8%, 33.8% (P=0.026 vs clarithromycin), 32.3% (P=0.049 vs clarithromycin) and 36.2% (P=0.009 vs clarithromycin), respectively. After stepwise Cox regression analysis among all groups, clarithromycin was the only treatment modality associated with a favourable outcome (hazard ratio 0.61; P=0.021). CAP resolved in 73.1%, 65.9% (P=0.226 vs clarithromycin), 58.5% (P=0.009 vs clarithromycin) and 61.5% (P=0.046 vs clarithromycin) of patients, respectively. It is concluded that the addition of clarithromycin to the treatment regimen of patients with severe CAP leads to better survival rates.