Efficacy of erythromycin compared to clarithromycin and azithromycin in adults or adolescents with community-acquired pneumonia: A Systematic Review and meta-analysis of randomized controlled trials

Background: It is debatable whether erythromycin has similar efficacy to other macrolides in treating communityacquired pneumonia (CAP). The aim of this meta-analysis is to compare the efficacy of erythromycin with clarithromycin and azithromycin. Methods: We performed this meta-analysis of randomized controlled trials (RCTs) of adults or adolescents with CAP which compared the efficacy of erythromycin monotherapy to either azithromycin or clarithromycin. We searched PubMed and EMBASE and Cochrane Library databases and three clinical trial registries up to November 02, 2021. We evaluated heterogeneity and used random-effects models to perform risk ratios with 95% confidence intervals. Results: We included four RCTs (total of 472 patients), which compared the clinical efficacy of erythromycin versus clarithromycin. No studies comparing monotherapy of erythromycin versus azithromycin were found. Erythromycin use was associated with significantly lower rates of clinical success (RR, 0.79; 95% CI, 0.64 to 0.98; P-value = 0.033; I-2 = 20.27%), clinical cure (RR,0.67; 95% CI, 0.48 to 0.92; P-value = 0.014; I-2 = 8.75%), and radiological success (RR, 0.84; 95% CI, 0.71 to 0.996; P-value = 0.045; I-2 = 20.12%) than clarithromycin. Conclusion: Erythromycin is less effective than clarithromycin as empiric treatment of CAP in adults and adolescents. Because of this and the higher rate of adverse reactions, erythromycin should not be used in the majority of CAP patients when azithromycin and clarithromycin are available.