Clinical outcomes of beta-bactam monotherapy versus beta-lactam plus azithromycin in hospitalized patients with community-acquired pneumoniae

Abstract Background We aim to assess the clinical efficacy of β-lactam plus azithromycin compared with β-lactam monotherapy in the empirical treatment of community-acquired pneumonia (CAP). Methods We conducted a retrospective matched cohort study in the Vigo Health Area (Spain), including adults discharged in 2023 with a primary diagnosis of CAP. Participants were classified according to the empirical therapy received and matched by severity. Exclusion criteria were immunocompromised status, alternative empirical regimens or initial admission to intensive care unit. Clinical efficacy was defined as the absence of oxygen requirement, fever and ≥50% reduction in C-reactive protein and/or procalcitonin at 72–96 h after treatment initiation. Results A total of 246 patients were included (121 receiving monotherapy and 125 receiving combination therapy). Although the SOFA score did not differ between groups, overall severity scores were higher in the monotherapy group. Clinical efficacy was similar between treatment groups (65% versus 62%, P = 0.597). In the multivariable analysis of the overall cohort, SOFA ≥2 was the only variable independently associated with reduced clinical efficacy odds ratio 0.5, 95% confidence interval (0.33–0.93), P = 0.026, whereas treatment strategy was not significantly associated with clinical efficacy. Conclusions The addition of azithromycin to β-lactam was not associated with improved clinical efficacy, either overall or in the subgroup with SOFA ≥2.