Clinical Effectiveness and Outcomes of Azithromycin versus Doxycycline Containing Regimen in Inpatients with Community Acquired Pneumonia: A Retrospective Cohort Study

Background. Community acquired pneumonia (CAP) is a common serious infection that is usually treated with a macrolide with a beta-lactam while doxycycline is considered an alternative due to limited evidence. Hence, we aimed to evaluate azithromycin versus doxycycline containing regimen in achieving clinical stability for inpatients with CAP. Materials and Methods. a retrospective cohort of inpatients with CAP receiving either azithromycin or doxycycline combined with a beta-lactam. The primary endpoint was the percentage of patients who achieved clinical stability within 3 days, while secondary endpoints were the average days required to achieve clinical stability. Results. A total of 447 were included of which 379 received azithromycin while 68 received doxycycline containing regimen.The average age of the study population was 65.4 +/- 21.1, of which 49% were females. Ceftriaxone was the most prescribed beta-lactam. Majority of this cohort had a length of hospital stay of 5 days or less. Total percentage of patients who achieved clinical stability within 3 days were 257 (57.5%), of which 222 (58.6%) were in azithromycin group versus 35 (51.5%) in doxycycline containing regimen group; p = 0.275. While the average day required to achieve clinical stability in both groups was 3.8 +/- 3.2, in which 3.8 +/- 3.3 in azithromycin versus 3.9 +/- 2.7 in doxycycline containing regimen; (95% CI -0.98-0.68; p. 0.727) Conclusions. These findings support that doxycycline is comparable in efficacy to macrolides with a beta-lactam for inpatients with CAP as supported by current guideline recommendations.