Oral versus intravenous clarithromycin in moderate to severe community-acquired pneumonia: an observational study.

Objectives: British Thoracic Society guidelines recommend clarithromycin in addition to beta-lactam antibiotics for patients with community-acquired pneumonia and CURB-65 score 2-5. Intravenous therapy is commonly used but there are few data on whether oral therapy is equally effective.

Methods: This observational study used propensity matching to compare two groups of patients with moderate to severe community-acquired pneumonia (CURB-65 score 2-5) treated with oral ( = 226) or intravenous ( = 226) clarithromycin on admission. Outcomes were 30-day mortality, intensive care unit admission, time to clinical stability, and length of hospital stay.

Results: There was no significant difference in 30-day mortality (16.8% for intravenous [IV] group vs. 14.6% for oral group, hazard ratio for IV group 1.11 95% CI 0.70-1.78), ICU admission (10.6% in both groups) or complications (10.6% for IV group and 9.3% for oral group) between the groups. The time to clinical stability in both cohorts was a median of 5 days (interquartile range 3-7 days,  = 0.3). The median length of hospital stay was 8 days in the IV group (interquartile range 4-14 days) and 7 days in the oral group (interquartile range 4-13 days),  = 0.5. No other differences were observed between oral and IV groups.

Conclusion: Where the oral route is not compromised, oral macrolides appear to be equivalent to IV in treating moderate to severe CAP.