SESSION TYPE: Pneumonia Treatment and Antibiotic Resistance
PRESENTED ON: Monday, October 22, 2012 at 04:00 PM - 05:30 PM
PURPOSE: S. pneumoniae (SP) represents a major pathogen in community-acquired pneumonia (CAP) and remains associated with substantial mortality. Prior research suggests that use of macrolides in CAP results in improved survival. However, earlier efforts indicating a beneficial effect of macrolide use have been limited. These analyses have pooled patients with CAP irrespective of pathogen, addressed only critically ill patients, and/or failed to adjust for the appropriateness and of initial antibiotic therapy. We sought to clarify the relationship between survival and macrolide use in SP pneumonia.
METHODS: We evaluated adult patients admitted with a diagnosis of SP pneumonia (Jan-Dec 2010). The diagnosis of pneumonia required a compatible clinical syndrome and radiographic evidence of an infiltrate. The identification of SP was based on a culture from blood, pleural fluid, or respiratory secretions or a urinary antigen. Mortality at 28 days served as the primary endpoint, and we compared subjects given a macrolide (only Azithromycin was utilized during the study period) to those not treated with a macrolide. Co-variates of interest included demographics, severity of illness, comorbidities, and infection related characteristics (eg, appropriateness of initial treatment, presence of bacteremia). After unadjusted analyses we employed Cox regression modeling to calculate adjusted hazard ratios (AHRs) to assess the independent impact of macrolide treatment of mortality.
RESULTS: cohort included 187 subjects (mean age: 67.0 ± 8.2 years, 50.3% male, 5.9% admitted to the ICU). The most frequently utilized non-macrolide antibiotics included: Ceftriaxone (n=111), Cefipeme (n=31), and Moxifloxacin (n=22). Approximately 2/3rds of the cohort received Azithromycin. Crude mortality was lower in persons given Azithromycin (5.6% vs. 23.6%, p<0.01). The final survival model included four variables: age (AHR 1.02; 95% CI: 0.99-1.06), need for mechanical ventilation (AHR 2.28; 95% CI: 0.83-6.27), initial appropriate therapy (AHR 0.26; 95% CI: 0.10-0.66), and Azithromycin use (AHR 0.32; 95% CI: 0.13-0.79).
CONCLUSIONS: SP pneumonia remains associated with significant mortality. Azithromycin treatment, along with another appropriate antibiotic, is associated with significantly higher survival rates. The impact of Azithromycin is independent of multiple potential confounders.
CLINICAL IMPLICATIONS: Addition of Azithromycin should be considered when treating patients with pneumonia at risk for SP.
DISCLOSURE: A. Shorr: Consultant fee, speaker bureau, advisory committee, etc.: Astellas, Bayer, Cubist, Pfizer, Trius, Theravance
M. Zilberberg: Consultant fee, speaker bureau, advisory committee, etc.: Astellas, Cubist, Optimer, Pfizer
S. Micek: Consultant fee, speaker bureau, advisory committee, etc.: Cubist, Forrest
M. Kollef: Consultant fee, speaker bureau, advisory committee, etc.: Trius, Cubist, J and J, Bayer, Forrest
No Product/Research Disclosure InformationWashington Hospital Center, Washington, DC