Empirical Antibiotic Treatment for Community-acquired Pneumonia

Abstract

At the time of diagnosis in patients with communityacquired pneumonia, the causative pathogen is rarely known. As a result, antibiotic therapy is most often empirical, with the intent to treat a wide variety of possible causative pathogens. Both national and international guidelines have provided a useful framework of recommendations for antibiotic treatment but are being challenged by the rapidly changing landscape in pneumonia. Several countries have reported a dramatic increase in the number of patients diagnosed with pneumonia who have encountered both antibiotic-resistant and multidrug-resistant pathogens, often associated with frequent health-care exposure (so-called health-care-associated pneumonia). The role of macrolides remains controversial. Broad-spectrum antibiotic therapy carries significant risks, not only by driving increasing resistance but also by exposing patients to adverse events, particularly gastrointestinal side effects and nephrotoxicity. These risks have been underestimated historically; however, there are consistent data to suggest that up to one third of hospitalized patients have experienced clinically important adverse effects from antibiotic therapy; thus, using narrower-spectrum therapy could cause a reduction in adverse events. New strategies to improve empirical antibiotic prescribing include improved microbiological testing techniques, the gaining of better evidence for short-course antibiotic regimens, the use of probabilistic scores to identify patients at risk of drug-resistant pathogens, and the introduction of new biomarkers. Severity assessment tools have been developed for community-acquired pneumonia, but have been shown to have a limited role only in the aid of empirical antibiotic prescribing. This article reviews current international guidelines, recent evidence, and investigates new perspectives on the issue of empirical antibiotic prescribing for community-acquired pneumonia.