Antimicrobial treatment of community-acquired pneumonia

CAP is a life-threatening condition that requires hospitalization and, in 10% to 20% of patients, intensive care unit admission. Underlying comorbid conditions (most commonly, chronic obstructive pulmonary disease, alcoholism, chronic heart disease, and diabetes mellitus) are frequently seen in this group of patients. The most common etiologic agents found in CAP are , Legionella spp, and gram-negative rods (especially Klebsiella pneumoniae and P aeruginosa in intensive care unit patients with risk factors [eg, bronchiectasis]), although half of cases lack a specific etiologic diagnosis. The early and rapid initiation of empiric antimicrobial therapy concordant with recommended clinical practice guidelines should be based on an epidemiologic approach, possible etiologic agents, and the severity of illness. Initial antimicrobial therapy should consist of an antipneumococcal fluoroquinolone alone or an intravenous beta-lactam antibiotic plus a macrolide for hospitalized patients. An intravenous beta-lactam antibiotic plus a macrolide or antipneumococcal fluoroquinolone should be provided for intensive care unit patients without risk of having pseudomonas. Antipseudomonal therapy is indicated in patients with risk factors for pseudomonas who are admitted to the intensive care unit. Modification of the initial regimen should be considered once specific pathogens have been identified. The optimal management of patients hospitalized with CAP requires further research and re-evaluation as new data are available.