Pneumonia medical therapy

Editor(s)-in-Chief: C. Michael Gibson, M.S., M.D. [mailto:mgibson@perfuse.org] Phone:617-632-7753; Philip Marcus, M.D., M.P.H.[mailto:pmarcus192@aol.com]

Overview
Antibiotics are used to treat bacterial pneumonia. In contrast, antibiotics are not useful for viral pneumonia, although they sometimes are used to treat or prevent bacterial infections that can occur in lungs damaged by a viral pneumonia. The antibiotic choice depends on the nature of the pneumonia, the most common microorganisms causing pneumonia in the local geographic area, and the immune status and underlying health of the individual. Treatment for pneumonia should ideally be based on the causative microorganism and its known antibiotic sensitivity. However, a specific cause for pneumonia is identified in only 50% of people, even after extensive evaluation. Because treatment should generally not be delayed in any person with a serious pneumonia,empiric treatment is usually started well before laboratory reports are available. In the United Kingdom, amoxicillin is the antibiotic selected for most patients with community-acquired pneumonia, sometimes with added clarithromycin; patients allergic to penicillins are given erythromycin instead of amoxicillin. In North America, where the "atypical" forms of community-acquired pneumonia are becoming more common,azithromycin, clarithromycin, and the fluoroquinolones have displaced amoxicillin as first-line treatment. The duration of treatment has traditionally been seven to ten days, but there is increasing evidence that shorter courses (as short as three days) are sufficient.

Antibiotics for hospital-acquired pneumonia include vancomycin, third- and fourth-generation cephalosporins, carbapenems, fluoroquinolones, and aminoglycosides. These antibiotics are usually given intravenously. Multiple antibiotics may be administered in combination in an attempt to treat all of the possible causative microorganisms. Antibiotic choices vary from hospital to hospital because of regional differences in the most likely microorganisms, and because of differences in the microorganisms' abilities to resist various antibiotic treatments.

People who have difficulty breathing due to pneumonia may require extra oxygen. Extremely sick individuals may require intensive care treatment, often including intubation and artificial ventilation.

Viral pneumonia caused by influenza A may be treated with rimantadine or amantadine, while viral pneumonia caused by influenza A or B may be treated with oseltamivir or zanamivir. These treatments are beneficial only if they are started within 48 hours of the onset of symptoms. Many strains of H5N1 influenza A, also known as avian influenza or "bird flu," have shown resistance to rimantadine and amantadine. There are no known effective treatments for viral pneumonias caused by the SARS coronavirus, adenovirus, hantavirus, or parainfluenza virus.