Diagnosis and treatment of community-acquired and hospital-acquired pneumonia.

The older drugs used to treat pneumonia may still be useful in self-limiting infections. Newer antibiotics--augmented penicillins, trimethoprim-sulfamethoxazole, third-generation cephalosporins, and others--are quite effective, but resistance can be a problem, and some patients cannot tolerate the adverse events associated with these agents. The fluoroquinolones are effective in treating pneumonia because of their broad spectra of activity against gram-negative and gram-positive organisms, including Streptococcus pneumoniae and Haemophilus influenzae. They are rapidly and nearly completely absorbed after oral administration; bioavailability ranges up to 100% for ofloxacin and lomefloxacin. Concentrations attained in lung tissues and sputum generally exceed the minimum inhibitory concentrations for the most common respiratory tract pathogens. The quinolones are also well tolerated; most adverse events are mild and do not lead to discontinuation of therapy. Ciprofloxacin and ofloxacin are available in parenteral as well as oral formulations. The high bioavailability of oral ofloxacin (> 95%) allows a patient to be started on the parenteral form in the hospital and continued taking the oral form at home with no loss of efficacy, but with reduced costs and improved quality of life.