Ofloxacin versus standard therapy in treatment of community-acquired pneumonia requiring hospitalization. Pneumonia Study Group.

Community-acquired pneumonia occurs 3 to 4 million times per year in the United States, accounting for about 500,000 hospitalizations annually. Empiric treatment is usually instituted because of a lack of early organism-specific diagnostic tests. This study compared empiric therapy with ofloxacin to standard antibiotic regimens (usually a beta-lactam with or without a macrolide) for patients hospitalized for community-acquired pneumonia. Therapy was administered to 298 patients (146 receiving ofloxacin and 152 receiving standard therapy); 227 patients (ofloxacin, 109; standard treatment, 118) were evaluable for treatment efficacy. The most common pyogenic respiratory pathogens were Haemophilus influenzae (30 isolates) and Streptococcus pneumoniae (24 isolates). There was evidence of infection with either Mycoplasma pneumoniae (38 patients), Chlamydia pneumoniae (40 patients), or a Legionella sp. (8 patients) in a total of 79 patients (35%). The clinical success rates were similar in both groups among evaluable patients (92%, ofloxacin; 87%, standard therapy) and among patients with atypical respiratory pathogens (88%, ofloxacin; 81%, standard therapy). The mean numbers (+/- the standard deviations) of intravenous doses of antibiotics were 7.5 +/- 8.0 in the ofloxacin group and 18.4 +/- 18.5 in the standard therapy group (P < 0.001); the mean number of oral doses of ofloxacin per patient was 19.7 +/- 11.2, compared with 30.2 +/- 16.0 oral antibiotic doses in the standard therapy group (P < 0.001). All treatments were well tolerated and associated with no significant clinical or laboratory abnormalities. The findings of this study indicate that ofloxacin is active against traditional bacterial pathogens as well as the major atypical respiratory pathogens. When given as monotherapy for the empiric treatment of community-acquired pneumonia, ofloxacin is as effective as standard antimicrobial therapy.