A Study of the Safety and Effectiveness of Levofloxacin Compared With Imipenem/Cilastatin in Patients With Pneumonia Acquired During Hospitalization

Inclusion Criteria: Diagnosis of hospital-acquired pneumonia as follows: hospitalization >= 48 but <= 72 hours, identification of a bacteria commonly found in hospital-acquired infections, absence of pneumonia on initial chest x-ray, normal white blood cell count, and diagnosis other than infection upon admission to hospital OR hospitalized >= 72 hours OR discharged from a hospital <= 48 hours after a hospitalization of >= 72 hours AND chest x-ray findings consistent with infection AND abnormal temperature (high or low) or abnormal white blood cell count Specimen from respiratory tract is available for laboratory analysis APACHE score <= 35 Have received at least 72 hours of treatment with antibiotics administered intravenously (through a vein) and have failed that treatment providing the previous drugs were not levofloxacin or imipenem/cilastatin and there is evidence of failure (specimen from respiratory tract documenting original bacteria causing pneumonia is still present or presence of a new bacteria causing pneumonia acquired in the hospital, continued abnormal temperature or worsening of x-ray findings and at least 1 of the following: increased white blood cell count or decrease in breathing ability/increase in oxygen requirements) Have received treatment with antibiotics administered intravenously (through a vein) for < 24 hours within 72 hours prior to study entry Hospitalized for >= 72 hours and develop acute signs and symptoms of pneumonia while on antibiotic(s) for another reason, providing that the previous antibiotic(s) were not levofloxacin or imipenem/cilastatin, no antibiotics have been given for the pneumonia and the previous antibiotic(s) can be discontinued Exclusion Criteria: Infection due to a bacteria that is know to be resistant to levofloxacin or imipenem or certain other drugs that may be used during the study Have received treatment with antibiotics administered intravenously for > 24 hours within 72 hours prior to study entry Previous allergic or serious adverse reaction to any of the drugs used in this study or to a drug similar to those used in this study Cystic fibrosis or other lung disorder or an infection not treatable with antibiotics Significantly decreased kidney function Pre-infection terminal illness (such as cancer) Decreased white blood cell count