BAY12-8039: 5 Days for Sinusitis vs Placebo

Inclusion Criteria: Subjects must meet all the following criteria at the time of enrollment: * Age \>/= 18 years * Clinical diagnosis of acute bacterial sinusitis with signs and symptoms present for = 7 days but \< 28 days as defined by A), radiographic, and B) clinical criteria, as follows: * Radiographic Criteria: The presence of one or more of the following on a radiographic paranasal sinus film (Waters' view): - Evidence of air-fluid levels - Opacification * Clinical Criteria: The presence of two major symptoms, or the presence of at least one major and one minor symptom as defined in the list below: * Major symptoms: - Purulent anterior or posterior nasal discharge - Unilateral facial pain or malar tenderness * Minor symptoms: - Frontal headache - Fever (oral = 38.0°C/100.4°F, tympanic = 38.5°C/101.2°F, axillary = 37.5°C/99.5°F) - Culture material obtained by sinus puncture; the aspirated specimen sent for Gram stain, quantitative culture and susceptibility testing prior to initiation of antimicrobial therapy Exclusion Criteria: Subjects with one or more of the following criteria will not be eligible for this study: * History of chronic sinusitis defined as greater than four weeks of continuous symptoms (subjects with recurrent acute sinusitis will be included) * History of sinus surgery (antral sinus puncture is not considered as a surgery) * Any symptoms that suggest the subject's current illness is allergic rhinitis (e.g. repetitive sneezing, itchy nose or eyes, provocation by an allergen) and not acute bacterial sinusitis * Known bacteremia, meningitis or infection infiltrating the tissues neighboring the sinuses