Study to Measure the Impact of Antibiotics on Bacterial Flora in Adults With Acute Sinusitis

Inclusion Criteria: * Adult patients, either males or non-pregnant females, aged 18 to 75 years of age with clinical findings of acute maxillary sinusitis (AMS), who are amenable to serial sampling of the nasopharynx and oropharynx. * Patients are required to have specimens of nasal and nasopharyngeal drainage collected for microbiological documentation within 24 hours prior to enrollment. All patients must produce sinus fluid drainage. * All patients will produce nasal or nasopharyngeal discharge sufficient for baseline culture. * Female patients of child bearing potential must agree to use an accepted method of contraception (i.e., oral or implanted contraceptive with a barrier method, spermicide and barrier methods, or intrauterine device \[IUD\]). The patient must agree to continue with the same method throughout the study. Exclusion Criteria: * Patients with a history of recurrent sinusitis defined as more than three episodes of sinusitis which required antibiotic therapy in the preceding 12 months * Patients with a history of chronic sinusitis defined as symptoms lasting greater than 28 days * Patients with nosocomial acquired sinusitis (e.g., hospitalization or non-ambulatory institutional confinement including nursing homes within 2 weeks) * Patients with a need for immediate surgery for maxillary sinusitis or previous sinus surgery within the past 6 months or sinus lavage within the past 7 days * Patients who are long-term (\> 4 weeks) users of nasal decongestants (e.g. oxymetazoline 0.05%) * Patients with a known or suspected hypersensitivity to, or a known or suspected serious adverse reaction to, any macrolide antibiotic * Impaired hepatic or renal function (creatinine clearance \[CCL\] \<20 ml/min) * Severe respiratory tract infections requiring hospitalization and parenteral antibiotic therapy. * Requirement for a concomitant antimicrobial agent other than topical, antiviral or antifungal agents. * Treatment with any macrolide, azalide, or ketolide antimicrobial within the 30 days prior to entry into the study.