Onset of symptom resolution in adults with acute bacterial rhinosinusitis treated with a single dose of azithromycin extended release compared with 10 days of levofloxacin: A retrospective analysis of a randomized, double-blind, double-dummy trial

Background: A previous study found that a single 2-g dose of azithromycin extended release (AZ-ER) was as efficacious as 10 days of levofloxacin (LFX) 500 mg QD in adults with acute bacterial rhinosinusitis (ABRS). The speed with which patients experience resolution of ABRS symptoms has not been reported. Objective: The purpose of this study was to evaluate the resolution of ABRS symptoms after a single 2-g dose of AZ-ER compared with 10 days of LFX. Methods: This was a retrospective analysis of data from a published international, randomized, double-blind, double-dummy clinical trial conducted between January 21, 2003, and February 20, 2004, that included 534 adult (age ≥18 years) outpatients with ABRS. All patients entering the study were required to have purulent nasal discharge, purulent drainage in the posterior pharynx, or purulent discharge from the maxillary sinus orifice and at least 1 of 3 other protocol-defined cardinal symptoms of ABRS (sinus pain, pressure, or tenderness) for ≥7 days. In addition, they were required to have at least 2 of the following 6 noncardinal symptoms at baseline: cough, fever, headache, nasal congestion, postnasal discharge, and leukocytosis. All patients who received medication were assessed for the occurrence of adverse events at study visits during and after therapy. At the ontreatment visit (between days 3 and 5), baseline symptoms were reassessed as resolved, improved, same, new, or worse. Resolution of symptoms was calculated as the proportion of patients with 3 or 4 cardinal symptoms either resolved (if present at baseline) or not new (if absent at baseline). Concomitant medications other than antibiotics were allowed as needed for symptomatic treatment. Results: Demographic characteristics were similar at baseline between the AZ-ER and LFX treatment arms (mean age, 38.4 and 39.5 years, respectively), although more women were randomized to receive LFX (62.9%) than AZ-ER (53.3%) (P = 0.025). More than 90% of patients in both arms had ≥3 ABRS symptoms at baseline. At the on-treatment visit, resolution of ≥3 ABRS symptoms was achieved in 88 of 270 AZ-ER patients (32.6%) and 61 of 261 LFX patients (23.4%) (P = 0.018). Resolution of individual symptoms in the AZ-ER and LFX groups at 3 to 5 days was as follows: sinus pain (92/253[36.4%] and 77/251 [30.7%]; P = NS), sinus pressure (97/243 [39.9%] and 68/244 [27.9%]; P = 0.005), sinus tenderness (83/218 [38.1%] and 73/214 [34.1%]; P = NS), and nasal discharge (57/270 [21.0%] and 49/264 [18.6%]; P = NS). Treatment-related adverse events were reported by 63 of 270 AZ-ER patients (23.3%) and 41 of 268 LFX patients (15.3%). Gastrointestinal disturbances were the most common adverse events, including nausea (4.4% and 3.4%) and abdominal pain (2.6% and 0.4%).