Abstract
Introduction Upper respiratory tract infections (URTIs) are commonly encountered in primary care. Azithromycin has emerged as a preferred therapy for URTIs due to its once-daily dosing, low resistance risk, and favorable gastrointestinal tolerability. This study evaluated the real-world effectiveness and safety of azithromycin (500 mg/day) in moderate to severe acute URTIs. Materials and methods This subgroup analysis of a retrospective, multicenter, observational study analyzed data from 184 ENT centers in India over 12 weeks. Medical records of adult patients with moderate to severe URTIs treated with azithromycin 500 mg daily for five days were included. Key clinical signs (pharyngeal and tonsillar erythema, exudates) and symptoms (sore throat, fever, daily activity interference) were assessed on a 3-point scale. Treatment effectiveness was evaluated through changes in cumulative symptom scores and Clinical Global Impression scores on day 5. Data were analyzed using paired t-tests and McNemar-Bowker tests, with p<0.05 indicating significance. Ethical approval was obtained, and all data collection adhered to Good Clinical Practice standards. Results Data from 427 patients with moderate to severe URTIs were analyzed. By day 5, significant improvements were observed across all clinical parameters. Proportion of patients with moderate pharyngeal erythema (40.7%) and severe cases (59.3%) reduced significantly to 16.6% and 0.2%, respectively, and severe tonsillar erythema (63%) reduced from baseline to no cases with severe tonsillar erythema at day 5. Tonsillar exudates reduced from 52.9% to 7.6% for moderate cases and from 47.1% to 0.2% for severe cases. Sore throat severity dropped from 73.5% to only 0.2% reporting difficulty swallowing. Fever resolved in 96.7% of patients, and work absenteeism reduced from 71.2% to 0.9%. Clinical Global Impression scores indicated improvement in 90% of patients. Adverse events were reported in only 2.1% of cases. Conclusion Azithromycin demonstrated significant clinical effectiveness in managing moderate to severe URTIs, with marked improvements in key symptoms and signs.