Efficacy assessment of azithromycin 1.5% eye drops versus tobramycin 0.3% on clinical signs of purulent bacterial conjunctivitis

Bacterial conjunctivitis is characterized by hyperemia and discharge of one or both eyes. These clinical signs appear quickly and are contagious. This study compares the clinical efficacy (signs and symptoms) and safety of azithromycin 1.5% eye drops with tobramycin 0.3%. This was a multicenter, randomized, investigator-masked study including 1,043 patients with purulent bacterial conjunctivitis. Patients received either azithromycin twice daily for 3 days or tobramycin, 1 drop every 2 hours for 2 days, then four times daily for 5 days. The primary variable was clinical cure at the test-of-cure (TOC) visit (D9) on the worst eye. The cure was defined as bulbar conjunctival injection and discharge scores of 0. Clinical signs were evaluated at D0, D3, and D9. In the azithromycin group 87.8% of patients and in the tobramycin group 89.4% were clinically cured at D9. Clinical cure with azithromycin was not inferior to tobramycin at D9: discharge was absent in 96.3% of patients treated with azithromycin and 95.1% with tobramycin. Azithromycin was well tolerated. Azithromycin 1.5% for 3 days (six drops) was as effective as tobramycin for 7 days (36 drops). Furthermore, patients on azithromycin presented earlier clinical cure on Day 3 than patients on tobramycin. Azyter, with its convenient dosing (bid for 3 days), is a step forward in the management of purulent bacterial conjunctivitis.