AzaSite: New formulation recently approved by FDA for azithromycin ophthalmic solution 1%

Key Points

INSPIREAntibacterial agent approved for the treatment of bacterial conjunctivitis

Azithromycin is a macrolide antibiotic that inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit of susceptible microorganisms. This agent was approved on April 27, 2007, for the treatment of bacterial conjunctivitis caused by susceptible isolates of the microorganisms CDC coryneform group G, Haemophilus influenzae, Staphylococcus aureus, Streptococcus mitis group, and Streptococcus pneumoniae.

Efficacy. The efficacy of this agent for the treatment of bacterial conjunctivitis was evaluated in a randomized, vehicle-controlled, double-blind, multicenter clinical study. Patients (N=279) were treated with azithromycin drops or vehicle twice daily for the first 2 days and once daily on Days 3, 4, and 5. On Days 6 and 7, azithromycin was demonstrated to be superior to vehicle: among azithromycin-treated patients (n=130), 82 (63%) demonstrated clinical resolution, and among vehicle-treated patients (n=149), 74 (50%) demonstrated clinical resolution (treatment difference, 13%; 95% CI, 2%–25%; P=.03). The microbiological success rate for eradication of the baseline pathogens was 88% among azithromycin-treated patients versus 66% among vehicle-treated patients (treatment difference, 22%; 95% CI, 13%–31%; P<.001).

Dosing. The recommended dosage regimen of azithromycin for the treatment of bacterial conjunctivitis is 1 drop in the affected eye twice daily (8 to 12 hours apart) for the first 2 days, followed by 1 drop in the affected eye once daily for the next 5 days.