Independent studies show promising potential of topical azithromycin 1% ophthalmic solution (AzaSite, Inspire Pharmaceuticals) for the treatment of both posterior and chronic anterior blepharitis.
Use of azithromycin for treatment of posterior blepharitis was investigated by Jodi Luchs, MD, who randomly assigned 21 patients to a 2-week course of standard therapy with twice-daily mechanical measures (warm compresses for 5 minutes followed by lid massage) alone or combined with topical azithromycin instilled twice daily for 2 days and then once daily on days 3 to 14. Twenty patients completed the study, and the results from analyses of multiple efficacy endpoints showed highly statistically significant benefits associated with azithromycin use.
Dr. Luchs observed that azithromycin has properties that make it very well-suited as a therapeutic modality for posterior blepharitis: it has well-documented anti-inflammatory activity as well as excellent penetration into eyelid tissue after topical administration.
"The anti-inflammatory effects of azithromycin have been best described in the lungs but have been demonstrated in other tissues as well, and the oral macrolide erythromycin is known to have benefits in improving the signs and symptoms of posterior blepharitis," he said. "If we can topically deliver a drug with the same properties but that can achieve even higher levels in the target tissue, we may have a home run. Results from my pilot study suggest this is the case."
The outcomes assessments in the randomized study showed that a 69% reduction from the baseline score for lid margin redness severity was achieved in patients using azithromycin in combination with lid therapy, compared with a 10% reduction in the control group. The difference in mean score at study conclusion favoring the azithromycin group was highly statistically significant.
In addition, in a self-rated global assessment of efficacy, 75% of patients who used azithromycin rated their treatment as good or excellent. In contrast, 18% of patients in the control group rated the efficacy of their treatment as good, and none considered it to be excellent.
"As seen by the outcomes in the control group, achieving good or excellent results after just 2 weeks of treatment for posterior blepharitis using standard therapy with warm compresses and lid massage is almost unheard of, and that is even true when oral doxycycline is added," said Dr. Luchs.
The study also included several efficacy endpoints relating to evaluation of meibomian gland findings. The results for those assessments also were equally dramatic in showing statistically significant improvements in the group treated with azithromycin combined with the mechanical therapy, he said.
The topical azithromycin was very well tolerated. Dr. Luchs reported that no concerns emerged in extensive safety evaluations that included visual acuity, ophthalmoscopy, slit-lamp biomicroscopy, and measurement of IOP.
Only two adverse events, burning and blurred vision, were reported, and both were reported in the same patient.