LEVELS OF VANCOMYCIN IN AQUEOUS-HUMOR AFTER TOPICAL EYE DROPS ADMINISTRATION

Vancomycin is an antibiotic which is especially active against Gram po sitive bacteria. At present, numerous infections of the anterior segme nt of the eye are caused by the Staphilococcus aureus and epidermis. S trains which are resitant to methicilin are more and more frequent and for this reason Vancomycin is becoming the antibiotic of choice to co mbat these infections since no resistance of the Staphilococcus to it has been demonstrated. The authors evaluated the levels of Vancomycin in aqueous humor after the administration of topical eye-drops. For th e first two hours after the last administration, levels of 0.52 mug/ml were detected. These inhibit the growth of the majority of bacteria s ensitive to Vancomycin. Between two and four hours, the levels decreas ed to 0.15 mug/ml; these are therapeutic levels for a large number of Gram positive bacteria. From four hours after the last administration, these levels are undetectable. Due to the success of its penetration, topical administration of Vancomycin should be considered as a therap eutic modality against infections by gram positive bacteria of the ant erior segment. The ideal guideline for administration would be one dro p every two hours, especially if the infection is severe. In this way, subconjunctival injection could be avoided.