Natamycin is a tetraene polyene antibiotic derived from Streptomyces natalensis. Natamycin probably exerts its antifungal effects by binding to sterols in the fungal cell membrane to produce a change in membrane permeability that allows loss of essential cellular constituents. It possesses in vitro activity against a variety of yeast and filamentous fungi, including Candida, Aspergillus, Cephalosporium, Fusarium and Penicillium. Although the activity against fungi is dose-related, Natamycin is predominantly fungicidal. Topical administration appears to produce effective concentration of Natamycin within the corneal stroma but not in intraocular fluid.
N-Mycin Eye Drop
For fungal keratitis: The preferred initial dosage is 1 drop instilled in the conjuntival sac (s) at 1-2 hours interval. The frequency of application can usually be reduced to 1 drop 6-8 times daily after the first 3-4 days. Therapy should generally be continued for 14 to 21 days or until there is resolution of active fungal keratitis. In many cases, it may be helpful to reduce the dosage gradually at 4 to 7 days intervals to assure the replicating fungus has been eliminated.
For fungal blepharitis & conjunctivitis: Less frequent initial dosage, 1 drop 4-6 times daily may be sufficient.