Erythromycin ophthalmic ointment is an antibiotic cream applied to the eye to treat eye infections. The ointment is sterile and is applied directly to the eye, where it flows freely over the conjunctiva of the eye. Erythromycin ophthalmic ointment treats such eye infections as conjunctivitis, commonly known as "pink eye;" trachoma, a contagious bacterial infection that is is leading cause of blindness in undeveloped nations; and blepharitis, a common infection of the eyelid and eyelash follicles.
A macrolide antibiotic, erythromycin is derived from the actinomycete Saccharopolyspora erythraea genus. It was first isolated from a soil sample from the Philippines in 1949. Available in various forms such as liquid injections or oral tablets, the ointment was developed especially for direct eye treatments for various bacterial infections.
In addition to the treatment of bacterial infections, erythromycin ophthalmic ointment is a preventative treatment for infants for neisseria gonorrhoeae or chlamydia trachomatis at birth. Erythromycin is safe for all ages, and its use has replaced the practice of silver nitrate drops for treating the eyes of newborns. Incidence of opthalmia in newborns has been found to decrease dramatically after a regimen of erythromycin ophthalmic ointment.
Common side effects of erythromycin ophthalmic ointment are mild and might include irritation, itching, redness, excessive tearing and light sensitivity. More severe side effects such as conjunctivitis and blepharitis might result. Secondary bacterial infections might occur from contaminated ointment or contaminated hands applying the eye medications. Some patients are allergic to erythromycin and might experience swelling of the eyelids and pain in the eye.
Erythromycin ophthalmic ointment is available only by prescription. The ointment must be applied with clean hands. The dosage for bacterial infections is generally 0.4-inch strip (1 cm) of the antibiotic cream applied in the lower eyelid. Dosage frequency can vary, depending on the severity and cause of eye infection.