Bacterial Ophthalmic Infections
Neomycin is used in fixed combination with other anti-infectives (i.e., polymyxin B sulfate and bacitracin zinc; polymyxin B and gramicidin) for the topical treatment of superficial infections of the eye (e.g., conjunctivitis, keratitis, keratoconjunctivitis, blepharitis, blepharoconjunctivitis) caused by susceptible bacteria.
Fixed-combination topical ophthalmic preparations containing neomycin sulfate, polymyxin B sulfate, and bacitracin zinc are considered active against Staphylococcus aureus, streptococci (including Streptococcus pneumoniae), Escherichia coli, Haemophilus influenzae, Enterobacter, Klebsiella, Neisseria, and Pseudomonas aeruginosa, but do not provide adequate coverage against Serratia marcescens.
Fixed-combination topical ophthalmic preparations containing neomycin sulfate, polymyxin B sulfate, and gramicidin are considered active against S. pneumoniae, E. coli, H. influenzae, Enterobacter, Klebsiella, Neisseria, and Ps. aeruginosa, but do not provide adequate coverage against S. marcescens.
Although mild, acute bacterial conjunctivitis often resolves spontaneously without anti-infective treatment, topical ophthalmic anti-infectives may shorten the time to resolution and reduce severity and risk of complications. Treatment of acute bacterial conjunctivitis generally is empiric and use of a broad-spectrum topical ophthalmic antibacterial usually is recommended; however, indiscriminate use of topical anti-infectives should be avoided. In vitro staining and/or cultures of conjunctival material may be indicated in the management of recurrent, severe, or chronic purulent conjunctivitis or when acute conjunctivitis does not respond to initial empiric topical treatment.
Because many forms of bacterial keratitis are associated with subsequent loss of vision as the result of corneal scarring or topographic irregularities and because untreated or severe bacterial keratitis may result in perforation of the cornea with the potential for endophthalmitis and possible loss of the eye, optimal management involves rapid evaluation and diagnosis, timely initiation of treatment, and appropriate follow-up. Treatment of community-acquired bacterial keratitis generally is empiric and use of a broad-spectrum topical ophthalmic antibacterial usually is recommended. Subconjunctival therapy with an appropriate anti-infective may be necessary if scleral spread or perforation is imminent. In vitro staining and/or cultures are indicated in the management of keratitis involving corneal infiltrates that are central, large, and extending to the middle to deep stroma; when keratitis is chronic or unresponsive to broad-spectrum topical anti-infective treatment; or when atypical features are present suggesting fungal, amebic, or mycobacterial infection.
Bacterial Otic Infections
Neomycin is used in fixed combination with colistin and hydrocortisone acetate or in fixed combination with polymyxin B sulfate and hydrocortisone for the topical treatment of superficial infections of the external auditory canal (otitis externa) caused by susceptible bacteria. These fixed-combination otic preparations also are used for the topical treatment of infections of mastoidectomy or fenestration cavities caused by susceptible bacteria.
Diffuse, uncomplicated acute otitis externa in otherwise healthy patients usually should be treated initially with topical therapy (e.g., otic anti-infective or antiseptic with or without an otic corticosteroid). Topical therapy should be supplemented with systemic anti-infective therapy if the patient has a medical condition that could impair host defenses (e.g., diabetes mellitus, human immunodeficiency virus [HIV] infection) or if the infection has spread into the pinna, skin of the neck or face, or into deeper tissues such as occurs with malignant otitis externa. Malignant otitis externa is an invasive, potentially life-threatening infection, especially in immunocompromised patients, and requires prompt diagnosis and treatment with systemic anti-infectives.
Topical ophthalmic preparations containing neomycin sulfate in fixed combination with polymyxin B sulfate and a corticosteroid (i.e., dexamethasone) or neomycin sulfate in fixed combination with polymyxin B sulfate, bacitracin zinc, and a corticosteroid (i.e., hydrocortisone or hydrocortisone acetate) are used for the treatment of corticosteroid-responsive ocular conditions when a corticosteroid is indicated and superficial bacterial ocular infection or risk of such infection exists.
Ophthalmic corticosteroids may be indicated in inflammatory conditions of the palpebral and bulbar conjunctiva, cornea, and anterior segment of the globe where the inherent risk of corticosteroid use in certain infective conjunctivitides is accepted to obtain diminution in edema and inflammation. Ophthalmic corticosteroids also may be indicated in the treatment of chronic anterior uveitis and corneal injury from chemical, radiation, or thermal burns or penetration of foreign bodies.
Although the manufacturers state that use of a fixed-combination ophthalmic preparation containing anti-infectives and a corticosteroid may be indicated in ocular inflammatory conditions when the risk of superficial ocular infection is high or when there is an expectation that potentially dangerous numbers of bacteria will be present in the eye, experts state that such preparations should be avoided in patients with bacterial conjunctivitis because of the risk of potentiating the infection.
Clinicians should consider that use of fixed-combination ophthalmic preparations containing anti-infectives and a corticosteroid may mask the clinical signs of bacterial, fungal, or viral infections; prevent recognition of ineffectiveness of the anti-infectives; and/or increase intraocular pressure.
(See Precautions Related to Use of Fixed Combinations Containing Corticosteroids under Cautions: Precautions and Contraindications.)
For other uses of neomycin, see 8:12.02 and see 84:04.04.