neomycin/polymyxin B/bacitracin ophthalmic (Rx)

Frequency Not Defined

Conjunctival edema

Rash

Allergic contact dermatitis

Itching

Failure to heal

Swelling

Irritation

Contraindications

Hypersensivity to neomycin, polymyxin B, zinc bacitracin

Glaucoma

Viral diseases of cornea and conjunctiva (epithelial herpes simplex keratitis, vaccinia, varicella)

Mycobacterial infection of eye & fungal diseases of ocular structures

Cautions

Not for injection into the eye; neomycin and polymyxin B sulfates and bacitracin zinc ophthalmic ointment should never be directly introduced into the anterior chamber of the eye; ophthalmic ointments may retard corneal wound healing

Topical antibiotics, particularly neomycin sulfate, may cause cutaneous sensitization; a precise incidence of hypersensitivity reactions (primarily skin rash) due to topical antibiotics is not known

The manifestations of sensitization to topical antibiotics are usually itching, reddening, and edema of the conjunctiva and eyelid; a sensitization reaction may manifest simply as a failure to heal

During long-term use of topical antibiotic products, periodic examination for such signs is advisable, and the patient should be told to discontinue the product if they are observed; symptoms usually subside quickly on withdrawing the medication

As with other antibiotic preparations, prolonged use of neomycin and polymyxin B sulfates and bacitracin zinc ophthalmic ointment may result in overgrowth of nonsusceptible organisms including fungi; if superinfection occurs, appropriate measures should be initiated

Bacterial resistance to neomycin and polymyxin B sulfates and bacitracin zinc ophthalmic ointment may also develop; if purulent discharge, inflammation, or pain becomes aggravated, the patient should discontinue use of the medication and consult a physician

There have been reports of bacterial keratitis associated with the use of topical ophthalmic products in multiple-dose containers which have been inadvertently contaminated by patients, most of whom had a concurrent corneal disease or a disruption of the ocular epithelial surface

Allergic cross-reactions may occur which could prevent the use of any or all of the following antibiotics for the treatment of future infections: Kanamycin, paromomycin, streptomycin, and possibly gentamicin

Pregnancy Category: C

Lacation: Excretion in breast milk unknown; caution

Pregnancy Categories

A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

NA: Information not available.

Mechanism of Action

Bacitracin: Inhibits bacterial cell wall synthesis by preventing the incorporation of amino acids and nucleotides into the cell wall

Neomycin: Interferes with bacterial protein synthesis by binding to 30S ribosomal subunits

Polymyxin B: Bactericidal; causes leakage of bacterial membrane