Superficial bacterial infection of the conjunctiva or cornea
Apply into the conjunctival sac 1 to 3 times daily.
OFF-LABELNot in the FDA label for this product
Anterior blepharitis (lid margin application)
Remove all scales and crusts, then spread uniformly over the lid margins, 1 to 3 times daily.
Cochrane · class-level only
Blepharitis appears only in this label's Dosage and Administration section; Indications and Usage is limited to conjunctiva and cornea, so lid-margin use sits outside the stated indication. No product-specific trial exists. A Cochrane systematic review and meta-analysis of 34 trials in 2,169 participants with chronic blepharitis found topical antibiotics as a class gave some symptomatic relief and eradicated lid margin bacteria in anterior blepharitis, but its overall conclusion was that there is no strong evidence that any treatment cures chronic blepharitis; that finding is class-level and was not measured on this product.
Ophthalmic ointment, 3.5 g (1/8 oz) sterile tamper-evident tube with ophthalmic tip, 500 units bacitracin per gram
Mechanism of Action
Polypeptide antibiotic; blocks cell wall synthesis by inhibiting dephosphorylation of the lipid carrier undecaprenyl pyrophosphate (C55-PP), stalling the carrier cycle that shuttles peptidoglycan subunits across the bacterial membrane. Spectrum per the label is qualitative: strong activity against many gram-positive pathogens including the common streptococci and staphylococci, destructive to certain gram-negative organisms, ineffective against fungi.
Warnings & Precautions
Deep or systemic-risk infections: Not for deep-seated ocular infections or infections likely to become systemic.
Nonsusceptible organism overgrowth: Prolonged use of antibiotic-containing preparations may allow overgrowth of nonsusceptible organisms, particularly fungi; institute appropriate alternative therapy if a new infection develops during treatment.
Tube contamination: Avoid gross contamination of the ointment when applying it directly to the infected eye.
Common Side Effects
Ocular: Local reactions rare; discontinue if one occurs.
Contact hypersensitivity: Dermatology patch-test surveillance ranks it second only to neomycin among allergens in medication-associated positive reactions (North American Contact Dermatitis Group, 2001 to 2018), so weigh it in periocular dermatitis that worsens on treatment.
Pregnancy & Lactation
Poorly absorbed after topical application and oral ingestion—considered a low risk to nursing infants and pregnant mothers.