Neomycin/polymyxin B/bacitracin

A topical combination of neomycin, polymyxin B, and bacitracin used against susceptible bacteria, especially in minor skin wounds. It is commonly sold as an ointment and is not effective against viruses or fungi.

Neomycin: An aminoglycoside antibiotic that binds bacterial ribosomes and disrupts protein synthesis. It targets susceptible bacteria by interfering with their production of proteins.
Minor wound: A small, superficial injury such as a minor cut, scrape, or burn. These are the common settings in which the combination is applied to reduce bacterial infection risk.
Bacitracin ointment: A topical preparation containing bacitracin as its antibacterial ingredient. It omits neomycin and polymyxin B, reducing exposure to those drugs but narrowing coverage.
Neomycin allergy: An immune-mediated hypersensitivity to neomycin, often presenting as an itchy rash after skin exposure. This ingredient is a frequent cause of allergic reactions to the combination.
Polymyxin B: A cyclic polypeptide antibiotic that disrupts the outer membrane of susceptible Gram-negative bacteria. It damages bacterial membranes, complementing the other drugs’ targets.
Topical antibiotic: An antimicrobial drug formulated for application to the skin or another body surface. This combination is a widely recognized example of a topical antibiotic preparation.
Mupirocin: A topical antibiotic that inhibits bacterial protein synthesis through isoleucyl-tRNA synthetase. It is a prescription alternative for certain localized bacterial skin infections.
Allergic contact dermatitis: A delayed immune reaction in the skin after contact with an allergen. Repeated application can provoke this reaction in people sensitized to an ingredient.
Bacitracin: A peptide antibiotic that blocks bacterial cell-wall synthesis, chiefly in Gram-positive bacteria. It attacks cell-wall construction through a mechanism distinct from the other ingredients.
Contact dermatitis: Skin inflammation caused by direct exposure to an irritating or allergy-triggering substance. Neomycin and bacitracin can trigger allergic contact dermatitis at the application site.

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