Bacitracin
Topical antibacterials
Topical antibacterials
A polypeptide antibiotic ointment that helps keep minor cuts, scrapes and burns from becoming infected; injected forms harm the kidneys.
Also called: bacitracin zinc
Quick facts
- Group
- Topical antibacterials
- Target
- Bacterial cell-wall synthesis (the lipid carrier that moves wall building blocks)
- Used for
- Prevention of infection in minor cuts
- Key effects
- Itching or rash where applied · Contact allergy
- Monitor
- Healing of the wound · Rash
- ATC
- D06AX05
No doses: the clinician sets them by the current guideline.
Mechanism of action
The figure shows bacitracin holding zinc and geranyl pyrophosphate, a short stand-in for the bacterial lipid carrier it traps; it is not a human protein.
Bacitracin is a mixture of polypeptide antibiotics made by Bacillus subtilis, mainly bacitracin A. It blocks bacterial cell-wall synthesis by trapping the pyrophosphate lipid carrier that ferries wall building blocks across the membrane. It acts mostly on gram-positive cocci and bacilli; most gram-negative rods are resistant.
- Bacitracin binds the bacterial lipid carrier with zinc
- Carrier cannot be recycled for cell-wall building
- Cell wall stops growing
- Gram-positive bacteria on the skin stop multiplying
Indications
- Prevention of infection in minor cuts, scrapes and burns
- Superficial eye infections (ophthalmic ointment)
Adverse effects
Common
- Itching or rash where applied
- Contact allergy (uncommon)
Contraindications
- Allergy to bacitracin or zinc
- Deep cuts, puncture wounds, animal bites, serious burns or large areas (these need medical care)
Key interactions
- Combination ointments with neomycin and polymyxin B
- Broader antibacterial cover, but more contact allergy, especially to neomycin and bacitracin.
What is monitored
- Healing of the wound; review if it is not better within a week
- Rash, itching or swelling at the site
Administration and safety
- For the skin only: kept out of the eyes, nose and mouth and not swallowed (a separate ophthalmic form exists).
- A thin layer is applied to the cleaned wound; a sterile dressing may cover it.
- Not used in a child's diaper area unless a clinician advises it.
- The tube tip does not touch the skin or other surfaces.
Pregnancy and breastfeeding
Pregnancy or breastfeeding is mentioned to the clinician before use.
Nursing care
- Clean the wound and check its depth: deep, punctured, bitten or burnt wounds need a clinician.
- Teach to stop the ointment and seek care for itching, rash, hives or trouble breathing.
- Teach to report a wound that is not improving or shows spreading redness, pus or fever.
Pharmacokinetics
- Absorption
- Used on the skin or eye; injected (parenteral) use damages the kidneys
Test yourself
Think of the answer, then tap the question to see it.
Which bacterial process does bacitracin block?
Cell-wall synthesis, by trapping the lipid carrier of wall building blocks.
Why is bacitracin now used almost only on the skin and eye?
Injected bacitracin is nephrotoxic.
Which wounds should not be treated with bacitracin ointment alone?
Deep cuts, puncture wounds, animal bites, serious burns or wounds over large areas.
Connections
← Back to the class: Topical antibacterials
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Bacitracin Topical: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2017); RCSB PDB - 4K7T: Structure of the ternary complex of bacitracin, zinc, and geranyl-pyrophosphate (RCSB Protein Data Bank, 2013); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).
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Representative model, for educational purposes only.