An antibiotic used on the skin and eyes
Bacitracin
An antibiotic used on the skin and eyes for infections, usually combined with other antibiotics, and reserved for topical use.
What is Bacitracin?
Bacitracin is an antibiotic used mainly on the surface of the skin or eyes to treat or prevent minor bacterial infections, often combined with other antibiotics such as polymyxin or neomycin. It works by stopping bacteria building their cell walls. Because it can seriously harm the kidneys if it gets into the body, it is reserved for topical use rather than being taken by mouth or injection. The most common problem is a skin reaction such as redness or itching where it is applied, and rarely it can cause a serious allergic reaction.
Education and reference only. This is a plain-language guide to Bacitracin — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Bacitracin is an antibiotic, a medicine that kills or stops the growth of bacteria. It is used almost entirely on the surface of the body — on the skin as an ointment or cream and in the eye as an eye ointment — to treat or help prevent minor bacterial infections. It is often combined with other antibiotics such as polymyxin or neomycin so that the mixture covers a wider range of bacteria. It is deliberately kept for topical use because, if absorbed into the body in significant amounts, it can damage the kidneys, so it is not given by mouth or by injection.
How it works
Bacitracin works by interfering with the way bacteria build their protective outer wall. Without a properly formed cell wall, the bacteria cannot survive, so the infection is cleared or prevented from taking hold. Because it acts directly where it is applied, it is well suited to treating surface infections of the skin and eyes. Combining it with other antibiotics broadens the range of bacteria it can deal with. Its action is local, which is one reason it is kept for use on the surface rather than inside the body.
Company & origin
Originated / developed by: Various manufacturers.
An antibiotic used in the UK mainly on the skin and eyes, often combined with other antibiotics such as polymyxin or neomycin, and kept for topical use because it can harm the kidneys if taken into the body.
Practical use
How to take Bacitracin
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Apply it to the skin or eye exactly as directed, using clean hands and only on the area advised.
- Use it only on the surface; it is never taken by mouth or by injection because of the risk to the kidneys.
- Do not use it for longer than advised, as prolonged use raises the chance of a skin allergy.
- Stop and seek advice if the area becomes more red, itchy, swollen or sore, which may be a reaction.
- Seek emergency help for any sign of a serious allergic reaction such as swelling of the face or trouble breathing.
Weighing it up
Advantages & disadvantages of Bacitracin
Advantages
- Treats and helps prevent minor bacterial infections of the skin and eyes where it is applied.
- Often combined with other antibiotics to cover a wider range of bacteria.
- Acts locally, so it avoids many of the whole-body effects of antibiotics taken by mouth.
Disadvantages
- Can cause skin reactions and contact allergy, especially with long or repeated use.
- Must be kept to the surface, as it can seriously harm the kidneys if absorbed into the body.
- Rarely, can trigger a serious whole-body allergic reaction.
Practical use
Good to know
The most important thing to understand is why bacitracin is only ever used on the surface: taken into the body it can cause serious kidney damage, so it is reserved for the skin and eyes and is not given by mouth or injection. Used topically, the most common issue is a local skin reaction — redness, itching or a rash where it is applied — which can sometimes be a sign of a contact allergy, especially with long or repeated use. Rarely, applying it can trigger a serious whole-body allergic reaction (anaphylaxis), which needs emergency help. Eye ointments can blur vision briefly after they are put in. Use it only as directed, for as long as advised, and stop and seek advice if the area becomes more red, sore or swollen, as that may mean a reaction or that the infection is not responding.
Who should not take it / use with caution
- People who have had a serious allergic reaction to bacitracin should not use it.
- It is not used by mouth or by injection because of the risk of serious kidney damage.
- Combined products containing neomycin are used with care, as neomycin can also cause skin allergy.
Monitoring
- Watching whether the infection is improving over the expected time.
- Checking for signs of a skin or eye reaction with continued use.
- Stopping and reviewing if a serious allergic reaction occurs.
Side effects
- Redness, itching, rash or irritation where it is applied.
- A contact allergy that can develop with long or repeated use.
- Brief blurring of vision after an eye ointment is applied.
- Rarely, a serious whole-body allergic reaction (anaphylaxis), which needs emergency help.
Key interactions
- Used on the skin or eye, it has few important interactions with medicines taken by mouth.
- It should not be combined with other treatments on the same area unless advised.
- Tell your prescriber about other skin or eye treatments you are using.
Available as: Skin ointment or cream and eye ointment, often combined with other antibiotics.
Answers
Bacitracin: frequently asked questions
What is bacitracin used for?
It is an antibiotic used on the surface of the skin or eyes to treat or help prevent minor bacterial infections, often combined with other antibiotics such as polymyxin or neomycin.
Why can't it be taken by mouth or injection?
If bacitracin gets into the body it can seriously damage the kidneys, so it is reserved for use on the skin and eyes only.
Can it cause an allergy?
Yes. A skin reaction such as redness or itching is the most common problem and can be a sign of contact allergy, especially with long or repeated use; rarely it can cause a serious whole-body reaction.
Why is it combined with other antibiotics?
Combining it with antibiotics such as polymyxin or neomycin lets the mixture cover a wider range of bacteria than bacitracin alone.
How long should I use it?
Use it only for as long as advised; prolonged use raises the chance of a skin allergy. Stop and seek advice if the area gets more red, sore or swollen.
The wider class
About Topical antibiotic
Bacitracin belongs to the topical antibiotic class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF
- NICE CKS
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