When should you not use Bactroban?: Critical warnings and contraindications for mupirocin

October 13, 2025 •

4 min read

According to the U.S. Food and Drug Administration (FDA), the only specific contraindication for mupirocin (Bactroban) is a known hypersensitivity or allergic reaction to the medication or any of its components. However, several other crucial situations exist where you should not use Bactroban, ranging from treating fungal infections to applying it on large, damaged skin areas.

Quick Summary

This guide covers the key instances where Bactroban is contraindicated or not recommended, including hypersensitivity, inappropriate application sites, and specific medical conditions like kidney impairment. It explains why the topical antibiotic is ineffective for fungal or viral infections and the risks associated with prolonged use or treating deep wounds.

Key Points

Known Allergy to Mupirocin: Avoid use if you have a known hypersensitivity or allergic reaction to mupirocin or its components, including polyethylene glycol.
Incorrect Application Sites: Do not apply Bactroban topical ointment or cream in or near the eyes, nose, or mouth, or on other mucosal surfaces.
Ineffective on Non-Bacterial Infections: Never use Bactroban for fungal or viral infections, as it is only effective against bacteria.
Renal Impairment and Large Wounds: Use with caution or avoid on large areas of broken skin, especially with moderate-to-severe kidney issues, due to potential absorption of polyethylene glycol.
Risk of Antibiotic Resistance: Limit prolonged use to prevent the development of antibiotic resistance; follow your doctor's prescribed duration.
Risks with Medical Devices: Do not apply Bactroban around intravenous cannulae or central IV sites, as it can increase the risk of infection.
Discontinue with New Symptoms: Stop using the medication and contact a doctor if the infection worsens or if you experience severe irritation or systemic side effects.

Allergic Reactions and Hypersensitivity

An allergic reaction is the most important reason to avoid Bactroban. If you have a known hypersensitivity to mupirocin or any of the inactive ingredients, such as polyethylene glycol (PEG) in the ointment, you should not use it. Allergic reactions can range from mild local irritation, such as a rash or redness, to more severe systemic reactions like anaphylaxis, hives, angioedema, or generalized rash. Signs of a serious allergic reaction, such as swelling of the face, lips, tongue, or throat, or difficulty breathing, require immediate medical attention.

Inappropriate Application Areas

Bactroban is a topical medication intended for external use on the skin only. It should not be used on mucosal surfaces or inside body orifices, unless a specific formulation is prescribed for that purpose.

Eyes, nose, and mouth: The topical ointment and cream are not safe for use in or near the eyes, nose, or mouth. A separate nasal formulation exists for treating nasal Staphylococcus aureus colonization, but the regular ointment should never be used for this. If accidental contact with the eyes occurs, rinse them thoroughly with water.
Intravenous sites: Bactroban should not be used around intravenous cannulae or at central intravenous sites. This is because the polyethylene glycol in the ointment can potentially be absorbed systemically, and there is a risk of promoting fungal infections and antibiotic resistance at these vulnerable sites.

When Renal Impairment is a Concern

The ointment formulation of Bactroban contains polyethylene glycol (PEG), a compound that can be absorbed through broken or damaged skin. It is then cleared from the body by the kidneys. For this reason, the use of Bactroban ointment on large areas of broken skin should be avoided, especially in individuals with moderate or severe renal impairment. In such cases, there is a potential for increased systemic absorption and potential nephrotoxicity due to PEG.

Ineffective Against Fungal or Viral Infections

Bactroban is a potent antibacterial agent, not an antifungal or antiviral. Using it for infections not caused by bacteria is inappropriate and could potentially worsen the condition by allowing the non-bacterial microorganisms to overgrow. This is especially true for fungal infections, where Bactroban is entirely ineffective. A key distinction to remember is that Bactroban targets bacterial protein synthesis, a mechanism that does not exist in fungal or viral pathogens.

Comparison: Bactroban vs. Other Topical Treatments

To clarify Bactroban's specific use, here is a comparison with other common topical medications.


Feature	Bactroban (Mupirocin)	Neosporin (Bacitracin/Neomycin/Polymyxin B)	Nystatin (Topical)
Indication	Bacterial skin infections (e.g., impetigo, folliculitis) and nasal MRSA decolonization.	Prevents infection in minor cuts, scrapes, and burns.	Fungal skin infections (e.g., yeast infections, candidiasis).
Organisms	Targets specific Gram-positive bacteria like Staphylococcus aureus.	Broad-spectrum antibiotic combination.	Targets various fungi and yeasts.
Prescription Status	Prescription only.	Over-the-counter (OTC).	Prescription only.
Active Ingredient	Mupirocin.	Bacitracin, Neomycin, Polymyxin B.	Nystatin.
Fungal Activity	Ineffective.	Ineffective.	Effective.
Common Side Effects	Burning, stinging, itching.	Allergic reactions, rash.	Burning, itching, rash.

The Danger of Prolonged Use

Using Bactroban for longer than the recommended duration (typically up to 10 days for topical infections) significantly increases the risk of developing antibiotic resistance. Overuse of mupirocin, particularly for non-indicated purposes like treating wounds or pressure sores, has been linked to the emergence of resistant strains of Staphylococcus aureus, including MRSA. To minimize this risk, it is crucial to use the medication only as directed by a healthcare professional and for the shortest effective period.

Risks in Specific Populations

While minimal systemic absorption is expected, caution is advised when considering Bactroban for certain individuals.

Pregnancy and Breastfeeding: Use during pregnancy should only occur if the potential benefit outweighs the risk, as there are insufficient human data to confirm complete safety. If applied to the breast or nipple while breastfeeding, the area must be washed thoroughly before nursing to prevent oral exposure to the infant.
Pediatric Use: While generally safe for children (ointment for ages 2+ months, cream for ages 3+ months), some precautions apply. The use of mupirocin in neonates and very young children requires caution, especially on large surface areas.

When to Stop Using Bactroban

Discontinuation is necessary in several scenarios, even before the full course of treatment is completed.

Lack of Improvement: If your skin condition does not improve within 3 to 5 days, or if it worsens, contact your doctor. This could indicate that the infection is not susceptible to mupirocin or is not bacterial.
Severe Irritation or Allergic Reaction: Stop using Bactroban immediately if you experience severe itching, rash, burning, or swelling at the application site, as this could be a severe local irritation or allergic reaction.
Symptoms of a New Infection: If you develop any signs of a new infection, including severe or bloody diarrhea (which can occur with any antibiotic and may be a sign of C. difficile infection), contact your doctor right away.

Conclusion

Bactroban is an effective prescription antibiotic for targeted bacterial skin infections like impetigo and nasal MRSA colonization. However, its use requires careful adherence to prescribing guidelines. Knowing when you should not use Bactroban is critical for both patient safety and preventing the spread of antibiotic resistance. Key scenarios include having a known allergy, application on mucosal surfaces, treating non-bacterial infections, use on large open wounds with renal impairment, and using it for prolonged periods. Always consult a healthcare provider for proper diagnosis and to confirm Bactroban is the right treatment for your condition, and immediately report any adverse reactions or lack of improvement.

For more detailed information, consult the official FDA label for Bactroban Ointment.

Frequently Asked Questions

Bactroban ointment should be used with caution on large areas of broken or damaged skin, such as large burns or open wounds. This is especially true for patients with kidney problems, as the polyethylene glycol base can be absorbed and harm the kidneys. Always consult your doctor before using it on such injuries.

No, Bactroban is an antibacterial medication and is not effective against fungal or viral infections. Using it on a fungal infection could allow the fungus to overgrow. You should use a specific antifungal medication for conditions like athlete's foot.

If you accidentally get Bactroban in your eye, you should rinse it thoroughly with water immediately. If irritation persists, contact your doctor.

Bactroban is classified as Pregnancy Category B, meaning animal studies have shown no harm, but human data are limited. It should only be used during pregnancy if clearly needed, and after consultation with a healthcare provider who can weigh the potential benefits against any risks.

The duration of treatment with Bactroban is typically up to 10 days for skin infections. Do not use it for a longer period than prescribed, as this can increase the risk of developing antibiotic resistance.

Signs of an allergic reaction can include hives, dizziness, wheezing, or swelling of the face, lips, tongue, or throat. Local reactions may include severe rash, itching, burning, or swelling at the application site. You should stop using Bactroban immediately and seek medical help if these symptoms appear.

Bactroban ointment should not be used near IV cannulae or central intravenous catheter sites due to the risk of promoting fungal infections and antimicrobial resistance. In these cases, alternative treatments would be used.