Mupirocin (Bactroban): Topical Antibiotic for Wound Care and Skin Infections
Mupirocin, sold under the brand name Bactroban and available as a generic, is a prescription topical antibiotic used to treat bacterial skin infections and to decolonize the skin or nose from Staphylococcus aureus, including MRSA (methicillin-resistant Staphylococcus aureus). It works by blocking an enzyme that bacteria need to make proteins, stopping bacterial growth. Mupirocin is available in two formulations: a skin ointment (2%) for wounds and skin infections, and a nasal ointment (2.15%) specifically for decolonizing bacteria inside the nostrils before surgery. These two formulations are not interchangeable.
What Mupirocin Treats and When It Is Prescribed
Mupirocin skin ointment (2%) is FDA-approved for impetigo (a superficial bacterial skin infection), and is widely used off-label for infected or at-risk surgical wounds, minor skin abrasions, and folliculitis (infected hair follicles). Your surgeon may prescribe it after wound closure to reduce surface bacterial counts.
Mupirocin nasal ointment (2.15%) is specifically formulated for intranasal use and is used to decolonize Staphylococcus aureus (including MRSA) from the inside of the nostrils before surgery. Carriers of nasal staph bacteria have higher rates of post-surgical wound infection. Nasal decolonization significantly reduces this risk.
The typical regimen for pre-surgical nasal decolonization is applying mupirocin nasal ointment inside both nostrils twice daily for 5 days before surgery. The skin ointment regimen for wound care is typically applied two to three times daily for 5 to 10 days.
Do not use the nasal ointment on skin wounds, and do not use the skin ointment inside the nostrils. The concentrations and excipients (inactive ingredients) differ and using the wrong formulation can cause irritation or reduce effectiveness.
Mupirocin is a prescription medication in the United States. It is not available over the counter. Common OTC antibiotic ointments such as bacitracin or Neosporin contain different antibiotics and are not equivalent to mupirocin, particularly for MRSA coverage.
How to Apply Mupirocin Correctly
For skin wounds: clean the wound gently with saline or water as directed. Pat dry. Apply a thin layer of mupirocin ointment to the affected area using a clean cotton swab or your fingertip. You may cover the area with a sterile bandage if your provider recommends it. Apply two to three times daily unless directed otherwise.
For nasal decolonization: place approximately half of the single-use tube (about a 0.5 gram amount) into each nostril. Close the nostrils by pressing the sides of the nose together gently and release, repeating for about 1 minute to spread the ointment inside. Avoid blowing the nose for at least a few minutes after application.
Wash your hands before and after applying mupirocin. Avoid getting the ointment in your eyes. If eye contact occurs, rinse thoroughly with water for several minutes.
Do not apply mupirocin to mucous membranes other than the nostrils as directed, and do not apply to deep open wounds, puncture wounds, or burns unless specifically directed by your provider.
Complete the full course of treatment even if the wound looks better before the course ends. Stopping early may allow resistant bacteria to survive.
Resistance, Duration of Use, and When to Stop
Mupirocin resistance is an increasing concern. High-level resistance occurs when bacteria acquire a modified form of the target enzyme, making mupirocin ineffective. This resistance can develop with prolonged or repeated use.
Do not use mupirocin for longer than the prescribed course (typically 5 to 10 days). Extended use increases resistance risk without providing additional benefit. Mupirocin is not appropriate as a long-term preventive agent applied continuously to wounds.
If you have been prescribed mupirocin for MRSA decolonization and you test positive for MRSA again in the future, do not self-treat with leftover mupirocin. A repeat culture and sensitivity test should confirm whether the bacteria are still susceptible before retreatment.
Signs that mupirocin is not working include worsening redness, swelling, warmth, or drainage at the wound site, spreading redness beyond the wound edges, fever, or red streaks extending from the wound. Contact your provider promptly if any of these develop.
No. Neosporin and bacitracin are over-the-counter antibiotic ointments that contain neomycin, polymyxin B, and/or bacitracin. These antibiotics cover a different and generally narrower spectrum of bacteria than mupirocin and are not effective against MRSA. Mupirocin has stronger activity against Staphylococcus aureus (including many MRSA strains) and is available by prescription only. For minor cuts and scrapes in healthy people without infection signs, OTC ointments are reasonable. For surgical wounds or MRSA concerns, mupirocin is the appropriate choice.
Can I use leftover mupirocin for a future skin infection?
This is not recommended. Using leftover antibiotics without a provider evaluation risks treating the wrong type of infection, missing a diagnosis that requires a different treatment, and contributing to antibiotic resistance. If you have a new skin infection, contact your provider for evaluation and a fresh prescription if appropriate. Dispose of unused mupirocin through a medication take-back program.
What is MRSA decolonization and who needs it before surgery?
MRSA decolonization is a process of temporarily eliminating MRSA bacteria from the skin and nose before surgery to reduce the risk of the patient infecting their own surgical site. Patients are often screened with a nasal swab before procedures such as joint replacement, spinal surgery, or cardiac surgery. If the swab is positive, a decolonization protocol using nasal mupirocin twice daily for 5 days and a chlorhexidine body wash is typically prescribed. Not all surgeries require screening; your surgeon's preoperative instructions will specify if this applies to you.
Can mupirocin cause an allergic reaction?
Yes, though it is uncommon. Signs of an allergic reaction to mupirocin include rash, itching, or swelling at or beyond the application site, and in rare cases a more widespread skin reaction. The polyethylene glycol base in mupirocin ointment can occasionally cause local irritation in people with polyethylene glycol sensitivity. If you develop increasing redness, rash, or swelling after starting mupirocin, stop use and contact your provider.
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This guide provides general information. For instructions tailored to your specific procedure, ask your provider about QR Rx care plans.
These medication guides are for educational purposes only and do not replace medical advice. Always follow your healthcare provider's specific medication instructions.
