Bactroban Nasal
Mupirocin 2% Nasal Ointment — Topical Antibacterial for Nasal Infections & MRSA Decolonization
Bactroban Nasal is a prescription nasal ointment containing mupirocin 2% (as calcium mupirocin). It is used to treat bacterial infections inside the nose and is one of the most widely recommended agents for nasal decolonization of methicillin-resistant Staphylococcus aureus (MRSA). Mupirocin works by inhibiting bacterial protein synthesis, making it effective against Gram-positive organisms including Staphylococcus aureus and Streptococcus species.
Quick Facts
Key Takeaways
- Bactroban Nasal contains mupirocin 2%, an antibacterial agent that kills bacteria inside the nose, including MRSA strains.
- The standard treatment course is a small amount (matchhead-sized) applied into each nostril twice daily for 5 days.
- It is one of the most effective agents for nasal MRSA decolonization, with clearance rates of 80–90% after a single course.
- Side effects are generally mild and localized; serious allergic reactions (anaphylaxis, angioedema) are very rare.
- Prolonged or repeated use should be avoided as it may promote development of mupirocin-resistant bacteria.
What Is Bactroban Nasal and What Is It Used For?
Bactroban Nasal belongs to a unique class of antibacterial agents derived from pseudomonic acid A, produced by the bacterium Pseudomonas fluorescens. Its active ingredient, mupirocin (as the calcium salt), has a distinctive mechanism of action that sets it apart from other antibiotics. Mupirocin reversibly binds to bacterial isoleucyl-transfer RNA synthetase (IleRS), an enzyme essential for incorporating the amino acid isoleucine into newly forming proteins. By blocking this process, mupirocin halts bacterial protein synthesis and, at the concentrations achieved with topical application, exerts a bactericidal (bacteria-killing) effect.
The drug demonstrates potent activity against the most clinically significant Gram-positive pathogens encountered in the nasal passages, particularly Staphylococcus aureus (both methicillin-sensitive and methicillin-resistant strains) and most Streptococcus species. This targeted spectrum of activity makes it especially suitable for treating nasal infections caused by these organisms and for reducing their carriage in the anterior nares (the front part of the nasal passages), which serves as the primary reservoir for staphylococcal colonization.
Clinically, Bactroban Nasal is employed in two main settings. First, it is prescribed for the treatment of bacterial infections of the nasal mucosa, where it delivers high local concentrations of mupirocin directly to the site of infection. Second, and perhaps more prominently, it plays a central role in MRSA decolonization protocols. The nose is the single most common site of Staphylococcus aureus carriage, and nasal carriers are at significantly increased risk of developing staphylococcal infections, particularly in healthcare settings and before surgical procedures. International infection control guidelines, including those from the Society for Healthcare Epidemiology of America (SHEA) and the European Centre for Disease Prevention and Control (ECDC), recommend intranasal mupirocin as a first-line agent for MRSA decolonization.
Pre-surgical decolonization with Bactroban Nasal has been shown to reduce the risk of surgical site infections caused by S. aureus by approximately 50%, according to systematic reviews and meta-analyses. This preventive approach is now considered standard practice in many hospitals worldwide, particularly before orthopedic, cardiac, and other high-risk surgical procedures. The medication is available as a 3 g aluminum tube of 2% nasal ointment formulated in a white soft paraffin base (white petroleum jelly and Softisan 649) optimized for nasal application.
What Should You Know Before Using Bactroban Nasal?
Contraindications
The primary contraindication for Bactroban Nasal is known hypersensitivity to mupirocin or any of the excipient ingredients in the formulation. The ointment base contains white soft paraffin (white petroleum jelly) and Softisan 649 (bis-diglyceryl polyacyladipate-2). If you have previously experienced an allergic reaction to mupirocin in any formulation (including the skin ointment Bactroban), you should not use Bactroban Nasal. Signs of allergy may include rash, itching, swelling, severe dizziness, or difficulty breathing.
There are no known absolute contraindications related to specific medical conditions beyond hypersensitivity. However, clinical judgment should be exercised in patients with severely compromised nasal mucosa or extensive nasal mucosal damage, as increased systemic absorption may occur in such situations, although this remains largely theoretical given the very low systemic bioavailability of intranasally applied mupirocin.
Warnings and Precautions
If you develop signs of a hypersensitivity reaction or severe local irritation while using Bactroban Nasal, discontinue the ointment immediately, wash off any remaining product, and contact your healthcare provider without delay.
Antibiotic resistance: As with all antibacterial agents, prolonged or repeated use of Bactroban Nasal may result in the overgrowth of organisms that are not susceptible to mupirocin, including resistant strains of bacteria or fungi. Mupirocin resistance, particularly high-level resistance mediated by the mupA gene, has been increasingly reported in clinical settings. The World Health Organization (WHO) and international infection control bodies have emphasized the importance of using mupirocin judiciously to preserve its clinical effectiveness. Treatment courses should not exceed the prescribed duration without medical reassessment.
Clostridioides difficile-associated diarrhea: Although rare with topical nasal mupirocin due to minimal systemic absorption, antibacterial agents can rarely disrupt normal gut flora. If you develop severe, persistent, or bloody diarrhea during or after treatment with Bactroban Nasal, discontinue use and consult your healthcare provider. This symptom could indicate pseudomembranous colitis, a condition that requires medical evaluation.
Avoid eye contact: Bactroban Nasal ointment is formulated exclusively for nasal use. The ointment should not come into contact with the eyes. If accidental ocular exposure occurs, rinse the eyes thoroughly with water until the ointment residue is completely removed. The paraffin base of the formulation can cause irritation if applied to mucous membranes of the eye.
Pregnancy and Breastfeeding
There is limited clinical experience with the use of Bactroban Nasal during pregnancy. Animal reproduction studies have not demonstrated evidence of teratogenicity or harm to the fetus, but these findings cannot always be directly extrapolated to humans. As a precautionary measure, consult your healthcare provider before using Bactroban Nasal if you are pregnant or suspect you may be pregnant. Your prescriber will evaluate whether the potential benefits of treatment outweigh the theoretical risks.
It is not known whether mupirocin or its metabolites are excreted in human breast milk following intranasal administration. Given the low systemic absorption associated with topical nasal application, significant exposure of a breastfed infant is considered unlikely. Nevertheless, consult your doctor before using Bactroban Nasal during breastfeeding, particularly if prolonged or repeated treatment courses are anticipated.
Driving and Operating Machinery
Bactroban Nasal has no known effect on the ability to drive vehicles or operate machinery. There are no pharmacological properties of mupirocin that would impair cognitive function, reaction time, or coordination. You can continue your normal daily activities while using this medication.
How Does Bactroban Nasal Interact with Other Drugs?
One of the clinical advantages of Bactroban Nasal is its low potential for drug interactions. Because mupirocin is applied topically to the nasal mucosa and undergoes minimal systemic absorption, it does not enter the bloodstream in pharmacologically significant quantities. As a result, interactions with oral or injectable medications are extremely unlikely. The drug is rapidly metabolized at the application site and in the skin to the inactive metabolite monic acid, which further reduces any potential for systemic interactions.
However, there are some important considerations regarding concurrent nasal medication use. Chloramphenicol, when applied intranasally, may interfere with the antibacterial activity of mupirocin. Laboratory studies have demonstrated that chloramphenicol can reduce mupirocin's efficacy through competitive binding at the protein synthesis level. These two agents should generally not be used concurrently in the nasal passages. Additionally, the physical properties of the ointment base should be considered when other intranasal products are being used simultaneously, as mixing formulations may alter the local concentration and distribution of each active ingredient.
Although no significant interactions with systemic medications have been identified, always inform your prescribing healthcare provider about all medications you are currently taking, including over-the-counter drugs, nasal sprays, and herbal supplements. This is particularly important if you are using other intranasal preparations such as corticosteroid nasal sprays, decongestant sprays, or saline irrigations, as the timing and order of application may influence the effectiveness of each product.
| Interacting Drug | Severity | Effect | Recommendation |
|---|---|---|---|
| Chloramphenicol (nasal) | Moderate | May reduce mupirocin efficacy through competitive binding | Avoid concurrent intranasal use |
| Other intranasal antibacterials | Minor | May dilute local concentration of mupirocin | Separate application times; consult prescriber |
| Intranasal corticosteroids | Minor | No direct pharmacological interaction | Space applications by at least 30 minutes |
| Nasal saline irrigation | Minor | May physically wash out ointment if used immediately after | Apply mupirocin after saline irrigation; allow to dry first |
No dose adjustments are required when Bactroban Nasal is used in patients taking systemic medications, including anticoagulants, antihypertensives, or immunosuppressants. The negligible systemic absorption profile of intranasal mupirocin means that hepatic or renal drug-metabolizing enzyme interactions are not a clinical concern.
What Is the Correct Dosage of Bactroban Nasal?
Always use Bactroban Nasal exactly as prescribed by your healthcare provider. The dosage and duration of treatment should not be altered without professional medical advice. The medication is designed for intranasal application only and should not be applied to other body areas, wounds, or mucous membranes outside the nose.
Adults
Standard Adult Dosage
Apply a small amount of ointment (approximately the size of a matchhead, which corresponds to roughly 30 mg of ointment) into each nostril twice daily for a total of 5 days. After placing the ointment into each nostril, close the nostrils by pressing the sides of the nose together for approximately one minute. This gentle compression helps distribute the ointment over the inner surfaces of the nasal passages, maximizing contact with the nasal mucosa where bacteria reside.
The 5-day treatment course is based on clinical evidence demonstrating optimal efficacy with acceptable resistance emergence rates. In some institutional protocols for MRSA decolonization, particularly in pre-surgical settings, the treatment may be extended or combined with body-washing regimens using chlorhexidine, as directed by infection control teams. However, individual prescriptions should always be followed as directed by your healthcare provider.
Children
Pediatric Dosage
The dosage for children is generally the same as for adults: a matchhead-sized amount in each nostril twice daily for 5 days. Clinical studies have included pediatric patients, and the safety profile in children appears comparable to that in adults. However, application in young children should be supervised by an adult to ensure correct placement and to prevent the child from removing the ointment immediately after application. Consult your pediatrician for specific guidance regarding use in infants and very young children.
Elderly
Elderly Dosage
No dose adjustment is required for elderly patients. The standard 5-day regimen at the same dose as younger adults is recommended. Given the minimal systemic absorption of intranasally applied mupirocin, age-related changes in hepatic or renal function do not affect the drug's safety profile. Elderly patients in institutional care settings may be offered repeated decolonization courses as part of infection prevention programs, under appropriate medical supervision.
Missed Dose
If you forget to apply a dose of Bactroban Nasal, apply it as soon as you remember. Then continue with your regular dosing schedule as prescribed by your healthcare provider. Do not apply a double dose to make up for a missed application. If you are unsure about what to do, consult your pharmacist or prescriber for advice. Consistency of application throughout the 5-day course is important for optimal outcomes.
Overdose
Due to the topical nature of Bactroban Nasal and the small amount of ointment used per application, overdose is unlikely. If an excessive amount is accidentally applied to the nose, wipe away the surplus with a tissue. In the event that the ointment is accidentally swallowed (for example, by a child), seek medical attention. The paraffin-based formulation may cause mild gastrointestinal discomfort if ingested, but serious toxicity from mupirocin ingestion is not expected given its rapid metabolism to the inactive metabolite monic acid. Contact your local poison control center or healthcare provider for assessment and advice if accidental ingestion occurs.
| Patient Group | Dose | Frequency | Duration |
|---|---|---|---|
| Adults | Matchhead-sized amount per nostril (~30 mg) | Twice daily | 5 days |
| Children | Matchhead-sized amount per nostril | Twice daily | 5 days |
| Elderly | Matchhead-sized amount per nostril | Twice daily | 5 days (no adjustment needed) |
| Pre-surgical MRSA decolonization | As per institutional protocol | Twice daily | 5 days (may vary per protocol) |
What Are the Side Effects of Bactroban Nasal?
Like all medicines, Bactroban Nasal can cause side effects, although not everybody experiences them. The majority of reported adverse effects are mild and self-limiting, relating to local irritation at the application site. The nasal mucosa may be more sensitive to topical agents than intact skin, so transient discomfort such as stinging, burning, or itching immediately after application is not unusual and typically resolves within minutes.
It is important to distinguish between expected mild reactions and signs of a genuine allergic response. If you experience swelling of the face, tongue, or throat, difficulty swallowing, hives (urticaria), or difficulty breathing after applying Bactroban Nasal, stop using the product immediately and seek emergency medical attention. These symptoms may indicate angioedema or anaphylaxis, which, while extremely rare, require urgent treatment.
Uncommon Side Effects
- Reactions in the nasal mucosa (irritation, stinging, burning sensation)
- Nasal itching or discomfort
- Transient nasal congestion
Very Rare Side Effects
- Skin hypersensitivity reactions at the application site
- Generalized allergic reactions (widespread rash, urticaria/hives)
- Angioedema (swelling of face, tongue, or throat)
- Anaphylaxis (severe systemic allergic reaction)
The favorable side effect profile of Bactroban Nasal is largely attributable to its minimal systemic absorption. Following intranasal application, mupirocin is predominantly retained locally within the nasal passages, where it exerts its antibacterial effect. Any small amount that is absorbed systemically is rapidly metabolized to the inactive metabolite monic acid. As a result, systemic adverse effects commonly associated with oral or intravenous antibiotics — such as gastrointestinal disturbance, hepatotoxicity, or nephrotoxicity — are not expected with Bactroban Nasal at recommended doses.
Post-marketing surveillance data spanning decades of clinical use have confirmed the overall safety of intranasal mupirocin. The European Medicines Agency (EMA) product information and the British National Formulary (BNF) both classify Bactroban Nasal as having a well-established safety profile. If you experience any side effects not listed here, or if a known side effect becomes severe or persistent, contact your healthcare provider or pharmacist for guidance.
Reporting suspected adverse reactions after a medicine has been authorized is important. It allows continued monitoring of the benefit-risk balance of the medicine. Healthcare professionals and patients are encouraged to report suspected adverse reactions to their national pharmacovigilance authority (for example, the FDA MedWatch program in the United States, the MHRA Yellow Card Scheme in the United Kingdom, or the EMA EudraVigilance system in the European Union).
How Should You Store Bactroban Nasal?
Proper storage of Bactroban Nasal is essential to maintain the integrity and effectiveness of the medication throughout its shelf life. The ointment should be stored at a temperature not exceeding 25°C (77°F). Exposure to excessive heat or direct sunlight should be avoided, as elevated temperatures may affect the consistency and stability of the paraffin-based ointment formulation. Do not freeze the product.
Keep the medication in its original aluminum tube with the screw cap tightly closed when not in use. This protects the ointment from contamination and environmental degradation. The tube should be stored out of the sight and reach of children at all times. Although accidental ingestion of a small amount is unlikely to cause serious harm, it is important to prevent unsupervised access by children.
Do not use Bactroban Nasal after the expiry date (marked as "EXP" on the tube and outer carton). The expiry date refers to the last day of that month. Once opened, the tube should be used within the treatment course period and discarded if not fully used within a reasonable time, as contamination of the remaining ointment may occur through repeated contact with the nasal passages.
Medicines should not be disposed of via wastewater or household waste. Unused or expired medication should be returned to a pharmacy for appropriate environmental disposal. Many countries operate pharmaceutical take-back programs to ensure that medications are disposed of safely without contaminating water supplies or the environment.
What Does Bactroban Nasal Contain?
Understanding the composition of your medication can help you identify potential allergens and understand how the product functions. Bactroban Nasal contains a single active pharmaceutical ingredient and a minimal number of excipients, reflecting its straightforward topical formulation design.
Active Ingredient
Calcium mupirocin equivalent to mupirocin 20 mg per gram of ointment (2% w/w). Calcium mupirocin is the calcium salt of mupirocin, chosen for its superior stability in the ointment base compared to the free acid form. Mupirocin itself is a natural antibiotic originally isolated from Pseudomonas fluorescens, a non-pathogenic soil bacterium. Its unique chemical structure (pseudomonic acid A) is unrelated to any other class of antibiotic, which means there is no cross-resistance with common antibacterial drug classes such as beta-lactams, aminoglycosides, macrolides, or fluoroquinolones.
Inactive Ingredients (Excipients)
- White soft paraffin (white petroleum jelly): The primary vehicle for the ointment, providing a protective occlusive barrier that maintains mucosal hydration and facilitates prolonged contact between the active ingredient and the nasal mucosa. It is an inert, well-tolerated substance with a long history of safe use in pharmaceutical and cosmetic products.
- Softisan 649 (bis-diglyceryl polyacyladipate-2): A semi-synthetic ester that improves the consistency and spreadability of the ointment, ensuring even application within the nasal passages. It helps achieve the correct viscosity for intranasal use without being too stiff or too fluid.
Packaging
Bactroban Nasal is supplied in a 3 g aluminum tube with a screw cap. The aluminum tube provides protection from light and air, helping to preserve the stability of the calcium mupirocin formulation. The small tube size is appropriate for the standard 5-day treatment course, minimizing waste and reducing the risk of storing partially used tubes for extended periods.
Frequently Asked Questions About Bactroban Nasal
Bactroban Nasal is used to treat bacterial infections inside the nose and for nasal decolonization of methicillin-resistant Staphylococcus aureus (MRSA). It contains mupirocin 2%, an antibacterial agent that kills or inhibits the growth of bacteria in the nasal passages. It is commonly prescribed as part of infection control protocols before surgical procedures to reduce the risk of post-operative staphylococcal infections.
Wash your hands before use. Squeeze a small amount of ointment (about the size of a matchhead) onto a clean fingertip or a cotton bud. Place the ointment just inside each nostril. Close your nostrils by gently pressing the sides of the nose together for about one minute. This helps spread the ointment inside the nasal passages. Repeat twice daily for 5 days. Wash your hands after application.
There is limited clinical experience with Bactroban Nasal use during pregnancy. Animal studies have not shown harmful effects, but human data are insufficient. It is not known whether mupirocin passes into breast milk after nasal application. Systemic absorption is minimal, so significant exposure is unlikely. However, always consult your healthcare provider before using Bactroban Nasal if you are pregnant, planning to become pregnant, or breastfeeding.
Yes, Bactroban Nasal is one of the most effective topical agents for nasal MRSA decolonization. Clinical trials have shown that a standard 5-day course eliminates MRSA from the nose in approximately 80–90% of carriers. It is recommended by major international guidelines (SHEA, ECDC, NICE) as a first-line decolonization agent. However, mupirocin resistance is an emerging concern, so susceptibility testing may be recommended in some settings before treatment.
Bactroban Nasal can generally be used alongside other nasal products such as corticosteroid sprays (e.g., fluticasone, mometasone) or saline rinses, but it is advisable to space applications by at least 30 minutes. If you use saline irrigation, perform this first, allow the nose to dry, and then apply the mupirocin ointment. This prevents the saline from washing out the ointment. Always inform your doctor about all medications you use, including nasal sprays.
Store the ointment at or below 25°C (77°F). Keep it away from direct sunlight and heat. Do not freeze. Keep the tube tightly closed when not in use and store out of the reach and sight of children. Do not use after the expiry date printed on the packaging. Return unused medication to your pharmacy for safe disposal.
References
- European Medicines Agency (EMA). Summary of Product Characteristics: Bactroban Nasal 2% w/w Nasal Ointment. EMA product database. Accessed January 2026.
- British National Formulary (BNF). Mupirocin: Nasal. National Institute for Health and Care Excellence (NICE). BNF online, 2025–2026.
- Poovelikunnel T, Gethin G, Humphreys H. Mupirocin resistance: clinical implications and potential alternatives for the future. Journal of Antimicrobial Chemotherapy. 2015;70(10):2681–2692. doi:10.1093/jac/dkv169
- Humphreys H, Becker K, Dohmen PM, et al. Staphylococcus aureus and surgical site infections: benefits of screening and decolonization before surgery. Journal of Hospital Infection. 2016;94(3):295–304. doi:10.1016/j.jhin.2016.06.011
- Septimus EJ, Schweizer ML. Decolonization in prevention of health care-associated infections. Clinical Microbiology Reviews. 2016;29(2):201–222. doi:10.1128/CMR.00049-15
- World Health Organization (WHO). WHO Model List of Essential Medicines, 23rd list. Geneva: World Health Organization; 2023.
- Bode LG, Kluytmans JA, Wertheim HF, et al. Preventing surgical-site infections in nasal carriers of Staphylococcus aureus. New England Journal of Medicine. 2010;362(1):9–17. doi:10.1056/NEJMoa0808939
- Society for Healthcare Epidemiology of America (SHEA). Strategies to prevent methicillin-resistant Staphylococcus aureus transmission and infection in acute care hospitals: 2014 update. Infection Control & Hospital Epidemiology. 2014;35(7):772–796.
- Hetem DJ, Bootsma MC, Bonten MJ. Prevention of surgical site infections: decontamination with mupirocin based on preoperative screening for Staphylococcus aureus carriers or universal decontamination? Clinical Infectious Diseases. 2016;62(5):631–636.
- U.S. Food and Drug Administration (FDA). Bactroban Nasal (mupirocin calcium ointment, 2%) prescribing information. FDA drug label database. Accessed January 2026.
Medical Editorial Team
This article was written and reviewed by iMedic's medical editorial team, composed of licensed physicians and clinical pharmacologists with expertise in infectious disease, dermatology, and antimicrobial therapy.
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