Mupirocin is a topical antibiotic that is primarily effective against gram-positive bacteria.
Mupirocin is used to treat bacterial infections, such as methicillin-resistant Staphylococcus aureus (MRSA), folliculitis, and impetigo. It is also used for insect bites, small wounds, and infections caused by gram-positive bacteria. Since it is an antibacterial medication, it will be ineffective for the treatment of viral and fungal infections.
Certain side effects are also reported with mupirocin use, and they include headache, nausea, swelling, rash, and burning. How long it takes for the medicine to take effect has not been clinically established, but it remains active up to 12 hours. The interaction of mupirocin with alcohol is not yet known. Although this medicine is safe to use during pregnancy, it is not recommended while breastfeeding.
Mupirocin is an FDA-approved drug since 1987 and sold under the brand names Bactroban and Centany. Several drug companies also manufacture a generic form of this drug.
This topical antibiotic was originally isolated from Pseudomonas fluorescens and is primarily effective against gram-positive bacteria. It has a bacteriostatic effect when used at low concentrations and is bactericidal when used at high concentrations.
Due to its structure and mechanism of action, this medication is regarded as a unique antibacterial agent. The antimicrobial activity of mupirocin involves inhibiting RNA synthesis and bacterial protein.
Mupirocin is usually prescribed for the treatment of any of the following skin conditions:
Impetigo is a bacterial skin infection that is usually caused by Staphylococcus (staph) or Streptococcus (strep) bacteria. This skin infection often begins when bacteria get into an open wound or a break in the skin from an insect bite, cut, or scratch. Children between the ages 2 and 6 are more prone to developing this skin infection.
The symptoms of impetigo begin with pimple-like sores that appear on the arms, legs, and face. These sores tend to be itchy and filled with pus. After a few days, they break open and form a thick crust. The sores can spread through scratching. You can get this infection through direct contact with the sores or nasal discharge of an infected person. Impetigo is treated using antibiotics such as mupirocin.
2. Furuncles (Boils)
A painful pus-filled bump, called a furuncle or boil develops under the skin when bacteria infect and inflame a hair follicle. As boils grow larger, they also become more painful until they rupture.
Treatment for boils includes the use of antibiotics, such as mupirocin to treat the underlying bacterial infection. Most boils are caused by Staphylococcus aureus bacteria, which can be treated using topical, oral, or intravenous (IV) antibiotics. In some cases, boils may require a minor surgical procedure to open and drain them.
3. Secondary Skin Infections
Mupirocin is also used to treat secondary skin infections, such as eczema, atopic dermatitis, and psoriasis.
Patients with atopic dermatitis tend to be more susceptible to developing bacterial infections. In fact, more than 90 percent of patients have S. aureus bacteria on their skin, and when their skin breaks due to scratching, an infection may develop. Maintaining a healthy skin barrier and other skin care measures should be followed to reduce the infection or colonization of bacteria.
Mupirocin ointment is often prescribed to treat small, localized bacterial infections. This topical medication is usually applied to the affected areas three times a day up for up to two weeks. For severe skin infections, oral antibiotics are usually given.
4. Methicillin-resistant Staphylococcus aureus (MRSA) Infections
This group of bacteria is genetically different from other Staphylococcus aureus strains. Infections in humans caused by MRSA can be more difficult to treat. The use of a nasal ointment with mupirocin is recommended to people who are exposed to patients with an MRSA infection.
Side Effects of Mupirocin
Although the use of topical mupirocin does not cause drowsiness, it can still cause other side effects, such as:
- Oozing at the site of infection
- Burning sensation
- Tenderness on the affected skin area
Mild side effects may go away after a few days or up to two weeks. A serious side effect may also include diarrhea that does not go away. Diarrhea may be caused by another type of bacteria called Clostridium difficile. Make sure to consult your healthcare provider if you experience diarrhea and severe or worsening symptoms while using mupirocin.
There are several warnings that come with the use of this drug.
A severe allergic reaction can occur with mupirocin use. An allergic reaction may include any of the following symptoms:
- Shortness of breath
- Chest tightness
- Panic attack (a feeling of impending doom)
- Severe dizziness
- Facial flushing or flushing in other areas of the body
- Trouble breathing
- Difficulty swallowing
- Swelling of the tongue or throat
Seek emergency medical help or go to the nearest emergency room if you experience these symptoms.
Using mupirocin repeatedly or for a long period of time may result in a new infection, particularly a fungal infection. Immediately inform your doctor if you notice any signs of new infection while using this medication.
Pregnancy and Breastfeeding
Mupirocin belongs to pregnancy category B, which means that there are not enough studies that show significant risks to the fetus. Consult your doctor if you are planning to become pregnant or if you are pregnant. Mupirocin should only be used if the benefits justify the risks.
It is still unclear whether this drug passes into breast milk and cause side effects in breastfed babies. Ask your doctor if it is safe for you to use mupirocin while breastfeeding.
The use of topical mupirocin has not been studied in babies who are younger than 2 months old.
Before using this medication, make sure to inform your doctor or pharmacist regarding your medical history, especially if you have kidney disease. Mupirocin topical contains polyethylene glycol, which can be absorbed from damaged skin and open wounds. Large amounts of polyethylene glycol can produce serious kidney damage.
When to See a Doctor
It is recommended to see a doctor if your condition does not improve after 3-5 days of mupirocin treatment.
Sutherland R, et al. Antibacterial activity of mupirocin (pseudomonic acid), a new antibiotic for topical use. Antimicrob Agents Chemother. (1985)
Impetigo. Strep. Staph. MedlinePlus. (2018). https://medlineplus.gov/impetigo.html
Additions/deletions for prescription drug product list. (2017) https://www.fda.gov/downloads/Drugs/InformationOnDrugs/UCM563481.pdf
Mupirocin-mupirocin ointment. (2017). https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=ff7428fb-9ce9-4743-b58c-01a05424a57a