What is Mupirocin?

Mupirocin is a medically active substance used to treat some illnesses caused by bacterial infection, such as impetigo.
Mupirocin was first discovered in 1971, isolated from a type of bacteria called Pseudomonas fluorescens. It is an important medication, and it has a place on the WHO list of essential medications. (1) It is very widely prescribed – in the USA, it is the 190th most commonly prescribed medication, over 3 million prescriptions. (2, 3)
This substance is used as topical treatment, that is medication that works by being applied directly on the affected part of the body. Mupirocin is used to treat skin infections caused by bacteria, and it does that by inhibiting certain processes that these bacterial cells need to grow and divide. Once the bacteria is unable to divide and spread, this gives the immune system of the body a chance to eliminate the infection.

Mupirocin Ointment Uses

As a substance, mupirocin is used to treat furuncles or impetigo, as well as other bacterial skin infections. It is most commonly used against some common types of bacteria called Staphylococcus aureus or Staphylococcus pyogenes. It is very effective in treating the strains of S. aureus that resist the action of other types of medication, strained called Methicillin-Resistant Staphylococcus aureus, or more commonly known as MRSA. It is not effective for all kinds of infection, however; it has no effect on other
kinds of microorganisms, including anaerobic bacteria, mycobacteria, which include tuberculosis, mycoplasma, yeasts or fungi.
Mupirocin is often prepared as an ointment, with a typical concentration of 2%. Unlike creams, ointments are more oily which give them different properties that work well for the purposes of using Mupirocin. Ointments are not as absorbed as quickly as creams, so they spend more time in contact with the affected skin and can prevent moisture from escaping, which is useful especially when the medication is applied on an open wound, where dryness can delay healing. They are also useful to apply on dry skin conditions.
Mupirocin can also be used as an ointment and applied in the nose. This is important when doctors suspect someone may be harbouring the antibiotic resistant MRSA strains. Mupirocin ointment is typically applied up to 3 times daily for up to a maximum of ten days. It is inadvisable to continue treatment over ten days, since this helps the development of resistant bacterial strains in the body, and eliminating these strains may be more difficult. It is licensed for use in children in general, but unadvised for use in children below the age of one year.

Mupirocin Ointment Side Effects

Mupirocin is generally a very safe medication, with the only relatively common side effect being a skin reaction. This may feel like skin burning or stinging. It is therefore advised to test the medication out first on a small part of the skin to assess the individual body’s reaction to it.

Long, inappropriate use of skin preparations may kill the helpful populations of bacteria that keep the skin healthy, and encourage the growth of harmful organisms, such as yeast and fungi.

With preparations designed to be used in the nose, it may uncommonly cause nasal mucosal disorder, which may cause sinusitis in long-term, inappropriate use of the medication. Therefore, it is important to stick to the dose, duration and frequency as advised by the treating physician.

There is currently no data available to outline any damage it may cause to pregnant women, and its use in pregnancy is indicated if benefit is expected to outweigh risk. It is unknown if this drug can pass into breast milk, and therefore it should only be used carefully in breastfeeding women.

Directions to Use

It is advised to let the physician or pharmacist know if you have any allergies to this, or any other medications before you start treatment. They should also know if you have any other medical conditions or receive any other medications. Kidney disease is particularly important as it may affect how the body responds to the medication.
This medication is not designed to be swallowed and serious harm may occur as a result of it being consumed by mouth. If the medication is swallowed in large doses, or if someone shows signs of overdose such as loss of consciousness or trouble breathing, seek emergency medical assistance without delay.


Always remember to follow the physician or pharmacist’s advice when taking medications, and to seek medical assistance if you have questions. The information in this article is not designed to replace a medical professional’s opinion.


World Health Organization (2019). World Health Organization model list of essential medicines:
21st list 2019. Geneva: World Health Organization. hdl:10665/325771.
WHO/MVP/EMP/IAU/2019.06. License: CC BY-NC-SA 3.0 IGO.
2) “The Top 300 of 2019“. ClinCalc. Retrieved 08 July 2022
3) “Mupirocin – Drug Usage Statistics“. ClinCalc. Retrieved 08 July 2022

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