What Is Bactroban? - Step To Health

What Is Bactroban?

The active substance in Bactroban, mupirocin, is an antibiotic that is obtained by the fermentation of Pseudomonas fluorescens.
What Is Bactroban?

Last update: 06 March, 2020

Bactroban is the trade name of an antibiotic ointment with the active ingredient mupirocin. Each gram of ointment contains 20 mg of mupirocin, an antibiotic made by fermenting Pseudomonas fluorescens. It’s an effective antibiotic ointment in treating the vast majority of bacteria that cause skin infections.

How does Bactroban work?

Bactroban antibiotics in a petri dish.

Bactroban works by preventing bacterial protein synthesis through the inhibition of the enzyme isoleucil-transfer RNA synthetase.

Due to its mechanics and its chemical structure, it doesn’t create cross-resistance with other antibiotics. Mupirocin is bacteriostatic at minimal inhibitory concentrations and bactericidal at the highest concentrations obtained when applied locally.

Why do physicians prescribe it?

You use Mupirocin for the treatment of skin infections caused by sensitive microorganisms. Therefore, physicians prescribe it for the treatment of primary skin infections, such as folliculitis, impetigo, or forunculosis.

However, a doctor may also prescribe mupirocin when secondary dermatological infections appear, such as infected contact dermatitis, infected wounds, atopic dermatitis and eczematous dermatitis, provided the infection is limited.

Mupirocin is a topical antibacterial agent that is active in vivo against Staphylococcus aureus, S. epidermidis and ß-hemolytic Streptococcus species .

However, in vitro, the spectrum of its activity includes bacteria such as:

  • Staphylococcus aureus y Staphylococcus epidermidis
  • Streptococcus species
  • Haemophilus influenzae
  • Neisseria gonorrhoeae y Neisseria meningitidis
  • Moraxella catarrhalis
  • Pasteurella multocida

If a doctor prescribed Bactroban to treat cracks in the nipple, it’s important to wash it very well before breastfeeding your baby.

How do you use Bactroban?

Bactroban ointment on finger.

Apply mupirocin  2-3 times a day for 5-10 days, depending on the response. If after 3-5 days of treatment, you don’t see any improvement, you should reconsider the diagnosis and/or treatment.

First, wash and dry the area you’re treating. Then apply a small amount of ointment and, if necessary, cover it with an occlusive bandage or gauze.

Don’t mix Bactroban with other ointments, since there is a risk of dilution. This would result in a decrease of antibacterial activity and, consequently, a possible loss of mupirocin stability in the ointment.

Adverse reactions and contraindications

The pooled data of a clinical trial population of 1,573 treated patients covering 12 clinical studies determined the adverse reactions that Bactroban can cause.

At skin-level and in the subcutaneous tissue, burning located in the area of ​​application may appear. Less commonly, itching, erythema and stinging may occur. Some users also reported allergic reactions that include anaphylaxis, generalized rash, urticaria and angioedema.

You may experience contraindications with the use of mupirocin if you have a history of hypersensitivity to its active substance and to the other ingredients that appear in its formula.

If you’re pregnant or think you might be, due to lack of available information, you shouldn’t use mupirocin. Similarly, you also shouldn’t use mupirocin if you’re breastfeeding, as it can pass into the milk and affect the baby.

What should you keep in mind?

In the event of sensitization or strong local irritation when using this medicine, you should stop the treatment and remove the applied product. As an antibiotic with antibacterial action, prolonged use of it can cause a proliferation of non-susceptible organisms.

Patients are unlikely to suffer from diarrhea during treatment with mupirocin, as you administer it topically. However, if the patient experiences prolonged or significant diarrhea, or abdominal cramps, they should discontinue the treatment and consult a doctor.

Don’t use Bactroban when there’s evidence of renal failure. This is because it has macrogol as the basis of its formula and this substance can be absorbed through the injured skin, being subsequently eliminated by the kidneys.

Don’t use Bactroban on very large areas of skin. In case of overdose, there’s no specific treatment, although, if it occurs, the patient should receive supportive treatment and, if necessary, ask a nurse or doctor to monitor them.


You can use mupirocin for the treatment of skin infections caused by sensitive microorganisms. When used, you must take into account the national recommendations regarding the appropriate use of antibacterials.

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  • Potel, C., Álvarez, P., Constenla, L., & Álvarez, M. (2009). Efectividad de la mupirocina frente a Staphylococcus aureus resistente a meticilina aislados en la provincia de Pontevedra. Enfermedades Infecciosas y Microbiología Clínica. https://doi.org/10.1016/j.eimc.2008.02.002

  • García, A. M., Villa, M. V., Escudero, M. E., Gómez, P., Vélez, M. M., Múnera, M. I., & Franco, G. (2003). Uso nasal de la mupirocina para Staphylococcus aureus: efecto en portadores y en infecciones nosocomiales. Biomédica. https://doi.org/10.7705/biomedica.v23i2.1209

  • Mônica, T., Dayana Souza, F., Cibele, G., Angélica Gonçalves Silva, B., & Dulce Aparecida, B. (2012). Uso profilático de Mupirocina em cateter venoso central de hemodiálise: revisão sistemática e metanálise. Acta Paulista de Enfermagem.