mupirocin

Mupirocin is an antibiotic that is used topically (on the skin) for the treatment of impetigo, a bacterial disease of the skin caused by Staphylococcus aureus, beta-hemolytic streptococcus, and Streptococcus pyogenes. It also is used intranasally (inside the nose) by patients and some people who work in healthcare centers to eliminate methicillin-resistant Staphylococcus aureus (MRSA) that have colonized the inside of the nose.

• Mupirocin is not recommended for use on the skin in serious burns because more of the inactive ingredient used for the ointment, polyethylene glycol (Miralax), may be absorbed and can damage the kidneys.
• The nasal ointment is used for the elimination of multi-drug resistant nasal Staphylococcus aureus infection in people who are colonized by Staphylococcus aureus. Mupirocin also may be used for secondary infections as determined by your doctor.

Unlike most other antibiotics that act on either bacterial DNA or the walls of bacteria, mupirocin blocks the activity of an enzyme called isoleucyl-tRNA synthetase within the bacteria. This enzyme is necessary in order for the bacteria to make proteins. Without the ability to make proteins, the bacteria die. Because of its unique mechanism of action, there is little chance that bacteria will have become resistant to mupirocin because of exposure to other antibiotics.

Mupirocin topical cream was approved by the FDA in December, 1987. The intranasal form was approved in October 1995.

Side effects are uncommon and mild with mupirocin. The most frequent side effects are:

• Burning
• Stinging
• Pain
• Itching at the area of application

Other side effects caused by the intranasal use of mupirocin include:

• Headache
• Runny nose
• Congestion
• Sore throat
• Dry skin
• Swelling (edema)
• Changes in taste perception
• Nasal irritation
• Cough

• For the treatment of impetigo, a small amount of ointment is applied to the affected area, usually three times daily (every 8 hours).
• The area may be covered with a sterile gauze dressing. If there is no improvement in 3-5 days the doctor should be contacted to re-examine the infected area.
• For other skin infections, the cream is applied to the affected area 3 times a day for 10 days, and the doctor should be contacted as well if there is no improvement after 3-5 days.
• When mupirocin is used for treating intranasal Staphylococcus aureus that is resistant to other antibiotics, patients who are aged 12 years and older require the application of about half of the ointment from a single-use tube of ointment into one nostril and the other half into the other nostril. This treatment is repeated twice daily for 5 days.
• Currently, there is not enough information to recommend the use of mupirocin for the treatment of intranasal Staphylococcus aureus in children younger than 12 years of age.

There are no known drug interactions with mupirocin. However, it should not be used at the same time with other drugs that are applied inside the nose.

• There are no adequate studies of mupirocin in pregnant women; however, studies in animals suggest no important effects on the fetus. Mupirocin, therefore, can be used in pregnancy if the physician feels that it is necessary.
• There is no information on the safety of mupirocin in nursing infants. It is unknown if any of the small amount of mupirocin that is absorbed from the skin into the blood of the mother concentrates in breast milk. It is advisable, therefore, not to nurse while using mupirocin.

• Mupirocin is available as:
  • Topical Ointment: 2% (20 mg/g).
  • Topical Cream: 2% (20 mg/g).
  • Nasal ointment: 2% (20 mg/g).
• Mupirocin tablets should be stored at room temperature, 15 C-30 C (59 F-86 F).
• Mupriocin is available in generic form.
• You need to get a prescription from your doctor to obtain it.
• Brand names for mupirocin available in the US are Bactroban Nasal and Centany. Bactroban has been discontinued in the US.