Pharmacy Author: Eni Williams, PharmD
Medical and Pharmacy Editor: Jay W. Marks, MD

GENERIC NAME: mupirocin, mupirocin calcium

BRAND NAME: Bactroban, Bactroban Nasal, Centany

DRUG CLASS AND MECHANISM: 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.

Unlike most other antibiotics which 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.

PRESCRIPTION: Yes

GENERIC AVAILABLE: No

PREPARATIONS: Ointment: 15 g tubes as 2% (20 mg/g). Cream: 15 and 30 g tubes as 2% (20mg/g). Nasal ointment: 1 g tubes as 2% (20 mg/g).

STORAGE: The tablets should be kept at room temperature, 15-30 C (59-86 F).

PRESCRIBED FOR: Mupirocin is used for the treatment of impetigo and infections of the skin caused by Staphylococcus aureus, beta-hemolytic streptococcus or Streptococcus pyogenes. Mupirocin is not recommended for use on the skin in serious burns, because more of the vehicle (the inactive ingredient) used for the ointment, polyethylene glycol (Miralax), may be absorbed and can damage the kidneys. The nasal ointment of mupirocin is used for the elimination of nasal Staphylococcus aureus that have become resistant to other antibiotics. Mupirocin also may be used for other infections as determined by the physician.

DOSING: For the treatment of impetigo, a small amount of the ointment is applied to the affected area, usually three times daily. The area may be covered with a sterile gauze dressing. If there is no improvement in 3-5 days, the physician 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 patients who harbor intranasal Staphylococcus aureus that are resistant to many other antibiotics, those who are age 12 years and older require the application of about half of the ointment from a single-use tube of nasal 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 use of mupirocin in children younger than 12 years of age.

DRUG INTERACTIONS: 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.

PREGNANCY: 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.

NURSING MOTHERS: 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.

SIDE EFFECTS: Side effects are uncommon and mild with mupirocin. The most frequent side effects are burning, stinging, pain, and itching at the area of application.

The intranasal use of mupirocin can cause headache (1 of every 11 patients), runny nose (1 in 17), congestion (1 in 20), sore throat (1 in 22), changes in taste perception (1 in 30), nasal irritation (1 in 50) and cough (1 in 50).

Reference: FDA Prescribing Information