Detailed Drug Information:

DRUG CLASS AND MECHANISM: Mupirocin is an antibiotic that isused topically (superficially) in the treatment of impetigo, a bacterialdisease of the skin caused by Staphylococcus aureus and beta-hemolyticstreptococci. Unlike most other antibiotics which act on either bacterialDNA or the cellular walls of bacteria, mupirocin blocks the activity of anenzyme called isoleucyl-tRNA synthetase within the bacteria. This enzymeis necessary in order for the bacteria to make proteins. Without the ability to make proteins, the bacteria die. Because of its uniquemechanism of action there is little chance that bacteria will have becomeresistant to mupirocin because they have been exposed to otherantibiotics. Mupirocin topical cream was approved by the FDA in December1987. The intranasal form was approved October 1995.

PREPARATIONS: Ointment: 15 g tubes as 2% (20 mg/g). Nasalointment: 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 impetigodue to Staphylococcus aureus or Streptococcus pyogenes, for the treatmentof infected eczema, or folliculitis (infection of the hair follicles).Mupirocin is not recommended for use on the skin in serious burns, becausemore of the vehicle (the inactive ingredient) used for the ointment,polyethylene glycol, may be absorbed and can cause kidney damage. A nasalointment of mupirocin also is used for the elimination of nasal Staphylococcus aureus that have become resistant to other antibiotics.

DOSING: For the treatment of impetigo, a small amount of theointment is applied to the affected area, usually three times daily. Thearea may be covered with a sterile gauze dressing. If there is noimprovement in 3-5 days, the physician should be contacted.

A specialized use of mupirocin is the intranasal application forpatients who harbor intranasal Staphylococcus aureus that are resistant tomany other antibiotics. Treatment requires the application of about halfof the ointment from a single-use tube of nasal ointment into one nostriland the other half into the other nostril. This treatment is repeatedtwice daily for 5 days. Children may need less ointment.

DRUG INTERACTIONS: There are no known drug interactions withmupirocin.

PREGNANCY: There are no adequate studies of mupirocin inpregnant women. However, studies in animals suggest no important effectson the fetus. Mupirocin, therefore, can be used in pregnancy if thephysician 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 nursewhile using mupirocin.

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

The intranasal use of mupirocin can cause headache (1 of every 11patients), runny nose (1 in 17), congestion (1 in 20), sore throat (1 in22), changes in taste perception (1 in 30), nasal irritation (1 in 50) andcough (1 in 50).